Preparation method of polypropylene fiber woven fabric lightweight helmet

Abstract

The invention relates to the technical field of helmets, in particular to a polypropylene fiber woven fabric lightweight helmet preparation method which comprises the following steps: S1, mixing modified polypropylene and auxiliaries, extruding through a screw, preparing 1000D yarns, winding the yarns, and shaping; s2, placing the shaped yarn in an environment of-15 DEG C for quenching for 16 hours, and cooling to normal temperature; s3, annealing the quenched yarns at 80-100 DEG C, preserving heat for 2 hours, and naturally cooling for 5-6 hours to normal temperature; s4, weaving the yarns into twill of which the gram weight is 115-125g / m < 2 > and the area is 80-120cm < 2 > by adopting an arrow shaft machine; and S5, the multiple layers of twill cloth are coated with polyurethane glue layer by layer, the twill cloth is attached to the helmet bottom shell mold, and demolding is conducted after drying. The method has the beneficial effects that the tensile strength of the polypropylene material is obviously improved and the weight of the helmet is reduced by optimizing the yarn modification, quenching and locking molecular chains, annealing and rearranging and multi-layer gluing processes.

Description

Technical Field

[0001] The present invention relates to the technical field of helmets, and particularly relates to a preparation method for a lightweight helmet made of polypropylene woven fabric. Background Art

[0002] With the continuous development of materials science, various high-performance lightweight materials such as carbon fiber, glass fiber, Kevlar fiber, etc. have emerged. These materials have the characteristics of high strength, high toughness, and low density, providing a material basis for manufacturing lightweight helmets. At the same time, the continuous improvement of manufacturing processes, such as advanced injection molding technology, one-piece molding technology, etc., enables helmets to achieve a thinner and more uniform design while ensuring structural strength and safety, further reducing the weight of the helmets. In modern society, people's demands for activities such as cycling and motorcycle driving are increasing day by day, and at the same time, the requirements for the comfort and performance of related equipment are also getting higher and higher. Traditional helmets are heavier, and long-term wearing is likely to cause neck fatigue and discomfort, affecting the cycling or driving experience. Therefore, the demand for lightweight helmets by users has gradually emerged, hoping to enjoy a more comfortable and convenient wearing experience while ensuring safety.

[0003] In the prior art, the weight of helmets is usually heavy, long-term wearing is likely to cause neck fatigue and discomfort, and the tensile strength of helmets is poor, affecting the applicability of helmets. Summary of the Invention

[0004] In view of the deficiencies of the prior art, the present application proposes a preparation method for a lightweight helmet made of polypropylene woven fabric, which significantly improves the tensile strength of polypropylene materials and reduces the weight of the helmet by optimizing yarn modification, rapid cooling to lock molecular chains, annealing and rearrangement, and multi-layer coating processes.

[0005] The following is the technical solution of the present invention. A preparation method for a lightweight helmet made of polypropylene woven fabric includes the following steps:

[0006] S1. Mix modified polypropylene and additives, and then extrude through a screw to prepare 1000D yarn. After winding the yarn, shape it.

[0007] S2. Place the shaped yarn in an environment of -15°C and rapidly cool it for 16 hours, then cool it to room temperature.

[0008] S3. Anneal the rapidly cooled yarn at 80 - 100°C, keep it warm for 2 hours, and naturally cool it for 5 - 6 hours to room temperature.

[0009] S4. Use a rapier loom to weave the yarn into twill fabric with a gram weight of 115 - 125 g / m 2 , and an area of 80 - 120 cm 2 ;

[0010] S5. Apply polyurethane glue layer by layer to several layers of twill fabric, bond it to the helmet bottom shell mold, and demold after drying.

[0011] As a preferred solution of the present invention, in S1, the modified polypropylene and additives include polypropylene substrate, maleic anhydride grafted polypropylene and antioxidant 1010.

[0012] As a preferred solution of the present invention, the mass percentages of polypropylene substrate, maleic anhydride grafted polypropylene and antioxidant 1010 are:

[0013] Polypropylene substrate, 93 - 97wt%;

[0014] Maleic anhydride grafted polypropylene, 3 - 5wt%;

[0015] Antioxidant 1010, 0.5 - 1wt%.

[0016] As a preferred solution of the present invention, in S1, during spinning, the draw ratio is controlled to be 4.5 - 5.0 times, the yarn breaking elongation is 13%, and the error of breaking elongation ≤ ±0.5%.

[0017] As a preferred solution of the present invention, in S3, the heating rate ≤ 5°C / min.

[0018] As a preferred solution of the present invention, in S3, a constant tension of 8 - 10N is applied to the yarn during annealing.

[0019] As a preferred solution of the present invention, in S4, a 2 / 2 twill weave is adopted, the warp density is 58 - 62 threads / cm, and the weft density is 32 - 35 threads / cm.

[0020] As a preferred solution of the present invention, in S4, the rapier loom weft insertion speed ≥ 450m / min.

[0021] As a preferred solution of the present invention, in S5, the polyurethane glue is a two-component polyurethane glue;

[0022] Among them, the first component is an isocyanate prepolymer, and the second component is a polyether polyol with a hydroxyl value of 110 - 130mgKOH / g.

[0023] As a preferred solution of the present invention, the mass ratio of the first component to the second component is 1:1.24.

[0024] The beneficial effects of the present invention are: By optimizing the yarn modification, rapid cooling to lock the molecular chain, annealing rearrangement and multi-layer coating process, the tensile strength of the polypropylene material is significantly improved and the weight of the helmet is reduced. Brief Description of the Drawings

[0025] Figure 1 It is a schematic diagram of the preparation method of the present invention. Detailed Description of the Invention

[0026] To make the technical problems solved by the present invention, the technical solutions adopted, and the achieved technical effects clearer, the technical solutions of the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative efforts fall within the protection scope of the present invention.

[0027] Embodiment 1:

[0028] As Figure 1 shown, a method for preparing a lightweight polypropylene woven helmet includes the following steps:

[0029] S1. Prepare yarn: Prepare 1000D yarn, and wind and shape the yarn after winding.

[0030] Mix modified polypropylene and additives and extrude them through a screw extruder to prepare 1000D yarn.

[0031] The modified polypropylene and additives are 93 - 97wt% polypropylene substrate, 3 - 5wt% maleic anhydride grafted polypropylene, and 0.5 - 1wt% antioxidant 1010, and are melt - blended at 190 - 220°C through a twin - screw extruder.

[0032] During spinning, the draw ratio is controlled to be 4.5 - 5.0 times to ensure that the breaking strength of the 1000D yarn ≥ 5.5 cN / dtex, the yarn breaking elongation is 13%, and the error of the breaking elongation ≤ ±0.5%.

[0033] Wind and shape the yarn after winding.

[0034] S2. Quenching treatment: Place the shaped yarn in an environment of - 15°C and quench it for 16 hours, then cool it to room temperature to lock the molecular chain structure.

[0035] S3. Annealing treatment: Anneal the quenched yarn at 80 - 100°C, with a heating rate ≤ 5°C / min, hold for 2 hours, and naturally cool for 5 - 6 hours to room temperature.

[0036] Apply a constant tension of 8 - 10 N to the yarn during the annealing process to promote the linear arrangement of molecular chains.

[0037] S4. Weaving and forming: Use a rapier loom to weave the yarn into twill fabric with a grammage of 115 - 125 g / m 2 and an area of 80 - 120 cm 2 .

[0038] Adopt a 2 / 2 twill weave, with a warp density of 58 - 62 ends / cm and a weft density of 32 - 35 picks / cm.

[0039] The weft insertion speed of the arrow rod machine is ≥ 450 m / min, and the shedding time is set to 300° - 310°, reducing yarn wear;

[0040] S5. Sizing and shaping: Coat the 6 - layer twill fabric with polyurethane glue layer by layer, fit it to the helmet bottom shell mold, and demold after drying;

[0041] The glue used is two - component polyurethane glue. Among them, the first component is isocyanate prepolymer, and the second component is polyether polyol with a hydroxyl value of 110 - 130 mgKOH / g. The mass ratio of the first component to the second component is 1:1.24;

[0042] The glue coating amount per layer is 25 ± 2 g / m 2 , the roller coating speed is 8 - 10 m / min, and the thickness of the cured glue layer is 30 - 40 μm.

[0043] Example Two

[0044] This example provides a method for preparing a lightweight helmet made of polypropylene woven fabric. Different from Example One, in step S4, the yarn is woven into twill fabric with a gram weight of 120 g / m 2 of twill fabric.

[0045] Example Three

[0046] This example provides a method for preparing a lightweight helmet made of polypropylene woven fabric. Different from Example One, in step S4, the yarn is woven into twill fabric with a gram weight of 115 g / m 2 of twill fabric.

[0047] Example Four

[0048] This example provides a method for preparing a lightweight helmet made of polypropylene woven fabric. Different from Example One, in step S4, the yarn is woven into twill fabric with a gram weight of 125 g / m 2 of twill fabric.

[0049] Perform performance tests on the helmets of Example Two to Example Four. The test items include puncture resistance strength, high - temperature deformation resistance at 60 °C, and low - temperature toughness at - 30 °C. The performance test results are shown in the following table.

[0050] Table 1 Performance test result table.

[0051]

[0052] The present invention significantly improves the tensile strength of the polypropylene material and reduces the weight of the helmet by optimizing yarn modification, rapid cooling to lock molecular chains, annealing and rearrangement, and multi - layer glue coating process.

[0053] Although the preferred embodiments of the present invention have been described, additional changes and modifications can be made to these embodiments by those skilled in the art once they learn of the basic inventive concept. Obviously, those skilled in the art can make various changes and variations to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the equivalent technology of the present invention, the present invention also intends to include these modifications and variations.

Claims

1. A method for preparing a lightweight helmet made of polypropylene woven fabric, characterized in that, It includes the following steps: S1. Mix the modified polypropylene and additives, then extrude them through a screw to prepare 1000D yarn, wind up the yarn and set its shape; S2. Place the shaped yarn in an environment of -15°C and rapidly cool it for 16 hours, then cool it to room temperature; S3. Anneal the rapidly cooled yarn at 80 - 100°C, keep it warm for 2 hours, and naturally cool it for 5 - 6 hours to room temperature; S4. Use a rapier loom to weave the yarn into twill fabric with a grammage of 115 - 125 g / m 2 , an area of 80 - 120 cm 2 ; S5. Coat polyurethane glue layer by layer on several layers of twill fabric, bond it to the helmet bottom shell mold, and demold it after drying.

2. The preparation method of a lightweight helmet made of polypropylene woven fabric according to claim 1, characterized in that, In S1, the modified polypropylene and additives include polypropylene substrate, maleic anhydride grafted polypropylene and antioxidant 1010.

3. A method for preparing a lightweight helmet made of polypropylene woven fabric according to claim 2, characterized in that, The mass percentages of the polypropylene substrate, maleic anhydride grafted polypropylene and antioxidant 1010 are: Polypropylene substrate, 93 - 97wt%; Maleic anhydride grafted polypropylene, 3 - 5wt%; Antioxidant 1010, 0.5 - 1wt%.

4. A method for preparing a lightweight helmet made of polypropylene woven fabric according to claim 1, characterized in that, In S1, during spinning, the draw ratio is controlled to be 4.5 - 5.0 times, the yarn breaking elongation is 13%, and the error of the breaking elongation ≤ ±0.5%.

5. A method for preparing a lightweight helmet made of polypropylene woven fabric according to claim 1, characterized in that, In S3, the heating rate ≤ 5°C / min.

6. The preparation method of a lightweight helmet made of polypropylene woven fabric according to claim 1, characterized in that, In S3, apply a constant tension of 8 - 10N to the yarn during the annealing process.

7. A method for preparing a lightweight helmet made of polypropylene woven fabric according to claim 1, characterized in that, In S4, adopt 2 / 2 twill weave, the warp density is 58 - 62 threads / cm, and the weft density is 32 - 35 threads / cm.

8. A method for preparing a lightweight helmet made of polypropylene woven fabric according to claim 1, characterized in that, In S4, the rapier loom weft insertion speed ≥ 450m / min.

9. The method for preparing a lightweight helmet made of polypropylene woven fabric according to claim 1, characterized in that, In S5, the polyurethane glue is two-component polyurethane glue; Among them, the first component is isocyanate prepolymer, the second component is polyether polyol, and the hydroxyl value is 110 - 130mgKOH / g.

10. A method for preparing a lightweight helmet made of polypropylene woven fabric according to claim 9, characterized in that, The mass ratio of the first component to the second component is 1:1.24.

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