KR810001156B1 - Device for the manufacture of short fibrils - Google Patents

Abstract

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Description

Apparatus for manufacturing single fibrils

1 is a cross-sectional view of the device of the present invention.

2 to 7 show a view of the end of the device according to FIG. 1 with various other embodiments.

8 is a cross-sectional view showing another embodiment of the device of the present invention consisting of a series of continuously arranged oscillation chambers.

9 is a cross-sectional view of the device of the present invention using a metal mesh.

10 is a cross-sectional view of a device consisting of two supply orifices.

11 is a cross-sectional view taken along the line AA ′ of FIG. 10.

12 is a cross-sectional view of another embodiment of the device according to FIG. 10.

13 shows a cross-sectional view of another embodiment of the spinneret according to the invention forming a continuous lubricating film on the wall of the pressure relief orifice.

The present invention relates to an apparatus for producing short fibrils.

Background Art It is well known to manufacture continuous fibril-like structures or rovings by rapidly releasing pressure acting on an ideal liquid mixture composed of a molten polymer and a solvent and under high temperature and high pressure. However, it is very difficult to directly manufacture these continuous fibril-like structures because the volume of the fibrillary structures is very large and the production speed is high. For this reason, in order to economically produce continuous fibril-like structures, they are first ground to reduce their size. However, such grinding treatments do not benefit their physical properties and lead to significant cost and energy consumption.

For this reason, the development of a method in which a short length of fibrils can be directly formed when the pressure acting on the above-mentioned mixture is rapidly released.

Belgian patent 787,032 describes a method for the direct preparation of short fibrils which is dispersed in the added fluid when the above liquid mixture rapidly releases the pressure acting on it. Belgian Patent No. 787,033 also describes a method for achieving a similar result by allowing the fibrillary structure obtained by rapidly releasing the pressure acting on the above liquid mixture to be pulverized by the cross flow of the fluid.

Although these methods have resulted in significant improvements in the manufacturing technology of discontinuous fibrils, these methods have other disadvantages, such as requiring a significant amount of added fluid for proper grinding.

Thus, the development of a method for producing short fibrils directly without the need for additional fluid supply has been studied.

Belgian Patent No. 811,780 “Method for producing discontinuous fibrils” describes a method for producing short fibrils consisting of a method of mechanically grinding an ejection cone formed by rapidly releasing pressure at an orifice outlet. However, this technique requires the use of a mechanical device such as a rotorcraft rotating on the highway at a very close distance from the pressure relief orifice. Although this technique is effective, special driving means are required, which not only complicates the device but also mechanical failures cause the manufacture to stop.

Despite considerable advances in technology, the company has successfully developed a reliable device that does not require any additional fluids to produce short fibrils directly by rapidly releasing pressure acting on the ideal liquid mixture of molten polymer and solvent. I didn't get it. It is therefore an object of the present invention to provide an improved apparatus for producing short fibrils directly while rapidly releasing pressure acting on an ideal liquid mixture consisting of a molten polymer and a solvent.

Another object of the present invention is to provide a reliable device which does not require other additional fluids.

In the present invention, the ideal liquid mixture is disturbed by rapidly releasing the pressure acting on the ideal liquid mixture of the molten polymer and the solvent to release the mixture through the pressure release orifice so that the solvent evaporates rapidly and the polymer is solidified. Provided are devices in which short length fibrils are made.

As used herein, the term “short fibrill” refers to a fibrillated structure having a thickness of microns and composed of fine filaments connected to each other in a three-dimensional network. The general form of these fibrils, which are hairy, is a rectangular form. Their length is approximately 0.5 mm-5 cm and the diameter is 0.01-5 mm.

The specific surface area of these products is greater than 1 m² / g and in some cases more than 10 m² / g. These fibrils are excellent starting materials for producing nonwoven fibers or synthetic paper in conventional manner.

As used herein, the expression “ideal liquid mixture of molten polymer and solvent” is defined as follows.

It can be seen that with a suitable concentration of polymer and applying a very high pressure to the mixture of the polymer and the appropriate solvent at a temperature above the melting point of the polymer, the mixture is in the form of a single liquid phase. When lowered, from a certain pressure varying under certain circumstances, the monolithic phase is clouded by the phenomenon of the two-liquid phase constituting the continuous polymer thickening phase in which small droplets of the polymer-sensitive phase are dispersed.

Substances composed of two liquid phases are the above-mentioned liquid mixtures. The pressure value at which this two-liquid phenomenon occurs can be easily determined experimentally at various values of temperature and polymer concentration. It is preferable to use a mixture in an abnormal state in order to obtain a good fibril structure while rapidly releasing pressure.

The apparatus of the present invention is provided for rapidly releasing pressure acting on an ideal liquid mixture of a molten polymer and a solvent to produce a fibrill of short length, the apparatus comprising at least one supply orifice for supplying an ideal liquid mixture and It consists of a spinneret formed with a disturbance chamber having opposing pressure relief orifices.

The present invention will be described in more detail based on the accompanying drawings.

The polymer present in the ideal liquid mixture at which pressure is rapidly released may be any polymer capable of forming the ideal liquid mixture in the presence of a suitable solvent.

In general, any polymer that can be spun can be used by the present invention.

For example, polyolefins, polyamides, thermoplastic polyesters, polyurethanes, polycarbonates, vinyl polymers (vinyl polymers such as vinyl chloride, polymers of vinyl acetate and vinylidene fluoride) and acrylic polymers (acrylonitrile or methyl acrylate) Acrylic polymers) may be used.

However, there is a use of a crystalline polymer having a crystallinity of 10% or more, in particular 20% or more, determined by X-ray diffraction. In fact, the extensive force exerted on the fine filaments that form fibrils by rapid movement of the solvent vapor during instantaneous evaporation of the solvent affects their orientation structure when the fibrils are crystalline polymers, thus exhibiting good mechanical properties. To appear.

The best results were obtained with crystalline polyolefin as starting material. Commercially available high-density polyethylene, iso-stack polypropylene, consisting of at least 50 mol% of alpha-olefins containing 2-6 carbon atoms, and a small amount of isotack polybut-1 produced -Enes and isotactic poly-4-methyl-pent-1-enes can be used.

As the solvent, those which do not dissolve the polymer at normal pressure and temperature (atmospheric pressure and 20 ° C) are preferably used. Under these conditions they should not dissolve more than 50 g of polymer per liter and preferably not more than 10 g of polymer per liter.

As a second condition, the boiling point of the solvent should be below the temperature at which the polymer plastically deforms. Their boiling point should be at least 20 ° C at normal pressure, and preferably at least 40 ° C, below the plastic temperature of the polymer. Furthermore, they must be able to form an ideal liquid mixture under temperature and pressure conditions which, as already mentioned, allow instantaneous evaporation of the solvent and solidification of the polymer.

It is also advisable to use a common solvent when several different polymers are used.

Solvents that can be used include aliphatic hydrocarbons (n-butane, n-pentane, n-hexane, n-heptane, n-octane and their isomers), cyclic aliphatic hydrocarbons (cyclohexane and methylcyclohexane), aromatic hydrocarbons (benzene, toluene And xylenes), halogenated alkanes (chloromethane, chlorofluoromethane, chloroethane and chlorofluoroethane), alcohols, ketones, esters, amides, nitriles and ethyl.

When one or more polymers selected from crystalline polyolefins are used, it is preferable to use solvents selected from aliphatic and cycloaliphatic hydrocarbons containing 4-8 carbon atoms, for example industrial amounts of hexane and cyclohexane.

In the present invention, it is preferable that the pressure of the mixture be selected to enable rapid release in the form of an ideal liquid mixture. The same applies to the temperature and concentration of the polymer. In general, a temperature of 100 ° -300 ° C is good, especially at a temperature of 125 ° -250 ° C. The concentration of the polymer is generally 1-500 g per kg of mixture, and it is preferable to use a mixture containing 10-300 g of polymer per kg of solvent, preferably 50-200 g / kg.

As mentioned above, such as antioxidants, light stabilizers, antistatic agents, surfactants, reinforcing agents, fillers, pigments, dyes and nucleating agents, together with solvents of polymers which may each be components or constitute their own mixtures Conventional additives for the polymer may be added to the ideal liquid mixture, which should be chosen so as not to adversely affect the formation of the ideal liquid mixture, the instantaneous evaporation of the solvent and the solidification of the polymer.

During the rapid release of pressure, the pressure value of the ideal liquid mixture reaches an atmospheric pressure, preferably less than 3 kg / cm², in a very short time, preferably less than 1 second. This pressure relief is achieved by passing the mixture through a cylindrical orifice with a diameter of 0.1-3 mm, preferably 0.5-1.5 mm and a length / diameter ratio of 0.1-10, preferably 0.5-2.

If the cross section of the orifice is not circular, the diameter of the orifice shall be taken into account the hydraulic diameter.

According to the invention, the flow of the ideal liquid mixture moving towards the inlet of the pressure relief orifice is disturbed just before the inlet. Since the continuous liquid phase of the ideal liquid mixture is a polymer vapor phase, the ideal liquid mixture has a very high viscosity. It is therefore believed that the mixture moves with the flow of fluid having parallel flow paths under a laminar flow state. The effect of this disturbance will change the flow state before the ideal liquid mixture enters the pressure relief orifice. This disturbance, of course, takes place as soon as the ideal liquid mixture enters the pressure relief orifice and is not yet relaxed.

In one embodiment of the invention, the flow of the ideal liquid mixture causes the flow portion of the ideal liquid mixture to be deflected upwards from the pressure relief orifice under rapid pressure release and the deflected portion is angled relative to the lateral line of the pressure relief orifice. It is stirred while letting it flow into the pressure releasing orifice in the forming direction.

The angle formed between the direction of the flow portion that is deflected to the maximum magnitude and the side of the pressure relief orifice is preferably between 30 ° and 135 °, and the best result can be obtained when the angle is between 75 ° and 120 °. This angle is at 90 °.

This deflection can be effected effectively by passing the liquid mixture over the pressure release rapidly through a disturbance chamber open towards the pressure relief orifice.

In a modified embodiment, the flow of abnormal liquid mixture entering the disturbance chamber is separated into multiple flows by the feed orifice.

This separation of the biphasic liquid mixture stream may be achieved by increasing the number of orifices provided in the disturbance chamber or by inserting elements or grids, preferably metal meshes, to separate the flow into the flows following this flow.

If a metal mesh is used, it can be mounted on top of the supply orifice of the disturbance chamber, ie on the upper side of the partition wall on which the supply orifice is formed. However, it is advisable to install the metal nets in disturbance chambers, especially in bulkheads with feed orifices. This metal mesh is preferably installed perpendicular to the flow direction of the ideal liquid mixture.

The mesh of the mesh should be at least 0.1 mm to avoid closure. The mesh size of the metal mesh may be equal to the size of the feed orifice, and may be set to a size larger than at least one strand may be formed on the opposite side of the feed orifice, i.e., the flow path following the abnormal liquid mixture flow.

In addition, it is possible to separate the flow of the abnormal liquid mixture by supplying the disturbance chamber through a plurality of supply orifices, these supply orifices are formed upstream of the partition wall or wall forming the disturbance chamber. The axes of these orifices may be parallel to one another or inclined with respect to the axes of adjacent orifices.

However, these two methods can be used in combination, and it is clear that it is possible to feed the disturbance chamber through several orifices or to install a metal net in the disturbance chamber.

Dispersion means may be provided at the outlet of the pressure relief orifice for guiding the short fibrils from the pressure relief orifice. However, it is preferable that the angle of the dispersing means be at least 150 °.

Finally, in order to introduce the ideal liquid mixture into the disturbance chamber through one or more orifices, the angle of the inlet wall of the disturbance chamber may be at least 30 ° or 150 °.

As mentioned above, short lengths of fibrils can be produced directly and economically but there are cases where a significant amount of pellets are unnecessarily produced. This pellet is a small-density particle having a film-like structure, the largest particle having a size of 0.5 mm or more.

These pellets produced in the short fibrils thus become an obstacle when processing the short fibrils to produce synthetic paper. In practice, these pellets are difficult to remove and generally they remain in the form of transparent spots or impurities that adversely affect the pulp of the finished product.

In the embodiment of the present invention, the production of such a pallet can be reduced, and the pellet can be completely removed by lubricating the wall of the pressure relief orifice by a lubricant film which is not mixed with the abnormal liquid mixture.

According to one embodiment of the invention it is possible to coat the walls of the pressure relief orifice with a coating of a suitable lubricant, for example a lubricant such as silicone.

However, this improvement is not permanent in terms of reducing many pellets. In fact, it should be seen that the pellets which can be significantly reduced when using the device of the present invention are gradually increased as well as the function of the device.

As a result, according to the embodiment of the present invention, the wall of the pressure relief orifice is lubricated by causing a film of liquid lubricant which does not mix with the abnormal liquid mixture to be continuously flowed at the inlet of the pressure relief orifice.

By doing so, it can be seen that a number of pellets generated during the passage through the pressure relief orifice are decelerated or removed.

The liquid lubricant used in this modified embodiment of the present invention may be any compound so long as it does not blend with the ideal liquid mixture, i.e., does not dissolve the polymer present in the mixture, which forms a continuous phase with the mixture. You can use it. The lubricant is preferably heated to a temperature close to the temperature of the ideal liquid mixture before being transferred to the wall of the pressure relief orifice.

However, for reasons of simplicity and economy, the lubricant used in the present invention is water containing a humectant. In fact, this type of lubricant has produced excellent results. Moreover, the short fibrils thus prepared are easily suspended in water when the polymer is hydrophobic. Finally, when the fibrils are produced, water is evaporated to form a protective film surrounding the flow of the fibrils to prevent them from adhering to the heated portion of the pressure release spinneret.

The liquid lubricant is injected at a flow rate of 30-250 liters per hour, preferably 40-150 liters per hour when using a pressure relief orifice with a diameter of 1 mm in the special device mentioned below.

These devices or spinnerets have at least one feed orifice and the pressure relief orifice coaxial and the disturbance chamber is rotationally symmetrical about their coaxial axis.

According to the first variant, the disturbance chamber can be equipped with a metal net and the mixture can be fed through a plurality of feed orifices.

According to the second variant, the disturbing chamber is defined as the peripheral chamber of the periphery, which is a liquid lubricant supplied to the disturbing chamber through an annular slit serving the inlet of the pressure relief orifice. It is connected to the source. In this way, the main chamber communicates with the disturbing chamber so that the liquid-lubricating film is continuously formed on the wall of the pressure relief orifice.

In the figure, as shown in FIGS. 1 to 7, the spinneret 1 according to the invention has a pressure relief orifice 2 and a pressure relief device. According to the invention, this pressure relief device consisting of the partition 3 with the central orifice 4 is not essential. The role of this pressure relief device is to cause a pressure drop in the mixture of the molten polymer and the solvent in the form of a single phase liquid passing through the spinneret for the formation of the ideal liquid mixture.

Such a device has several advantages. Firstly, the preparation of the single-phase mixture is simple, and secondly, the ideal liquid mixture is more uniform. However, the device should not be fed directly into the spinneret with an ideal liquid mixture of polymer and solvent.

The spinneret also consists of a disturbance chamber 5 formed of a wall 20 having a pressure relief orifice 2 and an upper wall 6 having a supply orifice 7 in the center. The feed orifice and the pressure relief orifice are opposed and lie coaxially.

The teaching room is cylindrical with a circular cross section. The orifice is formed in the center of the base. The distance (height) between the supply orifice and the pressure relief orifice should be less than 10 cm but less than 7.5 cm. This disturbance room will be described in detail later.

As shown in Figs. 2 to 7, the outlet of the pressure relief orifice 2 has various forms.

The spinneret chamber 8 is supplied with an ideal liquid mixture of a molten polymer and a solvent. The mixture has an orifice 7 and a pressure relief orifice 2 in the upper wall 6 in a row, so that 9) and flows through the disturbance chamber 5 along the side flow 10, in the vicinity of the pressure relief orifice 2, the side flow 10 is guided transversely to the midstream by the wall of the disturbance chamber. do. The angle of incidence of the axial flow is changed according to the shape change of the wall 20 in which the pressure release orifice 2 is formed, and as shown in FIGS. 2 to 7, the wall of the deformed shape is denoted by reference numerals 20a to 20f. There is a city outside). It is assumed that the angle between the axis of the pressure relief orifice and the wall on which the orifice is formed determines the angle of incidence of most deflected eccentric side streams. This angle is good between 30 ° and 135 °, with the best results between 75 ° and 120 °.

This angle is 90 ° in the simplest embodiment as shown in FIGS. 1, 3, 4, 7 and 8.

Furthermore, the shape of the disturbance chamber 5 is advantageous in that it is advantageous to remove the sharp angle such that the flow of axial flow, which is mostly deflected and moves in the vicinity of the wall, is tangential to all points of the wall. In this case, the speed of the most deflected flow section is maximum.

In addition, as shown in FIG. 8, it is advantageous to construct a spinneret having a type in which several disturbance chambers are provided in series.

In particular, it should be possible to satisfy various criteria so that the effect of disturbance room can be achieved in an optimal state.

Therefore, it is preferable that the disturbance chamber has a sufficient transverse size to form a side flow capable of disturbing the midstream at the inlet of the pressure relief orifice 2.

For similar reasons, the distance between the orifices of the disturbance chamber (the height of the disturbance chamber) should also be larger than the diameter of the feed orifice. In fact, if the height of the disturbance chamber is too small, the deflected side flow cannot be effectively guided transversely with respect to the midstream.

On the other hand, if the height of the disturbance chamber is too high, the deflected lateral flow tends to rejoin the midstream again and be parallel to the midstream before reaching the pressure relief orifice. It can be seen that the height that the disturbance chamber can have is related to the diameter of the disturbance chamber. In fact, to achieve the maximum effect, the ratio of the height (distance between the orifices) of the disturbance chamber to the lateral size of the disturbance chamber should be 5 or less, preferably 3 or less.

Finally, the diameter of the feed orifice is preferably at least half the size of the diameter of the pressure relief orifice.

As shown in FIG. 9, the metal mesh 12 may be installed in the disturbance chamber 5 in the spinneret for rapid pressure release. The teaching chamber 5 consists of a wall 20g having a pressure relief orifice 2 and an upper wall 6 having a supply orifice 7 at the center. The pressure relief orifice 2 and the supply orifice 7 are opposite and coaxial. The side wall of the cylindrical disturbance chamber 5 is composed of an annular ring 13. However, the disturbance chamber 5 can also be configured in other forms, for example in the form of a parallelepiped. The annular ring 13 performs two functions. Firstly, this ring determines the height of the disturbance chamber 5 and secondly has a function of fixing the fine mesh metal mesh 12 in the disturbance chamber with respect to the wall 6 with the supply orifice 7.

The spinnerets shown in FIGS. 10, 11 and 12 are the same as those shown in FIG. 9 except that they do not have a metal mesh in the disturbance chamber. Between the supply chamber 8 and the disturbance chamber 5, two supply orifices 7 are configured, their axes being inclined with each other and joined to form a single orifice at the supply chamber side. In this spinneret, the annular ring 13 forming the cylindrical sidewall of the disturbance chamber 5 is simply used to determine the height of the disturbance chamber.

In addition, as already mentioned, the spinnerets shown in FIGS. 10, 11, and 12 can also be provided with a metal mesh in the disturbance chamber, and two or more orifices with parallel axes can be provided.

As shown in FIG. 1, FIG. 2, FIG. 3, FIG. 4, FIG. 8 and FIG. 12, it is possible to provide the dispersing means 11 at the outlet of the pressure relief orifice with an angle of 150 It is better to be above °.

Finally, as shown in FIG. 13, the disturbance chamber (8) is provided in the pressure release chamber (8), the orifice (7) for supply to the disturbance chamber (5), and the spinneret (1) having the pressure relief orifice (2). 5) may be provided, and the partition wall separating these disturbances (5) and the main chamber (15) is pressured to form an annular slit (17) coaxial with the pressure relief orifice. At the inlet of the discharge orifice 2. The peripheral chamber 15 is also provided with a connector 16 for connection with a liquid lubricant source.

Example 1

The ideal liquid mixture is prepared using a mixture of 15 wt% ELTEX A 1050 and 85 wt% industrial hexane at a temperature of 195 ° C. and a pressure of 63 kg / cm 2. These conditions are the start of the two liquid phases. ELTEX A 1050 is a high melt polyethylene with a melt index of 5, manufactured and sold at Solvay Cie, Brussels, Belgium.

The pressure acting on this mixture is released by passing the mixture through a spinneret having a disturbance chamber as shown in FIG. 4 and having the following structural features.

(a) Ratio of disturbance chamber diameter to diameter of feed orifice = 16

(b) ratio of disturbance chamber height to diameter of feed orifice = 5

(c) Ratio of disturbance room height to disturbance room diameter = 0.313

(d) The diameter and height of the pressure relief orifice of the supply orifice = 1 mm

The dispersing means 11 formed in the orifice are opened at an angle of 150 degrees for rapid pressure release.

The above liquid mixture was released at a rate of 21.4 kg of polymer per hour.

Short fibrils having an average length of 1.7 mm were obtained directly. The surface area of these fibrils was 35 m 2 / g.

Example 2

The procedure of Example 1 is followed except that a 12 kg / cm 2 discharge pressure is applied to the mixture. Again, a short fibrill with an average length of 1.9mm is obtained.

The specific surface area of the product is 23 cm² / g.

Example 3

The process of Example 2 is followed except that the spinneret has a modified structural characteristic as follows.

Ratio of disturbance chamber height to the diameter of the feed orifice (7) = 200

Ratio of disturbance room height to disturbance room diameter = 12.5

A continuous fibrillable rovings are obtained.

This negative result is evidenced by the fact that the height of the disturbance chamber is too high for its diameter.

Example 4

Although the process of Example 2 was followed, spinnerets having a disturbance chamber as shown in FIG. 3 were used, and structural characteristics thereof were the same as those of Example 1.

Short skin reel with an average length of 1.8 mm is obtained.

Their specific surface area is 21 m² / g.

Example 5

The procedure of Example 4 is followed except that the spinneret has the following characteristics.

Ratio of disturbance chamber height to the diameter of the feed orifice (7) = 40

= 2.5 of disturbance room height for disturbance room diameter

A short fibrill with an average length of 2.3 mm was obtained and its specific surface area was 26 cm 2 / g.

Example 6

Although the process of Example 2 was followed, spinnerets as shown in FIG. 6 were used, and their structural characteristics are as follows.

(a) ratio of disturbance diameter to diameter of supply opis (7) = 6

(b) ratio of disturbance chamber height to the diameter of the supply office 7 = 3

(c) ratio of disturbance room height to disturbance room diameter = 0.5

(d) The diameters and heights of the supply and pressure release opirises are 1 mm, the specific surface area is 30 m² / g and the average length is 2.1 mm.

Example 7

Example 2 is followed except that the dispersing means 11 having a deployment angle of 150 ° is formed in the pressure releasing spinneret. In particular, the structural characteristics of spinnerets are changed as follows.

(a) Ratio of disturbance chamber diameter to diameter of supply office 7 = 13.3

(b) Ratio of disturbance chamber height to diameter of supply office (7) = 4.16

(c) Ratio of disturbance room height to disturbance room diameter = 0.313

(d) Diameter of supply opis (7) and pressure relief opiris = 1.2mm

(e) The height of the supply opless (7) and the pressure relief opiris = 1 mm

The polymer weight released was changed to 30 kg / hr and the average length of the short fibrils was 2.2 mm.

The specific surface area is 30 m² / g.

Example 8

The procedure of Example 7 was followed except that the spinneret was changed as follows.

(a) Ratio of the disturbance chamber diameter to the diameter of the supply offices = 10.7

(b) ratio of disturbance chamber height to diameter of supply office 7 = 3.34

(c) the diameter of the supply opless (7) and the pressure relief opiris = 1.5 mm

(d) the height of the supply opless (7) and the pressure relief opiris = 1 mm

The polymer weight released was changed to 49 kg / hr and the average length of the short fibrils was 2.6 mm.

The specific surface area is 23 m² / g.

Example 9

As shown in FIG. 8, the procedure of Example 8 is followed, except that three disturbance chambers use spinnerets in a form of excreted in series.

The diameters of the opiris continued in the flow direction of the above liquid mixture are 2 mm, 1.5 mm, 1.2 mm and 1 mm in turn.

The opening angle of the dispersing means 11 is 150 degrees.

Short fibrils with an average length of 1.9 mm and a specific surface area of 10 m² / g are obtained.

A mixture consisting of 10% by weight of PROFAX 6501 and 90% by weight of industrial pentane is sounded at a temperature of 195 ° C. and a pressure of 83 kg / cm². PROFAX 6501 is a polyflofilene with a melt index of 2.9, manufactured and sold by HERCULES INC.

The pressure acting on the mixture is raised by passing the mixture through a spinneret having a disturbance chamber with a metal mesh as shown in FIG. 9 and having the following structural properties.

(a) Ratio of disturbance chamber diameter to diameter of supply office 7 = 6

(b) ratio of disturbance chamber height to diameter of supply office (7) = 2

(c) Ratio of disturbance room height to disturbance room diameter = 0.333

(d) Diameter and height of the supply office (7) = 1 mm

(e) Diameter and height of pressure relief opiris (2) = 1.1 mm, 1 mm

In addition, the mesh diameter of the metal mesh 12 is 0.4 mm.

As soon as the mixture of polymer and solvent enters the feed chamber 8, it is subjected to a release pressure of 3 kg / cm² so that the mixture becomes an ideal liquid mixture.

The liquid mixture is discharged through the pressure relief office 2 at a rate of 10.3 kg of polymer per hour.

Short fibrils having an average length of 1.7 mm were obtained directly. The specific surface area of these short fibrils is 3 m 2 / g.

Example 11

The pressure acting on the mixture prepared according to Example 10 is released through a spinneret having the following properties with a disturbance chamber as shown in FIGS. 10 and 11.

The disturbance equation (5) has a height of 2 mm and a diameter of 4 mm.

The height and diameter of the pressure relief opiris 2 are 1 mm.

Between the supply chamber 8 and the disturbance chamber 5, two opirises having a diameter of 0.8 mm and a length of 1.43 mm are formed.

While the mixture of the molten polymer and the solvent is introduced into the feed chamber 8, it is subjected to a discharge pressure of 3 kg / cm² to form an ideal liquid mixture.

The ideal liquid mixture is discharged through the pressure relief office 2 at a rate of 13.9% polymer per hour.

Short fibrils having an average length of 1.9 mm were obtained directly. The specific surface area of these short fibrils is 3 m 2 / g.

Example 12

The pressure acting on the mixture prepared according to Example 10 is released by passing the mixture through a spinneret having a disturbance chamber as shown in FIG.

This spinneret is again shown in FIGS. 10 and 11 except that it is formed only at the edgeless side of the pressure release opis 2 and is provided with a dispersing means 11 with a deployment angle of 150 ° and Example 11 Same as the spinneret used in.

At the moment of entering the feed chamber 8, the molten polymer and the solvent mixture are subjected to a discharge pressure of 3 kg / cm² to form a liquid mixture.

The above liquid mixture is discharged at a rate of 14.3 kg of polymer per hour through the pressure release office (2).

Directly obtain short fibrils with an average length of 1.2 mm. The specific surface area of these short fibrils is 3 m 2 / g.

Example 13

A mixture of 15% by weight of ELTEXA1050 containing 85% by weight of industrial hexane and 0.5% by weight of calcium stearate is prepared and the mixture is raised to a temperature of 194 ° C. and a pressure of 66 kg / cm 2.

The pressure acting on this mixture is shown in FIG. 13 and released by passing the mixture through a disturbance chamber having the following characteristics.

(a) Diameter ratio of the disturbance chamber 5 to the diameter of the supply office 7 = 16

(b) ratio of the height of the disturbance chamber 5 to the diameter of the supply office 7 = 3

(c) Ratio of disturbance room height to disturbance room diameter = 0.187

(d) The diameter and height of the supply and pressure relief opisles = 1 mm

At the moment when the mixture of polymer and solvent enters the feed chamber 8, it is subjected to a discharge pressure of 3 kg / cm 2 to form a liquid mixture at least. During the pressure release, 195 ° C. water at 44 kg / cm 2 pressure is injected through the connection 16 at a rate of 95 liters / hour.

The above liquid mixture is discharged at a rate of 14.4 kg of polymer per hour. Directly obtain short fibrils with an average length of 2.3 mm. These fibrils did not produce pellets.

When the injection of water was stopped, the rate of passage of the mixture was changed at the rate of 16.4 kg of polymer per hour. The average length of the manufactured fibrils was 1.9 mm and pellets were produced. The synthetic paper produced from these fibrils was poor in lipid because there were 9 large pellets per dm².

In addition, the blood produced by the apparatus (LECHLER KS 11 crusher) having four supply opirises curved to inject the ideal liquid mixture into the disturbance chamber in a direction at an angle of about 45 ° on the side of the pressure relief opiris. Brill also contains a large number of pellets.

Claims (1)

A method for producing fibrils of short length by rapidly releasing pressure acting on the liquid mixture of the molten polymer and the solvent, and extruding the liquid mixture in a low pressure region at a position opposite to the at least one supply office for supplying the liquid mixture. In a device composed of a spinneret having a thread having a pressure-release opisil for forming, the distance between the supply opis and the pressure-release opris is less than three times the transverse size of the thread so that the thread acts as a disturbing chamber. Short fibrils production apparatus characterized in that.

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