SE526466C2 - Improving the characteristics of pulp, used for nappy, paper towel, etc. - by treating pulp at specified temp. in suspension with alkali soln. and recovering pulp - Google Patents

Abstract

Improving the characteristics of a pulp, useful for making a fluff pulp or a pulp for absorbency intensive applications, comprises treating the pulp at a temp. up to 60[deg]C, in a suspension, with an alkali soln. of a conc. of 2-25 wt. %, to obtain a pulp of improved absorbency characteristics; and recovering the pulp from the suspension. Also claimed is a process of constructing an absorbent device. Pref. the pulp suspension is treated at a temp. less than 45 (esp. 40)[deg]C (more esp. at 30[deg]C). The pulp fibre comprises 2-25 (esp. 2-20)% consistency and the caustic soln. is of concn. 5-25 (esp. 5-18 more esp. 5-10)%. The caustic soln. concn. is dependent on the amt. of lignin remaining in the pulp, as measured by the K number and severity of pulping of the pulp. The treatment time is 5 min.- 1 hr.

Description

on egg Inn 0 I Ü '.. n-'IO 0'. g, g u ao. , - “595 465 2 13,5:: å - g-. °. ° D t- š .; z: .Ii oc. .oo- no 00 '°' ° "These pulps are commonly used for hygienic absorption purposes such as baby diapers and the like and are constructed with an outer absorbent layer, which consists of a layer of pulp with good bulky properties and good absorption properties due to relative rigidity A material with good bulky properties will contain a high proportion of empty spaces or pores, and in the case of an absorbent product these pores are used for the absorption, transport and storage of liquid.

Long, rigid bridges create more bulky air-containing webs with more pore volume. Liquids are more easily absorbed and transported if the pore volume or bulk volume is large. The absorbent layer is placed between the baby's skin and the diaper's absorbent core. An absorbent layer with the correct characteristics and properties allows the liquid to pass quickly into the absorbent core during repeated wetting and at the same time this layer transfers liquid into the main absorbent core which holds the liquid. In a similar manner, an incontinence pad or a bandage can be constructed. Furthermore, dressing materials for wounds can be constructed in a similar manner. These devices are absorbent products which require pulps which exhibit high absorbent properties.

Additionally, absorbent multilayer papers such as kitchen towels can be made of your layers or layers comprising a core layer, and thus these layers can be formed according to the use for which the products are intended or for the purposes for which they are used.

Products such as diapers are constructed when used in conjunction with an outer absorbent layer and an inner substantially absorbent core, currently having a absorbent layer made of crosslinked compositions as shown, for example, in the following European patent applications 0 427 316 A2 and 0 427 317 A2 (Herr-on et al.) And US U.S. Patent No. 5,137,537 (Herron et al.) applicant Procter & Gamble Co. Furthermore, Canadian patent application 2,035,402 (Kokko) based on U.S. priority application 07 / 473,404 holder James River Corp. which describe such masses.

O u oo I U on c ooøo 0 u o I 'O 0000 OI OO .Û Crosslinked pulps are preferably prepared using formaldehyde-based compounds. Recently, it has been found that polycarboxylic acids, preferably citric acid, are effective crosslinking agents. Crosslinked fibers exhibit excellent wet stiffness. The crosslinking physically restricts the uptake of water into the fiber wall.

Because this is done, it retains better than conventional fibers the characteristic rigidity of dry fibers. A web of burnt fibers, therefore, retains its bulk volume and pore volume when wet, which improves fluid uptake, especially repeated soaking or soiling. However, chemically crosslinked fibers are substantially more expensive than fibers which can be used without any crosslinking.

In addition, masses used in prior art crosslinking processes are usually not available in the form of sheets (rolls or sheet bales). Although pulps have been bleached under various alkaline conditions, bleaching schemes and bleaching treatments are common in the art. Consequently, a variety of such schemes are used, which in most cases use at least one or more alkaline steps at reasonably high temperatures. In such sequences it has also been known to use caustic solutions at lower temperatures and thereafter the same solution is used to bring the temperature up to or higher than the boiling point of the solution shown in Canadian Patent 578,573 entitled "Purification of Wood Pulp" granted June 30, 1959. This patent uses the pulps so prepared as dissolving pulps, ie to produce cellulose acetate or other chemical derivatives of cellulose. No description has been found which addresses the improvements in absorbency, rewetting properties, stiffness, etc. described below for the pulps used for the devices or products described herein.

In addition, the difference between dissolving masses and fl uff should also be noted.

Brief Description of the Drawings With reference to the drawing in which fi g. 1 shows a top view of a typical bain diaper; fi g. 2 shows a cross section through the diaper shown in fi g. l along line 2-2; and J "526 466 fi g. 3 is a schematic self-explanatory presentation of the overall process / product improvements.

It has been found that cold alkali extraction (CAE) of pulps which are preferably obtained from conifers and deciduous trees results in fibers which have advantageous and unexpectedly improved absorption properties. Lots of other source materials can also be leathery (eg sugar cane, straw, etc.). The term "cold" refers to an alkaline treatment which does not exceed 60 ° C but which preferably takes place at a temperature lower than 50 ° C and preferably at a temperature between 15 ° C to 40 ° C. Cold alkaline extraction is synonymous with cold caustic extraction CCE when a caustic solution is used as the alkali source. The word “caustic” refers to sodium hydroxide solutions recently prepared or as a solution by-product of a pulp or a papermaking process, for example hemicaustic white liquor, oxidized white liquor and the like. Furthermore, ammonium hydroxide and potassium hydroxide and the like can be used. However, from a cost point of view, the caustic material sodium hydroxide is preferred. Cold alkali extradalione can be performed with additional chemicals added such as hydrogen peroxide, sodium hypochlorite, sodium borohydride, and various surfactants, etc.

The cold caustic extraction preferably takes place at a caustic strength in the range from about 3% to 25%, preferably from about 6% to 18% at a pulp consistency of from about 2% to 25%, but desirably from 2% to 10%, but preferably from 3% to 8%. Masses for high quality, fast absorbing applications are preferably treated with cold caustic concentrations from 13% to 18%. A large amount of pulps are suitable such as those obtained by mechanical or chemical-mechanical, sul- t, power processes, reject materials from pulp cooking, pulps with organic solvents, etc. Both softwood and hardwood pulp are useful. Banwood pulp is preferred.

Among pulps, those which have not been bleached hard are useful, for example pulps with a high K number (ie "potassium permanganate no." A high K or Kappa number, which indicates a relatively high lignin residue in the pulp). The slightly bleached pulp will improve less and also requires a weaker alkali hardening. If the pulps are treated in the manner which will be further described in the description below, the resulting fibers will be such that they exhibit good bulk properties. O I I O O (eg stiffness) and thereby exhibits much improved absorption and rewetting properties which make these masses attractive in a number of uses.

Not only are these pulps characterized by their improved properties, such as their ability to absorb and reabsorb water faster (than untreated standard pulp) when subjected to multiple rewetting tests, but these pulps are also useful for main core absorbent devices in such devices. In fact, the resulting improvements in absorption properties are so significant that the products can easily compete on an economic basis with the more expensive cross-linked products of the prior art described in the patents identified above.

As mentioned above, the newly discovered pulp preparation shows a broad applicability to all types of pulp / erk source material and shows improved properties for each of the pulps / ema brema (fi g. 3). In cold caustic treatment of the mass! the fibers exhibit these improved properties. For pulps produced under different pulp preparation conditions or processes such as salt, prehydrolysed power process, conventional power process, organic solvent processes or BCTMP (bleached chemical mechanical pulp), etc. the properties are improved without exception. The improved properties are observed for all rnassa and fi ber types examined. However, differences exist between masses obtained from different types of wood. Surprisingly, the improved properties have been obtained regardless of whether the types of wood that have been used are, for example, western hernlock, Douglas fi r, Sítka spnrce, Southem pine, Caribbean pine and the like. Other commercial tree species (eg spruce or pine) and hardwood species (eg rubber trees, oak, eucalyptus, poplar, beech, aspen, etc.) provide advantageous properties.

In a preferred embodiment, it appears that the best properties of the resulting resin have been observed for pulps that are unbleached or only slightly bleached.

Nevertheless, good results have also been observed with bleached or more bleached masses. One result of this is that the more bleached the mass, the lower the caustic strength required to obtain the desired effects. However, the desired absorption effects are slightly less when ironed on a direct basis with cold caustic extracted pulps obtained from unbleached pulps with a high K number (i.e. the products obtained from pulps with a high K number are noticeably better). nu i 0 lv n o 00 ococ 00 III: c 0 0 o n con in: 0000 o A oo oss, - 526 466; == With reference to an embodiment and the accompanying drawing below, a typical construction of a diaper in fi g is shown. 1 and 2. l fi g. 2, the diaper 3 is shown in a plan view in its open position with 4 ices 4 which form part of a Velcro strap component, the second component being shown as 5. Other diaper embodiments comprise fastening devices in the form of tape.

I frg. 2 is shown in a cross section along lines 2-2 in fi g. 1, the construction details of the diaper 3 with reference to it from top to bottom, each element in the cross-section 2-2 is described as follows: 11 shows a thermally bonded cover sheet of polypropylene. It is preferably carded or spun. 12 shows an air-filled absorbent cellulose layer. 13 consists of a tissue layer with a typical basis weight of about 16 g / m 2; the absorbent core is denoted by 14 and consists of a mixture of fl uff and SAP (super sorbent polymer and pulp mixture with a basis weight of 500-700 g / mz). The water barrier, which consists of a polyethylene sheet, is shown as 16.

While the above illustrations are for a diaper, other means may be similarly designed. Furthermore, for similar absorbent paper products, pulps that have been modified according to the above provide certain significant improvements with respect to product economy. Thus improved are products such as agents for menstruation and incontinence. Other uses for which the presently described pulps are suitable are paper towels, lrygien paper, industrial paper towels, etc. For the above applications, the modified pulps may constitute 100% of the improved pulps as constituent pulps in the product or may be used in the product in a smaller quantity. ie used in different mixtures with different mass from about 100% to about 25%.

In the tests described, the standard test procedures used in the iron industry have been used. If any changes in the procedure have been made, the change has been specifically described. 526 466 :: To evaluate the masses obtained and to describe the present invention, a number of tests were used to characterize the desired improvements in the final performance due to the use of the cold alkali extraction and to describe some of the analytical properties of mass products. In addition, some of the terminology used in the description of the products in the examples has been defined.

A summary of these tests and definitions follows below.

Analytical properties of the mass K-number or Kappa test are performed according to TAPPI standard method m 'T-214-SU71. This test is a measure of the residual lignin content in the rass. The test indicates the relative degree of residual lignin content in a pulp depending on the pulp preparation and the degree of hardness in the pulp preparation.

The brightness of the pulp is a measure of the whiteness of the pulp, with 100% being the maximum. Data regarding mass luminance are given here as ISO brightness values in percent. The ISO brightness test is described in TAPPI module numbers T-272 (hand sheet) and T-525 (instrumentation) and a data-colored 2000 brightness meter is used as the measuring device.

Properties of the pulp sheet The pulped masses consist of brittle end-use pulps (eg pulps) to which a chemical agent (debonder, defibrillator) has been added to prevent bonding between the pulps (addition of defibrillator results in a soft pulp sheet). The chemical agents, defrosting agents, consist of commercial products which are added to the pulps during sheet formation and make the pulp sheets softer and easier to rub. Defrosting parts are closely chemically related to fabric softeners and act in the same way. The force with which the pulp inder binds binds is measured indirectly by meshing the force (or energy) required to defrost or fl uff a given pulp sheet.

The basis weight of a pulp sheet described herein was determined on some of the products shown in the examples using a method based on TAPPI T220.

A pulp sheet, usually 30 cm x 30 cm or of another suitable size, was weighed and dried to determine the dry matter content (% O.D.). The surface area of the sheet was then determined and the ratio O.D. (oven dried) weight to a defined area was reported as the basis weight.

The thickness and sheet density were determined on certain products shown in the examples using a method based on TAPPI T220. The sheet thickness was determined on test specimens from the basis weight test using a motor-driven core grinder that meets the TAPPI T41 conditions. The sheet density was calculated as the ratio of the basis weight to the thickness.

Strength according to Mullen and burst index were determined on some of the products shown in the examples using a method based on TAPPI T807. A TMI Monitor Burst 1000 was used to measure the hydrostatic pressure required for rupture (burst strength) of the pulp sheet when the pressure was increased at a controlled constant velocity through a rubber membrane with a circular area 30.5 mm in diameter. Strength according to Mullen is registered as kPa (kilo Pascal) in the event of rupture, while the explosive index is the ratio between explosive strength to basis weight.

A Kamas Lab hammer mill model H-O l-C was used to deflate some of the products shown in the examples. Strips of 5 cm wide pulp sheets were fed into the hammer mill, with a 900 rpm motor speed, 50% feed speed and an 8 mm strainer. In some cases, the energy required to burn the pulp sheet was recorded and reported as W hr / kg fl uff, defrosting energy. Fluff was collected in a collection vacuum bag for further testing.

An M / K formation tester was used to measure the formation of the pulp sheets for some of the samples shown in the examples. The formation is an expression of the smoothness of the sheets.

The M / K formation tester consists of a rotating glass drum containing a moving light source. A pulp sheet is wrapped around the outer surface of the drum. The light from inside shines through the sheet and hits a detector outside the drum. During the test, Il IOII rotates IQ 00. ' I O O I O I O I I I I OQO OI! 0 0 0 0 0 00 0000 0 00 000 0 O Il OO I 0 I OQO IOI I O O 00 0: _ 526 466 _š. _: _ 9 ... .... .... ... the drummer with the inner light source and the outer detector for fl moves along the axial direction of the drums. In this way, the amount of light passing through the sheet at your various locations is measured. The variation in the amount of light that passes through the sheet from point to point on the sheet is used as a measure of the formation (uniformity of the formation) of the sheet.

Weighted average bearing length (WAF L) and fl rock roughness were also measured in some of the products shown in the examples using a Kajaani FS-200 Fiber Analyzer.

Fiber quality test test SCAN testing of properties of ff uff pulp was performed on some of the products in the examples. This test uses the SCAN / PFI method (SCAN-C 33:80) and test equipment to form an iron sample and to measure its elasticity, liquid capacity and absorption rate. The fluff samples are conditioned for at least 2 hours under standard conditions (23 J; 1 ° C and 50% in 2% relative humidity) before testing and kept in the conditioning atmosphere throughout the test.

A cylindrical ff uff sample (3.00 in 0.5 g and 5 cm diameter) is prepared using special equipment. The height of the cylinder below 260 g / 1.3 kPa load is measured and reported as elasticity. The sample is placed in contact with a water bath. The time required for the water to migrate vertically up to the top of the cylinder is reported as absorption time, the liquid capacity or the absorption capacity per g sample is calculated by weighing the saturated sample.

A uff test can also be subjected to simulated friend aging artificially (105 ° C for two hours) and tested by this method to determine the effects of aging on the absorption properties of the uff.

Dry classification of pulps was performed on some of the products shown in the examples. This test is a measure of the quality and the briquetting process. A Johnson Manufacturing Fluff F iberization Measuring Instrument, model 9010 OOOO ICO 'OQO' 526 k) n oo, u oo was used to separate the fl uffen into three fractions based on particle size. During the test, the tube is pneumatically stirred to separate the fibers from each other and from the non-defrosted pulp sheet. A vacuum pulls the initial sieve chips and then the long fi brims through a rotating sieve (16 mesh, 1.8 mm opening, USA standard series).

The sieve chips also pass through a second sieve and collect in a dust fi cka. The long fibers (approved) are collected on a second sieve (45 mesh, 0.36 mm opening, USA standard series).

Cushion integrity tests were performed on some of the products shown in the examples. Cushion integrity is a measure of the strength of the ät unit in fl uffed masses and indicates how well fl uffen will maintain the cushion integrity in a ton 'shaped absorption product.

The method is based on PFI method 1981 "Measurement of Network Strength in Dry, Fluffed Pulps". During the test, a cylindrical sample pad of 1,0 to 0,05 g and 50 mm diameter is prepared in a pad. Sample pads are placed in an explosion chamber, which is then installed in a stress-strain apparatus. An explosive body is forced vertically through the test pad. The force required to cause the i meter in the test pad to rupture is reported as pad integrity.

The potential of seed pulp for use as an absorbent layer can be described by, among other tests, a soil contamination or rewetting test. The multiple fouling absorption test procedure was performed as below. Pulp for comparison purposes was prepared, then air filtered into pads with a basis weight of about 200 g / m 2.

The dynamo is pressed at 200 psig for a period of two minutes and then trimmed to about 7 cm x 16 cm. The plastered and densified pads are placed on standard absorbent cores, such as disposable diapers, and covered with a single layer of conventional polypropylene cover material. Liquid is introduced into the absorbent product through a cylinder, which is permanently mounted on a weight-loaded plate, which applies a force of 0.1 psig to the absorbent product. A dam is used to control the liquid flow to the absorbent product. A timer is started when the dam is removed and liquid begins to move into the absorbent product.

Tirnem is stopped when all liquid has been absorbed and the elapsed time is registered. 90 seconds after the liquid is completely absorbed, a stack of five previously weighed blotting papers is placed on top and then a 1.0 psig load is applied to the absorbent product for a period of two minutes. The amount of liquid returned to the blotting paper is registered. The procedure is repeated twice for a total of three wets or sootings. This verwetting test characterizes the rate at which the fibers absorb as well as reabsorb a liquid.

As mentioned above, it has now been found that different pulps of various types of wood produced by various pulp preparation and bleaching processes provide improvements in these pulps by exhibiting improved dye and pulp sheet properties, e.g. after cold alkali extraction (CAE) or cold caustic extraction (CCE) of these masses in the right way in the right sequence when these masses are prepared ie when the mass is treated. Relatively high strengths of sodium hydroxide solutions are ideally used, 13% - 18% NaOH with respect to weight for high absorbency, rapid intensive absorption applications and 5% to 15% for general absorption application, preferably 6% to 10% for this purpose. “Cold caustic extraction” (CCE) refers to the treatment of pulp at a temperature lower than 60 ° C, preferably lower than 40 ° C, with sodium hydroxide solutions above. The process and production of the new pulps are described as an improvement of the new properties hitherto undiscovered in the state of the art. The improvement thus also lies in a method for improving, for example, the absorbency of the resin, the increase in the stiffness of the fibers and other properties which are further described herein and which have not hitherto been known or noticed.

In addition, it has been found that an embodiment where the appropriate absorption layer absorbency can be established after adequate bleaching of unbleached pulp with high K-grade is performed to obtain aesthetically acceptable brightness values for the pulps with slightly colder caustic treatment (eg 15% NaOH against 18% NaOH for unbleached pulps). At the lower concentrations of cold caustic solution, bleached pulps are obtained which are almost as good as pulps obtained with CCE of the unbleached pulps with a high K-number per se. Accordingly, it has been found that a specifically desirable pulp product process exists based on the process used and the selection of different products or criteria which will be further described below. For example, the absorption conditions mean that pulps in the characteristic pulp product program are particularly useful because the pulps and their use can now be easily phased out of the program including unattractive uses and pulps which do not exhibit the attractive characteristics. In addition, the conditions of this process have been determined so as to delimit with high certainty the process according to the invention with the new features and with these related techniques.

Furthermore, although cold caustic treatment has been known to use in high quality dissolving pulp as described above, e.g. to produce ot-cellulose and certain industrial pulp products, this treatment is correlated with the properties of fi brer and pulp sheets described above are new with with respect to pulps useful as absorbent pulps, for example for a supply layer for products, including diapers and agents used in incontinence and instruction, including use as absorbent core materials therein.

Additional advantages will be derived from the examples below and the illustrative embodiments. The examples are given only for the endpoint to describe and are not intended to limit the scope of the invention.

Example 1 Improved pulp sheet deposition: Cold alkali extraction defibrillators, Southern Pine kraft pulp Cellulose pulp is usually produced in dried sheet form for use as fl uff and other fi brittle end uses. Pulp making uses a pulping machine to form the sheet from an aqueous suspension of fibers; when the sheet is formed, it is dried to remove about 90% of the moisture. Large mills of dried, sheet-based pulp are produced in 526 466 ÉÜIIPÄ fi zzšf fi f-.I at the dry end of the pulping machine. These are usually cut into rolls and / or bales with smaller size sheets for distribution to end users.

It is an advantage that the dried sheet material is spread smoothly and evenly without damaging the individual fibers for the pulp types used for different fiber end-user applications. For example, an fl uff pulp will be converted by the end user from the dried sheet-shaped pulp to a cushion of “fl uff” fibers by mechanical action such as that produced by a hammer mill or some other form of abrasive mill. Chemical agents, debrisers, are sometimes added to the pulp during the formation of the sheet to prevent bonding between the debris, resulting in a softer, lighter debrised sheet. '. 526 Sample designation Sample description production wood species pulp alignment procedure sheet debrating agent used? cold alkali extraction mass analysis ISO brightness,% physical sheet properties basis weight (g / mZ) thickness (mm) density (g / cm3) strength according to Mullen (kPa) burst index (kPaømZ / g) Fluff properties according to Kama's elasticity (cm) Liquid retention absorption time (s ) control heat-aged dry separation weight-% acceptance fi berknodar chips dyn integrity 01) z: .o. oc 'Oon. .ol. OO. 0000 f 'Example 1, table ll åLi B- 1 in undefined defined standard procedure standard leading Southern pine mixture force no yes not used not used 88.5 89.4 640 634 1.36 1.36 0.47 0.47 ll l3 417 1.74 0.66 4, l 3.7 13.4 ll .4 3.5 7.9 4.4 8.9 84.4 91.0 13.3 6.8 2.4 2, 2 7.2 7.0. cold alkali extraction use alkali solution strength% temperature ° C time H: M consistency% analysis of the mass ISO brightness,% fl cyclic sheet properties base fold (g / mZ) thickness (mm) density (g / cm3) strength according to Mullen (kPa) burst index ( kPa-m2 / g) Fluff properties according to Kama's elasticity (cm) liquid retention (b / w) absorption time (s) control heat-aged dry separation (weight%) acceptance de erad brated cold alkali standard extraction procedure Southern pine blend force no no not used used NaOH 7.5 35 10 3 88.6 89.6 644 666 1.12 1, 17 0.57 0.57 1494 829 2.32 1.25 4.1 3.6 12.9 13.2 3.3 2.9 4.9 4.6 81.2 91.4 15.9 6.0 2.9 2.7 7.2 7.4 0 0 000 I 0 I 0 ~ - - ':: .. ::: _ § _'_ = -' - 526 466, ¿- ;; == __ = '= .. = 2.- ..

Example 1, Table III-1 Sample designation A- 1 iii B- 1 iii C- liii Sample description Preparation Non-de-brated de fi brated cold alkali standard procedure Standard procedure Extraction procedure Wood type Southern pine mixture Mass adjustment method Arkde fi Bretting- No Yes No The agent used? cold alkali extraction not used not used used used alkali NaOH solution strength% 8.5 temperature ° C 35 time H: M 0:10 consistency% 3 mass analysis ISO brightness,% 86.6 88.4 88.9 physical sheet properties basis weight (g / mZ) 642 639 652 thickness (mm) 1.36 1.30 1.33 strength according to Mullen 1126 716 770 (kPa) jump index (kPæmZ / g) 1.75 1.12 1.18 Fluff properties according to Kama's elasticity ( cm) 4.1 3.9 3.6 liquid retention 13.5 12.4 12.5 (s / s) absorption time (s) control 3.3 7, 1 2.5 heat aged 4, "7.7 3.0 dry separation (weight%) acceptance 84.2 87.4 94.6 fi berknutar 13, 1 1 0.3 3.6 chips 2.7 2.3 1.8 it 526 466 Å É ~ §, É Éšïb-ÃÉɧ Table II, belonging to Example 1, compares the sheet properties and fluff characteristics of certain conventionally prepared sheets of "non-debrinated" bleached kraft pulp of Southern-Pine (Sample A-li) with the bleached (with chemical debrinizer added) bleached kraft pulp of Southem-Pine (sample B-li) The pulp sheet products are produced on a commercial pulp machine. the properties (or sheet physics) as well as characteristics of the fr uffade frbem were tested after production with a hammer scale on a small scale. The data provided are averages of several mass samples from several production runs. A description of expressions and tests has been given above.

In comparison with the standard non-debrinized sheet-shaped pulp, the fi brinated sheet-shaped pulp according to the standard procedure is softer, which is indicated by the substantially lower pulp sheet strength according to Mullen as well as by the lower burst index. Note that the characteristics of the fluff from the debrinized pulp are worse as shown by the lower tethering ability, lower liquid retention and increased (slower) absorption times compared to those of standard pulp fl uff.

However, classification data regarding the dry separation of the unwound fibers from the debrinized pulp indicate that better and smoother defrbrination was achieved (higher acceptances, smaller knots). The integrity of the fluff pad was found to be the same for both types of pulp.

In Table II-1 of Example 1, pulp produced by the process of the invention is ironed, cold alkali extraction (Sample B-IIi) with a pulp prepared by standard process (Sample A111). Both of these types of pulp were prepared by the process of producing kraft pulp from a Southern Pine chip and bleached to the same pallor using standard chemicals / chlorine, chlorine dioxide, sodium hydroxide and sodium hypochlorite ratios. The data provided are average data for prov your samples tested during standard production and experimental production periods. The conditions used during the cold alkali extraction averaged 7.5% NaOH solution strength, at about 35 ° C for about 10 minutes with a pulp consistency of about 3%.

ID OI 0000 00 0 0 00 00 0000 00 0000 0 0 0 0 0 0 ou 000 000 0 0 0 u OO IOOC IO IDC rä '"" nn Note that the sheet produced by cold alkali extraction was softer (about 45% lower with respect to on strength according to Mullen and with respect to burst index) compared to a pulp sheet produced according to the standard procedure. In addition, dry repair data for the fl uff produced during fl uffrering show small-scale improvements with a larger percentage of acceptors and in a lower percentage of knots, indicating improved debrisability relative to pulp sheets prepared according to the standard procedure. In these respects, the effect of the cold alkali extraction process on pulp and the fluff properties relative to the usual non-defibrated pulp is similar to the effects of using a chemical pulp sheet briquetting agent according to the standard procedure (Table I-1, Example 1) and, in fact, exhibited the new masses improved absorption properties. However, the cold alkali extraction process did not result in any adverse effects on the absorption times as occurs with the use of a briner.

The liquid retention of the ffen uffen produced by the pulp prepared by cold alkali extraction was equivalent to that of the standard pulp (Table II-1, samples Aiij and .B_-li_í). the cold alkali extraction process iron feed with fl uff from standard pulp (Table II-1) is the comparable improvement associated with the use of a sheet defibrillator (Table I-1). The percentage of dry separation acceptors was 12% higher and the free radicals 62% reduced in the cold alkali extraction process mass relative to control mass prepared according to standard procedure, while acceptances for the debrinized mass increased by only 8% with a berknut content reduced by only 49% relative to the control mass according to the standard procedure. In addition, these relative improvements of the cold alkali extraction-produced pulp were obtained from a sheet which was in fact slightly harder than the brinated pulp sheet (829 strength according to Mullen / 1, 25 explosive index against 417 strength according to Mullen / 0.67 explosive index).

The data shown in Table III-1, Example 1, for factory production of debrinised and non-debrinised standard pulps with experimental production of cold alkali extracted pulp. All mass types (samples A-liii, B-liii and C-liii) were prepared from «. ' 526 466 * = is '0 v'. g o n q g O O g Q 000 O OO Ö o on z o o ..,. .g 0000 00 Û Starting material from Southem pine shavings by force. All pulps were bleached with chlorine dioxide, sodium hydroxide, oxygen and / or hydrogen peroxide to the indicated brightness level. The conditions for the cold alkali extraction averaged about 8.5% NaOH strength, at about 35 ° C for about 10 minutes on a pulp with a consistency of 3%. About 0.2% H 2 O; (O.D .-- young dried - rnassase base) was added during the cold alkali extraction.

Note that the sheet of the fi brinated mass and of the cold alkali extracted mass, respectively, was prepared with approximately the same strength according to Mullen and the same burst index, both of these indicators of sheet hardness being significantly reduced for both types of treated mass, defibrinated or extracted with cold alkali relative to the control according to the standard procedure. Again, the cold alkali extracted pulp shows some similarities to the pulp prepared according to the standard procedure with the fi brining agents added: elasticity and liquid retention were lower both relative fl uff from standard pulp. However, the absorption times for fl uff from the cold alkali extracted pulp were better (faster) than for fl uff from the defibrinated pulp or from the standard pulp. Weight% acceptance and fiber knots in the dry classification were better for fl uff than from test pulp from cold alkali-extracted pulp.

Thus, the cold alkali extraction results in advantages which are not present in pulp according to the standard procedure and / or were not expected from known technology to add sheet defoamers to standard pulp as a way of "softening" the pulp sheet.

Example 2. Cold alkali extraction to improve fiber properties, prehydrolyzed kraft pulp of Southem Pine Pulp.

The data shown in Tables 1-2 and II-2 of Example 2 show pulp sheet and fi bearing properties improvements that occurred when cold alkali extraction was applied to pulps cooked from Southern Pine feedstocks by a prehydrolyzed power process.

The hydrolyzed kraft process is a two-step pulping process, in which the feedstock is first treated under mildly acidic conditions (pH of about 3-626 666 4) followed by an alkaline step, which is essentially the pulping process illustrated in Example 1. 6 6 526 466 2; EXAMPLE 2, TABLE I-2 TEST NO.

SAMPLE DESCRIPTION Manufacture Wood species Mass production Sheet preparation used (?) COLD ALKALIE EXTRACTION Alkali used Strength of the solution,% Temperature, ° C Time H: M Consistency,% ANALYSIS PROPERTIES FOR THE MASS ISO brightness,% ARCH PROPERTIES (Bas. g / cm3) Strength according to Mullen (kPa) burst index (kPaJnZ / g) FLUFF CHARACTERISTICS ACCORDING TO KAMAS Elasticity (if) Liquid retention (g / g) Absorption time (s) Control Heat aged Dry separation (wt%) Accept Fiber knots Chips Dyninteg fi tet (N) TEST WITH SEVERAL WETS Absorption times (s) First wetting Second wetting Third wetting A-2i Icke standard procedure Bzli Cold alkali extraction procedure Southern pine blend ----- à Prehydrolyzed kraft pulp -_> No No Not used Use NaOH 15 25 0:10 3 89.4 86.7 652 818 1.32 1.28 0.50 0.64 1 154 716 1.77 0.88 3.8 4.0 13.2 13.1 3.4 3.4 4.2 6.1 95.0 97.3 1.8 0.7 3, 2 2.0 6.8 7.3 4.3 3.1 30.6 23.1 45.1 31.1 »_ 525 466 '32 'En: 1 :: ° _¿ _.__: 2' 2 EXAMPLE 2, TABLE 11-2 TEST NO. A-2ii B-2ii SAMPLE DESCRIPTION Preparation Non-debrated Cold alkali Standard procedure Extraction procedure Wood species Southern pine blend _._____; Pulp setting Prehydrolysed kraft pulp ---) Sheet defoamer used (?) No - N fi j COLD ALKALIE EXTRACTION Not used Use Alkali used NaOH Strength of the solution,% 10 Temperature, ° C 25 Time HM 0110 Consistency,% 3 ANALYSIS PROPERTIES light FOR, PULP 90% 5 87.2 ARCH PROPERTIES - Base wine (g / mZ) 247 891 Thickness (mm) 1.05 1.16 Density (g / cm3) 0.81 0.77 Strength according to Mullen (kPa) 1,090 671 Explosion index (kPamz / g ) 1.29 0.75 Energy according to Kamas (wh / kg) 116 83 FLUFF CHARACTERISTICS ACCORDING TO. KAMAS Elasticity (cm) 3.8 3.7 Liquid retention (w / w) 14.1 13.9 Absorption time (s) Control 4.2 3.8 Heat aged 5.6 5, 1 Toxrseparation (wt%) Accept 95, 3 95.4 F iber knots 1, l 1.4 Chips 3.6 3.2 Dynint integrity (N) 8.1 6.1 IOOQ 00 0000 tu 526 466 ¿~ ë "Samples gi in Table I-2 consist of a prehydrolyzed Southern Pine bleached pulp with the conventional bleaching agents chlorine, chlorine dioxide, hypochlorite and / or hydrogen peroxide and / or oxygen and sodium hydroxide to a brightness level according to ISO indicated. Sample B kraft pulp, bleached to the same pallor as indicated before cold alkali extraction.

The preparation of the B-2i sample involves the cold alkali extraction process under the conditions recorded (average conditions are used). Both the A-2i and åli samples were produced on a factory scale during production and in experimental batches.

Regarding the bleached kraft pulp of Southern pine discussed in Example 1, the use of the cold alkali extraction resulted in a softer sheet of pulp (ie a lower strength according to Mullen and a lower burst index). Note that the higher base density and density at which the sample mass was produced would have had a negative effect on these sheet properties. In addition, the elasticity and liquid retention in the cold alkali extracted sample _l§; 2_i were equivalent to those of the sample 1_X _-_ 2_i and the results from the dry separation of fl uff showed some improvements for sample ß¿2_i.

The fluff absorption times according to Kamas were similar (slightly longer for samples e-li after heat aging), but the specialized flwatering absorption test (as described above) showed that cold alkali extraction improved the absorption properties of the resulting fi bem.

The data shown in Table II-2 also compare bleached prehydrolyzed kraft pulp of Southern pine (the pulp preparation conditions were stronger than those used for the samples in Table I-2 in this example).

Sample A_r-2_ii was prepared without, sample Bli with cold alkali extraction. Both types were also produced in a full-scale equipment, using standard bleaching techniques to achieve the light fixture levels shown. The concentration of the sodium hydroxide solution used was lower than that used for the samples described in Table I-2 in this example, 10% versus 15%.

QIO! OQO.

OI 5: 2 e 46 e 2: '- 1 :? = .. = Comparison of sheet property data again shows the emollient effects on the sheets that the use of cold alkali extraction gives: lower strength according to Mullen, lower burst index. An energy parameter according to Karnas (see description above) was also included to describe the relative ease with which they spread the pulp sheet during opening in the laboratory. The mass extracted with cold alkali was easier to fl uffa (with less energy consumption). Fluff absorbances were slightly faster for the cold caustic-extracted sample. Dry separation of the fluffed fibers was the same for both samples with respect to elasticity and liquid retention. However, fl uffdyn integrity (see description above) was worse for sample B_ subjected to cold caustic extraction (this was not the case with sample _l_3_-2_ii compared to sample ¿\ _-_ 2_i in Table I-2 in this example).

Example 3: Cold Alkali Extraction Process: Variable Solution Strength From the data given in Tables 1-3 to VI-3 in this example, it is obvious that no set of cold alkali extraction process conditions will result in exactly the same consequences on each type of pulp. Raw material / investment used, pulp driver used, and the location of the cold alkali extraction within a bleaching sequence have implications for what may be the optimal conditions for each type of sample. Furthermore, it seems that the conditions for the cold alkali extraction can be selected to enhance some of the properties in the resulting mass but then at the expense of the others. Not all fiber end uses require improvements of the same properties, thus this obvious versatility of the cold alkali extraction conditions can be used to tailor pulp fibers to different brittle end products and / or customers. This will be discussed in this and the following examples.

EXAMPLE 3, TABLE 1-3 TEST NO.

SAMPLE DESCRIPTION Preparation Wood type Mass production K-number, ml COLD ALKALE EXTRACTION Alkali used Strength of the solution,% Temperature, ° C Time H: M Consistency,% ANALYSIS PROPERTIES FOR THE MASS ISO brightness,% ARCH PROPERTIES Base thickness (g / mZ) Thickness (g / mZ) g / cm3) Strength according to Mullen (kPa) Explosion index (kPamz / g) FLUFF CHARACTERISTICS ACCORDING TO. KAMAS Elasticity (cm) Liquid retention (w / w) Absorption time (s) Control Friend-aged Dry separation (% by weight) Acceptable Fiber Knots Chip Dynam integrity (N) pine blendí-í-á Kraftmassa ß 18 å Not used Used --_-_--> (Control) NaOH NaOH 7 12 35 35 0:15 0.15 3 3 83.3 92.2 91.4 725 737 691 1.75 2.14 2.41 0.41 0.35 0.29 1 179 527 70 1.63 0.72 0.10 3.8 3.9 3.7 13.3 12.2 14.6 3 .7 2.9 3.9 4.3 3.6 4.1 97.5 98.5 89.0 1.2 0.1 8.6 1.3 1.4 2.4 6.7 6.4 5.3 5 2 6 4 66 2% ”112 = __ = '= .. = 221'.: I.

EXAMPLE 3, TABLE 11-3 PRGV NO. Aiii å; êi_i LL-ëä SAMPLE DESCRIPTION Preparation Non-de fi brated Cold alkali extraction standard procedure procedure --í> Wood species Southern pine blend ------> Mass production Kraftrnassa> K-tal, ml 18> COLD ALKALIE EXTRACTION Alkali used water) NaOH-e ----_-> Strength of the solution,% 0 3 7 14 Temperature, ° C 35 7 Time H: M 0210> Consistency,% 3> ANALYSIS PROPERTIES OF THE MASS ISO brightness,% 87.9 90.3 92.1 92.0 ARCH FEATURES Basvikr (g / m2) 71 1 677 676 691 Thickness (mm) 1.87 2.03 2.06 2.79 Density: (g / 6m3) 0.38 0.34 0.33 0.26 Strength according to Mullen (kPa) 1 189 1 005 501 83 sphange index (RPaJnZ / g) 1.67 1.48 0.75 0.12 Energy according to Kamas (wh / kg) 109.5 99 92.7 - FLUFF CHARACTERISTICS ACCORDING TO. KAMAS Elasticity (cm) 3.8 3.5 3.3 3.3 Liquid retention (w / w) 1 1.8 11.3 11.2 13.2 Absorption time (s) l Control 4.1 2.8 2, 6 4.0 Dry Separation (% by weight) Acceptance 94.6 94.3 94.0 75.9 Fiber knots 2.0 2, 7 3.2 21, 1 Chips 3.4 3.0 2.8 3.1 Dynintegntet (N) 7.4 6.4 5.7 4.2 526 466 0 0 0 00 0 0 0 0 o 0 0 0 0 oo 00 0000 00 OO OIIQ 00 OOIO lO-I OOOO OOO II O OQO 'I EXAMPLE 3 , TABLE III-3 TEST NO.

SAMPLE DESCRIPTION Preparation Wood species Mass fraction setting K-number, ml COLD ALKALIE EXTRACTION Alkali used Strength of the solution,% Temperature, ° C Time H: M Consistency,% ANALYSIS PROPERTIES FOR THE MASS ISO brightness,% TEST WITH SEVERAL WETTING Wetting times Wetting time A-3iii B3-iii C-3 iii D-3iii E-3iii Cold alkali extraction process> Southern pine blend> Prehydrolyzed kraft pulp ------% 18 '> Sodium hydroxide (NaOH) in ----> 7.0 11 .0 13.1 15.1 18.2 35 * f 0:15 ï 88.0 88.3 85.3. 85.3 85.7 7.6 6.6 6.8 6.2 6.5 37.6 26.2 25.1 21.8 22.4 56.6 44.9 36.5 35.0 33, 0 SAMPLE NO.

SAMPLE DESCRIPTION Production Wood species Mass production K-number, ml COLD ALKALI EXTRACTION Alkali used Solution strength,% Temperature, ° C Time H: M Consistency,% TEST WITH SEVERAL WETS Absorption times (s) First wetting Second wetting Third wetting 0 0 000 0 u 6: z ', °. .gg- .ou. oc. 0:00 .oo EXAMPLE 3, TABLE IV-3 A-3iv B-3iv C-3iv D-3iv E-3iv F-3iv Unbleached pulp Unbleached pulp before cold alkali- after cold alkali extraction extraction A; Southern pine 9 blend Kraftnrassa à 8,2> Not used Used (Control) NaOH 6 9 12 15 18 30 2 0: l 5 à 3,0 7 8,9 8,2 6,7 7,5 7,4 8, 3 43.8 43.7 30.7 32.8 29.6 31.7 64.5 68.5 51.2 48.3 50.0 46.3 526 4662§ * Ü * Ü = 5 ɧï3 ' ÃÉɧ'¿i «§ EXAMPLE 3, TABLE V-3 TEST NO. A_-3_ \ ¿B-3V SAMPLE DESCRIPTION Preparation Non-de fi brated Cold alkali standard procedure extraction Wood type Southern pine blend-a K-fal, m1 12.4> COLD ALKALI EXTRACTION Not used Used Alkali used (Control) NaOH Solution strength,% 6 Temperature, ° C 23 Time HM 0115 Consistency,% 3 ANALYSIS PROPERTIES FOR THE MASS ISO brightness,% 34.3 34.3 ARCH PROPERTIES Base weight (g / 1n2) 644 599 Thickness (mm) 1.33 1.40 Tärhe: (g / cm3 ) 0.53 0.44 Strength according to Mullen (kPa) l 656 834 sphincter index (kPaJnZ / g) 2.63 1.44 Energy according to Kamas (wh / kg) 69.5 47.9 FLUFF CHARACTERISTICS ACCORDING TO. KAMAS Elasticity (cm) 4.1 3.7 Fluid retention (w / w) 12.0 11.8 Absorption time (s) Control 3.2 2.9 Heat aged 4.8 4.5 Dry separation (wt%) Accept 86, 6 88.7 Fiber knots 1 1.8 9.3 Chips 1.6 1.9 Dynintegritet (N) 7.1 7.0 0000 00 00 0 0 EXAMPLE 3, TABLE VI-3 TEST NO. A-3vi B-3vi C-3vi D-3vi E-3vi SAMPLE DESCRIPTION »Preparation Non-de fi brated Cold alkali extraction procedure-è standard procedure Wood type Southern hardwood A7 blend Mass production Power mass> K-number, ml 1 1.0 ö COLD ALKALYH Hydroxide Extraction Alkali used (Control) Strength of the solution,% - 9 12 15 18 Temperature, ° C 39 M9 Time HM 0: 15 å Consistency,% 3> ANALYSIS PROPERTIES FOR THE MASS ISO light,% 31.5 43.2 38.6 37.6 37.8 FLUFF CHARACTERISTICS ACCORDING TO KAMAS Elasticity (cm) 3.4 2.9 2.9 3.0 2.7 Liquid retention (w / w) 12.5 12.2 13.0 13.2 12.6 Absorption time (s) Control 6.2 4 .5 4.0 4.3 3.8 Heat aged 12.9 8, 1 9.3 7, 1 6.5 Dry separation (weight%) Acceptance 93.2 93.7 91.6 91.5 90.4 Fiber bundles 0.7 0.6 0.6 0.7 0.5 Chips 6, 1 5.7 7.6 7.8 9.1 Dynintegrltet (N) 3.6 4.4 4.1 4.3 4, 1 TEST WITH SEVERAL WETS Absorption times (s) First wetting 13.3 11.9 11.4 11.7 10.7 Second wetting 55.3 46.1 46.8 45.8 45.9 Third wetting 98.5 64, 2 67.3 73.6 74.3 IOCOIOIO CCI I Ü 526 4.66 The data given in Table I-3 in this example cover laboratory experiments on bleached OQO.

ICO mass of Southem pine. All samples A-ii to Q-åj were bleached to the brightness shown with the usual bleaching chemicals chlorine dioxide, hydrogen peroxide and sodium hydroxide. The cold alkali extralated samples ß-jj and _C_-§i_ were further bleached with chlorine dioxide after the cold alkali extraction (this contributed to the higher brightness levels of samples _B_-3_i and _C_-§i). The strength of the NaOH solution used in the cold alkali extraction of sample B-3i was relatively low (7% compared to that used for sample Q-ii, 12%). These samples were formed into sheets (sheets without the direction of a laboratory sheet form) and dried under the same standard conditions in the laboratory (but dried without force unlike a commercial pulp machine) so that the changes in the pulp sheet and the fis / fl properties measured completely reflect only the cold. the alkali extraction process. Thus, for sample Bji, cold alkali extraction resulted in fibers which formed a sheet which fl was blended into fibers having the following properties relative to sample ï fi (non-cold caustic extraction): the same basis weight, higher thickness, lower density, lower strength according to Mullen and lower burst index; equivalent fl uff elasticity but reduced liquid retention, faster absorption times and slightly improved pro fi l for dry separation of fl uff. For sample Q-Qj (cold caustic extraction with NaOH, strength 12%) relative to sample A-3i (non-cold caustic extraction) the comparison / contrast was as follows: slightly reduced basis weight, greater thickness, lower density, much lower strength according to Mullen and burst index (very weak sheet, equivalent ff uff elasticity, higher fl uffretention, similar absorption times according to Kamas and poorer dry liquid separation profile).

Thus, if an end user requires a fiber with the highest liquid retention, a higher caustic solution strength can be selected; in order to maximize acceptance at fl uf fi ng, a lower caustic strength should be preferred.

Table II-3 of this Example 3 shows additional data on bleached kraft pulp of Southern pine, produced in the laboratory over a wider range of strengths of cold alkali extraction. All samples were bleached with the usual bleaching agents chlorine, chlorine dioxide, hydrogen peroxide and oxygen (before the cold alkali extraction) to the indicated brightness levels. Even with a 3% NaOH solution strength, the pulp sheet can be slightly softer without any major negative consequences on ff uff products. 526 466 § "É"? = F ɧfÉ'ÄÉÜf'Lf = I However, it seems that cold caustic extraction at 14% NaOH solution strength results in a pulp sheet that was fl opened with apparently negative consequences on dry separation and elasticity and without any benefits' in absorption time but with a slightly higher fluid retention.

Results from a similar series of pre-hydrolysed bleached Southern pine blanks subjected to cold caustic extraction over a range of 7 to 18% NaOH solution strength are shown in Table III-3. All samples were bleached with chlorine, chlorine dioxide, sodium hypochlorite and sodium hydroxide before the cold caustic extraction. The results of the multiple dehydration absorption tests indicate that little benefit would be achieved by using NaOH solution strength in the cold caustic extraction (below the temperature, time and textures shown) greater than about 13% for this type of pulp and that absorption times are improved (reduced) progressive when a 7% to 13% caustic solution is used.

Similarly, data are given in Table IV-3 in this example which illustrates a smoothing of the improvements in absorption time with increasing cold alkali extraction solution strength (6-18%). Samples i to i were all subjected to cold alkali extraction from the starting material sample i. No bleaching chemicals were used on any of the samples A¿_3_iy to Lä. Sample gray ice consisted of Southern pine pulp which is boiled to a very very low K-number in a single step of conventional kraft mass boiling in the laboratory.

The times for testing with fl your av hit v brains were improved with the use of 9% NaOH solution strength but no further benefit was seen above the 9% strength.

Thus, a similar trend towards an equalization of the absorption times with increasing solution strength seen from the application of cold alkali extraction was observed for this unbleached kraft pulp of Southern pine with low K-number which had been observed for the bleached prehydrolysed kraft pulp series given in Table III-3 in this example. .

However, the level of absorption times for each type of pulp and the solution strength at which the absorption times improved occurred under different parameters depending on the type of extracted pulp. For bleached kraft pulp with a very low K-number, cold alkali extraction at relatively low NaOH solution strengths has many advantages over fast absorption times. Data are given in Table V-3 in this example which compares two samples (A _-? ¿\ _ / Without and Lä with cold alkali extraction) of pulp prepared to K number 12.4 and bleached to 84.8% ISO brightness.

The conditions of the cold caustic extractor used for sample _B¿3 _'_ v consisted of a relatively low solution strength of 6%, at 28 ° C for 15 minutes and a pulp consistency of 3%. This cold alkali extraction was scarred before bleaching to the indicated brightness. Both types of rnassa samples (average data are given for i and Big) were bleached using chlorine dioxide, hydrogen peroxide and sodium hydroxide.

One of the major disadvantages in the production of pulp to a low K number by means of a pulp process is the negative effects on the pre-property which is a result of the extended boiling. Please compare the higher strengths according to Mullen and the burst index for the sheets in sample A _-_ Iš_y, Table V-3 with those for the samples in Tables 1-3 and II-3 in Example 3. When preparation used on the masses with low K-number includes cold alkali extraction (sample 1_3_-II \ _ /, Table V-3), these disadvantages are overcome. In addition, the rak uf rak characteristics of the fibers in the 33331 pulp sample with a low K-number were equivalent or better than those for the ggy pulp sample with a low K-number (Table V-3, similar liquid retention, slightly faster Karnas fl uff absorption times and slightly improved dry separation fl uffprofrl).

Table VI-3 in this example shows data for a series of unbleached kraft pulps cooked from a Southeast United States mixture of hardwood pulp (rubber trees, oak, etc.) to a low (1.0 1.0) K number. Cold caustic NaOH solution strength was varied from 9 to 18% for samples fi-3_ vi to Eid; sample; Sample A-_3¿i was the starting mass before the cold alkali extraction. No bleaching chemicals were used on these samples. The NaOH 9% solution strength seems to be the optimum for the conditions studied for this type of pulp in the unbleached stage: Kamas fl uff and test with fl your wettings are essentially constant at 9% and higher solution strengths. The dry separation profile for ff uff degenerates at solution strengths equal to or above 12%. For this type of deciduous tree mass, even lower NaOH strengths may prove to be desirable. Note that lots of hardwood do not match lots of softwood masses in these types of fi accounting 526 466; ~ @ ~ r, f tat: -aßt fi- sit: tests. However, cold alkali extraction can be used to improve some of these fi ber / ff properties to some extent for both types of starting materials.

Exemgel 4 Sul n ttnassor: de fi brbrering; cold alkali extraction Debrisants can be used on salt masses as well as on kraft masses. Data are shown in Table 1-4, Example 4 for commercially available starch pulps. The cooking procedure used is sour sul fi t (also known as sour bisulñt); both of these masses are bleached to a brightness shown with a common bleaching agent such as chlorine, chlorine dioxide, hydrogen peroxide and sodium hydroxide. Data provided are averages from ester your tests of each type of production, the non-fi brated (A-4i) and the fi brated (B-4i). 526 466, EXAMPLE 4, TABLE I-4 TEST NO.

SAMPLE DESCRIPTION Production Wood species Mass production Sheet preparation used (?) COLD ALKALIE EXTRACTION ANALYSIS PROPERTIES FOR THE MASS ISO brightness,% ARCH PROPERTIES Base weight (g / mz) Thickness (mm) Density (g / c1n3) Strength according to MpP Kamas (wh / kg) FLUFF CHARACTERISTICS ACCORDING TO KAMAS Elasticity (cm) Liquid retention (w / w) Absorption time (s) Control Friend-aged Dry separation (% by weight) Acceptable Fiber Knots Chips Dynam integrity (N) A-4i B-4i Non-debrised Non-debrised standard procedure Standard Northwest U.S. softwood blend, predominantly Douglas -% Sul fl t> Yes No Not used Not used 91.8 91.2 698 684 1.25 1.34 0.56 0.5 l 479 279 0.69 0.61 41.0 41.0 28, 7 3.7 3.6 13.2 12.1 1 1.8 6.3 43.6 6.0 77.9 87.5 16.0 7.1 6.1 5.4 6.3 6.4 00 OC OO IQ OOII II CCI- ø oc 0 I oo lol 000 vitt u O OO 5 2 6 4 6 6 3 ¿- - - EXAMPLE 4, TABLE II-4 PROV NO. Affm MA Q-Aä àetä SAMPLE DESCRIPTION Preparation Non-de-brated Non-de-brated Cold alkali Cold alkali standard- standard- extraction- extraction- procedure procedure procedure procedure Bleach Bleach Bleach Wood type Southern pine blend fi Mass production Acid sul, v ml v * K-tal 34 28 34 28 COLD ALKALIE EXTRACTION Not used Not used Used Alkali used NaOH NaOH Strength of the solution,% 15 15 Temperature, ° C 30 39 Time HgM 0:15 0:15 Consistency,% 3 3 ANALYSIS PROPERTIES OF THE MASS ISO brightness,% - 35 - 85 TESTS WITH SEVERAL WETS Absorption times (s) First wetting 13.2 7.9 5.3 3.1 Second wetting 36.3 37.2 2Û .9 27.3 Third wetting 45.1 63.5 30, 1 38,6 '3: 7: 2' fn '' hf .of n. 0:00 70 :.

EXAMPLE 4, TABLE 111-4 TEST NO. A-4iii B-4iii SAMPLE DESCRIPTION Preparation Non-de fi brated Cold alkali standard extraction procedure Extraction procedure Carboniferous Caribbean pine ----> Mass production Su1 fi tí -_----> K-tal, m1 24 * f COLD ALKALIE EXTRACTION Not used Used Alkali Not used NaOH Strength of the solution,% 15,4 Temperature, ° C 30 Time H: M 0137 Consistency,% 3 ANALYSIS PROPERTIES FOR THE MASS ISO brightness,% 37,3 77.5 FLUFF CHARACTERISTICS ACCORDING TO. KAMAS Elasticity (cm) 3.4 2.9 Liquid retention (w / w) 12.1 13.0 Absorption time (s) Control 2.8 3.5 Friend aged 4.4 4.4 Dry separation (wt%) Accept 92, 4 80.4 Fiber bundles 1.6 1 1.3 Chips 6.0 8.3 TEST WITH SEVERAL WETS Absorption times (s) First wetting 38.1 15.9 Second wetting 88.2 45.0 Third wetting 135.8 69, 6 l I Olin I ~ f). Z 2 '. ° .. ".. °' .. 'n' J .. '..' 526 466 3, EXAMPLE 4, TABLE IV-4 TEST NO. A-4iv B_-4_i \ _f TEST DESCRIPTION Preparation Not -de fi brated Cold alkali- standard procedure extraction Wood species Douglas fi r-íê Mass production Sul fi t ö K-tal, ml 26.6 * IN COLD ALKALI EXTRACTION Not used Used Alkali used NaÛH Solution strength,% 15.4 Temperature, ° C 30 Time H: M IIÛÛ Consistency,% 13 ANALYSIS PROPERTIES OF THE MASS Iso brightness,% 90.4 83.4 FLUFF CHARACTERISTICS ACCORDING TO KAMAS Elasticity (cm) 3.5 2.5 Liquid retention (g / g) 14.1 13.0 Absorption time (s) Control 4 .6 3.8 Heat aged 6.2 4.5 Dry separation (weight%) Acceptance 87.8 65.4 Fiber bundles 6.6 26.6 Chips 5.6 8.0 TEST WITH SEVERAL WETS Absorption times (s) _ _ First wetting 47.2 28.9 GET? Second wetting 103.3 59.9 'Third wetting 137.9 77.2 526 466 As in Example 1, Table II, which shows the effects of the defibration properties of 39 sheets of bleached kraft pulp, the act as a “plasticizer” on sheets of hardwood pulp. e strength according to Mullen, explosive index and Kama's energy in sample Qgli compared to sample A341. There is also a similar trend towards lower fluid retention for the debrised mass in the same way as was seen with the kraft mass. The Flufftoir separation process is also improving in the direction of larger acceptances, and smaller fiber knots as was the case with kraft pulp. However, salt pulps differ from kraft pulps in that the use of defibrillators improves the absorption times of sulphite pulps (related to the differences in wood extracted in acid salt pulp). Note the long absorption times for the non-defibrated starches.

However, the use of cold alkali extraction for style fi tinasses can have additional benefits and can improve the performance in tests with fl your wets. Data given in Table II-4 in this example which compare unbleached to bleached sulphite pulps of Southern pine prepared with and without cold alkali extraction. Samples eaten and Q; Q was bleached with common bleaching agents such as chlorine, chlorine dioxide, hydrogen peroxide and sodium trihydroxide. Samples Qíij and _Q¿4_ii_ represent two unbleached sulphite masses of Southern pine with a high K-number. Sample C-4ii cold alkali was extracted using the conditions shown in Table II-4 from Sample A-4ii; Sample D-4ii was subjected to cold alkali extraction from Sample B-4ii.

These data indicate that cold alkali extraction can minimize differences in tests with wettings for these salt masses of Soutem pine visible to non-bleached resp. bleached mass. Please compare A for the first absorption times for (Aiii to å-g fi) of 5.3 seconds except for delta the first absorption times for (Q fifi to Q¿_ <1_i_i) of 1.3 seconds; delta for the third absorption times for (§-_4i_i to åílii) of 18.4 seconds, but only a delta of 8.5 seconds for the third absorption times for (LL-gg to _C_; 4_ii). Thus, the cold alkali extraction reduces the magnitude of the differences in absorption times between unbleached and bleached pulps as well as improves the level to which the two cold caustic extracted samples Q and _12 showed (reduced all absorption times, further discussion of these samples is given in Example 5).

Data shown in Tables III-4 and IV-4 in Example 4 for sulfur pulps which show the effects of using relatively high sodium hydroxide solution strengths for cold alkali extraction at longer retrieval times and at higher consistency than those used in the previous examples and tables. All four pulp samples (A-_4_ii_i and l_3_-4; ii_i, Table III, i and gig, Table IV) were bleached using standard pulp bleaching chemicals chlorine dioxide, hydrogen peroxide and sodium hydroxide. Acid salt cooking was used to boil a Caribbean pine chip furnish to K-number 24 (Table III-4); acid sulfur boiling was used to boil Douglas's to about K number 27 (Table IV-4). When cold alkali extraction was used (for the B samples in both of these tables, i.e. B-4iii and B-4iv) it followed an initial bleaching treatment of the unbleached pulp with chlorine dioxide.

Bleaching was continued after the cold alkali extraction to a brightness level shown using chlorine dioxide, hydrogen peroxide and sodium hydroxide.

For the salt mass of Caribbean pine, the use of cold alkali extraction at 1.54% NaOH under the specified conditions in fibers showed significant improvements in the test with wets (all three wetting times were reduced by about 50%).

Kamas fl uff characteristics were the same for the sample compared to the sample with the exception of a poorer dry separation profile for those with cold caustic extract). This may be due to an optimally high NaOH solution strength for this type of pulp observed for certain types of kraft pulps discussed under Example 4 and / or the higher consistency and / or longer time at which the relatively high concentration was used and could be non-optimal. .

For the Douglas starch pulp from Table IV-4, the use of the cold alkali extraction also improved the times in the hydrogen absorption test; Kama's fluff absorption times were also faster, but uffelasticity and fluid retention appeared to be more affected for Caribbean pine in Table Ill-4. The dry drying separation process was also worse with cold alkali extraction of this salt mass and Douglas frr. Again, as in the Caribbean pine salt sample and with the kraft pulp samples discussed in Example 4, these cold alkali extraction conditions may be non-optimal for fiber properties other than absorption time enhancers for this type of bleached softwood fiber. 526 466 41 = Example 5.

Southern pine kraft pulp and sulphine pulp The following unbleached kraft pulp (Sample II - Table I-5, Example 5) with a K number of 30 was obtained from a Southern pine malt composite. This pulp was produced by a conventional kraft pulp production process using a method common in the industry. A salting process was used on a target composition of Southern pine shavings to characterize the behavior of fibers cooked of the same species via different cooking processes. This pulp was produced by an acidic bisulphate process (starch addition) common in the industry. This mass (sample _A¿5_i - Table I-5, Example 5) showed a K number of 34. f)::: sas 466 42 EXAMPLE 5, TABLE 1-5 EXAMPLE NO. Aii _13_-S_i <_l; fi_ i SAMPLE DESCRIPTION Production Unbleached pulp before Unbleached pulp after Bleached pulp after cold alkali extraction Cold alkali extraction Cold alkali extraction Southern pine blend? Type of wood Solid mass å Mass production 30 - - K-number, ml COLD ALKALI EXTRACTION Not used Used Used Alkali used NaOH NaOH Strength of the solution,% 15 18 Temperature, ° C 30 30 Time I-LM 0:15 0:15 Consistency,% 3 , 9 3.0 ANALYSIS PROPERTIES FOR THE MASS ISO brightness,% - ~ - TEST WITH SEVERAL WETS Absorption times (s) First wetting 9.5 5.6 5.3 Second wetting 36.3 20.2 18.7 Third wetting 56.9 32.4 26.7 f, °:; 2f :: = - 2..f °:; 2 -.,;: -_: = 526 466 ß EXAMPLE 5, TABLE II-S TEST NO. A-Sii B-Sii C-Sii SAMPLE DESCRIPTION Preparation Unbleached pulp before Pulp after cold Pulp after cold cold alkali extraction alkali extraction alkali extraction Wood type Southem pine blend * f Mass production Sul fi t? K-tal, ml 34 - - COLD ALKALIE EXTRACTION Not used Used Used Alkali used NaOH NaOH Strength of the solution,% 15 18 Temperature, ° C 30 30 'fm HM 0: 15 0: 15 Consistency,% 3.0 3.0 TEST WITH SEVERAL WETS Absorption times (s) First wetting 13.2 6.9 5.1 Second wetting 36.3 24.5 18.6 Third wetting 45.1 32.3 23.2 SAMPLE NO.

SAMPLE DESCRIPTION Production Wood species Pulp preparation COLD ALKALI EXTRACTION Alkali used Strength of the solution,% Temperature, ° C Time H: M Consistency,% ANALYSIS PROPERTIES FOR THE MASS ISO brightness,% TEST WITH SEVERAL WETS Absorption times (s) First wetting - O IC IÛ Oil OI OO Û II OI .O EXAMPLE 5, TABLE III-5 A-Siii B-Siii C-Siii Bleached mass before Bleached mass after Bleached mass after cold cold alkali extraction cold alkali extraction alkalrextractron Southern pine blend> Kraftrnassa y Ej used Used Used NaOH NaOH 15 18 30 30 O: 15 O: 15 3.0 3.0 92 - - 8.9 5.5 6.4 41.6 18.8 23, 1 69.1 33.4 37, 3 OI OO II Oil.

I I OQO! OOOO ICO.

O f 526 466 f. 45.

Despite the different pulp cooking procedures, the inlet composition of Southern pine shavings gave vilka which showed excellent absorption results after cold alkali extraction (Tables I-5 and II-5 in Example 5, the alkali used was sodium hydroxide). Each of the unbleached masses was treated with a cold caustic solution of 15% and 18% NaOH (% by weight). The cold caustic extraction was performed as follows. Lots with a 3% consistency [O.D. Weight / total weight (caustic solution + O.D. mass) x 100] was treated at about 30 ° C for 15 minutes by stirring the suspension. For each sample treated with a different caustic solution, the absorbance was determined and compared with the resp. kraft- and sul fi trnassoma. It was noted that the extraction with 18% NaOH gave the best result for each of the pulps.

For comparison, the unbleached pulp of Southern pine was bleached to an ISO brightness of 92% before using the cold alkali extraction procedure (Sample Table III-S, Example 5). This pulp was sarruna pulp used as a starting material for bleaching in Example 5 (Sample Table 1-5). However, it was bleached with chemicals such as chlorine, chlorine dioxide, hydrogen peroxide, oxygen and sodium hydroxide. The results obtained are shown in Table III-5 following the same cold caustic extraction procedure shown above.

From the comparison of the data in Tables 1-5 and II-5 in this example, it is clear that for the unbleached pulp an increase in the concentration of the cold caustic solution to 18% NaOH improved the absorption properties; for bleached pulp (sample & 5_i_i_i, Table III-S) the higher concentration (ie 18% NaOH) reduced the absorption properties ironed with extraction at 15% NaOH. However, note that the absorption properties of the bleached pulp extracted with cold caustic with 15% NaOH were clearly better than those of the bleached pulp prepared without any cold alkali extraction.

Example 6 Prehydrolyzed kraft pulp of bleached Southern pine In a manner similar to that used for Example 5, the absorption properties of a bleached, dry hydrolyzed kraft pulp of Southern pine wood were determined. This pulp was prepared by a mechanically prehydrolysed kraft pulp production process using a method common in the industry and was bleached using chemicals chlorine, chlorine dioxide, sodium hydroxide and sodium hypochloride to an ISO brightness of 86%. The K number of the unbleached mass was about 18 mL. 000 00 0000 t 0 0 0 OO 0 0 I c I 0 CIO í 5 526 466 SAMPLE NO SAMPLE DESCRIPTION Production Wood species Mass production COLD ALKALI EXTRACTION Alkali used Solution strength,% Temperature, ° C Time H: M Consistency,% ANALYSIS PROPERTIES FOR THE PULP ISO brightness,% TEST WITH SEVERAL WETS Absorption times (s) First wetting Second wetting Third wetting 4 7 IOIIIIIOII IQ IC IOII EXAMPLE 6, TABLE 1-6 A-ei 3:61 Li Bleached mass before Bleached mass after Bleached mass after cold alkali extraction cold alkali extraction cold alkal extraction Southern pine blend? With steam pre-hydrolysed kraft pulp> Not used Used Used NaOH NaOH 15 18 30 30 0: 15 0:15 3.0 3.0 86 - - 6.7 4.9 6.2 46.6 19.6 25.5 77.2 32.3 41.9 QOO OO Û OO OIIU 0 00 OO 526 466 The absorption results after cold alkali extraction of this mass with 15% and 18% NaOH are shown in Table I-6 and confirm the effect caused by CCE treatment on the absorption capacity of the mass. Again, this pine pulp was subjected to extraction after bleaching with 15% NaOH (Sample A-6i, Table 1-6, Example 6) and gave better results than when the extraction was done with 18% NaOH.

In comparison with the absorption property data given in Example 5, Tables I-5 to III-5, the absorption test results of the prehydrolysed kraft pulp of Southern pine fiber show that their absorption capacity is within a good range even though they have been bleached to their relatively high brightness before cold alkali extraction.

Example 7 Strength of Southern pine; unbleached K-number interaction The accompanying Table I-7, Example 7 shows a comparative series of power masses of Southern pine where the K-number of the unbleached mass was varied (relatively hard boiling - low K-number indicates a stronger boiling with less lignin remaining in the mass after inassa cooking). To determine the desired pulp property regime and pulping procedures, the bleaching of all three unbleached stocks was performed to an equivalent brightness (92% ISO). Bleaching chemicals chlorine, chlorine dioxide, hydrogen oxide, oxygen and sodium hydroxide were used. It is noted that as the unbleached K number increased, the resulting absorption properties improved after cold caustic extraction (lower absorption times are better). : mmm 1% Qom - w.ww o.w> å: QS m3 - ÉN QS wa ma Qw - Q å - No - No - No oxf. om od w: Ho w _ Ho w: Ho om om w _ w: w: 9 IO ~ Z IOQZ IO ~ Z 4 ocm> a <: E23 .E Emo / E: Ewšæ .om Ew> = <Emšæ E / \ om A NN A m: A umäcsoåv: A »En Föšsom: orxæbxvšëëw: o fi ßbx fl šmšw: ouåbx fl šåww = c: v: ~ bx @:«: _ ~: ozšbxå fl šæ: ouxßbx š å: » »: Å 0.6:: Å hä»: Å 05: 892: E fi m 83 .: äßm 32 :. CBE 338 å fl m åâë šßm 392: E05 ä ä En md Em É <b: Aqmmad. .ß Amräàmvmm wEEm> »FEB minä? 3: 9: wišï Såå Go öoumcou fi omn <M <ÜÉZH <> Émqm Bmw: HmmE. Û c UC O I CO .x .såå om.

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Uo uBwoumEuH X. .ücšw mšwëšo: Ewšë: $: <ZOF ~ M: E: SQ wic: fi w fi ä.cmmäå w fi wwä. wic: fi mëw_m OëšæMmmm> O ~ É .MZ> O ~ É 00 ll I ICO! UI ll O! I Û I Û O I O 0000 III OO! I n I I I! IN!! I O O I I O I I Û O I ÛIÛI OO IÖOO O 'CI IQ CO. 526 466 Example 8 Salty pulp of Sitka pine In a similar way to that used for Southern pine chip stocking, the original material was salt-boiled from pine. The salt procedure used was acid salt (also known as acid bisulfate) as in Example 5. The unbleached mass was subjected to cold caustic extraction. Data for the cold caustic extracted masses treated with 15% and 18% NaOH are shown in Table I-8, Example 8.

It is noted that although not all rrtgåiigsinassoi 'showed the same level, there was nevertheless a significant improvement in the absorbency after cold caustic solution treatment for each of the masses obtained from this species. Both pine pulp samples ßåi and C _, - §i were performed in a similar manner (no significant difference between 15% NaOH and 18% NaOH extractions).

E. E ..: ..C ..: OI:. zll:. . :: I .IO: 51 EXAMPLE 8, TABLE I-8 SAMPLE NO. A-8i '§-_8_i Qjåi SAMPLE DESCRIPTION Preparation Unbleached pulp before Unbleached pulp after Bleached pulp after cold alkali extraction Cold alkali extraction Cold alkali extraction Wood species Sitka Spmce? Pulp setting Sul Å t Å / K ratio, ml 31 å * COLD ALKALI EXTRACTION Alkali used Not used Used Used Solution strength,% NaOH NaOH Temperature, ° C 15 13 Time H: M 30 30 Consistency,% 0215 0315 ANALYSIS PROPERTIES 3.0 3 , 0 FOR THE MASS ISO brightness,% - - - TEST WITH SEVERAL WETS Absorption times (s) First wetting 70.0 12.2 10.0 Second wetting 43.7 22.3 24.1 Third wetting 64.8 33.6 33 , 2,526,466 S; Example 9 Sulfur Mass by Westem Hemlock This example illustrates the absorption properties obtained for a pulp prepared from a Westem Hemlock chipmeat assimilation by a salt boiling procedure (sour sul fi t). Cold caustic extraction of the bleached hemlock mass (ISO brightness = 88%) again showed the improvement obtained with cold alkali treatment: higher rate of absorbency of the fibers produced by cold caustic solution extraction. Data are given in Table I-9, Example 9. {'526 4e6É ~ Ä 53 SAMPLE NO.

SAMPLE DESCRIPTION Manufacture Wood species Mass production COLD ALKALI EXTRACT Alkali used Strength of solution,% Temperature, ° C Time H: M Consistency,% ANALYSIS PROPERTIES FOR MASS ISO brightness,% TEST WITH SEVERAL WETS Absorption times (s) , TABLE 1-9 A-øi B-øi C_-9_i Bleached pulp before Bleached pulp after Bleached pulp 'after cold cold alkali extraction cold alkali extraction alkali extraction Westexm Hemlock) Sul å t å Not used Used Used NaOH NaOH l5 18 30 30 0:15 O: 3.0 3.0 88 - - 12.3 7.7 9.4 47.2 31.9 39.9 75.1 44.7 62.0 I 9 Û Ö 526 4e6¿ "00000 Example 10 BCTMP ( bleached chemical-thermal-mechanical pulp) and cold alkali extraction In this example, BCTMP (a bleached chemical-chemical mechanical pulp) was extracted commercially from Tembec Co. with 15% and 18% NaOH. Test data from the absorption (Table I-10, Example 10) shows significant improvements in stronger solutions of cold caustic solution.The K number of this BCTMP mass was 36 mL. Even higher strengths of caustic solution (eg about 20%) may prove useful for the absorbency properties of fibers produced by this type of stock via this pulping process. The stock of wood is an North American, Eastern Canadian bam / ed. Descriptions of chemical mechanical pulp and bleaching processes can be found in texts on pulp boiling and bleaching. 5:26 466 SAMPLE NO.

SAMPLE DESCRIPTION Preparation Wood type Mass fi- composition K-number, ml COLD ALKALI EXTRACTION Alkali used Strength of the solution,% Temperature, ° C Time H: M Consistency,% ANALYSIS PROPERTIES FOR THE MASS ISO brightness,% TEST WITH SEVERAL WETS Absorption) Second wetting Third wetting EXAMPLE l0, TABLE I-10 A-IOi Bleached pulp before B-10i Unbleached pulp after g QQIOI IC OI IOII OO C-l0i Unbleached pulp after cold alkali extraction cold alkali extraction 'cold alkali extraction Northern Søftwood S r Pale chemical- thermal mass 9 36 * f Not used Used Used NaOH NaOH 15 l8 30 30 0: l5 0: 15 3.0 3.0 9.7 8.8 4.0 39.8 37.8 25.1 61.2 59 , 8 35,4 o 2 ": .i 'Éušfjš' 5¿__6 ggg oo oo Example ll Use of cold alkali extraction on semi-bleached masses with lower brightness The strength of caustic solution required to achieve optimal absorption properties is related to the type of raw materials and to the pulp cooking and bleaching steps used.In general, however, the less bleached (lower brightness) the mass exhibits the higher concentration of NaOH solution required to achieve optimum properties. The absorption properties obtained are also better when the mass is less bleached before the use of the cold caustic treatment. This is shown below in Table I-11, Example 11, where two masses of Southern pine bleached to different brightness levels (ISO brightness 51 and 88) were subjected to cold alkali extraction at 15 and 18% NaOH solutions. The results for both of these pulps show that 15% NaOH gave the best overall absorption time results (the third hydrogenation time is the most significant) with pulp with lower brightness (semi-bleached pulp) giving excellent properties.

EXAMPLE 1 L, TABLE I-1 L SAMPLE NO. A-11i B-lli C-lli D-lli SAMPLE DESCRIPTION Preparation Semi-bleached pulp Bleached pulp (ISO brightness = (ISO brightness = s 1%) fi ss%) b After cold After cold alkali extraction-è alkali extraction -_> Tfäslag Southem pine blend t * Pulp production Kl-aftmass> COLD ALKALI EXTRACTION Used A fl VILL Use Alkali used NaOH Strength of the solution,% 15 18 15 18 Temperature, ° C 30 30 30 30 TimeHgM 0¿15 0215 015 0:15 Consistency,% 3.0 3.0 3.0 3.0 TEST WITH SEVERAL WETS Absolution times (s) First wetting 5.0 3.3 6.2 4.9 Second wetting 22.1 21.2 22.2 24.3 Third warning 25.1 36.7 33.9 38.6 (a) Prepared by bleaching a sample (Example 11, Table 11) with chlorine, chlorine dioxide, hydrogen peroxide, oxygen and sodium hydroxide to an ISO brightness of 51, (b) Prepared by bleaching samples (Example 11, Table 11) with chlorine, chlorine dioxide, hydrogen peroxide, oxygen and sodium hydroxide to an ISO brightness of 88 000 000 000 IOI 00: Uli non 526 466 É "É" š = -:? As'.É: §'¿; = s 7 II OO OOIO OO 0 0 0 0 0 0 0 0 0 000 0 0 0 0 0 00 0000 0 00 SAMPLE NO. A- 1 lii B-l ln C-l1i1 D-l lin PROV DESCRIBED.

Preparation Semi-bleached pulp Bleached pulp (ISO brightness = (ISO I brightness = 38%) a 44%) a After cold After cold alkali extraction ___; alkali extraction __; Tfäslag Southem pine blend ß, Mass production 51,15; > COLD ALKALI- Used Used Used Used EXTRACTION Alkali used Nam; 7 * Strength of the solution,% 15 18 15 18 Temperature, ° C 30> Time H: M 1); 15> Consistency,% 3.0> MULTIPLE WATER TEST Absorption times (s) First wetting 4.5 4.5 5.8 4.7 Second wetting 24.5 18.8 24.1 20.2 Third wetting 36.4 30.2 41.1 31.2 (a) Prepared by bleaching Sample A-5ii (Example 5, Table II-5) with chlorine dioxide, hydrogen peroxide and sodium hydroxide II III CIO CIO DIGI OO IO 0 t II 00 000 OO I CI IN! ÛIÛÛ ÛO ÛÛOO I Ü II Û I Ü II 0 III OI IIIÛ 526 466 '::? ÏII =' 5..ï ':: ï °. =: I-.I Alla provema _A¿_l_li till Q¿ll_i (tabell ll I, Example ll) was prepared by bleaching the kraft pulp of Southern pine with a K number equal to 30 as described in Example 5 (Sample Aii, Table I-5) to the indicated l brightness levelii and then cold caustic extraction under the conditions as shown. Note that in the unbleached state, 18% NaOH results in better absorption properties and that these absorption times were better than those associated with semi-bleached pulps described in Table I-II, Example II. ~ When the unbleached salt mass of Southern pine with a K number equal to 34 from Example 5, Table II-5 (Sample A_-§_i_i) was half bleached to 10O Brightness levels of 38 and 44, before cold caustic extraction with 15% and 18 % NaOH, 18% NaOH was still required to provide optimal absorption properties. The results of this work are shown in Table II-I l, Example l 1. Note that less bleached pulp (ISO brightness = 38%) still gives the best results as they are extracted with 18% NaOH (sample l_3_-ll_ii against sample D_¿_l_ii ); however, the results are not as good as those observed at 18% NaOH extraction of the unbleached pulp itself with 18% NaOH (see results for sample table 11-5, example 5).

Example 12 The placement of the cold alkali extraction oil in a multi-stage bleaching sequence The winemaking of cold caustic extraction in improving the absorbency occurs regardless of where it is performed in the bleaching sequence (eg at the beginning, middle or end). In the same eg step bleaching sequence to produce high brightness pulps, there is also some indication that when the same quantity of chemicals are used, improved absorption properties can be obtained by using the step in the middle of the sequence. Such an example is now shown in which the only bleaching variable, in a five-step sequence to produce a completely bleached pulp from the same unbleached stock, was the position of the CCE step in the sequence; 15% NaOH solution was used. 526 466 s PROV NO.

SAMPLE DESCRIPTION Production Wood species Mass production COLD ALKALI EXTRACTION Alkali used Strength of the solution,% Temperature, ° C Time H: M Consistency,% ANALYSIS PROPERTIES FOR THE MASS ISO brightness,% TEST WITH SEVERAL WETS Absorption times (s) First wetting Wetting. E ..: ..o ..: oc:. : oo: O 0:00 .IU- EXAMPLE 12, TABLE 1-12 A-l2i B-l2i C-12i Fully bleached pulp Fully bleached pulp Fully bleached pulp (five bleaching steps) (five bleaching steps) (five bleaching steps) with cold alkali- with cold alkali- with cold alkali extraction in step 1 extraction in extraction in step 3 step 5 Southern pine 2 Prehydrolyzed kraft pulp ~, Used, NaOH> l5> 3G 7 0: 15> 3.0 2 84 87 84 17.7 14.4 19.2 44.5 3 1.2 43.4 67.7 57.2 70.4 The results above (Table II-12) indicate that when CCE was used in the middle of the sequence (step 3), the absorption times became clearly better (sample _B _-_ l2_i) than when CCE was used in the first or fifth step. It was of interest to note that the ISO brightness of the completely bleached pulp (sample ß-lgi) also improved relative to the others (i.e. 87 and 84%, respectively). 526 466 @ É '?' Example 13 Reject material kraft 'from kraft pulp production In an attempt to look at pulp that is "raw" or less cooked than is normally used in conventional, fully chemical pulp cooking processes, certain "fiber knots" are the result of a conventional kraft pulp production from a reported composition of Southern pine chip cold caustic was extracted with 18% NaOH.

“Fiber knots” essentially consist of pulp rejectin materials that are poorly cooked (relatively large in size as opposed to tip and separable from the cooked fi brema by means of equipment called “coarse sieves”). It was necessary to first defibrate these fiber nodes in a Waring mixer and to flatten this the fi brated material to remove reject material which still did not remain de fi brated before cold alkali extraction with 18% NaOH. The fibers showed a very high K-number (> 50). 526 466 6 "oono I O 0 o o o o o o 0 I g o ooo o o o o o o o o I I. Oo oo oooo oo EXAMPLE 13, TABLE 1-13 TEST NO.

SAMPLE DESCRIPTION Preparation Wood species Pulp production K-number, m1 (80 ml test) COLD ALKALIE EXTRACTION Alkali used Strength of the solution,% Temperature, ° C Time H: M Consistency,% ANALYSIS PROPERTIES FOR THE MASS ISO brightness,% TEST WITH SEVERAL WETTINGS Absorbs) Wetting Second Wetting Third Wetting A-13i The Rejected Berknots (Reject) After Cold Alkali Extraction Søuthexn pine blend Power Mass> 50 NaOH Used 1 8 30 O: 15 3.0 5.4 13.9 25.9 63 'Multi-wetting absorption test results shown in table 1-3, Example 13 indicates that these types of fibers after cold alkali extraction exhibit good absorption times.

The absorption times are equivalent to those of cold alkali extraction 30 K unbleached kraft pulp from Southern pine (Sample Table 1-5, Example 5) and to those obtained with cold alkali extracted unbleached sul- tin mass of Southern pine with K number 34 (Sample Qii, Table II-5, Example 5), regardless of the fact that the raw material consisted essentially of a waste material. A cold caustic extraction would add significant value in converting this waste fiber into a useful absorption product.

It is expected that similar results would be obtained by stopping the initial kraft pulping process at a point or points corresponding to less total deligiiation and by combining mechanical defibration and sieving steps before the cold alkali extraction and / or any bleaching desired to increase the brightness (ie semi-chemical rather than all-chemical inassa boiling).

Example 14 Alkali sources other than sodium hydroxide: White liquor from kraft pulp recycling A potential source of sodium hydroxide in a pulp mill is white liquor used in the production of kraft pulp. White liquor consists of a mixture of sodium hydroxide and sodium salt. One suggestion is to perform the cold alkali extraction using an alkali present in the white liquor (WL) as the source of NaOH; It is also possible that the sodium sulphide present in the white liquor will have some positive benefits. Table I-14 shows the results of extraction of an unbleached kraft pulp of Southern pine with 9-18% NaOH in which some or almost all of the need for sodium hydroxide in the cold caustic extraction came from the white liquor itself (the contribution of sodium sulphite to the alkalinity was ignored). For comparative purposes, cold caustic extraction with 9, 15 and 18% NaOH solutions was introduced as a control (samples _F-_14_i, Q-_1_1_1_i and L-l; _l_4_i, Table I-14).

O O I QR QR mä QS mä n? Nä nå GN .än nå ... S få m8 ma 5 å E 3 Q É A1 ca m Sa f »2 m: 2 a M: 2 9 Q SB SB SB Sš Ewa .så Ewa: mb .äs .äš. äs .xåv m? u šàš mosa: saw âša a fl mšš E »do minä, 082% N.ß m wG fl H-Éf mu fl â o§ wi fi? Swöm 3 .öEHm: oc & o3 <M Émqm Qmå Hwmh ° \ ..: m fi ëmaom EMI EH Un: Båvmëuh .ä .šï fi m Évwcwcmæq: o fi z: oßz: oßz: oßz mc fl z: så moßz êoš E zo: .v_ <~ _, _ xxm _._ m S: .E .Ei f? wmäccw fi h! w _: = __ = fl w == 2. fi wmm «2 A» En Föšzom wšmw fi Al || l \ ^ = obcovö ß ||||||||||| wAJQ / v 2.1.5: oušbxu m2:: ouäëxu: osšwaxuzæxww - = § = ~: å Eco -ësš: å ba »: E 23 mmäE 3,030 292: 3330 392: 3030 wE: = m ~ mEw.m Oššævmmmm> O ~ E ÉTE ..- EG såå flm: lå G70 TE m GT <.MZ> O ~ EE; Aqmma fifi .É Ammïmvmm n 0 0 nu: non too 000 Q u 0 0 I -0 0 n 9 I ICO IOI Q 0 0 0 Q 0: Ino n 100. oo ou nu Sell: šoozš š: una E.; 0 0 š get OIO: '.0 .. O: 65: É Ü' Ü u '.of H ß fl "" The use of white liquor to add alkali was found to be equivalent to the use of sodium hydroxide at I5 and | 8% sodium hydroxide strength (iron samples i and Q-_1 <_1_i, Q-líi and Egil, Table l-l4, Example 14) to achieve improved absorption properties relative to those of unbleached kraft pulp of Southern pine not treated with cold alkali extraction. At 9% solution strength, the use of white liquor appeared to result in some improvements over the use of NaOH alone (compare sample ß-Llii to fine, Table I-14, Example 14). It is believed that an even lower alkali solution strength of white liquor may also result in advantages over the use of sodium hydroxide alone.

Example 15 Use of Hemikaustics for Cold Alkali Extraction When using sodium hydroxide for cold alkali extraction, a caustic solution is obtained which contains certain organic material which has been removed or extracted from the pulp. This type of caustic solution is called "hemi catistics". The organic material which has dissolved during the cold alkali reaction with the pulp is considered to be predominantly hemicellulose material (hemicellulose is a non-cellulosic carbohydrate material composed of xylose, rhinose or mixtures of these monomers with glucose, etc. ). For pulps to be used in the form of fibers, cold alkali extraction can also remove some of these hemicellulose materials or other organic materials. However, the desired end result is not chemically purifying pulps. Purity is required when dissolving pulps because these pulps must act as chemical feedstocks in chemical end-user processes (esters such as acetates, butyrates and nitrates, ethers, regenerated cellulose, etc.). For end use applications such as fibers, the desired end result from the use of cold alkali extraction is that the produced fi brems exhibit improved properties as fibers - as ff uncooked fibers in absorbent products, etc. such estimation of the desired end result has not been confirmed or known so far. 5226 PROV NO.

SAMPLE DESCRIPTION Production Wood species Mass production K-number, rn] COLD ALKALI EXTRACTION Alkali used Strength of the solution,% Temperature, ° C Time H: M Consistency,% ANALYSIS PROPERTIES FOR THE MASS ISO brightness,% TEST WITH SEVERAL WETTINGS Other Absorption times s) Absorption times Wetting Third Wetting 466 5-66 EXAMPLE 15, TABLE I-15 A-l5i B-l5i C-l5i Standard Cold Alkali Extraction Procedure (Bleached Mass After (Bleached Mass Cold Alkali Extraction): 9 Before Cold Alkali Extraction) Southem pine blend- _------> Kaftmass ö 17,4> Not used Used ------ fi (Control) 100% 100% NaOH hemikaustik 15 3 '30 9 o; 15: ---- e 3 884, 4 85.5 84.4 4.7 4.9 4.9 25.6 l8.8 20.4 44.8 29.9 36.6 OI QIO! QI oo 00 0 OIO 0 0 u lo O i 0 0 0 526 466 The data presented in Example 15, Table 1-5 show that hemikaustics (ie caustics separated from the mass after reaction during initially pure sodium hydroxide-cold caustic extraction) can be reused to replenish the alkali source for subsequent cold caustic extractions for pulps with improvements in absorbency.

Absorption times are improved relative to the bleached kraft pulp of Southern pine which has not been treated with cold caustic extraction when the alkali source used was either sodium hydroxide or hemaustic. The hemicaustic solution used showed 24.5% sodium hydroxide by weight and contained 2.9% hemicellulose material. The improvements when hemikaustics were used were not as great as those when pure sodium hydroxide was used. However, it is expected that certain modifications to the conditions of the cold caustic extraction (eg, increasing the solution strength when using hemikaustics) would make the effects of both types of caustic equivalent.

It would also follow that other sources of alkali when used in initial contact with the pulp in cold alkali extraction could be reused in subsequent extractions for these types of non-dissolving pulps intended for end use which er burn.

In the above examples, the cold caustic solution treatment or cold caustic extraction of the pulp was usually carried out at the indicated solution strength, at the indicated consistency, for the indicated time at the indicated temperatures, followed by a rinsing with pure water, an acid wash (usually a sulfuric acid - solution with a pH of about 3) and a final clean water rinse.

Other test data obtained also show that for whole concentration ranges of the cold caustic solution, the concentration can vary between about 5% to 25% and higher but 13% to 18% gave the best results for the different pulp starting materials used for recording layers, ie. intensive, rapid absorption uses. A suitable concentration depends on the relative bleaching hardness, the harder bleached masses requiring a milder treatment. To improve the absorbency in general and also to improve yields and other mass properties, lower concentrations of caustic can be used, i.e. about 526,466 äs ... 5%. The usefulness of the process has also been demonstrated for a variety of pulp originating materials.

As illustrated in the above example, the cold caustic solution has been a sodium hydroxide solution, but other alkali materials may be used. Other alkali materials such as potassium hydroxide etc. can be used but at such a high cost that their use is too expensive.

In the same way, a combination of sodium hydroxide solution and a water-soluble, non-toxic glycol (eg propylene glycol solution) can also be used, but the increased cost is not justified for large product volumes.

When describing the characteristics of the acceptable starting materials and the process conditions for CCE treatment, this characteristic can be characterized as follows: for improvements in rapid absorption capacity such as those measured by wetting test, especially the third wetting; The K-number related to absorption capacity and the extent of mass boiling; the extent of boiling which can be avoided in the practice of the present use of various forms in the bleached and unbleached state; improved yields of accepted fibers at opening; advantageous use of shrimp material; use of factory by-products; the motion equipment to introduce the CCE step into any bleaching sequence in the bleaching treatment steps; fluff pulp properties that do not require the lubricants, ie without additives, etc. etc. Such improvements, especially in combination with each other, have hitherto not been recognized, known or used for pulps and have thus not shown the way to achieve the unique combinations of properties described above.

The basis weight of the acquisition layer in current products varies from 75 to 200 g / m 2. For example, the acquisition layer is l2 shown in fi g. 2 an air-filled fl uff fabric with 200 g / mz. This fabric is separated from the absorbent core 13 by a layer of conventionally wet tissue paper 13. The core may be wrapped in such tissue paper. The absorbent core is a blend of cellulosic fibers, uncoated and aerated with superabsorbent polymer (sap) available from 526 466 commercial sources. The basis weight is about 500-700 g / in2. There is a polymer sheet 16 which is moisture proof under the core with a thickness of 0.5 mil. Wet sheets can also be used.

The above-described examples, embodiments and comparisons are intended to illustrate the various aspects of tinnitus titanium delimiting the same but the appended claims and its constituent parts including reasonable equivalents thereto define the scope of the invention.

Claims (18)

5 2 6 4 6 6 a 910 Patent Claims A process for preparing an improved absorbent pulp comprising: treating a pulp fiber suspension at a temperature below 60 ° C, in a fiber suspension having from about 2% to about 25% consistency with an alkali solution having a concentration of about 2 up to 25% by weight characterized in that during a treatment time from about 5 minutes to about an hour; recovering and drying the treated pulp from the suspension; and opening the dried mass to form a mass. Process according to Claim 1, characterized in that the temperature is about 40 ° C. The process according to claim 1, characterized in that the concentration of the alkali solution is between 6 and 18% by weight. Process according to Claim 1, characterized in that the concentration of the alkali solution is between 13 and 18% by weight. Process according to Claim 1, characterized in that the pulp is prepared from a raw material of Southern Pine, White Pine, Western Hemlock, Sitka Spruce, Caribbean Pine, Douglas Fir, eucalyptus, poplar, beech, aspen, sugar cane or a mixture thereof. An absorbent article comprising: a pulp prepared according to a process comprising the steps of: treating a pulp at a temperature below 60 ° C, in a suspension, with an alkali solution having a concentration between 2 up to 25% by weight for a treatment time of from 5 minutes to about 1 hour to obtain an alkali-treated pulp containing pulp; recovering and drying the treated pulp from the suspension; and ff opening of the dried mass; and at least one liquid pencil arranged on the ground mass. 526 466 f H Absorbent article according to claim 6, characterized in that the suspension has a consistency of from about 2% up to 25%. Absorbent article according to claim 6, characterized in that the temperature is less than 40 ° C. Absorbent article according to Claim 6, characterized in that the alkali solution has a concentration of between 6 and 10% by weight. Absorbent article according to Claim 9, characterized in that the alkali solution has a concentration of between 13 and 18% by weight. Absorbent article according to claim 6, characterized in that the method further comprises drying the recovered pulp. Absorbent article according to claim 6, characterized in that the absorbent article is a diaper with a liquid barrier layer, wherein the liquid permeable layer and the liquid barrier layer are arranged on opposite sides of the absorbent interior of the absorbent article. A method of making an absorbent article comprising: arranging at least one liquid permeable topsheet; arranging a pulp formed by a process comprising treating a pulp at a temperature of up to about 60 ° C in a suspension, with an alkali solution having a concentration between 2 up to 25% by weight, for a treatment time of from 5 minutes to about 1 hour To obtain an alkali-treated pulp containing pulp fi brer; recovering and drying the treated pulp from the suspension; and ff opening of the dried mass; and forming an absorbent article with pulp inside and arranging a liquid penile upper layer. 526 466 NL Process according to Claim 13, characterized in that the suspension has a consistency of between about 2% and up to 25%. Process according to Claim 13, characterized in that the temperature is less than 40 ° C and in that the suspension has a consistency of from 2 to 18% by weight. Process according to Claim 13, characterized in that the alkali solution has a concentration of between 6 and 18% by weight. Process according to Claim 16, characterized in that the alkali solution has a concentration of between 13 and 18% by weight. A method according to claim 13, characterized in that the method comprises drying the recovered pulp.