High-transparency, high-strength and high-rigidity flat filament and manufacturing method thereof
The preparation of high-transparent, high-strength, high-rigid flat wire through special formulas and processes has solved the problem of insufficient performance of polypropylene flat wire in the prior art, and achieved the effects of high transparency, high-strength and high-rigidity. It is suitable for plastic-woven packaging field, reducing production costs and environmental pollution.
Patent Information
- Application Number
- CN202510228134.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-27
- Publication Date
- 2025-04-25
AI Technical Summary
The prior art is difficult to manufacture polypropylene flat wires that are both highly transparent, high-strength and high-rigid, and cannot meet the needs of the plastic-woven packaging industry.
Flat wires are prepared by high-speed stirring, twin screw extrusion, sink cooling, thermal drafting and winding processes using a combination of low-melt finger homopolymer polypropylene, low-melt finger copolymer polypropylene, permeability enhancer, antioxidant, lubricant, antistatic agent and rheology regulator.
High transparent, high-strength, high-rigid flat wire with light transmittance ≥85%, haze <26%, relative tensile load ≥0.56N/tex, and bending modulus of modified PP materials ≥1360MPa to meet the needs of plastic braided packaging, reduce production costs and reduce environmental pollution.
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Abstract
Description
Technical Field
[0001] The invention relates to a flat wire manufacturing technology, in particular to a high-transparency, high-strength and high-rigidity flat wire and a manufacturing method thereof, belonging to the technical field of polymer material manufacturing. Background Art
[0002] Flat filament is a chemical fiber monofilament with a flat cross section. It is also called cutting fiber in the plastic weaving industry. It is the basic material for producing plastic woven fabrics. Flat filament is made of a specific variety of polypropylene and polyethylene resin through melt extrusion into a film, and then cut into strips longitudinally. The strips are heated, stretched and oriented at the same time to shape them, and finally wound into flat yarn spindles. In my country, tens of millions of tons of flat yarn are put on the market in various forms of products every year, and the largest application area of flat yarn is in the plastic weaving industry. Plastic weaving is a traditional manufacturing industry with an output value of more than 100 billion yuan and hundreds of thousands of employees.
[0003] With the development of the industry, flat wire materials are constantly emerging. Among them, polypropylene materials occupy the largest share of flat wire materials due to their advantages such as excellent processing performance, high toughness, oil and chemical resistance, light weight and high cost performance. However, polypropylene materials also have poor heat resistance, poor rigidity, low strength, and their transparency, especially haze, increases after modification.
[0004] With the continuous improvement of packaging requirements in different application fields, especially for the traditional plastic weaving manufacturing industry, the development and industrialization of high value-added products play a leading role in the scientific and technological progress of the entire plastic weaving industry, while reducing the cost of production raw materials. Market demand has put forward higher requirements in terms of increasing transparency, improving strength and rigidity, and it is necessary to meet the above-mentioned multiple performance indicators at the same time.
[0005] At present, the industry has also made many effective attempts to modify polypropylene materials to improve stiffness, strength and heat resistance, such as adding glass fiber or adding talcum powder. However, the former has the disadvantages of poor molding and processing performance and poor surface quality of the product, and the latter has the disadvantages of increased density and weight of the modified polypropylene. In terms of improving the transparency of flat yarns, many methods use the method of coating the surface with a high-transparency layer, which also increases the thickness of the flat yarn. At the same time, the peel strength between the substrate and the composite layer and the transparency of the substrate itself have an impact on the final product. Polypropylene is a crystalline polymer, and its rigidity is mainly determined by the crystallinity of the material, while the regularity of the material affects the crystallinity. At the same time, the transparency of modified polypropylene is also related to the crystallinity. The addition of different additives seriously affects the regularity of the molecular chain after polypropylene blending, thereby affecting the crystallinity. In the process of preparing flat yarns, various parameters such as cooling temperature, stretching temperature, and drafting multiple affect the orientation of the molecular chain, which also affects the crystallinity.
[0006] Therefore, the existing methods are difficult to manufacture polypropylene flat yarns with multiple properties such as high transparency, high strength and high rigidity, and cannot be applied to the field of plastic woven packaging to meet the market demand. Therefore, the prior art urgently needs a polypropylene flat yarn with high transparency, high strength and high rigidity to meet the needs of the plastic woven packaging industry. Summary of the invention
[0007] The present invention provides a novel high-transparency, high-strength and high-rigidity flat wire and a manufacturing method thereof. Through a special formula and process, a polypropylene flat wire with high transparency, high strength and high rigidity can be obtained to solve the technical problem that various performance requirements of polypropylene flat wire in the prior art cannot be met.
[0008] The high-transparency, high-strength and high-rigidity flat yarn of the present invention comprises the following components in weight percentage: 85-95% of low-melting-index homopolymer polypropylene, 3-15% of low-melting-index copolymer polypropylene, 0.01-0.30% of anti-transmission enhancer, 0.05-0.20% of antioxidant, 0.05-0.30% of lubricant, 0.05-0.15% of organic or inorganic antistatic agent and 0.2-1% of rheology regulator; The total weight percentage of the low melt index homopolymer polypropylene and the low melt index copolymer polypropylene is 100%.
[0009] The high-transparency, high-strength and high-rigidity flat wire as described above, wherein the transmittance enhancer is a targeted nano-agent with a side group, a long or short carbon chain or an aromatic functional group; the weight percentage of the transmittance enhancer is 0.01%-0.30%.
[0010] In the high-transparency, high-strength and high-rigidity flat wire as described above, the weight percentage of the antioxidant is 0.01%-0.20%; the weight percentage of the lubricant is 0.05%-0.30%; and the weight percentage of the rheology regulator is 0.2%-1%.
[0011] In the high-transparency, high-strength and high-rigidity flat yarn as described above, the antistatic agent is an organic or inorganic antistatic agent; the weight percentage of the antistatic agent is 0.05%-0.15%.
[0012] As described above, the high-transparency, high-strength and high-rigidity flat yarn, wherein the melt index of the low-melt-index homopolymer polypropylene is 3-4 g / 10 min at 230° C. and 216 kg load.
[0013] As described above, the high-transparency, high-strength and high-rigidity flat wire, wherein the melt index of the low-melt-index copolymer polypropylene is 2.2-3 g / 10 min at 230° C. and 216 kg load.
[0014] The present invention also provides a method for manufacturing a high-transparency, high-strength and high-rigidity flat wire, comprising the following steps: The first step is to weigh low melt index homopolymer polypropylene, low melt index copolymer polypropylene, anti-transmission enhancer, antioxidant, lubricant, antistatic agent and rheology regulator according to weight ratio; The second step is to mix the raw materials prepared in the first step in a high-speed mixer for 10-20 minutes; The third step is to feed the mixed raw materials into the twin-screw extruder through the silo, and the materials stay in the screw for 1-2 minutes; In the fourth step, after the material is extruded by a twin-screw extruder, it is cooled in a water tank, and the water temperature is controlled at 23-28°C to control cooling and slow crystallization to obtain a primary membrane sheet; The fifth step is to cut the primary film into primary flat wires with a width of 3-10 mm; Step 6: The raw flat yarn is hot drawn at 160-180°C with a drawing ratio of 5.8-6.5; Step 7: heat-set the drawn flat yarn at 160-180°C; In the eighth step, the heat-set flat yarn is wound at a speed of 30-200 m / min to obtain a finished flat yarn with a width of 2-6 mm and a thickness of 15-60 μm.
[0015] The method for manufacturing high-transparency, high-strength and high-rigidity flat wire as described above, wherein, in the third step, the twin-screw extruder has four temperature zones, wherein zone one is 185-195°C, zone two is 190-210°C, zone three is 190-210°C, and zone four is 195-215°C; the rotation speed of the twin-screw extruder is 300-700 rpm.
[0016] The present invention mixes the above-mentioned various raw materials in a high-speed mixer, and then draws them into flat wires through a specially designed twin-screw extruder and its temperature control, wire drawing process parameter control and other equipment and process parameter adjustment. The flat wire prepared by this formula and process has the characteristics of high transparency, high strength and high rigidity, and obtains a light transmittance of ≥85%, a haze of <26%, a relative tensile load of ≥0.56N / tex, and a bending modulus of the modified PP material of ≥1360MPa. The plastic woven bags produced by the extruder meet the packaging requirements of multiple occasions.
[0017] The high-transparency, high-strength, high-rigidity flat wire and the manufacturing method thereof of the present invention can at least produce the following technical effects: The high-transparency, high-strength, high-rigidity flat wire formula and its preparation method provided by the present invention are used in the plastic woven packaging industry, which not only meets the needs of different packaging fields and markets for plastic flat wires with high transparency, high strength, and high rigidity and woven bags prepared therefrom, but also for the traditional plastic woven manufacturing industry, the development and industrialization of high value-added products have a leading role in the scientific and technological progress of the entire plastic woven industry, and have a good demonstration effect on industrial upgrading and intelligent manufacturing, especially the development of complete sets of process technology and key equipment, and also have a reference significance for the development of industry-related products. The launch of high-performance flat wire plastic woven packaging bags on the market can meet the packaging needs of more areas of the market, and through the optimization of the processing technology, the processing temperature can be reduced by more than 30°C, achieving energy saving and low carbon in the production process, saving costs while reducing the pollution of the industry to the environment, and having good ecological benefits. DETAILED DESCRIPTION
[0018] The high-transparency, high-strength, high-rigidity flat wire and the manufacturing method thereof described in the present invention can be made of the following materials and components, but are not limited to the following materials and components, for example: low melt index copolymer polypropylene, etc.
[0019] The high-transparency, high-strength and high-rigidity flat wire of the embodiments of the present invention are specifically described in the following embodiments: In embodiments 1 to 7, a high-transparency, high-strength and high-rigidity flat wire is prepared, and the amount of raw materials added (in weight percentage) is shown in Table 1 below.
[0020] Table 1 Example formula raw materials Example 1 (1) Weigh the raw materials according to the raw material ratio requirements of Example 1 in the above Table 1 Example Formula Raw Materials Table; (2) Mix the homopolymer polypropylene, copolymer polypropylene, permeability enhancer, antioxidant, lubricant, organic or inorganic antistatic agent, and rheology modifier weighed above in a high-speed mixer for 15 minutes; (3) The mixed raw materials are fed into a twin-screw extruder through a silo. The material stays in the screw for 1-2 minutes. The screw temperature is: 185-195°C in zone 1, 190-210°C in zone 2, 190-210°C in zone 3, and 195-215°C in zone 4. The speed of the twin-screw extruder is 300-700 rpm. (4) After the material is extruded by a twin-screw extruder, it is cooled in a water tank. The water temperature is controlled at 23-28°C to control cooling and slow crystallization to obtain a primary membrane sheet; (5) Cutting the primary membrane into primary flat wires with a width of 7 mm; (6) The raw flat yarn is hot drawn at 160-180°C with a drawing ratio of 6; (7) Heat setting the drawn flat yarn at 160-180°C; (8) The heat-set flat yarn is wound at a speed of 100 m / min to obtain a flat yarn with a width of 4 mm and a thickness of 40 μm.
[0021] Example 2 (1) Weigh the raw materials according to the raw material ratio requirements of Example 2 in the raw material table of the embodiment formula in Table 1 above; (2) Mix the homopolymer polypropylene, copolymer polypropylene, permeability enhancer, antioxidant, lubricant, organic or inorganic antistatic agent, and rheology modifier weighed above in a high-speed mixer for 15 minutes; (3) The mixed raw materials are fed into a twin-screw extruder through a silo. The material stays in the screw for 1-2 minutes. The screw temperature is: 185-195°C in zone 1, 190-210°C in zone 2, 190-210°C in zone 3, and 195-215°C in zone 4. The speed of the twin-screw extruder is 300-700 rpm. (4) After the material is extruded by a twin-screw extruder, it is cooled in a water tank. The water temperature is controlled at 23-28°C to control cooling and slow crystallization to obtain a primary membrane sheet; (5) Cutting the primary membrane into primary flat wires with a width of 7 mm; (6) The raw flat yarn is hot drawn at 160-180°C with a drawing ratio of 6; (7) Heat setting the drawn flat yarn at 160-180°C; (8) The heat-set flat yarn is wound at a speed of 100 m / min to obtain a flat yarn with a width of 4 mm and a thickness of 40 μm.
[0022] Example 3 (1) Weigh the raw materials according to the raw material ratio requirements of Example 3 in the raw material table of the embodiment formula in Table 1 above; (2) Mix the homopolymer polypropylene, copolymer polypropylene, permeability enhancer, antioxidant, lubricant, organic or inorganic antistatic agent, and rheology modifier weighed above in a high-speed mixer for 15 minutes; (3) The mixed raw materials are fed into a twin-screw extruder through a silo. The material stays in the screw for 1-2 minutes. The screw temperature is: 185-195°C in zone 1, 190-210°C in zone 2, 190-210°C in zone 3, and 195-215°C in zone 4. The speed of the twin-screw extruder is 300-700 rpm. (4) After the material is extruded by a twin-screw extruder, it is cooled in a water tank. The water temperature is controlled at 23-28°C to control cooling and slow crystallization to obtain a primary membrane sheet; (5) Cutting the primary membrane into primary flat wires with a width of 7 mm; (6) The raw flat yarn is hot drawn at 160-180°C with a drawing ratio of 6; (7) Heat setting the drawn flat yarn at 160-180°C; (8) The heat-set flat yarn is wound at a speed of 100 m / min to obtain a flat yarn with a width of 4 mm and a thickness of 40 μm.
[0023] Example 4 (1) Weigh the raw materials according to the raw material ratio requirements of Example 4 in the raw material table of the embodiment formula in Table 1 above; (2) Mix the homopolymer polypropylene, copolymer polypropylene, permeability enhancer, antioxidant, lubricant, organic or inorganic antistatic agent, and rheology modifier weighed above in a high-speed mixer for 15 minutes; (3) The mixed raw materials are fed into a twin-screw extruder through a silo. The material stays in the screw for 1-2 minutes. The screw temperature is: 185-195°C in zone 1, 190-210°C in zone 2, 190-210°C in zone 3, and 195-215°C in zone 4. The speed of the twin-screw extruder is 300-700 rpm. (4) After the material is extruded by a twin-screw extruder, it is cooled in a water tank. The water temperature is controlled at 23-28°C to control cooling and slow crystallization to obtain a primary membrane sheet; (5) Cutting the primary membrane into primary flat wires with a width of 7 mm; (6) The raw flat yarn is hot drawn at 160-180°C with a drawing ratio of 6; (7) Heat setting the drawn flat yarn at 160-180°C; (8) The heat-set flat yarn is wound at a speed of 100 m / min to obtain a flat yarn with a width of 4 mm and a thickness of 40 μm.
[0024] Example 5 (1) Weigh the raw materials according to the raw material ratio requirements of Example 5 in the raw material table of the embodiment formula in Table 1 above; (2) Mix the homopolymer polypropylene, copolymer polypropylene, permeability enhancer, antioxidant, lubricant, organic or inorganic antistatic agent, and rheology modifier weighed above in a high-speed mixer for 15 minutes; (3) The mixed raw materials are fed into a twin-screw extruder through a silo. The material stays in the screw for 1-2 minutes. The screw temperature is: 185-195°C in zone 1, 190-210°C in zone 2, 190-210°C in zone 3, and 195-215°C in zone 4. The speed of the twin-screw extruder is 300-700 rpm. (4) After the material is extruded by a twin-screw extruder, it is cooled in a water tank. The water temperature is controlled at 23-28°C to control cooling and slow crystallization to obtain a primary membrane sheet; (5) Cutting the primary membrane into primary flat wires with a width of 7 mm; (6) The raw flat yarn is hot drawn at 160-180°C with a drawing ratio of 6; (7) Heat setting the drawn flat yarn at 160-180°C; (8) The heat-set flat yarn is wound at a speed of 100 m / min to obtain a flat yarn with a width of 4 mm and a thickness of 40 μm.
[0025] Example 6 (1) Weigh the raw materials according to the raw material ratio requirements of Example 6 in the raw material table of the embodiment formula in Table 1 above; (2) Mix the homopolymer polypropylene, copolymer polypropylene, permeability enhancer, antioxidant, lubricant, organic or inorganic antistatic agent, and rheology modifier weighed above in a high-speed mixer for 15 minutes; (3) The mixed raw materials are fed into a twin-screw extruder through a silo. The material stays in the screw for 1-2 minutes. The screw temperature is: 185-195°C in zone 1, 190-210°C in zone 2, 190-210°C in zone 3, and 195-215°C in zone 4. The speed of the twin-screw extruder is 300-700 rpm. (4) After the material is extruded by a twin-screw extruder, it is cooled in a water tank. The water temperature is controlled at 23-28°C to control cooling and slow crystallization to obtain a primary membrane sheet; (5) Cutting the primary membrane into primary flat wires with a width of 7 mm; (6) The raw flat yarn is hot drawn at 160-180°C with a drawing ratio of 6; (7) Heat setting the drawn flat yarn at 160-180°C; (8) The heat-set flat yarn is wound at a speed of 100 m / min to obtain a flat yarn with a width of 4 mm and a thickness of 40 μm.
[0026] Example 7 (1) Weigh the raw materials according to the raw material ratio requirements of Example 7 in the raw material table of the embodiment formula in Table 1 above; (2) Mix the homopolymer polypropylene, copolymer polypropylene, permeability enhancer, antioxidant, lubricant, organic or inorganic antistatic agent, and rheology modifier weighed above in a high-speed mixer for 15 minutes; (3) The mixed raw materials are fed into a twin-screw extruder through a silo. The material stays in the screw for 1-2 minutes. The screw temperature is: 185-195°C in zone 1, 190-210°C in zone 2, 190-210°C in zone 3, and 195-215°C in zone 4. The speed of the twin-screw extruder is 300-700 rpm. (4) After the material is extruded by a twin-screw extruder, it is cooled in a water tank. The water temperature is controlled at 23-28°C to control cooling and slow crystallization to obtain a primary membrane sheet; (5) Cutting the primary membrane into primary flat wires with a width of 7 mm; (6) The raw flat yarn is hot drawn at 160-180°C with a drawing ratio of 6; (7) Heat setting the drawn flat yarn at 160-180°C; (8) The heat-set flat yarn is wound at a speed of 100 m / min to obtain a flat yarn with a width of 4 mm and a thickness of 40 μm.
[0027] The above Example 1 is compared with the blank Example 2 without adding the transmittance enhancing modifier, Example 3 is compared with the blank Example 4 without adding the transmittance enhancing modifier, and other comparisons are made by adjusting different addition ratios.
[0028] In Example 1-Example 7, a highly transparent, high-strength, and high-rigidity flat wire is prepared, whose transparency is characterized by light transmittance and haze, its strength is characterized by single-filament tension and elongation at break, and its stiffness is characterized by measuring the bending strength and bending modulus of the mixed material specimen. The various performance characteristics in Example 1-Example 7 are shown in Table 2 below.
[0029] Table 2 Transparency, strength and stiffness properties of flat yarns prepared with different formulations in the examples The present invention mixes the above-mentioned various raw materials in a high-speed mixer, and then draws them into flat wires through a specially designed twin-screw extruder and its temperature control, wire drawing process parameter control and other equipment and process parameter adjustment. The flat wire prepared by this formula and process has the characteristics of high transparency, high strength and high rigidity, and obtains a light transmittance of ≥85%, a haze of <26%, a relative tensile load of ≥0.56N / tex, and a bending modulus of the modified PP material of ≥1360MPa. The plastic woven bags produced by the extruder meet the packaging requirements of multiple occasions.
[0030] The high-transparency, high-strength, high-rigidity flat wire and the manufacturing method thereof of the present invention can at least produce the following technical effects: The high-transparency, high-strength, high-rigidity flat wire formula and its preparation method provided by the present invention are used in the plastic woven packaging industry, which not only meets the needs of different packaging fields and markets for plastic flat wires with high transparency, high strength, and high rigidity and woven bags prepared therefrom, but also for the traditional plastic woven manufacturing industry, the development and industrialization of high value-added products have a leading role in the scientific and technological progress of the entire plastic woven industry, and have a good demonstration effect on industrial upgrading and intelligent manufacturing, especially the development of complete sets of process technology and key equipment, and also have a reference significance for the development of industry-related products. The launch of high-performance flat wire plastic woven packaging bags on the market can meet the packaging needs of more areas of the market, and through the optimization of the processing technology, the processing temperature can be reduced by more than 30°C, achieving energy saving and low carbon in the production process, saving costs while reducing the pollution of the industry to the environment, and having good ecological benefits.
[0031] The serial numbers of the above embodiments of the present invention are for description only and do not represent the advantages and disadvantages of the embodiments. Through the description of the above implementation methods, those skilled in the art can clearly understand that the above embodiment methods can be implemented by means of some deformations plus the necessary general technology superposition; of course, they can also be implemented by simplifying some important technical features. Based on this understanding, the technical solution of the present invention is essentially or contributes to the prior art in the following aspects: the overall structure and connection method, and the structure described in each embodiment of the present invention.
[0032] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.
Claims
1. A high-transparency, high-strength and high-rigidity flat wire, characterized in that: The invention comprises the following components in weight percentage: 85-95% of low melt index homopolymer polypropylene, 3-15% of low melt index copolymer polypropylene, 0.01-0.30% of anti-transmission enhancer, 0.05-0.20% of antioxidant, 0.05-0.30% of lubricant, 0.05-0.15% of organic or inorganic antistatic agent and 0.2-1% of rheology regulator; Wherein, the weight percentage of the low melt index homopolymer polypropylene and the low melt index copolymer polypropylene is 100%.
2. The high-transparency, high-strength, high-rigidity flat wire according to claim 1, characterized in that: The permeability enhancer is a targeted nano-agent with a side group, a long or short carbon chain or an aromatic functional group; the weight percentage of the permeability enhancer is 0.01%-0.30%.
3. The high-transparency, high-strength and high-rigidity flat wire according to claim 1, characterized in that: The weight percentage of the antioxidant is 0.01%-0.20%; the weight percentage of the lubricant is 0.05%-0.30%; and the weight percentage of the rheology regulator is 0.2%-1%.
4. The high-transparency, high-strength, high-rigidity flat wire according to claim 1, characterized in that: The antistatic agent is an organic or inorganic antistatic agent; the weight percentage of the antistatic agent is 0.05%-0.15%.
5. The high-transparency, high-strength, high-rigidity flat wire according to claim 1, characterized in that: The low melting index homopolymer polypropylene has a melting index of 3-4 g / 10 min at 230° C. and 216 kg load.
6. The high-transparency, high-strength, high-rigidity flat wire according to claim 1, characterized in that: The low melting index copolymer polypropylene has a melting index of 2.2-3 g / 10 min at 230° C. and 216 kg load.
7. A method for producing the high-transparency, high-strength and high-rigidity flat wire according to any one of claims 1 to 6, characterized in that: The following steps are involved: The first step is to weigh low melt index homopolymer polypropylene, low melt index copolymer polypropylene, anti-transmission enhancer, antioxidant, lubricant, antistatic agent and rheology regulator according to weight ratio; The second step is to mix the raw materials prepared in the first step in a high-speed mixer for 10-20 minutes; The third step is to feed the mixed raw materials into the twin-screw extruder through the silo, and the materials stay in the screw for 1-2 minutes; In the fourth step, after the material is extruded by a twin-screw extruder, it is cooled in a water tank, and the water temperature is controlled at 23-28°C to control cooling and slow crystallization to obtain a primary membrane sheet; The fifth step is to cut the primary film into primary flat wires with a width of 3-10 mm; Step 6: The raw flat yarn is hot drawn at 160-180°C with a drawing ratio of 5.8-6.5; Step 7: heat-set the drawn flat yarn at 160-180°C; In the eighth step, the heat-set flat yarn is wound at a speed of 30-200 m / min to obtain a finished flat yarn with a width of 2-6 mm and a thickness of 15-60 μm.
8. The method for producing a high-transparency, high-strength, high-rigidity flat wire according to claim 7, characterized in that: In the third step, the twin-screw extruder has four temperature zones, wherein zone one is 185-195°C, zone two is 190-210°C, zone three is 190-210°C, and zone four is 195-215°C; the rotation speed of the twin-screw extruder is 300-700 rpm.