Regenerated chinlon 6 slice and preparation method thereof

Abstract

The invention provides a regenerated chinlon 6 slice and a preparation method thereof. The regenerated chinlon 6 slice is prepared from the following components in percentage by weight: 90 parts of chinlon 6 waste silk material, 0.5-1 part of chain extender, 0.1-0.4 part of binary compound system antioxidant and 8.6-9.4 parts of chinlon 6 slice powder, the chain extender is an epoxy type chain extender YMX-20 which contains glycidyl methacrylate (GMA); the binary compound system antioxidant is formed by compounding a hindered phenol antioxidant 1010 and an amine antioxidant DNP according to a ratio of 1: 1. The components are sequentially subjected to quantitative feeding, melting plasticizing, screw shearing, water-cooling pelletizing, vibration screening and vacuum drying, and the regenerated chinlon 6 slice is prepared. The regenerated chinlon 6 slice manufactured by the method is relatively high in viscosity and relatively good in spinnability and oxidation resistance.

Description

Technical Field

[0001] The invention belongs to the technical field of textiles, and in particular relates to a regenerated nylon 6 slice and a preparation method thereof. Background Art

[0002] In recent years, driven by the rising demand in the downstream textile field, the production of nylon 6 fiber in my country has grown rapidly. In the production process of nylon 6 fiber and its products, waste is generated in every process after polymerization or polycondensation. These industrial solid wastes account for 8-10% of the total production of polyamide fiber. With the rapid development of the nylon 6 industry, the problem of handling nylon 6 waste is becoming more and more urgent.

[0003] At present, the recycling of nylon 6 mainly adopts two methods: physical recycling and chemical recycling. In the preparation process of chemical recycling method of nylon 6, the whole depolymerization and repolymerization process is fully enclosed, so the cleanliness of waste silk is extremely high, especially the separation of spinning oil, and 10% of oligomers will be produced during the polymerization process, which will enter the spinning process and seriously affect the fiber quality. Due to the complex process flow of chemical recycling method, high preparation cost and difficulty in industrial production, my country mainly adopts physical method to recycle and reuse nylon waste.

[0004] The physical recycling method is to crush, melt and extrude the nylon 6 waste into regenerated chips, and then prepare nylon regenerated fibers through melt spinning. At present, domestic companies such as Yongrong Jinjiang, Hengshen, Xinhui Meida, and Yiwu Huading use physical methods (screw granulation) manufacturing technology to prepare spinning-grade regenerated polyamide 6 chips.

[0005] Chinese invention patent CN202111611556.0 discloses a method for realizing a regenerated nylon 6 slice production system, comprising the following steps: step S1, crushing the nylon 6 waste silk mixed raw material through a crusher to obtain a nylon 6 waste silk mixture; step S2, then putting the nylon 6 waste silk mixture into a feeder; step S3, the quantitative feeder conveys the nylon 6 waste silk mixture to the auxiliary screw extruder through the main screw extruder for voltage stabilization and temperature reduction; step S4, the cold water in the cooling water tank cools and solidifies the regenerated polyamide melt, and then blows and dries the regenerated polyamide melt through a shaking water and wind cooling rack; step S5, the regenerated nylon 6 slices enter the vibrating screen for screening and dust removal; step S6, then the regenerated nylon 6 slices in the storage hopper enter the continuous drying device for drying; the invention can realize the batch continuous production of waste silk regenerated nylon 6 slices, but the regenerated nylon slices manufactured by the invention have low viscosity and poor spinnability. Summary of the invention

[0006] The technical problem to be solved by the present invention is to provide a regenerated nylon 6 chip with good spinnability, viscosity and oxidation resistance.

[0007] The present invention is achieved in that:

[0008] In a first aspect, a regenerated nylon 6 chip comprises the following components in weight percentage: 90 parts of nylon 6 waste silk, 0.5-1 parts of chain extender, 0.1-0.4 parts of binary compound system antioxidant, and 8.6-9.4 parts of nylon 6 chip powder;

[0009] The chain extender is an epoxy chain extender YMX-20 containing glycidyl methacrylate GMA;

[0010] The binary compound system antioxidant is: hindered phenol antioxidant 1010 and amine antioxidant DNP, which are compounded in a ratio of 1:1.

[0011] Furthermore, the nylon 6 waste silk material is obtained by washing, removing impurities, drying and crushing the nylon 6 waste silk, and the nylon 6 waste silk is one of glossy, semi-gloss and matte.

[0012] Furthermore, the nylon 6 slice powder is the powder generated by the friction of slices in the slice conveying pipeline during the nylon 6 preparation process.

[0013] In a second aspect, a method for preparing a regenerated nylon 6 slice comprises the following steps: subjecting the above components to quantitative feeding, melt plasticization, screw shearing, water-cooled pelletizing, vibration screening and vacuum drying in sequence to obtain the regenerated nylon 6 slice.

[0014] Furthermore, the quantitative feeding step is carried out by coupling the main feeding position and the side feeding position: nylon 6 waste silk is added through the main feeding position, and the composite antioxidant, chain extender and nylon 6 chip powder are added through the side feeding position.

[0015] Furthermore, in the melt plasticization step, the melting temperature of each temperature zone is 250-280° C., and the main engine speed is 70-80 r / min.

[0016] Furthermore, in the water-cooling pelletizing step, the pelletizer speed is 380-400 r / min.

[0017] The present invention has the following advantages:

[0018] 1. The nylon 6 slices prepared by the regenerated slices prepared by the present invention have a relative viscosity of 2.50-2.70, an oxidation induction time OIT of 13.7 min, and good spinnability.

[0019] 2. The present invention adopts hindered phenol antioxidant 1010 and amine antioxidant DNP to form a binary composite stabilizing system, which can ensure that the antioxidant of nylon 6 waste silk material is durable and effective during the re-melting and plasticizing process, thereby achieving a good antioxidant effect.

[0020] 3. The present invention adopts the linkage feeding mode of the main feeding position and the side feeding position. After the antioxidant and the slice powder are fully mixed, they are added and mixed from the fourth heating zone of the twin-screw extruder, thereby solving the problem of the difficulty in uniformly mixing the chain extender, antioxidant powder and nylon 6 waste silk material in the prior art equipment. DETAILED DESCRIPTION

[0021] The embodiment of the present application provides a recycled nylon 6 slice and a preparation method thereof.

[0022] The technical solution in the embodiment of the present application has the following general idea:

[0023] Embodiment 1:

[0024] A regenerated nylon 6 chip and a preparation method thereof, wherein the regenerated nylon 6 chip comprises the following components in weight percentage: 90 parts of nylon 6 waste silk material, 0.5 parts of YMX-20 chain extender, 0.2 parts of binary compound system antioxidant (0.1 parts of hindered phenol antioxidant 1010 and 0.1 parts of amine antioxidant DNP) and 9.3 parts of nylon 6 chip powder.

[0025] The preparation method specifically comprises the following steps:

[0026] Step 1: Add 90 parts of nylon 6 waste silk into the main feeding position of the parallel co-rotating twin-screw extruder granulator, and add 0.5 parts of YMX-20 chain extender, 0.2 parts of binary compound system antioxidant (0.1 parts of hindered phenol antioxidant 1010 and 0.1 parts of amine antioxidant DNP) and 9.3 parts of nylon 6 chip powder into the side feeding position of the parallel co-rotating twin-screw extruder granulator.

[0027] Step 2: After melt plasticization, screw shearing, water-cooled pelletizing, vibration screening and vacuum drying, recycled nylon 6 slices, i.e., sample 1, are obtained.

[0028] In the melting and plasticizing step, the temperature of each temperature zone is controlled as follows: 255°C for the first section, 260°C for the second section, 260°C for the third section, 260°C for the fourth section, 260°C for the fifth section, 260°C for the sixth section, 270°C for the seventh, eighth and ninth sections, 265°C for the die head, and 70r / min for the main engine. In the water-cooling pelletizing step, the pelletizer speed is 380r / min.

[0029] Embodiment 2:

[0030] A regenerated nylon 6 chip and a preparation method thereof, wherein the regenerated nylon 6 chip comprises the following components in weight percentage: 90 parts of nylon 6 waste silk material, 0.75 parts of YMX-20 chain extender, 0.3 parts of binary compound system antioxidant (0.15 parts of hindered phenol antioxidant 1010 and 0.15 parts of amine antioxidant DNP) and 9.3 parts of nylon 6 chip powder.

[0031] The preparation method specifically comprises the following steps:

[0032] Step 1: Add 90 parts of nylon 6 waste silk into the main feeding position of the parallel co-rotating twin-screw extruder granulator, and add 0.75 parts of YMX-20 chain extender, 0.3 parts of binary compound system antioxidant (0.15 parts of hindered phenol antioxidant 1010 and 0.15 parts of amine antioxidant DNP) and 8.95 parts of nylon 6 chip powder into the side feeding position of the parallel co-rotating twin-screw extruder granulator.

[0033] Step 2: After melt plasticization, screw shearing, water-cooled pelletizing, vibration screening and vacuum drying, recycled nylon 6 slices, i.e., sample 2, are obtained.

[0034] In the melting and plasticizing step, the temperature of each temperature zone is controlled as follows: 260°C for the first section, 265°C for the second section, 265°C for the third section, 265°C for the fourth section, 265°C for the fifth section, 265°C for the sixth section, 275°C for the seventh section, the eighth section and the ninth section; 270°C for the die head; and 75r / min for the main engine speed. In the water-cooling pelletizing step, the pelletizer speed is 385r / min.

[0035] Embodiment 3:

[0036] A regenerated nylon 6 chip and a preparation method thereof, wherein the regenerated nylon 6 chip comprises the following components in weight percentage: 90 parts of nylon 6 waste silk material, 1 part of YMX-20 chain extender, 0.4 parts of binary compound system antioxidant (0.2 parts of hindered phenol antioxidant 1010 and 0.2 parts of amine antioxidant DNP) and 9.3 parts of nylon 6 chip powder.

[0037] The preparation method specifically comprises the following steps:

[0038] Step 1: Add 90 parts of nylon 6 waste silk into the main feeding position of the parallel co-rotating twin-screw extruder granulator, and add 1 part of YMX-20 chain extender, 0.4 parts of binary compound system antioxidant (0.2 parts of hindered phenol antioxidant 1010 and 0.2 parts of amine antioxidant DNP) and 8.6 parts of nylon 6 chip powder into the side feeding position of the parallel co-rotating twin-screw extruder granulator.

[0039] Step 2: After melt plasticization, screw shearing, water-cooled pelletizing, vibration screening and vacuum drying, recycled nylon 6 slices, i.e., sample 3, are obtained.

[0040] In the melting and plasticizing step, the temperature of each temperature zone is controlled as follows: 265°C for the first section, 270°C for the second section, 270°C for the third section, 270°C for the fourth section, 270°C for the fifth section, 270°C for the sixth section, 280°C for the seventh, eighth and ninth sections, 275°C for the die head, and 80r / min for the main engine. In the water-cooling pelletizing step, the pelletizer speed is 400r / min.

[0041] Comparative Example:

[0042] A method for preparing a regenerated nylon 6 slice comprises the following steps:

[0043] Step 1: Add 100 parts of nylon 6 waste yarn into the main feeding position of the parallel co-rotating twin-screw extruder granulator.

[0044] Step 2: After melt plasticization, screw shearing, water-cooled pelletizing, vibration screening and vacuum drying, recycled nylon 6 chips, namely comparison sample 1, are obtained.

[0045] The temperature of each section is controlled as follows: the first section is 255℃; the second section is 260℃; the third section is 260℃; the fourth section is 260℃; the fifth section is 260℃; the sixth section is 260℃; the seventh section, the eighth section and the ninth section are 270℃; the die head is 265℃. The main machine speed is 70r / min, and the pelletizer speed is 380r / min.

[0046] The antioxidant content, relative viscosity, water content, terminal amino group content, terminal carboxyl group content, spinnability and component life cycle of the regenerated nylon 6 slices obtained in the above-mentioned Examples 1-3 and the regenerated nylon 6 slices obtained in the comparative example were tested. The results are shown in Table 1 below.

[0047] Table 1 Performance of samples 1-3 and comparative sample 1

[0048] performance Sample 1 Sample 2 Sample 3 Comparative sample 1 Antioxidant content (%) 0.2 0.3 0.4 0 Relative viscosity 2.52 2.68 2.69 2.40 Moisture content (ppm) 810 800 805 808 Terminal amino content 46 47 46 42 Terminal carboxyl content 68 66 66 80 Spinnability better better better Poor Component life cycle (days) 15 18 18 11

[0049] From the above "Table 1 Performance Table of Samples 1-3 and Comparative Sample 1", it can be seen that after adding the chain extender YMX-20 and the binary compound system antioxidant, the relative viscosity of the recycled nylon 6 chips increased, the terminal carboxyl content decreased, and the terminal amino content increased, indicating that the chain extender YMX-20 can effectively increase the viscosity of the recycled chips, thereby increasing the molecular weight. The binary compound system antioxidant can effectively inhibit the decrease in viscosity and molecular weight of polyamide 6 under high temperature conditions and the formation of terminal carboxyl groups. By comparing the products of sample 1, sample 2 and sample 3, it can be found that when the chain extender content is greater than 0.75 and the antioxidant content is greater than 0.3%, the viscosity and the effect of inhibiting the thermal oxidation of polyamide 6 do not change much, and gelation may occur during the chain extension reaction. Therefore, based on cost and preparation process considerations, to prevent crosslinking during reaction extrusion, it is recommended that the chain extender content be 0.75% and the antioxidant content be 0.3%.

[0050] Although the specific implementation modes of the present invention are described above, those skilled in the art should understand that the specific implementation modes described are only illustrative and are not intended to limit the scope of the present invention. Equivalent modifications and changes made by those skilled in the art in accordance with the spirit of the present invention should be included in the scope of protection of the claims of the present invention.

Claims

1. A regenerated nylon 6 slice, characterized in that: The invention comprises the following components in weight percentage: 90 parts of nylon 6 waste silk material, 0.5-1 parts of chain extender, 0.1-0.4 parts of binary compound system antioxidant, and 8.6-9.4 parts of nylon 6 chip powder; The chain extender is an epoxy chain extender YMX-20 containing glycidyl methacrylate GMA; The binary compound system antioxidant is: hindered phenol antioxidant 1010 and amine antioxidant DNP, which are compounded in a ratio of 1:

1.

2. The regenerated nylon 6 slice according to claim 1, characterized in that: The nylon 6 waste silk material is obtained by washing, removing impurities, drying and crushing the nylon 6 waste silk, and the nylon 6 waste silk is one of glossy, semi-gloss and matte.

3. The regenerated nylon 6 slice according to claim 1, characterized in that: The nylon 6 slice powder is the powder produced by the friction of slices in the slice conveying pipeline during the nylon 6 preparation process.

4. A method for preparing a regenerated nylon 6 slice, characterized in that: The following steps are involved: The components in claim 1 are sequentially subjected to quantitative feeding, melt plasticization, screw shearing, water-cooled pelletizing, vibration screening and vacuum drying to obtain the regenerated nylon 6 chips.

5. The method for preparing a regenerated nylon 6 slice according to claim 4, characterized in that: The quantitative feeding step is carried out by a linkage feeding method of a main feeding position and a side feeding position: nylon 6 waste silk material is added through the main feeding position, and a composite antioxidant, a chain extender and nylon 6 chip powder are added through the side feeding position.

6. The method for preparing a regenerated nylon 6 slice according to claim 4, characterized in that: In the melting and plasticizing step, the melting temperature of each temperature zone is 250-280° C., and the main engine speed is 70-80 r / min.

7. The method for preparing a regenerated nylon 6 slice according to claim 4, characterized in that: In the water-cooling pelletizing step, the pelletizer speed is 380-400 r / min.