Production process of high-strength stretching and wrapping film

Abstract

The invention relates to a high-strength stretching and wrapping film production process, belongs to the technical field of film materials, and particularly relates to an outer layer material prepared from low-density polyethylene, isotactic polypropylene and the like. Preparing a material for the barrier layer by using an ethylene-vinyl alcohol copolymer and a reinforcing agent; preparing composite reinforced plant fibers from plant fibers, and preparing a core layer material from ultra-low density polyethylene, ultra-high molecular weight polyethylene, the composite reinforced plant fibers and the like; ethylene-vinyl acetate, bonding resin and a plasticizer are used for preparing a bonding layer material; finally, the outer layer, the first bonding layer, the isolation layer, the second bonding layer and the core layer are sequentially arranged from outside to inside, extrusion is conducted through multi-layer co-extrusion equipment, and the high-strength stretching wrapping film is prepared. And the urgent demand of the market on the high-performance wrapping film is met.

Description

Technical Field

[0001] The present invention belongs to the technical field of film materials, and in particular relates to a production process of a high-strength stretch wrap film. Background Art

[0002] Stretch film is a crucial material used in packaging, securing, and protecting various items. Its performance directly impacts packaging efficiency, item safety, and transportation costs. While traditional stretch film has met basic market needs to a certain extent, the rapid development of the logistics industry and growing environmental awareness are placing more stringent demands on stretch film performance. Specifically, the market urgently needs a high-tensile-strength stretch film to further ensure the safety and stability of packaged items.

[0003] Currently, the performance improvement of stretch films in existing technologies often leads to a significant increase in costs. For example, high-end stretch films use a large amount of metallocene linear polyethylene, which will significantly increase costs. At the same time, metallocene linear polyethylene also has problems such as difficulty in processing, high energy consumption, and environmental pollution.

[0004] In response to the above problems, there is an urgent need for a high-strength stretch wrap film production process that can significantly improve the strength performance of the wrap film and meet the market's urgent demand for high-performance wrap film. Summary of the Invention

[0005] The present invention aims to provide a production process for high-strength stretch wrap film, and aims to provide a production process for preparing high-strength stretch wrap film.

[0006] To achieve the above object, the technical solution adopted by the present invention is to provide a high-strength stretch wrap film production process, the production process comprising the following steps:

[0007] S1. Select low-density polyethylene, isotactic polypropylene, styrene block copolymer, plasticizer, ultraviolet absorber, and antistatic agent, mix them evenly, and obtain the outer layer material;

[0008] S2. Selecting ethylene-vinyl alcohol copolymer and a reinforcing agent, mixing them evenly and then performing ultrasonic dispersion to obtain a barrier layer material;

[0009] S3, selecting plant fibers and using a chemical grafting method to prepare amino-modified plant fibers, and further reacting the amino-modified plant fibers with a reinforcing agent to prepare composite reinforced plant fibers;

[0010] S4, mixing ultra-low density polyethylene, ultra-high molecular weight polyethylene, acrylonitrile-butadiene-styrene, styrene block copolymer and the composite reinforced plant fiber described in step S3, stirring and reacting at 180-200° C. for 2-5 hours to obtain a core layer material;

[0011] S5. Select ethylene vinyl acetate, adhesive resin, and plasticizer and mix them evenly to obtain a bonding layer material;

[0012] S6. The outer layer, the first adhesive layer, the isolation layer, the second adhesive layer, and the core layer are arranged in order from the outside to the inside through a multi-layer co-extrusion device to obtain a high-strength stretch wrap film, wherein the first adhesive layer and the second adhesive layer both use the adhesive layer material.

[0013] Furthermore, the step S3 is specifically as follows:

[0014] (1) adding the plant fiber to an amino-modified solution in a dark environment, wherein the amino-modified solution is composed of deionized water, ethanol, concentrated ammonia water, and dopamine hydrochloride aqueous solution, reacting for 40-60 minutes, adding a polyamine and continuing the reaction for 7-10 hours, and then washing and drying to obtain the amino-modified plant fiber;

[0015] (2) The reinforcing agent in step S3 is a gelatinized aldehyde starch solution. The amino-modified plant fiber is added to the gelatinized aldehyde starch solution, and the temperature is maintained at 50-60° C. under a nitrogen protective atmosphere for 5-8 hours. After the reaction is completed, the composite reinforced plant fiber is washed and dried to obtain the composite reinforced plant fiber.

[0016] Furthermore, the mass fraction of ammonia in the concentrated ammonia water in the amino-modified solution is 22% to 25%, and the concentration of the dopamine hydrochloride aqueous solution is 2 mg / mL.

[0017] Furthermore, the volume ratio of the deionized water, ethanol, concentrated ammonia water, dopamine hydrochloride aqueous solution, and polyamine is 100:40:1.5:80:5.

[0018] Furthermore, the polyamine is one or more of ethylenediamine, propylenediamine, dimethylethylenediamine, and isophoronediamine.

[0019] Furthermore, the gelatinized aldehyde starch solution is composed of aldehyde starch, deionized water, and glycerol in a mass ratio of 10:40:3.

[0020] Furthermore, the step S1 is specifically as follows: take 60-80 parts of low-density polyethylene, 10-15 parts of isotactic polypropylene, 3-6 parts of styrene block copolymer, 1-3 parts of plasticizer, 0.5-2 parts of ultraviolet absorber, and 1-3 parts of antistatic agent, add them into a mixer, stir and mix at a speed of 800-1000 r / min for 30 minutes, and control the temperature at 160°C-180°C to obtain the outer layer material.

[0021] Furthermore, the step S2 specifically comprises: selecting 30-50 parts of ethylene-vinyl alcohol copolymer and 2-5 parts of a reinforcing agent, mixing them evenly, and then performing ultrasonic dispersion for 60 minutes to obtain a material for the barrier layer.

[0022] Furthermore, the amounts of the components used in step S4 are: 60-90 parts of ultra-low density polyethylene, 10-20 parts of ultra-high molecular weight polyethylene, 20-50 parts of acrylonitrile-butadiene-styrene, 8-15 parts of styrene block copolymer, and 10-20 parts of the composite reinforced plant fiber mixture described in step S3.

[0023] Furthermore, the amounts of the components in step S5 are: 20-30 parts of ethylene vinyl acetate, 6-10 parts of adhesive resin, and 0.5-1 part of plasticizer.

[0024] The beneficial effects of the high-strength stretch wrap film production process provided by the present invention are: the high-strength stretch wrap film production process of the present invention greatly improves the tensile strength of the stretch wrap film by using self-prepared composite reinforced plant fibers, and at the same time, performance tests show that the performance is superior to that of high-end material metallocene linear polyethylene, which greatly saves production costs while significantly improving the strength performance of the stretch film; at the same time, the composite reinforced plant fiber is a biodegradable material, which provides a more environmentally friendly option with better performance in today's increasingly severe white pollution situation. DETAILED DESCRIPTION

[0025] Below in conjunction with embodiment, technical scheme of the present invention is clearly and completely described, obviously, described embodiment is only a part of embodiment of the present invention, rather than whole embodiment. Based on the embodiment in the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative work premise all fall within the scope of protection of the present invention. Below reagent or raw material, if not otherwise specified, all derive from open commercial channels.

[0026] The present invention specifically discloses a high-strength stretch wrap film production process, comprising the following steps performed in sequence: S1, selecting low-density polyethylene, isotactic polypropylene, styrene block copolymer, plasticizer, ultraviolet absorber, and antistatic agent, and mixing them uniformly to obtain an outer layer material;

[0027] S2. Selecting ethylene-vinyl alcohol copolymer and a reinforcing agent, mixing them evenly and then performing ultrasonic dispersion to obtain a barrier layer material;

[0028] S3, selecting plant fibers and using a chemical grafting method to prepare amino-modified plant fibers, and further reacting the amino-modified plant fibers with a reinforcing agent to prepare composite reinforced plant fibers;

[0029] S4, mixing ultra-low density polyethylene, ultra-high molecular weight polyethylene, acrylonitrile-butadiene-styrene, styrene block copolymer and the composite reinforced plant fiber in step S3, stirring and mixing at 120-150° C. for 2-5 hours to obtain a core layer material;

[0030] S5. Ethylene vinyl acetate, adhesive resin, and plasticizer are mixed uniformly to obtain a bonding layer material;

[0031] S6. The outer layer, the first adhesive layer, the isolation layer, the second adhesive layer, and the core layer are arranged in order from the outside to the inside, and the stretch film material is obtained by extruding through a multi-layer co-extrusion device, wherein the first adhesive layer and the second adhesive layer are both made of adhesive layer materials.

[0032] The following is further described with reference to specific embodiments.

[0033] Example 1

[0034] This embodiment discloses a high-strength stretch wrap film production process, and the steps are as follows:

[0035] Take 70g of low-density polyethylene, 15g of isotactic polypropylene, 5g of styrene block copolymer (SEBS is selected in this embodiment), 1.5g of plasticizer (epoxidized soybean oil is selected in this embodiment), 1g of ultraviolet absorber (2-hydroxy-4-n-octyloxybenzophenone is selected in this embodiment), and 1.5g of antistatic agent (stearylamine polyoxyethylene ether is selected in this embodiment), add them to a high-speed mixer and stir and mix at a speed of 1000r / min for 30min at a mixing temperature of 170°C to prepare the outer layer material;

[0036] 40 g of ethylene-vinyl alcohol copolymer and 3 g of a reinforcing agent (montmorillonite is used in this embodiment) are mixed and then ultrasonically dispersed for 60 minutes to prepare a barrier layer material.

[0037] Under light-proof conditions, an amino-modified solution was prepared by taking 100 mL of deionized water and 40 mL of ethanol and mixing them evenly. Then, 1.5 mL of 25% ammonia water was added and stirred evenly at room temperature. Then, 80 mL of a 2 mg / mL dopamine hydrochloride aqueous solution was added. Then, 10 g of plant fiber (in this embodiment, the plant fiber was pine fiber powder with a size of 0.1-0.3 mm) was added to the above solution. After reacting at room temperature for 50 minutes, 5 mL of ethylenediamine was added and the reaction was continued for 8 hours. The product was filtered and washed with distilled water 6 times. After that, the product was dried in a vacuum drying oven at a drying temperature of 55°C for 36 hours to obtain an amino-modified plant fiber.

[0038] Take 40g of aldehyde starch (aldehyde content 70%), add 100g of deionized water and 12g of glycerol, and stir at 80°C for 50min to prepare a gelatinized aldehyde starch solution. Take 10g of the prepared amino-modified plant fiber and add it to the gelatinized aldehyde starch solution. Keep the reaction temperature at 50°C and react continuously for 7h under nitrogen protection. After the reaction, wash the product with distilled water 6 times, and then heat it in a hot air circulation oven at 50°C for 24h to obtain a composite reinforced plant fiber.

[0039] 70 g of ultra-low density polyethylene, 15 g of ultra-high molecular weight polyethylene, 30 g of acrylonitrile-butadiene-styrene, 10 g of a styrene block copolymer (SEBS is selected in this embodiment), and 15 g of composite reinforced plant fiber were mixed and stirred at 190° C. for 4 h to prepare the core layer material;

[0040] Take 25g of ethylene vinyl acetate, 8g of adhesive resin (rosin resin is used in this embodiment), and 0.5g of plasticizer (dioctyl phthalate is used in this embodiment) and mix them evenly to obtain the adhesive layer material;

[0041] The outer layer, first adhesive layer, isolation layer, second adhesive layer, and core layer are arranged in order from the outside to the inside, and extruded through a multi-layer co-extrusion device. The thickness ratio of each layer is controlled to be approximately: outer layer: first adhesive layer: isolation layer: second adhesive layer: core layer = 3:0.5:2:0.5:4, thereby obtaining a high-strength stretch wrap film.

[0042] Example 2-Example 4

[0043] The high-strength stretch wrap film production process disclosed in Examples 2 to 4 is the same as the steps disclosed in Example 1, except that the mass of the raw materials (unit: g), specifically see Table 1, and the process conditions, specifically see Table 2. Comparative Examples 1-2 are the same as Example 1 except that composite reinforced plant fibers are not used, specifically see Tables 1 and 2.

[0044] Table 1 Raw material ratios of Examples 1-4 and Comparative Examples 1-2

[0045]

[0046] Table 2 Process conditions of Examples 1-6 and Comparative Examples 1-2

[0047]

[0048]

[0049] Performance Testing

[0050] The performance parameters of Examples 1-4 and Comparative Examples 1-2 are shown in Table 3

[0051] Table 3 Parameter comparison table

[0052]

[0053] Tensile strength: Determined according to GB / T 1040-2006 Tensile properties of plastics;

[0054] Thickness: Determined according to GB / T6672-2001 Plastic film and sheet thickness determination mechanical measurement method,

[0055] It can be seen from the above table that the strength performance of Examples 1-4 of the present invention is much better than that of Comparative Example 1, and is also better than that of Comparative Example 2 using metallocene linear polyethylene.

[0056] Finally, it should be noted that the above-described embodiments are only specific implementation methods of the present invention, which are used to illustrate the technical solutions of the present invention rather than to limit them. The protection scope of the present invention is not limited thereto. Although the present invention has been described in detail with reference to the above-mentioned embodiments, ordinary technicians in this field should understand that any technician familiar with this technical field can still modify the technical solutions recorded in the above-mentioned embodiments within the technical scope disclosed by the present invention, or make equivalent replacements for some of the technical features therein. These modifications, changes or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be covered by the protection scope of the present invention.

Claims

1. A high-strength stretch wrap film production process, characterized in that: The production process comprises the following steps: S1. Select low-density polyethylene, isotactic polypropylene, styrene block copolymer, plasticizer, ultraviolet absorber, and antistatic agent, mix them evenly, and obtain the outer layer material; S2. Selecting ethylene-vinyl alcohol copolymer and a reinforcing agent, mixing them evenly and then performing ultrasonic dispersion to obtain a barrier layer material; S3, selecting plant fibers and using a chemical grafting method to prepare amino-modified plant fibers, and further reacting the amino-modified plant fibers with a reinforcing agent to prepare composite reinforced plant fibers; S4, mixing ultra-low density polyethylene, ultra-high molecular weight polyethylene, acrylonitrile-butadiene-styrene, styrene block copolymer and the composite reinforced plant fiber described in step S3, stirring and reacting at 180-200° C. for 2-5 hours to obtain a core layer material; S5. Ethylene vinyl acetate, adhesive resin, and plasticizer are mixed uniformly to obtain a bonding layer material; S6. The outer layer, the first adhesive layer, the isolation layer, the second adhesive layer, and the core layer are arranged in order from the outside to the inside through a multi-layer co-extrusion device to obtain a high-strength stretch wrap film, wherein the first adhesive layer and the second adhesive layer both use the adhesive layer material.

2. A high-strength stretch wrap film production process according to claim 1, characterized in that: The step S3 is specifically as follows: (1) adding the plant fiber to an amino-modified solution in a dark environment, wherein the amino-modified solution is composed of deionized water, ethanol, concentrated ammonia water, and dopamine hydrochloride aqueous solution, reacting for 40-60 minutes, adding a polyamine and continuing the reaction for 7-10 hours, and then washing and drying to obtain the amino-modified plant fiber; (2) The reinforcing agent in step S3 is a gelatinized aldehyde starch solution. The amino-modified plant fiber is added to the gelatinized aldehyde starch solution, and the temperature is maintained at 50-60° C. under a nitrogen protective atmosphere for 5-8 hours. After the reaction is completed, the composite reinforced plant fiber is washed and dried to obtain the composite reinforced plant fiber.

3. A high-strength stretch wrap film production process according to claim 2, characterized in that: The mass fraction of ammonia in the concentrated ammonia water in the amino-modified solution is 22%-25%, and the concentration of the dopamine hydrochloride aqueous solution is 2 mg / mL.

4. A high-strength stretch wrap film production process according to claim 3, characterized in that: The volume ratio of the deionized water, ethanol, concentrated ammonia water, dopamine hydrochloride aqueous solution and polyamine is 100:40:1.5:80:

5.

5. A high-strength stretch wrap film production process according to claim 4, characterized in that: The polyamine is one or more of ethylenediamine, propylenediamine, dimethylethylenediamine and isophoronediamine.

6. A high-strength stretch wrap film production process according to claim 5, characterized in that: The gelatinized aldehyde starch solution is composed of aldehyde starch, deionized water, and glycerol in a mass ratio of 10:40:

3.

7. The high-strength stretch wrap film production process according to claim 1, characterized in that: The step S1 specifically comprises: adding 60-80 parts of low-density polyethylene, 10-15 parts of isotactic polypropylene, 3-6 parts of styrene block copolymer, 1-3 parts of plasticizer, 0.5-2 parts of ultraviolet absorber, and 1-3 parts of antistatic agent to a mixer, stirring and mixing at a speed of 800-1000 r / min for 30 minutes, and controlling the temperature at 160° C.-180° C. to obtain the outer layer material.

8. The high-strength stretch wrap film production process according to claim 1, characterized in that: The step S2 specifically comprises: selecting 30-50 parts of ethylene-vinyl alcohol copolymer and 2-5 parts of a reinforcing agent, mixing them evenly, and then performing ultrasonic dispersion for 60 minutes to obtain the barrier layer material.

9. The high-strength stretch wrap film production process according to claim 1, characterized in that: The amounts of the components used in step S4 are: 60-90 parts of ultra-low density polyethylene, 10-20 parts of ultra-high molecular weight polyethylene, 20-50 parts of acrylonitrile-butadiene-styrene, 8-15 parts of styrene block copolymer, and 10-20 parts of the composite reinforced plant fiber mixture described in step S3.

10. The high-strength stretch wrap film production process according to claim 1, characterized in that: The amounts of the components used in step S5 are: 20-30 parts of ethylene vinyl acetate, 6-10 parts of adhesive resin, and 0.5-1 part of plasticizer.

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