TWI417327B - Regenerated fibers and method for producing the same - Google Patents

Description

Recycled fiber and its manufacturing method

The present invention relates to a method for producing a regenerated fiber, and more particularly to a method for producing a regenerated polyamido 6 fiber.

The process of recycling recycled polyamide 6 fibers is mainly divided into a chemical recovery method and a physical recovery method.

The chemical recovery method is to reduce the incomplete reactant produced in the polymerization stage to the polymerization raw material caprolactum (CPL) of the polyamidamine 6 by a dispersion technique, and recover and polymerize into polyamine 6. The physical recovery rule is to use a recycled granulating extruder to granulate the waste fibers of the polyamide 6 by melting.

However, the existing recycling method destroys the polyamide 6 molecule, so that the recycled polyamine 6 fiber can only be applied to engineering plastics, and can no longer be used for spinning. In addition, the waste fiber is easily contaminated by dust and debris during packaging, storage, and transportation, resulting in inefficient use of the waste fiber in the spinning process after re-granulation.

Therefore, in the present invention, a method for regenerating polyamine 6 fibers is provided, in which a composite additive composed of an antioxidant, a chain extender or the like is added during the recovery and regeneration process to control the degree of deterioration of the product, so that the recovered polyamine 6 is recovered. Achieve the spinnable grade.

One aspect of the present invention is to provide a method of making a regenerated fiber comprising adding a composite additive to a polyamido 6 waste fiber to form a mixture. The polyamine 6 waste fiber has a titanium dioxide content of 0.3 to 0.5 by weight and does not contain oil. The composite additive is added to the polyamido 6 waste fiber in an amount of 0.1 to 0.5 by weight, and the composition of the composite additive comprises a plurality of additives, and the additives include the compound of the formula (I), the compound of the formula (II) and the formula (III). ) Compound:

The content of such additives in the composite additive is 10% by weight to 70% by weight, respectively. Next, the mixture is heated and melted to form a molten polymer, wherein the molten polymer has a relative viscosity of 2.46 to 2.50. Then, the impurities of the molten polymer are removed, and the molten polymer is made into regenerated granules. Thereafter, the regenerated granules are produced into regenerated fibers by a spinning device.

According to an embodiment of the invention, the additive is present in the composite additive in an amount of from 20 to 40 weight percent.

According to an embodiment of the present embodiment, the above-mentioned composite additive is added to the polyamido 6 waste fiber in an amount of 0.3% by weight.

According to an embodiment of the present embodiment, the step of removing the impurities is performed by using a sieve to filter out the impurities.

According to an embodiment of the present embodiment, the filter has a pore size of 12 microns.

Still another aspect of the present invention is to provide a regenerated fiber which is produced by any of the above manufacturing methods and examples.

Another aspect of the present invention is to provide a fabric comprising recycled fibers produced by any of the above manufacturing methods and examples.

According to the above, the present invention is characterized in that a composite additive is added to the polyacetamide 6 waste fiber to enhance the molecular chain strength of the polymer, and after being melted at a high temperature, it can still be applied to the spinning process.

In the present invention, the addition of a composite additive to the polyacetamide 6 waste fiber improves the chain strength of the regenerated polyamine 6 granulation, and increases the feasibility of being applied to the spinning process after regeneration.

The polyamido 6 waste fiber to which the present invention is applied has a titanium oxide content of 0.3 to 0.5 by weight, and which does not contain an oil.

The composite additive used in the present invention includes an amine salt compound and a derivative thereof to enhance the molecular chain strength of the polymer. The composite additive may contain a plurality of additives, and the various compounds contained in these additives have different effects such as an antioxidant, a chain extender, and the like. The content of each additive in the composite additive is 10% by weight to 70% by weight, respectively. In one example, the amount of each additive in the composite additive is from 20% by weight to 40% by weight. In other examples, the ratio of addition of various additives may be the same or different.

Please refer to Table 1 for the chemical structure and properties of the various additives of the composite additive of the present invention. The compound of formula (I) (trade name CIBA 1098) is a thermal stabilizer and antioxidant which prevents thermal oxidative degradation of the polymer during processing and use, thereby improving product life and heat resistance.

The compound of formula (II) (trade name DSM PBO) is a chain extender which increases the relative viscosity (RV) value but is still supplemented with an antioxidant to maintain thermal stability. If no antioxidant is added, the polyamine can be degraded under auto-oxidation conditions, causing a loss of molecular weight, an increase in the acidic end, and a decrease in the amino terminus.

The compound of formula (III) (trade name Klein P-EPQ) is a thermal stabilizer and auxiliary antioxidant (also known as Processing Stabilizer), which enhances the effectiveness of the primary antioxidant and prevents the polymer from being processed or Fading and aging caused by the use of the process.

The method for producing the regenerated fiber of the present invention is to add a composite additive to the polyamido 6 waste fiber to form a mixture, wherein the composite additive is added to the polyamido 6 waste fiber in an amount of 0.1% by weight to 0.5% by weight. In one example, the amount of the composite additive added to the polyamido 6 waste fiber is 0.3 weight percent. The molten polymer is then formed by a high temperature melting technique. If the addition amount of the composite additive to the polyamide 6 waste fiber is 0.1% by weight or more and 0.5% by weight or more, the subsequent regenerated granulation cannot reach the spinnable grade.

According to an embodiment of the present invention, the mixture containing the composite additive is melted at a high temperature via a recovery granulator to form a molten polymer. The recycling of the granulator is mainly divided into two sections: the temperature of the first section of the main melt granulator is set from 250 ° C to 280 ° C, and the melt is discharged by the main granulator and then volatilized by the pumping equipment. The oil and gas is removed and then enters the second section of the secondary granulator. The temperature is set from 235 ° C to 250 ° C. In one example, the temperature of the first stage primary melt granulator is set to 270 ° C to 275 ° C, and the temperature of the second stage secondary granulator is set from 240 ° C to 250 ° C. If the relative viscosity of the molten polymer is lower than 2.46, the spinning efficiency is not good; if the viscosity is higher than 2.50, the temperature of the spinning equipment needs to be high, which is liable to cause cracking and damage the structure, so that the subsequent spinning process is easy to break. Silk and other issues.

According to an embodiment of the present invention, after heating and melting, it further comprises removing impurities of the molten polymer, for example, filtering the impurities of the molten polymer (for example, dust, contaminants or other impurities, etc.) by using a sieve. In one example, the screen has a pore size of 12 microns. In this embodiment, since the polyamido 6 waste fiber is easily contaminated by dust and impurities during packaging, storage and transportation, the polyamide 6 waste fiber is used in the spinning process after being melt-regenerated. not effectively. Even if the polyamide 6 waste fiber is protected by a two-layer outer bag during the collection process, it is still difficult to completely avoid the contamination. Removal of dust and contaminants in the recycled polyamine 6 fiber can increase the cleanliness of the finished product during the recycling process, and improve the spinnability and production efficiency of the back-spinning.

Then, it is cut into granules through a granulation system, and the output product is regenerated granulation, wherein the granulation granulation system can use a conventional cold granulation system or a die face hot granulation system, and the obtained regenerated granulation is regenerated granulation. The indoleamine 6 is granulated and can be subjected to subsequent spinning. After the regenerated polyamine 6 is granulated and melted by a spinning extruder, the remelted polymer is extruded through a spun yarn by a press motor, and the extruded strand is passed through a circulating cooling bellows and a drafting roller. The coiler is taken up to form recycled fibers. Among them, the recycled fiber setting specification is 70D/48f, the extruder temperature setting is 256°C to 270°C, the draft ratio is set to 1.4, and the coiler rotation speed is set to 4300 m/min. The output product is recycled fiber, and the recycled fiber is Regenerated polyamine 6 fibers.

The following is a test of the regenerated granulation obtained in the present invention to demonstrate that the process of the present invention can produce granulated regenerated polyamide 6 having a spinning grade.

Example 1: Evaluation of physicochemical properties of regenerated polyamine 6 granulation

The relative viscosity of the conventional polyamide 6 before processing is about 2.48 to 2.50, but after being re-granulated by the melt regeneration and spinning, the relative viscosity is reduced due to the destruction of the molecular strength and the inclusion of other impurities. About 2.43, the spinnable grade could not be reached.

Please refer to Table 2 for the composite additive formulation of the embodiment of the present invention. Formulation a, Formulation b, and Formulation c are composite additives containing different proportions of additives, respectively. Please refer to Table 3 for the effect of adding a composite additive on the melt compoundability. The blank sample is a molten polymer to which no composite additive is added during the recycling process.

Among them, the relative viscosity value can indicate the extent to which the molten metal is destroyed by the high temperature processing of the molten compound. The results show that in the process of recycling, the addition of composite additives with different proportions can significantly improve the relative viscosity of the molten polymer, and the relative viscosity is close to the conventional molten polyamine 6, thereby increasing the subsequent recycled products (such as regeneration granulation, regeneration). Molecular strength of fibers, etc.).

Therefore, from this data, it is known that the addition of a composite additive to the polyamide fiber 6 waste fiber can increase the relative viscosity of the molten polymer and increase the molecular strength of the subsequently recycled product.

Furthermore, please refer to Table 4, which is a filtration test result of the polyamine 6 molten polymer according to an embodiment of the present invention. From the results of Table 4, the pressure rise of the polyamide polymer 6 after the filtration of the molten polymer was significantly lowered, indicating that the impurities in the molten polymer of the polyamide 6 were reduced.

Example 2: Evaluation of the spinning processability of recycled polyamine 6 fibers

Please refer to Table 5 for the evaluation of the effect of adding composite additives on the spinning processability and physical properties of recycled polyamido 6 fibers. The advantages and disadvantages of spinning processability are mainly evaluated according to indicators such as full pipe rate, flying wire and broken wire rate. The blank sample is recycled polyamido 6 fiber without adding a composite additive in the recycling process; formula a, formula b, and formula c are respectively composite additives containing different proportions of additives (as shown in Table 2).

In Table 5, the full tube ratio of the recycled polyamide 6 fiber and the strength of the fiber can be evaluated as an index of spinnability. Among them, the calculation method of the full pipe rate is, for example, charging 100 tubes of 4 kg of fibers, and the number of tubes capable of continuously winding 4 kg of full tube doffing is 95 tubes, and the full tube rate is 95%.

The spinning test is an evaluation indicator of mass production. After the regenerated polyamine 6 is granulated and melted by a spinning extruder, the remelted polymer is extruded through a spun yarn by a press motor, and the extruded strand is passed through a circulating cooling bellows and a drafting roller. The coiler is taken up to form recycled fibers. The regenerated fiber setting specification is 70D/48f, the extruder temperature setting is 256°C to 270°C, the draft ratio is set to 1.4, and the coiler rotation speed is set to 4300 m/min. The results of the spinning test showed that the full tube rate of the recycled polyamido 6 fiber added with the composite additive was significantly improved compared with the blank sample.

The fiber strength test is an evaluation of the machinability index of the fiber. In the fiber strength test, after the fibers were clamped on both ends of the strength testing machine, a fixed pulling force was applied to break the fibers, and the strength measured by the strength testing machine was the fiber strength. The results of the fiber strength test also showed that the strength of the fibers of the regenerated polyamine 6 fibers to which the composite additive was added was improved as compared with the blank.

In summary, it is known from the above data that the addition of the composite additive to the polyamido 6 waste fiber of the present invention is better than the spinning processability and fiber properties of the recycled polyamidamine 6 fiber without the addition of the composite additive. For spinning.

It can be seen from the above embodiments of the present invention that the method for producing the regenerated fiber of the present invention has the advantages that the composite additive is added to the polyamido 6 waste fiber, so that it can be applied to the spinning process after being melted at a high temperature, so that regeneration can be performed. Polyamide 6 granulation is no longer only used in engineering plastics, but has other applications.

The present invention has been disclosed in the above embodiments, and is not intended to limit the present invention. Any one of ordinary skill in the art to which the present invention pertains can make various changes without departing from the spirit and scope of the invention. The scope of protection of the present invention is therefore defined by the scope of the appended claims.

Claims (7)

A method for producing a regenerated fiber, comprising: adding a composite additive to a polyamido 6 waste fiber to form a mixture, wherein the polyamido 6 waste fiber has a titanium dioxide content of 0.3 to 0.5 by weight and does not contain oil The composite additive is added to the polyamido 6 waste fiber in an amount of 0.1 to 0.5 by weight, the component of the composite additive comprises a plurality of additives, and the additives comprise a compound of the formula (I) and a compound of the formula (II) And a compound of formula (III): Wherein each of the additives is present in the composite additive in an amount of 10% by weight to 70% by weight; the mixture is heated and melted to form a molten polymer, wherein the relative viscosity of the molten polymer is 2.46 to 2.50; One of the molten polymers is impure; the molten polymer is made into a plurality of regenerated granules; and the regenerated granules are formed into a plurality of regenerated fibers by a spinning apparatus. The method for producing a regenerated fiber according to claim 1, wherein each of the additives is present in the composite additive in an amount of from 20 to 40% by weight. The method for producing a regenerated fiber according to claim 1, wherein the composite additive is added to the polyamido 6 waste fiber in an amount of 0.3% by weight. The method for producing a regenerated fiber according to claim 1, wherein the step of removing the impurities is carried out by using a sieve to filter out the impurities. The method of producing a regenerated fiber according to claim 4, wherein the sieve has a pore size of 12 μm. A regenerated fiber obtained by the method of any one of claim 1 to claim 5. A fabric comprising the regenerated fiber of claim 6.