A degradable rubber industrial feeding bag and preparation method thereof

Abstract

This invention provides a biodegradable feed bag for the rubber industry and its preparation method. The raw materials, by weight, include: 70-85 parts plastic and 15-30 parts biodegradable resin. The plastic is EVAC plastic with a melt flow index of less than 3 g / 10 min. The biodegradable resin, by weight, includes: 40-50 parts bio-based corn starch, 45-55 parts thermoplastic elastomer, and 2-10 parts structural modifier. This invention, by adding biodegradable resin to the plastic, not only improves the biodegradability of the plastic but also reduces production costs, thus alleviating environmental problems and achieving economic benefits.

Description

Technical Field

[0001] The invention relates to the field of C08L15 / 00, and in particular to a degradable rubber industrial feeding bag and a preparation method thereof. Background Art

[0002] Rubber is a non-degradable material. With the advancement of environmental protection and technology, more and more modified materials are used in the rubber industry, and rubber degradation technology has made great progress. In the future, more and more rubber products will be made of bio-based materials.

[0003] CN110437511A discloses a degradable rubber material and its preparation method and application. The degradable rubber material comprises, by weight, polyisoprene, butadiene rubber, styrene-butadiene rubber, a bioswelling agent, a glutamic acid composition and a biocomplex enzyme. The glutamic acid composition and the biocomplex enzyme of the degradable rubber material can attract microorganisms in the soil to approach the rubber material, and degradation is achieved under the joint action of the bioswelling agent. However, the degradable rubber material is not suitable as a material for a feeding bag for the rubber industry.

[0004] Rubber industrial feeding bags are brought into rubber during the rubber processing process and become part of the rubber material. Studies have shown that the current conventional rubber industrial feeding bags are EVAC materials, which cannot be naturally degraded and are not environmentally friendly, flame retardant, or antistatic. Summary of the invention

[0005] The present invention discloses a degradable rubber industrial feeding bag. The raw materials for preparing the bag include 70-85 parts of plastic and 15-30 parts of degradable resin in parts by weight.

[0006] In one embodiment, the plastic is selected from any one of thermoplastics, thermosetting plastics, and elastomers.

[0007] Preferably, the plastic is a thermoplastic.

[0008] Further preferably, the thermoplastic plastic is EVAC plastic.

[0009] In one embodiment, the EVAC plastic has a melt index of less than 3 g / 10 min.

[0010] Preferably, the melt index of the EVAC plastic is less than 2.2 g / 10 min.

[0011] More preferably, the melt index of the EVAC plastic is 1.5-2 g / 10 min.

[0012] The melt index is measured at 190°C and 2.16 kg.

[0013] In one embodiment, the raw materials for preparing the degradable resin include, by weight: 40-50 parts of bio-based corn starch, 45-55 parts of thermoplastic elastomer, and 2-10 parts of structure modifier.

[0014] Preferably, the raw materials for preparing the degradable resin include, by weight: 47 parts of bio-based corn starch, 48 parts of thermoplastic elastomer, and 5 parts of structure modifier.

[0015] The mass percentage standard of raw materials for preparing biodegradable resin is different from that of raw materials for preparing feeding bags.

[0016] The bio-based corn starch complies with the (GB / T8885-2017) quality standard.

[0017] In one embodiment, the thermoplastic elastomer is selected from any one of styrene-based thermoplastic elastomers, thermoplastic polyurethanes, thermoplastic polyolefin-based elastomers, and polyester elastomers.

[0018] Preferably, the thermoplastic elastomer is a styrene-based thermoplastic elastomer.

[0019] Further preferably, the styrene-based thermoplastic elastomer is a thermoplastic starch material Thermoplasticstarch TPS.

[0020] In one embodiment, the structure modifier is an alcohol and / or carboxylic acid organic compound.

[0021] Preferably, the structure modifier is a carboxylic acid organic compound.

[0022] More preferably, the carboxylic acid organic compound is polylactic acid.

[0023] In one embodiment, the average molecular weight of the polylactic acid is greater than 4w.

[0024] Preferably, the average molecular weight of the polylactic acid is greater than 6w.

[0025] In one embodiment, the preparation method of the biodegradable resin is: placing the raw materials in an internal mixer, extruding them into strands through a twin-screw extruder, cooling and drying, and granulating them to obtain the resin.

[0026] Preferably, the volume of the internal mixer is 80-150L, ​​more preferably 100L.

[0027] Preferably, the temperature of the internal mixer is 180-220°C, more preferably 200°C.

[0028] Preferably, the working time of the internal mixer is 15-30 min, more preferably 20 min.

[0029] Preferably, the cooling process is specifically: cooling through a 50-meter cooling water tank.

[0030] Preferably, the drying process is air-cooled drying.

[0031] In one embodiment, the method for preparing the feeding bag comprises the following steps: stirring the raw materials in a stainless steel high-speed mixer and extruding the raw materials in an extruder.

[0032] Preferably, the parameters of the stainless steel high-speed mixer are 350-450 kg, 5-6 KW, and 380V.

[0033] Further preferably, the parameters of the stainless steel high-speed mixer are 400 kg, 5.5 KW, and 380 V.

[0034] Preferably, the stirring time in the stainless steel high-speed stirrer is 8-15 min, more preferably 10 min.

[0035] In one embodiment, the diameter of the extruder is 60-80 mm, more preferably, the diameter of the extruder is 65 mm, and the aspect ratio is 28:1.

[0036] Preferably, the temperature of the extruder is: zone 1 100-110°C, zone 2 110-120°C, zone 3 120-130°C, zone 4 115-125°C.

[0037] Further preferably, the temperature of the extruder is: 105°C in zone 1, 115°C in zone 2, 125°C in zone 3, and 120°C in zone 4.

[0038] Preferably, the extrusion capacity of the extruder is 30-40 kg / h.

[0039] The invention not only improves the degradability of the plastic by adding degradable resin into the plastic, but also reduces the production cost, thereby alleviating environmental problems and meeting economic benefits. However, the applicant discovered a phenomenon during the experiment. Sometimes the feeding bag obtained has good performance, is uniform and does not collapse, but sometimes it is not good. In response to this phenomenon, the applicant found through a lot of research that the melt index of EVAC plastic must be controlled to be less than 3g / 10min, especially at 1.5-2g / 10min, and the average molecular weight of polylactic acid is greater than 4w, and the best is about 6w. The obtained feeding bag has excellent mechanical properties. The applicant believes that the possible reason is that the shear dispersion is prone to unevenness during the blending of polylactic acid, plastic and starch, thereby affecting the mechanical properties of the feeding bag. This phenomenon is particularly serious when the melt index of EVAC plastic is greater than 3g / 10min. Controlling the melt index of EVAC plastic to be less than 3g / 10min ensures that the molecular weight of the polymer in the system is high, and the plastic molecules and polylactic acid molecules can support each other to form a spatial network structure, ensuring that the shear force of other components in the system is reduced and evenly dispersed in the system, thereby ensuring that the plastic bag does not collapse.

[0040] Beneficial Effects

[0041] 1. The melt index of EVAC plastic is controlled to be less than 3g / 10min, and the average molecular weight of polylactic acid is greater than 4w. The obtained feeding bag has excellent mechanical properties.

[0042] 2. The biodegradable resin prepared by the present invention using bio-based corn starch, thermoplastic elastomer and structural modifier has good biodegradability.

[0043] 3. The structural modifier selected in the present invention is polylactic acid, which has excellent degradability and improves the mechanical properties of the resin.

[0044] 4. The present invention not only improves the degradability of plastics by adding degradable resins to plastics, but also reduces production costs, thereby alleviating environmental problems and meeting economic benefits.

[0045] 5. The raw materials and process of the present invention are simple, safe and pollution-free. DETAILED DESCRIPTION

[0046] Example 1

[0047] This Example 1 provides a degradable rubber industrial feeding bag, and the raw materials for preparation are, by weight: 70 parts of EVAC plastic and 30 parts of degradable resin.

[0048] The EVAC plastic was purchased from Shaanxi Yanchang Petroleum Co., Ltd. and had a melt index of 2 g / 10 min.

[0049] The raw materials for preparing the degradable resin include, by weight: 47 parts of bio-based corn starch, 48 parts of thermoplastic elastomer, and 5 parts of structure modifier.

[0050] The mass percentage standard of raw materials for preparing biodegradable resin is different from that of raw materials for preparing feeding bags.

[0051] The bio-based corn starch was purchased from Zhuhai Yiked Environmental Protection Materials Co., Ltd.

[0052] The thermoplastic elastomer is a thermoplastic starch material, Thermoplastic starch TPS, purchased from Zhuhai Yikede Environmental Protection New Materials Co., Ltd., model number TPS-F.

[0053] The structure modifier is polylactic acid, purchased from Zhejiang Hisun PLA, with an average molecular weight of 6w.

[0054] The preparation method of the biodegradable resin is as follows: placing the above raw materials in a 100L internal mixer, at 200°C for 20 minutes, extruding through a twin-screw extruder to form a strip, cooling through a 50-meter cooling water tank, and air-cooling and drying to obtain the product.

[0055] On the other hand, this embodiment 1 discloses a method for preparing the feeding bag, which comprises the following steps: stirring the raw materials in a stainless steel high-speed mixer for 10 minutes, and extruding the raw materials in an extruder.

[0056] The parameters of the stainless steel high-speed mixer are 400 kg, 5.5KW, 380V

[0057] The extruder has a diameter of 65 mm and an aspect ratio of 28:1.

[0058] The temperature of the extruder is: zone 1 105°C, zone 2 115°C, zone 3 125°C, zone 4 120°C

[0059] The extrusion rate is 35 kg / h.

[0060] Example 2

[0061] This embodiment is basically the same as the embodiment 1, except that the raw materials used in the preparation are: 80 parts of EVAC plastic and 20 parts of degradable resin.

[0062] Example 3

[0063] This embodiment is basically the same as the embodiment 1, except that the raw materials used in the preparation are: 85 parts of EVAC plastic and 15 parts of degradable resin.

[0064] Example 4

[0065] This embodiment is basically the same as the embodiment 1, except that the raw materials used in the preparation are: 60 parts of EVAC plastic and 40 parts of degradable resin.

[0066] Example 5

[0067] This embodiment is basically the same as Embodiment 1, except that: the EVAC plastic is purchased from Zhuhai Yikede, and the melt index is 3g / 10min.

[0068] Example 6

[0069] This embodiment is basically the same as embodiment 1, except that the polylactic acid is purchased from Zhejiang Hisun and has an average molecular weight of 3w.

[0070] Performance Testing

[0071] For the appearance and tensile test of the rubber industrial feeding bag in the above embodiment, each group was tested 5 times and the average value was taken. Specifically, the test conditions were: tensile rate 100m / min; test standard: GB / T-1040.3-2006 Determination of tensile properties of plastics Part 3: Test conditions for films and sheets, and the results are shown in the following Tables 1 and 2.

[0072] Table 1 Color comparison of feeding bags

[0073] Serial number Example 1 Example 2 Example 3 Appearance White and transparent White and transparent White and transparent

[0074] Table 2 Comparison of tensile properties of feeding bags

[0075]

[0076]

[0077] The above test data can support that the color of the industrial rubber feeding bag filled with 30% bio-based filler meets the white and transparent appearance requirements. From the comparison of the mechanical properties of the products, the mechanical properties of the industrial rubber feeding bag mixed with 30% bio-based filler prepared by the above invention method meet the requirements.

Claims

1. A degradable rubber industrial feeding bag, characterized in that: The raw materials for the preparation include, by mass: 70 parts of EVAC plastic, 30 parts of biodegradable resin; The EVAC plastic was purchased from Shaanxi Yanchang Petroleum Co., Ltd., and the melt index was 2g / 10min; The raw materials for preparing the degradable resin include, by weight: 47 parts of bio-based corn starch, 48 parts of thermoplastic elastomer, and 5 parts of structural modifier; The mass percentage standard of the raw materials for preparing the degradable resin is different from the mass percentage standard of the raw materials for preparing the feeding bag; The bio-based corn starch was purchased from Zhuhai Yikede Environmental Protection Materials Co., Ltd. The thermoplastic elastomer is a thermoplastic starch material, Thermoplastic starch TPS, purchased from Zhuhai Yikede Environmental Protection New Materials Co., Ltd., model number TPS-F; The structural modifier is polylactic acid, purchased from Zhejiang Hisun PLA, with an average molecular weight of 6w; The preparation method of the biodegradable resin is as follows: placing the above raw materials in a 100L internal mixer, at 200°C for 20 minutes, extruding through a twin-screw extruder to form a strip, cooling through a 50-meter cooling water tank, and air-cooling and drying to obtain the product.

2. A degradable rubber industrial feeding bag, characterized in that: The raw materials for the preparation include, by mass: 80 parts of EVAC plastic, 20 parts of biodegradable resin; The EVAC plastic was purchased from Shaanxi Yanchang Petroleum Co., Ltd., and the melt index was 2g / 10min; The raw materials for preparing the degradable resin include, by weight: 47 parts of bio-based corn starch, 48 parts of thermoplastic elastomer, and 5 parts of structural modifier; The mass percentage standard of the raw materials for preparing the degradable resin is different from the mass percentage standard of the raw materials for preparing the feeding bag; The bio-based corn starch was purchased from Zhuhai Yikede Environmental Protection Materials Co., Ltd. The thermoplastic elastomer is a thermoplastic starch material, Thermoplastic starch TPS, purchased from Zhuhai Yikede Environmental Protection New Materials Co., Ltd., model number TPS-F; The structural modifier is polylactic acid, purchased from Zhejiang Hisun PLA, with an average molecular weight of 6w; The preparation method of the biodegradable resin is as follows: placing the above raw materials in a 100L internal mixer, at 200°C for 20 minutes, extruding through a twin-screw extruder to form a strip, cooling through a 50-meter cooling water tank, and air-cooling and drying to obtain the product.

3. A method for preparing a feeding bag according to any one of claims 1 to 2, characterized in that: The raw materials are placed in an internal mixer, extruded through a twin-screw extruder, cooled and dried, and granulated to obtain the product.

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