CN1046977C - Thermal and mechanical treatment of nonwoven fabric processing methods - Google Patents

Abstract

A method for processing non-woven fabric by heat treatment and mechanical treatment is to process the non-woven fabric with thermal bonding and thermal plasticity and a part of mixed non-thermal plasticity, and stretch at low stretching rate to achieve the purposes of enhancing softness and comfortable touch of the fabric and achieving elasticity with high commercial value, and the prepared fabric is very suitable for the occasions where the non-woven fabric with softness and elasticity is needed to be used. After the treatment, unidirectional elasticity is generated, two designs can achieve the elasticity in the machine direction or the width direction of the cloth, and almost all kinds of non-woven fabrics can be treated by the method to obtain the effects of softness and elastic elasticity as long as more than 70 percent of thermoplastic silk is contained.

Description

Thermal and mechanical treatment of nonwoven fabric processing methods

The invention relates to a processing method of non-woven fabrics in the textile field, in particular to a non-woven fabric processing method of heat treatment and mechanical treatment.

The non-woven fabric industry quickly developed into a huge industry because it adapted to the needs of low-cost consumer goods, and it was used to replace woven fabrics for the manufacture of disposable products. Such items include: hygiene items, such as adult and child diapers, sanitary pads; medical items, such as masks, surgical gowns, head coverings, surgical drapes, protective clothing; and personal items, such as underwear.

Although non-woven fabrics are cheap, they have a number of negative defects. The first point is that the strength of non-woven fabrics is not as good as that of woven fabrics. The second point is that non-woven fabrics themselves are relatively stiff and rough. The third point is that non-woven fabrics The cloth does not have stretchability, is uncomfortable to wear, and does not have the softness of sagging.

Most of the non-woven fabrics are made of thermoplastic fibers. This kind of cloth can be flattened by mechanically laying short fibers or directly extruding fibers in the molten state of thermoplastic molecules to form cloth, and after another Before the step of thermal bonding, this piece of cloth has no strength. The step of thermal bonding is to heat-bond the intersecting fibers together with hot pressing rollers or other heating methods.

The main disadvantages of nonwovens are lack of elasticity or stretch, strength, softness and consistency. Among them, strength is very important, and its importance involves the durability and applicability of disposable products. Although disposable items are only used for a short time, they are very important issues for their practical functions. Softness is also important, especially in applications such as disposable diapers, disposable medical gowns, coverings, pillow covers, industrial protective clothing, and all nonwovens used in contact with the skin. Softness is even more important.

Stretchability is a highly desired feature in woven or non-woven fabrics, as it can improve product strength, comfort, and form-fitting properties. This kind of stretching property is generally called elasticity, and the elasticity required for disposable items is only in the range of 30-50%. For example, disposable pants with a waist circumference of 24 inches can be applied to 36 inch waist.

In the past, some methods were to add elastic glue to make the non-woven fabric stretchable, so as to increase its strength and comfort. The method of adding elastic glue is mainly to add natural elastic glue or synthetic elastic glue to the film, tape or thin glue thread to bond non-woven fabrics. For disposable consumer goods made of non-woven fabrics, if Applying the above-mentioned addition of elastic glue to achieve stretchability or elasticity is very uneconomical in cost, thus limiting the wider use of non-woven fabrics in industry.

One of the methods is to squeeze the non-woven fabric from both sides to cause wrinkles in the direction of the machine. Although this method can make the non-woven fabric more comfortable and have a little stretch and fit, But its vertical and horizontal tension and strength have not changed, and the recovery force of this kind of shrinkage cloth is very poor, and the softness is also reduced.

U.S. Patent No. 5,244,482 disclosed a treatment method by Heisenbao et al. (1993), which uses a very high stretch rate to reduce the interfiber pores in the cloth body and make the difference in pore size closer. The purpose of using a very high stretch rate as the main treatment is to change the shape of the non-woven fabric and cause the pores to shrink, and this treatment method also causes a certain amount of stretching elasticity, but the finished fabric is thicker and harder than the original fabric , and the modulus of elasticity is also very low. In addition, this patent has strict requirements on the selection of raw fabrics in terms of physical properties, such as the molecular crystallinity of the raw fabrics, the content of thermoplastic fibers, the thickness of fibers, the distribution of fibers, chemical and physical stretchability and There are stricter requirements for low tension, stretching and destructiveness.

The above-mentioned U.S. Patent No. 5,244,482 discloses a high-stretch treatment method, which causes the fibers to be pushed, and the appearance of the cloth body is also changed accordingly. These changes are more obvious in the shrinkage of the fiber pores and the improvement of its fineness. The filtering effect of non-woven fabrics has a more significant contribution.

The aforementioned US Patent No. 5,244,482 does not mention the use of a "low elongation" processing method, but instead limits the elongation to 5 to 10 times the lower limit of the elongation.

The similarities between U.S. Patent No. 5,244,482 and U.S. Patent No. 5,053,066 are that non-woven fabrics are post-processed to change the cloth structure to meet the requirements of filter applicability. Elongation" processing.

U.S. Patent No. 4,048,364 is a method of applying high stretch rate processing disclosed by Harding et al in 1977 to increase the tensile strength of melt-blown polypropylene fibers, but the fibers before this processing method must not It has fiber crystallinity and directionality. It is not mentioned in this patent whether elasticity will be produced after treatment.

U.S. Patent No. 5,441,550 and No. 5,443,606 are inventions of Heisenberg et al. in 1995, which are the same as the processing method of U.S. Patent No. 5,244,482, but disclose the use of different original fabrics.

The treatment method of applying high stretch rate is a well-known method, which has been often used in the production of film products. By giving the film molecules directionality, the strength and stiffness of the film can be enhanced. For the typical film stretching method, see US Patent No. 4,408,974 proposed by Camry in 1983.

Another well-known example is the application of high elongation ratios to draw thermoplastic textile fibers through a series of rolls after melting, with the take-up speed being increased segment by segment in successive rolls.

The main purpose of the present invention is to overcome the defects of the prior art, and provide a non-woven fabric processing method of thermal treatment and mechanical treatment, so that it can contain thermoplastic fibers for all non-woven fabrics that are thermally bonded. Or a mixture of thermoplastic fibers and thermoplastic fibers, which can be changed in physical properties through special treatment methods, and can produce softer, less rigid new cloth materials, which are more comfortable to the touch and have commercial value. Stretchable and elastic; and suitable for various non-woven fabrics and non-woven laminated fabrics bonded to other materials.

Another object of the present invention is to provide a non-woven fabric processing method of heat treatment and mechanical treatment, which is equipped with a mechanical stretching device, and the above-mentioned treatment method is combined with special equipment to achieve the joint utilization of mechanical force and heat treatment , non-woven fabrics that can be thermally bonded to process thermoplastic or thermoplastic and non-thermoplastic fibers.

The purpose of the present invention is achieved by the following technical solutions. A non-woven fabric processing method of heat treatment and mechanical treatment, characterized in that the processing steps include:

(a) Non-woven fabrics of non-isotropic tensile strength, with more than 70% thermoplastic fibers and less than 30% non-thermoplastic or natural fibers, heat-treated to a temperature controlled at 70°F above the plastic point of the original fabric within the temperature range.

(b), the heat-treated non-woven fabric is stretched longitudinally by a stretching device, and the total stretching rate is controlled above 3.5 inches per minute per inch, but below 9.5 inches per minute per inch; and the total stretching The calculation of the rate is based on the distance between the rods of the stretching device; the width of the processed elastic cloth is reduced, and the length is extended to produce elasticity perpendicular to the direction of extension. The degree of elasticity is at least 85% after stretching 50%. shrinkage; and the processed elastic cloth also increases the softness and enhances the comfortable touch, the basis weight also increases by more than 5%, and the fiber pores shrink by no more than 20%;

(c) Rolling the cooled finished cloth onto a mandrel.

The purpose of the present invention can also be achieved by the following technical solutions. A non-woven fabric processing method of heat treatment and mechanical treatment, characterized in that the method for making the cloth body has elasticity in the machine direction, and its steps include:

(a) without coiling a thermally bonded non-anisotropic blend of thermoplastic and non-thermoplastic fibers, the aforementioned blend comprising at least 70% thermoplastic fibers, into a temperature not greater than that of the aforementioned raw fabric In raw fabric heating devices within 70°F above the plastic point;

(b) The heated cloth moves longitudinally continuously, enters the stretching device installed in the heating device, pulls the two sides of the cloth laterally, and keeps the stretch rate at 3.5 inches per minute and 9.5 inches per inch the following ranges;

(c) At the same time, the longitudinal speed after stretching is reduced according to the increase of the cloth width, so that the cloth width increases and the cloth length decreases; and the cloth surface made of cloth has elasticity perpendicular to the stretching direction, the The elasticity is released after stretching by 50%, and all have a retraction of more than 85%. At the same time, the softness of the fabric is also increased, increasing the basis weight by more than 5% and reducing the fiber pores below 20%;

(d) The finished cloth after cooling is wound on the shaft, and the speed of the shaft is controlled by a tensile tester placed between the heating device and the shaft.

The object of the present invention can also be further realized by the following technical measures. The non-woven fabric processing method of heat treatment and mechanical treatment, wherein the stretching device is a plurality of take-up wheels, each of which is coated with a material that increases surface friction, and the winding speed and gradual winding speed of each take-up wheel are gradually increased. Large take-up wheel distance processing can achieve a total draw rate of more than 3.5 inches per minute per inch and less than 9.5 inches per minute per inch. The non-woven fabric processing method of heat treatment and mechanical treatment, wherein said stretching device has at least 4 take-up wheels, but no more than 20. The non-woven fabric processing method of heat treatment and mechanical treatment, wherein the position of the stretching device is set in the heating device. The non-woven fabric processing method of heat treatment and mechanical treatment, wherein the position of the stretching device is set outside the heating device. The non-woven fabric processing method of heat treatment and mechanical treatment, the raw fabric method of the prepared non-woven fabric is, wherein the applied non-isotropic tension non-woven fabric is composed of more than 70% thermoplastic fibers and 30% The following non-thermoplastic fibers are thermally bonded non-woven fabrics. The fabric is continuously stretched by the stretching device in the hot box device, but the stretching rate is maintained between 3.5 inches per minute and 9.5 inches per inch. The calculation of the elongation is based on the distance between the coiling wheels in the stretching device. The characteristics of the finished cloth are that the lateral width in the direction of the tension is reduced and it is made to have stretching elasticity, while the length in the direction of the tension increases, and the elasticity of the cloth body is under tension. After being stretched by 50%, it has a retraction rate of more than 85%, and at the same time, the cloth becomes softer and improves the comfortable touch. Non-woven fabric processing method of heat treatment and mechanical treatment, wherein said non-woven fabric is at least one of the group consisting of polyolefin family, polyester family, polyamide family and their individual copolymers Composed of thermoplastic fibers. Non-woven fabric processing method of heat treatment and mechanical treatment, wherein said non-woven fabric raw fabric is selected from the group consisting of wood fiber, regenerated wood fiber, natural fiber, cotton, glass fiber, inorganic fiber or metal fiber composed of at least one non-thermoplastic fiber. The non-woven fabric processing method of heat treatment and mechanical treatment, wherein said raw fabric is laminated on a thermoplastic elastic film. Non-woven fabric processing method of heat treatment and mechanical treatment, wherein the raw fabric is selected from spunbonded nonwoven fabric, meltblown nonwoven fabric, thermal bonding nonwoven fabric, thermoplastic foamed plastic and thermoplastic A laminate formed by thermally bonding at least two kinds of thermoplastic raw fabrics in a group composed of films. The non-woven fabric processing method of thermal treatment and mechanical treatment, described stretching device that causes mechanical longitudinal elasticity it comprises the following devices:

(a), a set of variable stretching device, set in the heating device, fix the original fabric with two parallel tracks with continuous selvedge clamps set in opposite directions, the selvedge clamps are installed on a chain belt that continuously moves superior;

(b) The continuously moving chain belt is along the track, and the cloth clips in the opposite direction sandwich the cloth edge and separate outwards according to the advancing direction of the cloth surface in a semi-arc curve, reaching the maximum point of pulling, and turning back parallel to the cloth surface The direction of advancement; and the distance drawn by the track defines that the new width of the finished cloth is at least increased by more than 40% than the original cloth width before entering the tension device.

The non-woven fabric processing method of heat treatment and mechanical treatment, wherein the arc curve of the stretching device that causes mechanical longitudinal elasticity is specially designed, and its design parameters are:

(a) The transverse stretch rate is in the range of 3.5 inches to 9.5 inches per minute per inch, calculated by dividing the stretching distance by the longitudinal movement speed when the heat-treated cloth enters the stretching device;

(b) The speed in the machine-making direction is reduced in proportion to the transverse stretching speed, so that the longitudinal stretching rate is less than 1 inch per inch per minute.

The non-woven fabric processing method of heat treatment and mechanical treatment, the non-woven fabric produced by it, wherein the non-isotropic tensile value of the original fabric is made of 70-100% thermoplastic fibers and 30% non-woven fabrics uniformly mixed by thermal bonding. Composed of thermoplastic fibers; the original fabric is continuously stretched in the heat treatment box, but the operating stretch rate is above 3.5 inches per minute per inch and below 9.5 inches; the stretch rate is calculated according to the spacing set in the stretching device , the cloth made has the phenomenon of extending in the direction of tension and shrinking laterally; and the lateral direction is therefore elastic, and it has a retraction degree of more than 85% after being stretched by 50% and released, and the cloth can increase softness and comfort touch.

The non-woven fabric processing method of heat treatment and mechanical treatment, said non-woven fabric, wherein the thermoplastic fiber is selected from the group consisting of polyolefin family, polyester family, polyamide family and their individual copolymers of at least one fiber.

The non-woven fabric processing method of heat treatment and mechanical treatment, the non-woven fabric raw fabric, wherein the non-thermoplastic fiber is selected from the group consisting of natural wood fiber, regenerated wood fiber, cotton, glass fiber or metal fiber at least one fiber.

The non-woven fabric processing method of heat treatment and mechanical treatment, the non-woven fabric raw fabric, wherein the raw fabric used is selected from spun-bonded non-woven fabrics, melt-blown non-woven fabrics, heat-bonded non-woven fabrics and heat-bonded non-woven fabrics. A laminate formed by thermally bonding at least two kinds of thermoplastic raw fabrics in the group consisting of plastic foamed plastics and thermoplastic films.

Compared with the prior art, the present invention has obvious advantages and positive effects, which are described below in conjunction with the features of the present invention. Because it is made of non-woven fabrics with "low stretch rate" and precisely controlled heat treatment conditions, this treatment unexpectedly results in a high degree of elasticity of the non-woven fabrics, and at the same time enhances the fabric Softness and comfortable touch. However, the improvement of the cloth quality does not change the uniformity of the pores of the cloth fibers or the size of the pores, nor does it cause a reduction in the softness and comfort of the cloth material.

What is even more surprising is that the treatment and the resulting results of the present invention do not require restrictions on the properties of the original cloth, and it is not necessary to restrict the properties of the original cloth like the existing processing methods before processing . The only requirement is that the original non-woven fabric must be thermally bonded, with more than 70% thermoplastic fibers and less than 30% non-thermoplastic fibers. The present invention is suitable for processing non-woven fabrics made by melt-blown method, spunbond method and carding thermal bonding method, as well as multi-layer adhesive fabrics and non-woven fabrics with thermoplastic films as described above. Laminated cloth.

In the present invention, thermally bonded non-woven fabrics are attached with more than 70% thermoplastic fibers, under precisely controlled tension, with low elongation, and the application temperature is within the range of 70°F above the melting point of plastics. processing. And the low elongation treatment of the present invention, its elongation direction can be the longitudinal direction of mechanical operation or the transverse direction of cloth width. The treated fabric exhibits highly commercially valuable elastic properties, softer, less stiff, and higher strength than the original fabric, and the elastic properties occur in the vertical direction of the stretching process.

It has a high degree of stretching elasticity in the longitudinal and transverse directions, so that the original fabric with non-isotropic tension can be made with a stretch rate of less than 9.5 inches per inch per minute. From the above description, it can be known that the features of the present invention are obviously different from the invention of US Patent No. 5,244,482, and are more technologically progressive, and thus more suitable for practical use.

In addition to the purpose and advantages of the processing process and the use of non-woven fabrics as the original fabric, the present invention also provides the following advantages and effects:

(a) The production method of the present invention can provide the non-woven fabric with a softer, more comfortable touch and the effect of stretching elasticity, and is suitable for making disposable consumer clothing and other products in contact with the skin.

(b) Provide a method for producing non-woven fabrics at high speed to make them softer, more comfortable to the touch and more elastic, so that the manufactured consumer goods are more economical and have more commercial value.

(c), providing a production method with wider and more diversified selection of original cloth.

In summary, the present invention can post-process the raw fabric, which can increase the softness and comfortable touch of the nonwoven fabric and create a meaningful and commercially valuable high stretch elasticity, and make the stretch elasticity of the nonwoven fabric scalable. It is formed to have longitudinal elasticity or transverse elasticity through the arrangement of equipment devices.

The concrete method of the present invention and the concrete structure of relevant device are provided in detail by following embodiment and accompanying drawing.

Fig. 1 shows the arrangement of the take-up wheel and the area of heat treatment in the present invention, so that the cloth body is stretched in the longitudinal direction of the machine, so that the transverse direction of the cloth width is elastic.

Fig. 2 shows the arrangement of the auxiliary device in the present invention to stretch the cloth width transversely, so that the cloth body produces elasticity in the machine longitudinal direction.

In order to describe the present invention clearly, the terms related to the present invention are explained as follows. The definitions of the following terms are general industrially acceptable and technical terminology definitions, so as to more clearly describe the device and equipment of the present invention, the processing methods and experimental results described later.

Cloth elasticity: The structure and appearance of the material can be stretched to 200%, and then it can be retracted to more than 85% of the original size within a few seconds when released.

Plasticity point: defined in the present invention as a specific temperature at which the non-woven fabric can be stretched and extended by more than 40% within 5 seconds with 10% of the normal tensile strength.

Stretch rate: Stretch is the shape change caused by an object when a force is applied. Typical elongation is the one-sided extension of the shape in one direction. The measured value is expressed as the length of the original one-inch object per minute, how many inches it is stretched; it can also be expressed as a percentage of stretching per minute.

In ASTM D-368 A2, item 13, the stated elongation rate is divided by the distance between the original two chucks and the "moving length of the chuck". In the processing method in the method of the present invention, "chuck" is equal to the clamping point of forcefully pulling the cloth. In the test, as long as there is no obvious change in the cross-section, such as breaking, the test value can be regarded as correct. The calculation formula of the mechanical stretch rate can be expressed as:

In the formula:

L1 is the length of the original object;

L2 is the length after stretching;

t is the stretch time.

First, the stretching treatment method of the present invention will be described below. See also shown in Fig. 1, for being manufactured into a preferred specific embodiment of the arrangement of cloth width transverse elasticity, raw cloth (2), it is released by sending wheel (1), passes through a series of take-up wheels (3) , Reel 4, Reel 5, Reel 6, Reel 7, Reel 8, Reel 9, Reel 10, Reel 11, Reel 12, Reel 13 , take-up wheel 14 to take-up wheel (15), wherein each take-up wheel is all covered with rubber or other surface substances (16) to improve friction, and these take-up wheels are all arranged in a heating oven ( 17), the cloth body is stretched in the heating oven (17) and through each winding wheel, and is wound up by the winding wheel (15).

Take-up wheel 5 to take-up wheel 13, each take-up wheel has a higher take-up speed than the previous one, and the absolute speed of each take-up wheel depends on the number of take-up wheels and the volume The distance between the wheels is determined to achieve a cumulative stretch rate of less than 9.5 inches/inch/minute. Overall speed and split speed are controlled by appropriate gears or individual variable speed motors. Regardless of how many (several) coiling rolls are used, the spacing between the coiling rolls is determined by maintaining a stretch rate of less than 9.5 in/in/min. The calculation formula of stretch rate is: stretch rate=(length change/original length)×1/time, where: length change is the growth length of the cloth in the reel, the original length can be represented by the distance between the reel, and the time is Refers to the time it takes for a point on the cloth to move from one take-up wheel to the next. The temperature of the heating oven (17) is maintained within the range of 70°F above the melting point of the original cloth. In the case of this special processing, the extension of the cloth body also causes the reduction of the cloth width, and the basis weight of the cloth is also increased compared with the original cloth. The finished product has the stretch elasticity of the width and width of the cloth.

Please refer to Figure 2, which is an alternative embodiment of the present invention, which is an embodiment of another arrangement of equipment, which causes mechanical longitudinal elasticity for processing cloth, that is, stretching the cloth longitudinally as described above Transverse elasticity is formed, and the transverse stretching of the cloth material to cause longitudinal elasticity will be described in detail below.

The device for achieving longitudinal elastic treatment of the present invention includes a hot box or other heating equipment, and is attached with a set of two opposite continuous tracks (33a), (33b). The front section of the track is laid parallel to the longitudinal direction of the machine, and at the design point when the cloth body is heated to the extensible melting temperature in the hot box, the track begins to separate to the outside, according to the specially designed curve, the distance to the opening is equal to The degree of stretching to be achieved is roughly about 40%. After reaching the degree of stretching, the track turns back to the longitudinal direction of the machine, and then is arranged in a parallel direction until the track at the tail end of the heating box is turned into an arc and goes out, and the track (39a), (39b), back to the start of the track. These two tracks (33a), (33b) are all attached with chains (40a), (40b), and are equipped with general industrial cloth folder (41) on the chain, and chain is then by a speed-changing motor, and joins acceleration and deceleration transmission controlled by.

The curve (35) of the track is very important and carefully designed so that the velocity component vector in the transverse direction of the cloth width increases at an appropriate velocity rate to achieve the required transverse stretch rate. At the same time, the component vector in the longitudinal direction of the machine must be reduced to match the necessary relaxation of the cloth surface. If there is no correct track curve and component vector control, the machine cannot relax in the longitudinal direction, and the stretching effect is two-way instead of one-way, so the fabric cannot form elasticity.

The formula for calculating the elongation ratio is as follows:

Elongation rate=(ΔL/L)×1/t

In the formula: L refers to the increase of cloth width;

     ΔL is the length of the cloth width between the two cloth clamps before entering the hot box;

t is the time required to cause ΔL.

Apply above-mentioned device, former cloth (27) is released by sending wheel (25), enters heating treatment area (37). The cloth surface is corrected on the longitudinal rails (33a), (33b), and the edges of the cloth width have been set in advance on the rails. Before entering the heating treatment zone (37), the original cloth (27) is aligned by the selvedge clamping wheels (34a), (34b), and clamped by the cloth clamps (41), (41). When the chains (40a), (40b) move forward, the next pair of cloth clips (41) are driven by the aligned clip wheels to move upwards for cloth clipping. This procedure repeats automatically, makes chain (40a), (40b) enter heat treatment zone (37) continuously with the cloth body of original cloth 2. The previous section of track (33a), (33b) moves along the machine direction, so that the cloth surface can have a lead time to be heated to reach a plastic point. And when the temperature is kept within 70°F above the plastic point, the track starts to go outwards, reaching the requirement that the opening distance is equal to the degree of stretch according to the specially designed curve, and then the cloth surface continues to be fixed by the cloth clips 41a, 41b to reach the ultimate The stretch rate of the wide edge must be less than 9 inches/inch/minute, so that the fabric has elasticity, softness and comfortable touch.

After completing the stretching step, the cloth surface leaves the hot box and is cooled by indoor air or blowing air. When the temperature is below the plastic point of 50°F, the cloth clamps (41a), (41b) are released by the release cams (36a), ( 36b) Untie and release, then take up the cloth by the take-up wheel 28, the take-up wheel 28 of the cloth is controlled by the tensile tester (45), so as to avoid stretching the cloth again before the take-up.

The experimental data related to the heat treatment and mechanical treatment of the nonwoven fabric processing method of the present invention are described below. Through a series of experiments, different non-woven fabrics were subjected to the mechanical treatment and heat treatment of the present invention to determine their elasticity, softness and comfortable touch. The non-woven raw fabric is not necessarily limited like US Patent No. 5,244,482: after pre-limited tensile strength, it can be stretched by more than 40% on room temperature objects or has other physical and chemical properties.

The raw fabrics used in the experiment include different non-woven fabrics such as spun-bonded, melt-blown, thermal-bonded non-woven fabrics and laminated fabrics. Fiber types include thermoplastic materials such as polypropylene (PP), polyester (PET), and nylon (Nylon), as well as adhesive laminates of spunbond fabrics and PU foam thin fabrics. These raw fabrics are all stretched in the machine direction to achieve the elastic effect in the transverse direction.

The original fabric is processed by mechanical heat treatment at a temperature range of 40-50°F above the plastic point at a speed of 400 feet per minute to achieve new properties of softness, comfortable touch and high elasticity.

The elasticity test of all samples is to measure a 10 cm long cloth strip and stretch it to 15 cm or 50% stretch. The recovery of the cloth was measured twice at 10 seconds and 5 minutes after the tension was released. The obtained results show that the cloth body shrinks by 85% within 10 seconds, and shrinks by more than 90% in 5 minutes. The test results are shown in Table 1 respectively.

Table 1

Elasticity recovery after 50% stretch Sample Type of non-woven fabric Type of fiber Basis weight g/m ² Recovery in 10 seconds Recovery in 5 minutes (%) (%) 1 MB 100% PP 60 90 962 TB 70% PP/30% Rayon 30 86 913 SB 100% PP 30 92 944 SB 100% Nylon 45 90 975 SB 100% PP 100 88 906 SB 100% PET 24 93 957 MB 100% PET 75 92 948 TB 65% PET/35% Rayon 24 88 939 SB 100% PP 18 91 9310 SB/PU 100% PP/100% PU Film 32 97 99 SB: Spunbond MB: Meltblown TB: Carded and Thermally Bonded PET: Polyester PU: PU film (Polyurethane film) PP: Polypropylene )

Softness is a very difficult property to measure. In the textile industry, it is generally determined by the personal evaluation value of the person's cheek. In the measurement of the present invention, the above various raw fabrics are subjected to blind sampling and measurement by five assessors. Each sample of the cloth made from the original cloth is tested separately, and the measured value is measured on a scale of 1 to 10, with 10 being the softest. Each sample is represented by a code, and it is not indicated whether it has been processed. The results are shown in Table 2. All kinds of cloths have significantly improved softness after treatment.

Table 2

Comparison of softness before and after treatment

Sensory test with blinded eyes (scored from 1 to 10) Sample Type of non-woven fabric Type of fiber Basis weight g/ ^m2 Before softness treatment After softness treatment 1 MB 100% PP 60 4 62 TB 70% PP/30% Rayon 30 7 83 SB 100% PP 30 6 84 SB 100% Nylon 45 2 55 SB 100% PP 100 1 46 SB 100% PET 24 5 87 MB 100% PET 75 2 58 TB 65% PET/35% Rayon 24 7 99 SB 100% PP 18 6 810 SB/PU 100% PP/100% PU Film 32 5 6 SB: Spunbond MB: Meltblown TB: Carded and Thermally Bonded PET: Polyester PU: PU film (Polyurethane film) PP: Polypropylene )

In testing transverse elasticity, it was found that the reduction in cloth width was an index of observed resulting elasticity. The inventors found that the reduction in cloth width should be within the percentages shown in Table 3 below.

table 3

Cloth width reduction percentage during transverse stretch Sample Non-woven Fiber type Basis weight g/m ² Cloth width in CM Cloth width in CM Reduction rate % Cloth type Before treatment After treatment 1 MB 100% PP 60 70 45.5 352 TB 70% PP/30% Rayon 30 70 46.9 333 SB 100% PP 30 50 32 364 SB 100% Nylon 45 50 35 305 SB 100% PP 100 50 30.5 3406 SB 20 50 30.5 397 MB 100% PET 75 50 35 308 TB 65% PET/35% Rayon 24 70 42 409 SB 100% PP 18 50 31 381 SB/PU 100% PP/100% PU Film 32 50 32 36

The treatment method of U.S. Patent No. 5,244,482 can significantly improve the filtration efficiency, because the treatment can cause the shrinkage of the fiber pores and improve the uniformity of the pore size. This special phenomenon and result are obviously related to the special high elongation ratio adopted in the patent No. 5,244,482. The inventor also conducted a filter test on the treated cloth of the present invention, and found that there was no effect of increasing the filter degree. This shows that the present invention is different from the processing method of US Patent No. 5,244,482.

Table 4

Filtration effect after heat treatment and mechanical treatment Sample Type of non-woven fabric Type of fiber Basis weight g/ ^m2 Before filtration effect % After filtration effect % 1 MB 100% PP 60 85 852 TB 70% PP/30% Rayon 30 35 353 SB 100% PP 30 33 334 SB 100% Nylon 45 41 415 SB 100% PP 100 37 376 SB 100% PET 24 33 337 MB 100% PET 75 81 818 TB 65% PET/35% Rayon 24 35 379 SB 100% PP 18 18 1810 SB/PU 100% PP/100% PU 32 N/A N/AFilm

SB: Spunbond MB: Meltblown

TB: Carded and Thermally Bonded PET: Polyester

PU: PU film (Polyurethanefilm) PP: Polypropylene (Polypropylene)

The processing method in another direction of the present invention will be described below.

The processing of this kind of test run can produce stretching elasticity in the machine direction, and the inventor also adopts spunbonding method, melt blown method, thermal bonding method and multi-sheet bonded laminated cloth. Fiber types include polypropylene, polyester and nylon. The laminated fabric is a bonded fabric of spunbonded fabric and PU foam sheet. These materials are stretched across the width of the cloth to produce mechanical longitudinal stretch elasticity.

These materials are mechanically and thermally processed at speeds of 250 feet per minute to achieve softness and a high degree of elasticity.

When testing the elasticity of all sample cloth strips, stretch a 10 cm long cloth strip to 15 cm and then release it, measure the retraction degree after 10 seconds and 5 minutes, and all samples will recover after 10 seconds after stretching and releasing. Shrink more than 85%, and retract more than 90% after 5 minutes. The results are shown in Table 5 below.

table 5

Lateral elastic recovery after 50% extension Sample Type of non-woven fabric Type of fiber Basis weight g/m ² Recovery in 10 seconds (%) Recovery in 5 minutes (%) 1 MB 100% PP 60 91 932 TB 70% PP/30% Rayo 30 87 903 SB 100% PP 30 89 916 SB 100% PET 24 91 949 SB 100% PP 18 89 92

SB: Spunbond MB: Meltblown

TB: Carded and Thermally Bonded PP: Polypropylene

PET: Polyester

The conclusions of the present invention are described below. According to the experimental data, the non-woven fabric processing method of the present invention can make the non-woven fabric produce novel and unique non-woven fabric materials, which has unique advantages, can improve the functionality of the non-woven fabric, and can be widely used in the manufacture of Products with elasticity, softness and comfortable touch. Furthermore, this method of mechanical force treatment and heat treatment can also achieve the following additional advantages with a low-stretch processing method:

1. It softens rough cloth and can be applied to cloth that comes into contact with the skin.

2. Use a new type of cloth to replace the high-priced soft non-woven fabric.

3. Because the processed cloth is stretchable, it can improve comfort and reduce the area of cloth used.

4. Because of the low stretch rate processing method, it can be applied to non-woven fabrics containing non-plastic or natural fibers. This kind of non-woven fabrics can be breathable and moisture-permeable, and can be used more widely.

It should be pointed out that the specific application equipment and processing methods described in the above embodiments are only for the purpose of describing some specific methods and devices of the present invention to make the technical solution of the present invention clearer, but not to use To limit the present invention, all simple modifications and equivalent transformations made to the above embodiments according to the technical essence of the present invention should still fall within the scope of the technical solutions of the present invention.

Claims (17)

1. A non-woven fabric processing method of heat treatment and mechanical treatment, characterized in that the processing steps include: (a) Non-woven fabrics of non-isotropic tensile strength, with more than 70% thermoplastic fibers and less than 30% non-thermoplastic or natural fibers, heat-treated to a temperature controlled at 70°F above the plastic point of the original fabric within the temperature range. (b), the heat-treated non-woven fabric is stretched longitudinally by a stretching device, and the total stretching rate is controlled above 3.5 inches per minute per inch, but below 9.5 inches per minute per inch; and the total stretching The calculation of the rate is based on the distance between the rods of the stretching device; the width of the processed elastic cloth is reduced, and the length is extended to produce elasticity perpendicular to the direction of extension. The degree of elasticity is at least 85% after stretching 50%. shrinkage; and the processed elastic cloth also increases the softness and enhances the comfortable touch, the basis weight also increases by more than 5%, and the fiber pores shrink by no more than 20%; (c) Rolling the cooled finished cloth onto a mandrel. 2. The non-woven fabric processing method of heat treatment and mechanical treatment according to claim 1, wherein said stretching device is a plurality of take-up wheels, each of which is coated with a material that increases surface friction, and The progressive winding speed of each take-up wheel and the increasing distance between take-up wheels can achieve a total stretch rate of more than 3.5 inches per minute per inch and less than 9.5 inches per minute per inch. 3. The non-woven fabric processing method of heat treatment and mechanical treatment according to claim 1, wherein said stretching device has at least 4 take-up wheels, but no more than 20. 4. The non-woven fabric processing method according to any one of claims 1 to 3, wherein the stretching device is located inside the heating device. 5. The non-woven fabric processing method according to any one of claims 1 to 3, wherein the stretching device is located outside the heating device. 6. The non-woven fabric processing method of heat treatment and mechanical treatment according to claim 1, characterized in that the original fabric method of the obtained non-woven fabric is, wherein the applied non-isotropic tension non-woven fabric is made of uniformly mixed More than 70% of thermoplastic fibers and less than 30% of non-thermoplastic fibers are thermally bonded non-woven fabrics. The fabric is continuously stretched by the stretching device in the hot box device, but the stretching rate is maintained at a rate of 10 minutes per minute. Between 3.5 inches and 9.5 inches, the calculation of the stretch rate is based on the distance between the take-up wheels in the stretching device. The length increases, and causes the elasticity of the cloth body to release more than 85% of the retraction rate after being stretched by 50%, and at the same time, the cloth becomes softer and improves the comfortable touch. 7. The non-woven fabric processing method of heat treatment and mechanical treatment according to claim 6, wherein said non-woven fabric raw cloth is made of polyolefin family, polyester family, polyamide family and individual Composed of at least one thermoplastic fiber in the group consisting of copolymers. 8. The non-woven fabric processing method of heat treatment and mechanical treatment according to claim 6, wherein said non-woven fabric former cloth is made of wood fiber, regenerated wood fiber, natural fiber, cotton, glass fiber, At least one non-thermoplastic fiber in the group consisting of inorganic fibers or metal fibers. 9. The non-woven fabric processing method of heat treatment and mechanical treatment according to claim 6, wherein said raw fabric is laminated onto a thermoplastic elastic film. 10. The non-woven fabric processing method of heat treatment and mechanical treatment according to claim 6, wherein said raw fabric is selected from spun-bonded non-woven fabrics, melt-blown non-woven fabrics, and heat-bonded non-woven fabrics. A laminate formed by thermally bonding at least two kinds of thermoplastic raw fabrics in the group consisting of fabric, thermoplastic foamed plastic, and thermoplastic film. 11. The non-woven fabric processing method of heat treatment and mechanical treatment according to claim 1, characterized in that the stretching device causing mechanical longitudinal elasticity comprises the following devices: (a), a set of variable stretching device, set in the heating device, fix the original fabric with two parallel tracks with continuous selvage clamps set in opposite directions, the selvedge clamps are installed on a chain belt that moves continuously superior; (b) The continuously moving chain belt is along the track, and the cloth clips in the opposite direction sandwich the cloth edge and separate outwards according to the advancing direction of the cloth surface in a semi-arc curve, reaching the maximum point of pulling, and turning back parallel to the cloth surface The direction of advancement; and the distance drawn by the track defines that the new width of the finished cloth is at least increased by more than 40% than the original cloth width before entering the tension device. 12. According to the non-woven fabric processing method of heat treatment and mechanical treatment according to claim 11, it is characterized in that the arc curve of the stretching device that causes mechanical longitudinal elasticity is specially designed, and its design parameters are: (a) The transverse stretch rate is in the range of 3.5 inches to 9.5 inches per minute per inch, calculated by dividing the stretching distance by the longitudinal movement speed when the heat-treated cloth enters the stretching device; (b) The speed in the machine-making direction is reduced in proportion to the transverse stretching speed, so that the longitudinal stretching rate is less than 1 inch per inch per minute. 13. According to the non-woven fabric processing method of heat treatment and mechanical treatment according to claim 11, it is characterized in that the non-woven fabric raw fabric prepared by it, wherein the non-isotropic tensile value raw fabric is made of 70-100 % thermoplastic fibers and less than 30% non-thermoplastic fibers; the original fabric is continuously stretched in the heat treatment box, but the operating stretch rate is above 3.5 inches per minute per inch and below 9.5 inches; stretching The rate is calculated according to the distance set in the stretching device, and the fabric produced has the phenomenon of elongation in the direction of tension and shrinkage in the side direction; and the side is elastic, and has a retraction degree of more than 85% after being stretched by 50% and released. And made into cloth can increase softness and comfortable touch. 14. The non-woven fabric processing method of heat treatment and mechanical treatment according to claim 13, characterized in that said non-woven fabric, wherein the thermoplastic fiber is selected from polyolefin family, polyester family, polyamide family and At least one fiber in a population composed of its individual copolymers. 15. The non-woven fabric processing method of heat treatment and mechanical treatment according to claim 13, characterized in that said non-woven fabric raw fabric, wherein the non-thermoplastic fiber is selected from natural wood fiber, regenerated wood fiber, cotton, glass At least one fiber in the group consisting of fibers or metal fibers. 16. The non-woven fabric processing method of heat treatment and mechanical treatment according to claim 11, characterized in that said non-woven fabric raw fabric, wherein the raw fabric used is selected from spun-bonded non-woven fabric, melt-blown non-woven fabric A laminated product formed by thermally bonding at least two kinds of thermoplastic raw fabrics in the group consisting of fabric, thermally bonded non-woven fabric, thermoplastic foamed plastic, and thermoplastic film. 17. A non-woven fabric processing method of heat treatment and mechanical treatment, characterized in that the method for making the cloth body has elasticity in the machine direction, and its steps include: (a) without coiling a thermally bonded non-anisotropic blend of thermoplastic and non-thermoplastic fibers, the aforementioned blend comprising at least 70% thermoplastic fibers, into a temperature not greater than that of the aforementioned raw fabric In raw fabric heating devices within 70°F above the plastic point; (b) The heated cloth moves longitudinally continuously, enters the stretching device installed in the heating device, pulls both sides of the cloth laterally, and keeps the stretching rate at 3.5 inches per minute and below 9.5 inches per inch range; (c) At the same time, the longitudinal speed after stretching is reduced according to the increase of the cloth width, so that the cloth width increases and the cloth length decreases; and the cloth surface made of cloth has elasticity perpendicular to the stretching direction, the The elasticity is released after stretching by 50%, and all have a retraction of more than 85%. At the same time, the softness of the fabric is also increased, increasing the basis weight by more than 5% and reducing the fiber pores below 20%; (d) The finished cloth after cooling is wound on the shaft, and the speed of the shaft is controlled by a tensile tester placed between the heating device and the shaft.

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