Method for preparing biodegradable fiber compound having improved strength and processability

Abstract

The present invention relates to a method for preparing a biodegradable fiber compound, and a biodegradable fiber compound prepared using same, the method comprising the steps of: pulverizing polypropylene and / or thermoplastic starch so that same have microparticle unit diameters; and injecting, into a feed, a mixture of the pulverized polypropylene and thermoplastic starch and extruding the mixture through a twin screw extruder that has a vacuum pump provided at a discharge part thereof. According to the present invention, the method for preparing a biodegradable fiber compound, of the present invention, enables a biodegradable fiber in which both processability such as flowability (MFI), fineness (de), fiber draw ratio (%) and yield (%), and fiber strength (g / de) are improved to be obtained.

Description

Method for producing a biodegradable fiber compound with improved strength and processability

[0001] The present invention relates to a method for producing a biodegradable fiber compound having improved strength and processability.

[0002] The textile industry has been facing persistent issues with non-biodegradable textile waste, particularly due to fast fashion. Beyond disposables, the waste generated by discarded clothing is a serious problem in Asia and Africa. To address this, biodegradable synthetic resin technologies utilizing PLA, PBS, and PCL are being developed. Recently, a fiber compound technology utilizing blends of thermoplastic starch (TPS) and PP or PET synthetic resins is being developed.

[0003] However, when the TPS blend compound is spun into fibers, it is very difficult to process into fibers due to poor dispersibility and physical bonding strength caused by differences in the interfacial properties of the hydrophilic TPS and the hydrophobic PP and PET, and its strength is also significantly lower than that of the existing PP and PET.

[0004] To solve such difficulties, the present invention provides a method for manufacturing a biodegradable fiber compound that simultaneously improves strength and processability in a TPS and PP blend.

[0005] The present invention provides a method for producing a biodegradable fiber compound that simultaneously improves strength and processability.

[0006] The above and other objects and advantages of the present invention will become apparent from the following description of preferred embodiments.

[0007] The present invention comprises the steps of: grinding polypropylene and thermoplastic starch to have a diameter of microparticles; and

[0008] A method for producing a biodegradable fiber compound is provided, comprising the step of feeding a mixture of pulverized polypropylene and thermoplastic starch into a feed and extruding the mixture through a twin-screw extruder having a vacuum pump installed at a discharge portion.

[0009] In addition, the present invention provides a biodegradable fiber compound manufactured according to the method for manufacturing the biodegradable fiber compound.

[0010] According to the method for manufacturing a biodegradable fiber compound of the present invention, a biodegradable fiber can be obtained that simultaneously improves processability such as flowability (MFI), fineness (de), fiber elongation ratio (%), and yield (%), and fiber strength (g / de).

[0011] However, the effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the description below.

[0012] Figure 1 is a process diagram of a method for manufacturing a biodegradable fiber compound according to one embodiment of the present invention.

[0013] Hereinafter, the present invention will be described in detail.

[0014]

[0015] The method for manufacturing a biodegradable fiber compound of the present invention comprises the steps of: crushing polypropylene and thermoplastic starch to have a diameter of microparticles; and feeding the mixture of crushed polypropylene and thermoplastic starch into a feed and extruding it through a twin-screw extruder having a vacuum pump installed at a discharge portion.

[0016] The present invention can improve fiber strength by installing a vacuum pump at the discharge portion of a twin-screw extruder in the extrusion step and applying the vacuum pump to remove gas generated from thermoplastic starch.

[0017] In one embodiment of the present invention, the pressure of the vacuum pump may be 0.30 to 0.90 Mpa, preferably 0.60 to 0.90 Mpa.

[0018] The present invention improves fiber processability by pulverizing polypropylene, thermoplastic starch, or both into microparticles to improve dispersibility.

[0019] In one embodiment of the present invention, one or both of the polypropylene and the thermoplastic starch may have a diameter of 10 to 70 μm.

[0020] Preferably, the polypropylene is 10 to 50 μm and the thermoplastic starch is 30 to 70 μm.

[0021] The above polypropylene may have a melting flow index (MFI) of 20 to 70 g / 10 min under conditions of 190°C and 2.1 kg.

[0022] In one embodiment of the present invention, the polypropylene may be a mixture of a polypropylene having a melting flow index (MFI) of 20 to 40 g / 10 min under conditions of 190°C and 2.1 kg and a polypropylene having a melting flow index (MFI) of 50 to 70 g / 10 min under conditions of 190°C and 2.1 kg.

[0023] The above polypropylene may be included in an amount of 70 wt% to 90 wt% based on the total weight of the mixture.

[0024] The thermoplastic starch may be included in an amount of 10 wt% to 30 wt% based on the total weight of the composition.

[0025] In the present invention, the starch may be modified starch in which amylopectin starch is converted into amylose starch through chemical treatment.

[0026] According to one embodiment of the present invention, the amylopectin starch and amylose starch can form esterified starch by bonding an ester functional group to a terminal group.

[0027] Esterified starch can impart heat resistance to starch and durability to compounds.

[0028] In one embodiment of the present invention, the starch may be a plasticized thermoplastic starch.

[0029] In one embodiment of the present invention, the mixture may further comprise polypropylene grafted with maleic anhydride (PP-MAH Graftmer).

[0030] Preferably, the PP-MAH grafter is included in an amount of 1.0 wt% to 3.0 wt% based on the total weight of the mixture, thereby simultaneously improving the processability (flowability) and strength of the fiber.

[0031] In one embodiment of the present invention, the mixture may further include epoxidized soybean oil (ESO) as a plasticizer.

[0032] Preferably, the epoxidized soybean oil (ESO) is included in an amount of 1.0 wt% to 2.0 wt% based on the total weight of the composition, thereby improving the processability of the fiber by improving the single-filament phenomenon.

[0033] Epoxidized soybean oil is an environmentally friendly, non-toxic plasticizer that can be used as a replacement for conventional plasticizers, particularly polyvinyl chloride (PVC). Using epoxidized soybean oil as an additive can effectively remove unwanted acids, such as hydrochloric acid, that are present in or contribute to the deterioration of materials such as films.

[0034] In addition, the present invention provides a biodegradable fiber compound manufactured according to the method for manufacturing the biodegradable fiber compound.

[0035] Hereinafter, the composition and resulting effects of the present invention will be described in more detail through specific examples and comparative examples. However, these examples are intended to more specifically illustrate the present invention, and the scope of the present invention is not limited to these examples.

[0036]

[0037] [ingredient]

[0038] Polypropylene having a melting flow index (MFI) of 34 g / 10 min under conditions of 190°C and 2.1 kg and polypropylene having a melting flow index (MFI) of 60 g / 10 min under conditions of 190°C and 2.1 kg were used.

[0039] The starch powder used was potato starch (commercially available from Youngheung Foods, OTTO Potato). Thermoplastic starch (TPS) was prepared by mixing potato starch with glycerol, a plasticizer. The glycerol content ranged from 20 to 35 wt.%, and the TPS was produced using a twin-screw extruder.

[0040]

[0041] <Examples 1 to 13>

[0042] The raw materials of Examples 1 to 13 were each fed to a feed to have a composition as shown in Table 1 below, and extruded to produce a pellet-shaped compound. At this time, a twin-screw extruder with a screw diameter of 44 mm was used as the extruder, and the extrusion speed was 300 rpm, the raw material feeding speed was 40 rpm, the barrel temperature was 150°C, the die nozzle diameter was 3.5 mm, the heat exchange method was countercurrent, and the cooling water temperature was 20°C.

[0043]

[0044] <Comparative Examples 1 to 4>

[0045] A compound was prepared in the same manner as Example 1, except that the raw materials of Comparative Examples 1 to 4 were used to have a composition as shown in Table 1 below and a vacuum pump was not applied.

[0046]

[0047] Composition (weight%) Process conditions Ingredients PP (MFI 34) PP (MFI 60) TPS (MFI 5) PP-MAH Graftmer ESO Vacuum pump (Mpa) Average pellet diameter (㎛) 3500 30 3500 30 3200 50--Not applied Comparative example 1 10000000--Not applied Comparative example 2 80000 200--Not applied Comparative example 3--100000--Not applied Comparative example 4--800 200--Not applied Example 1 800--020-0.0 Not applied Example 2 080--200-0.0 Not applied Example 3 080--020-0.0 Not applied Example 4 800--2 00-1.0 Not Applied Example 5800--200-2.0 Not Applied Example 6080--020-2.0 Not Applied Example 7800--200-00.30 Example 8800--200-00.85 Example 9080--020-2.00.85 Example 10080--020-2.00.85 Example 11080--020-2.00.85 Example 12--800200-2.00.85 Example 13--080020-2.00.85

[0048]

[0049] Fibers were manufactured using the pellet-shaped compounds manufactured in the above examples and comparative examples. Specifically, the pellet compound was melted to produce a melt, and the melt was spun at a temperature of 250 to 310°C at a speed of 500 to 1,500 m / min to produce filaments. The spun filaments were then cooled, and the cooled filaments were drawn at a draw ratio of 1.0 to 1.5 to produce biodegradable fibers.

[0050] The processability of the manufactured biodegradable fibers, including flowability (MFI), fineness (de), fiber elongation ratio (%), and yield (%), and fiber strength (g / de), were evaluated, and the results are shown in Table 2 below.

[0051]

[0052] ProcessabilityFiber Strength(g / de)Flowability(MFI)Fineness(de)Fiber Elongation Ratio(%)Yield(%)Comparative Example 134.21.8350(maximum)≥974.1Comparative Example 211.8399.49130.71Comparative Example 359.82.0350(maximum)≥973.5Comparative Example 437.8294.264130.88Example 112.4271.410850.64Example 212.8274.311180.61Example 313.174.8187530.93Example 417.8198. 4244611.21Embodiment 521.4144.7287781.45Embodiment 623.041.2321861.57Embodiment 713.2381.0101511.96Embodiment 811.9378.1107492.53Embodiment 919.638.4312852.51Embodiment 1013.276.3288712.78Embodiment 1110.891.5267632.94Embodiment 1224.521.7311812.87Embodiment 1328.19.4347943.01

[0053]

[0054] Comparing the evaluation results of Comparative Examples 1 and 3 and Comparative Examples 2 and 4, it can be seen that the compound blended with PP and TPS that was not pulverized into microparticles has a significantly reduced melting flow index (MFI), fiber draw ratio, yield, and fiber strength.

[0055] By comparing the evaluation results of Comparative Example 2 and Examples 1 to 3, 6, and 9, it can be seen that processability can be improved by crushing PP, TPS, or both into microparticles.

[0056] By comparing the evaluation results of Comparative Example 2 and Examples 4 to 6, it can be seen that processability can be improved by adding ESO as in Examples 4 to 6, and that there is an effect of dramatically increasing the fineness, elongation ratio, and yield.

[0057] By comparing the evaluation results of Example 3, Example 10, and Example 11, it can be seen that the fiber strength can be improved by adding PP-MAH Graftmer as in Example 10 and Example 11.

[0058] By comparing the evaluation results of Comparative Example 2 and Examples 7 to 9, it can be seen that the fiber strength can be improved by applying a vacuum process as in Examples 7 to 9.

[0059] Comparing the evaluation results of Examples 11, 12, and 13, it can be seen that when PP MAH Graftmer is added, flowability is reduced and yield is lowered, but processability can be improved by applying PP (MFI 60) as in Examples 12 and 13.

Claims

1. A step of grinding polypropylene, thermoplastic starch or both into microparticles having a diameter of unit size; and A method for producing a biodegradable fiber compound, comprising the step of feeding a mixture of pulverized polypropylene and thermoplastic starch into a feed and extruding the mixture through a twin-screw extruder having a vacuum pump installed at a discharge portion.

2. In paragraph 1, A method for manufacturing a biodegradable fiber compound, wherein the pressure of the vacuum pump is 0.30 to 0.90 MPa.

3. In paragraph 1, A method for producing a biodegradable fiber compound, wherein the polypropylene and thermoplastic starch have a diameter of 10 to 70 μm.

4. In paragraph 1, A method for producing a biodegradable fiber compound, wherein the polypropylene has a melting flow index (MFI) of 20 to 70 g / 10 min under conditions of 190°C and 2.1 kg.

5. In paragraph 1, The above polypropylene has a melting flow index (MFI) of 20 to 40 g / 10 min under the conditions of 190°C and 2.1 kg, A method for producing a biodegradable fiber compound, the method comprising mixing a mixture of materials having a melting flow index (MFI) of 50 to 70 g / 10 min under conditions of 190°C and 2.1 kg.

6. In paragraph 1, A method for producing a biodegradable fiber compound, wherein the polypropylene is contained in an amount of 70 wt% to 90 wt% based on the total weight of the mixture.

7. In paragraph 1, A method for producing a biodegradable fiber compound, wherein the thermoplastic starch is included in an amount of 10 wt% to 30 wt% based on the total weight of the mixture.

8. In paragraph 1, A method for producing a biodegradable fiber compound, wherein the mixture further comprises polypropylene grafted with maleic anhydride (PP-MAH Graftmer).

9. In paragraph 8, A method for producing a biodegradable fiber compound, wherein the polypropylene grafted with the above maleic anhydride (PP-MAH Graftmer) is included in an amount of 1.0 wt% to 3.0 wt% based on the total weight of the composition.

10. In paragraph 1, A method for producing a biodegradable fiber compound, wherein the mixture further comprises epoxidized soybean oil.

11. In paragraph 10, A method for producing a biodegradable fiber compound, wherein the epoxidized soybean oil is contained in an amount of 1.0 wt% to 2.0 wt% based on the total weight of the composition.

12. A biodegradable fiber compound manufactured according to any one of the manufacturing methods of clauses 1 to 11.

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