Regenerated polyethylene, regenerated EVA and recycled leftover material blending modified fluoride-free foam board and preparation method thereof

Abstract

The invention discloses a regenerated polyethylene, regenerated EVA (Ethylene Vinyl Acetate) and recycled leftover material blending modified fluoride-free foam board and a preparation method thereof. The preparation method comprises the following preparation steps: preparing the following components in parts by weight: 30-40 parts of regenerated polyethylene; 20 to 25 parts of regenerated EVA particles; recovering 30-35 parts of mixed color corner particles; 2-7.5 parts of an alkaline agent; 10 to 15 parts of a filling material; 0.8 to 4 parts of a stable accelerant; 1.5-6 parts of a foaming agent; 0.1 to 0.5 part of an antioxidant; and 0.1 to 0.5 part of a weather-resistant agent. The invention has the following beneficial effects: 1) the cost performance is high, and processing is easy; 2) the product is non-toxic, and detection results show that the product meets European Union detection standards;

Description

Technical Field

[0001] The invention relates to the technical field of fluorine-free foamed boards, and in particular to a fluorine-free foamed board modified by blending recycled polyethylene, recycled EVA and recycled scraps, and a preparation method thereof. Background Art

[0002] In the prior art, recycled EVA foam board materials are used in central air conditioning, construction, chemical industry, metallurgy, shipbuilding, vehicles, electrical appliances and other industries. During the use of EVA foam materials, fluorine is a non-metallic chemical element, which is a light yellow and highly toxic gas. Fluorine gas is highly corrosive and has extremely active chemical properties. It is one of the most oxidizing substances and can even react with some inert gases under certain conditions, causing harm to the human body.

[0003] CN 103788463 A discloses: an EVA foam material and a preparation method thereof. The foam material is made of the following components in parts by weight: EVA 100, a foaming agent 2-10, a foaming promoter 0.5-5, a bridging agent 0.05-1, a filler 5-30, a deodorant 0.5-5, and a lubricant 0.5-5; the above raw materials are uniformly mixed and dried in an oven at 60-80° C. for 6-12 hours to obtain a dried mixture, the dried mixture is mixed and injection-molded to obtain an EVA sheet, the EVA sheet is cut and placed in a flat vulcanizer for mold loading and hot pressing, and then the pressure is automatically released, and the mold is cooled to obtain the EVA foam material. Compared with the prior art, the present invention utilizes a deodorant with absorption and reaction in one, which is added to EVA and various additives. The deodorant has good dispersibility, reacts with ammonia radicals through a chelating mechanism, strongly adsorbs ammonia gas, effectively removes ammonia radicals and ammonia gas, can destroy the conditions for the formation of formamide before it is formed, and has no effect on the properties of the produced products, and has a wide range of uses.

[0004] After February 25, 2023, the new EU regulations prohibit the production and sale of other substances, preparations and articles containing PFCAs, their salts and related compounds within the EU, unless the total concentration of PFCAs and their salts is less than 25ppb or the total concentration of PFCAs-related compounds is less than 260ppb.

[0005] In summary, in the field of prior art recycled EVA foam board materials, there is an urgent need for a fluorine-free foam board modified by blending recycled polyethylene, recycled EVA and recycled scraps and a preparation method thereof.

[0006] The present invention provides a defluorination and deodorization process and a preparation method of an EVA foam board based on the prior art, solves the problem of fluorine-containing elements in the material, and also optimizes the production process of ordinary EVA foam boards to meet EU regulations. Summary of the invention

[0007] The purpose of the present invention is to provide a fluorine-free foamed board blended with recycled polyethylene, recycled EVA and recycled scraps and a preparation method thereof.

[0008] To achieve the above object, the present invention is implemented by the following technical solutions:

[0009] A fluorine-free foamed board made by blending recycled polyethylene, recycled EVA and recycled scraps, comprising the following components in parts by weight:

[0010] 30-40 parts of recycled polyethylene;

[0011] 20-25 parts of recycled EVA particles;

[0012] Recover 30-35 portions of variegated corner particles;

[0013] 2 to 7.5 parts of alkaline agent;

[0014] 10-15 parts of filler;

[0015] 0.8 to 4 parts of stabilizing accelerator;

[0016] 1.5 to 6 parts of foaming agent;

[0017] Antioxidant 0.1-0.5 parts;

[0018] Weathering agent 0.1-0.5 parts.

[0019] As a further improvement of this solution, the regenerated EVA particles are recycled granulated particles of regenerated ethylene-vinyl acetate copolymer.

[0020] As a further improvement of the present solution, the filler is any one or more of variegated scraps, calcium powder, and talcum powder.

[0021] As a further improvement of this solution, the stabilizing agent and the foaming agent are any one or more of ZNO, ZNST, BIBP, AS, OBSH, and ADC.

[0022] As a further improvement of this solution, the antioxidant is BASF antioxidant 1010 and BASF antioxidant 168.

[0023] As a further improvement of this solution, the weathering agent is hexamethylphosphoric triamide.

[0024] As a further improvement of this scheme, the alkaline agent is H powder, X powder, or A powder;

[0025] in,

[0026] H powder is: activated alumina;

[0027] X powder is: calcium hydroxide Ca(OH)2;

[0028] Powder A is: magnesium hydroxide Mg(OH)2.

[0029] A fluorine-free foamed board modified by blending recycled polyethylene, recycled EVA and recycled scraps, wherein the preparation steps of the fluorine-free foamed board modified by blending recycled polyethylene, recycled EVA and recycled scraps are as follows:

[0030] S1 single screw mixed color scraps

[0031] Crushing-mixing-water ring cutting particles;

[0032] S2 produces variegated corner particles and polyethylene recycled particles

[0033] Twin-screw granulation - adding alkaline agent H powder, X powder, A powder - adjusting the screw-scale ratio speed ratio - preparing mixed granules, wherein the screw-scale ratio speed ratio is 44:1;

[0034] S3 Secret Refining

[0035] The specific steps of internal mixing are as follows:

[0036] Add recycled EVA, twin-screw granulation material, calcium powder, chemical additives, foaming agent, colorant, mix, knead and plasticize evenly.

[0037] As a further improvement of the present scheme, the internal mixer includes a frame and an auger conveying mechanism arranged on the frame, a shearing machine is arranged above the auger conveying mechanism, the shearing machine includes a hopper, a crushing motor fixedly arranged on the outside of the hopper, and a crushing auger rotatably arranged inside the hopper, the hopper is arranged through-through from top to bottom, and two groups of crushing augers are arranged, the side ends of the two groups of crushing augers are meshed with gears, and one group of the side ends of the crushing augers is transmission-connected to the crushing motor.

[0038] As a further improvement of the present solution, the auger conveying mechanism includes an extrusion bin, an extrusion motor arranged outside the extrusion bin, and an extrusion auger rotatably arranged in the extrusion bin, one end of the extrusion auger penetrates the side wall of the extrusion bin and is transmission-connected to the extrusion motor; a material discharge notch is provided on the middle blade of the crushing auger.

[0039] The preparation method of the felt silicone coated heat-resistant pad of the present invention has the following beneficial effects:

[0040] 1. The fluorine-free foam board modified by blending recycled polyethylene, recycled EVA and recycled scraps prepared by the present invention complies with relevant EU regulations. After February 25, 2023, the new EU regulations prohibit the production and sale of other substances, preparations and articles containing PFCAs, their salts and related compounds in the EU, unless the total concentration of PFCAs and their salts is less than 25ppb or the total concentration of PFCAs-related compounds is less than 260ppb. The present invention provides a defluorination and deodorization process and a preparation method of a fluorine-free EVA blended modified foam board in the prior art, solves the problem of fluorine-containing elements in the material, optimizes the production process of ordinary PE and EVA foam boards, and can meet EU regulations;

[0041] 2. The internal mixer of the present invention breaks the raw material into several strips by rotating the crushing auger, and performs a certain degree of heat dissipation to avoid partial condensation due to excessive internal temperature of the raw material, which leads to bubbles in the finished product. At the same time, since the size of the raw material after breaking is small, it is convenient for the auger conveying mechanism to transport it, and effectively avoids the inability of the auger in the auger conveying mechanism to effectively extrude the raw material due to the large size of the raw material mass, and will not eventually cause the raw material to cool and solidify in the auger conveying mechanism. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 This is a physical picture of the black foam of the fluorine-free foam board modified by blending recycled polyethylene, recycled EVA and recycled scraps prepared in Example 3 of the present invention;

[0043] Figure 2 This is a black foam test chart of the fluorine-free foam board modified by blending recycled polyethylene, recycled EVA and recycled scraps prepared in Example 3 of the present invention;

[0044] Figure 3 This is a working state diagram of the prior art where the auger cannot effectively extrude the raw material mass;

[0045] Figure 4 This is a schematic diagram of the structure of the banbury raw material extrusion device of the present invention;

[0046] Figure 5 It is a structural schematic diagram of a shearing machine of a banburying raw material extrusion device of the present invention;

[0047] Figure 6 It is a top view of the shearing machine of the internal mixing raw material extrusion device of the present invention. DETAILED DESCRIPTION

[0048] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention is further described below in conjunction with embodiments and drawings:

[0049] Embodiment 1:

[0050] Preparation of recycled polyethylene plus recycled EVA and recycled scraps blended modified fluorine-free foam board as follows:

[0051] 20 parts of recycled polyethylene

[0052] 35 parts of recycled EVA particles;

[0053] Recycle 30 pieces of colorful corner particles;

[0054] 6 parts H powder;

[0055] 15 parts of 1250 mesh calcium carbonate;

[0056] 3 parts of stabilizing accelerator;

[0057] 3 parts of foaming agent;

[0058] 0.1 part of antioxidant (0.05 part of BASF antioxidant 1010 and 0.05 part of BASF antioxidant 168);

[0059] The weathering agent is 0.1 part of hexamethylphosphoric triamide.

[0060] Both recycled polyethylene granules and recycled EVA granules are single-screw granulated materials.

[0061] H powder is activated alumina, a defluorination alkaline agent.

[0062] Embodiment 2:

[0063] Preparation of recycled polyethylene plus recycled EVA and recycled scraps blended modified fluorine-free foam board as follows:

[0064] 20 parts of recycled polyethylene

[0065] 35 parts of recycled EVA particles;

[0066] Recycle 30 pieces of colorful corner particles;

[0067] 3 parts H powder;

[0068] 3 parts of X powder;

[0069] 15 parts of 1250 mesh calcium carbonate;

[0070] 3 parts of stabilizing accelerator;

[0071] 3 parts of foaming agent;

[0072] 0.1 part of antioxidant (0.05 part of BASF antioxidant 1010 and 0.05 part of BASF antioxidant 168);

[0073] The weathering agent is 0.1 part of hexamethylphosphoric triamide.

[0074] Both recycled polyethylene granules and recycled EVA granules are single-screw granulated materials.

[0075] H and X powders are defluorination alkaline agents activated alumina and calcium hydroxide Ca(OH)2.

[0076] Example 3

[0077] Preparation of recycled polyethylene plus recycled EVA and recycled scraps blended modified fluorine-free foam board as follows:

[0078] 20 parts of recycled polyethylene

[0079] 35 parts of recycled EVA particles;

[0080] Recycle 30 pieces of colorful corner particles;

[0081] 2 parts H powder;

[0082] 2 parts of X powder;

[0083] 2 parts of A powder;

[0084] 15 parts of 1250 mesh calcium carbonate;

[0085] 3 parts of stabilizing accelerator;

[0086] 3 parts of foaming agent;

[0087] 0.1 part of antioxidant (0.05 part of BASF antioxidant 1010 and 0.05 part of BASF antioxidant 168);

[0088] The weathering agent is 0.1 part of hexamethylphosphoric triamide.

[0089] Both recycled polyethylene granules and recycled EVA granules are single-screw granulated materials.

[0090] H, X, and A powders are defluorination alkaline agents: activated alumina, calcium hydroxide Ca(OH)2, and magnesium hydroxide Mg(0H)2.

[0091] Examples 1 to 3 are carried out according to the following steps:

[0092] Process flow:

[0093] first step

[0094] Single screw extruder for mixed color scraps → crushing → mixing →

[0095] Water ring cutting particles

[0096] Step 2

[0097] Prepare the variegated corner particles and polyethylene recycled particles → twin-screw granulation → add H, X, A additives → adjust the screw Scale ratio Speed ​​ratio (44:1) → making mixed particles (purpose → removing odor → filtering impurities → making materials more evenly compatible)

[0098] Step 3

[0099]

[0100] (2) comprising the following preparation steps:

[0101] Step 1) Raw material preparation

[0102] Formulate materials according to components for internal mixing and internal refining;

[0103] Step 2) Mixing

[0104] The internal mixer is fed with mixed rice and color powder chemicals for simultaneous mixing and kneading, and then the mixing process is carried out;

[0105] Step 3) Refining process:

[0106] in,

[0107] 1) The temperature range of the front axle of the mixing mill is 95-98°C, and the temperature range of the rear axle is 92-95°C;

[0108] 2) Put the material poured out of the mixing into a thick layer three times, with a thickness of 8-10mm, to dissipate heat; cross-make triangular thin packages for refining, with a thickness of 0.8-1mm; make thin layers three times;

[0109] 3) Cold water sheet dispensing machine temperature: roller temperature is 20-25°C;

[0110] Step 4) Preparation before vulcanization:

[0111] The specific gravity of the raw material sheet is measured according to the capacity of a certain mold size;

[0112] Step 5) Vulcanization foaming process:

[0113] Load the measured raw material into the inner cavity of the vulcanizer mold, increase the pressure to 20MPa, control the vulcanization temperature at 182℃, and the vulcanization time at 30min;

[0114] Step 6) Discharging and shaping process:

[0115] After vulcanization is completed, take out the foamed board and dissipate heat separately for 1 hour, then stack it and cool it naturally for 72 hours before it can be processed into the required products.

[0116] The process of step 2) banburying is specifically as follows:

[0117] Process flow:

[0118]

[0119] (3) The corresponding products are finally obtained. Examples 1, 2, and 3 correspond to black foam 1, black foam 2, and black foam 3, respectively.

[0120] Finally, according to the test results, it can be known that the black foam 3 corresponding to Example 3 is the fluorine-free EVA blended modified foaming material that meets the requirements of the present invention and does not contain fluorine element.

[0121] In the product preparation process of Examples 1 to 3, if the equipment used for banburying adopts the mechanism in the prior art, the following problems will occur: in the production process of foamed boards, polystyrene (EPS), polyurethane (PU), polypropylene (PP) and other materials are usually banburyed, and then the banburying raw material mass is formed into a raw sheet through an extrusion mechanism and a calendering mechanism. However, due to the high internal temperature of the banburying raw material mass, it is easy to cause internal condensation, and finally cause bubbles to form on the surface of the product foamed board; at the same time, due to the large size of the banburying raw material mass, it is easy for the auger in the extrusion mechanism to be unable to effectively extrude the raw material mass, and finally the raw material is cooled and solidified in the auger conveying mechanism (such as Figure 3 shown).

[0122] In view of the above technical problems, the raw material extrusion device in the mixing process was improved, see Figures 4 to 6 ;

[0123] The specific technical solutions are as follows:

[0124] A device for extruding raw materials after internal mixing, comprising: a frame 1 and an auger conveying mechanism 2 arranged on the frame 1, a shearing machine 3 is arranged above the auger conveying mechanism 2, the shearing machine 3 comprises a hopper 31, a crushing motor 32 fixedly arranged on the outside of the hopper 31 and a crushing auger 33 rotatably arranged inside the hopper 31, the hopper 31 is arranged through-through from top to bottom, and the crushing auger 33 is provided with two groups, the side ends of the two groups of crushing augers 33 are meshed by gears, and the side end of one group of the crushing augers 33 is transmission-connected to the crushing motor 32.

[0125] The crushing auger 33 includes a crushing auger 1 and a crushing auger 2 which are arranged adjacent to each other. A notch 1 331 is arranged on the middle blade of the crushing auger 1, and a notch 2 332 is also arranged on the adjacent blade of the blade closest to the crushing auger 1 on the adjacent crushing auger 2.

[0126] Only by setting the gap 1 331 and the gap 2 332, can the specific working process be achieved. Figure 6 As shown, during the rotation of the auger, a continuous downward squeezing force is continuously provided to the raw material mass through the gap 1 331 and the gap 2 332, which effectively avoids the situation in the prior art that the raw material mass rolls between the two groups of crushing augers 33 and cannot enter the crushing augers 33 for crushing.

[0127] like Figures 4 to 6 As shown, in actual use of the present invention, the lump raw materials after internal mixing and internal refining are transported to the hopper 31 through the output mechanism, and are crushed by the rotating crushing auger 33, so that the lump raw materials are broken into a number of strip-shaped raw materials, and a certain degree of heat dissipation is performed to avoid partial condensation due to excessive internal temperature of the raw materials, which leads to the appearance of bubbles inside the finished product. At the same time, since the size of the crushed raw materials is small, it is convenient for the auger conveying mechanism 2 to transport them, and it is effectively avoided that the auger in the auger conveying mechanism 2 cannot be effectively extruded due to the large size of the raw material lumps, and finally the raw materials are cooled and solidified in the auger conveying mechanism 2.

[0128] As a further preferred embodiment, the auger conveying mechanism 2 includes an extrusion bin 21, an extrusion motor 22 arranged outside the extrusion bin 21, and an extrusion auger 23 rotatably arranged in the extrusion bin 21, and one end of the extrusion auger 23 penetrates the side wall of the extrusion bin 21 and is transmission-connected to the extrusion motor 22.

[0129] Specifically, the extrusion motor 22 drives the extrusion auger 23 to rotate in the extrusion bin 21, and the crushed raw materials are extruded to the calendering mechanism for stretching and forming to form raw material sheets.

[0130] As a further preferred embodiment, three groups of the extrusion augers 23 are provided, and the included angle between the projections of the extrusion augers 23 on both sides and the middle extrusion augers 23 on the horizontal plane is an acute angle. By providing three groups of extrusion augers 23, the extrusion efficiency is improved.

[0131] As a further preferred embodiment, baffles 311 are arranged around the hopper 31, and the baffles 311 are used to prevent the raw material mass from rushing out of the hopper 31 during the feeding process.

[0132] As a further preferred embodiment, the baffle 311 close to the internal mixer is horizontally arranged, and the other baffles 311 are inclinedly arranged.

[0133] The test results of the products obtained in Examples 1 to 3 are shown in Table 1

[0134] Table 1

[0135] Example Sample description Organic fluorine content / mg / kg 1 Black Foam A 117mg / kg 2 Black Foam B 66mg / kg 3 Black Foam C Not detected

[0136] As can be seen from the above table, the fluorine-free foamed board modified by blending recycled polyethylene, recycled EVA and recycled scraps and the preparation method thereof of the present invention are as follows:

[0137] 1) High cost performance and easy to process.

[0138] 2) This product is non-toxic and complies with EU testing standards (EN15343, REACH, ROSHD, etc.), and is the preferred choice for export products.

[0139] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent changes made using the present invention are within the patent protection scope of the present invention.

Claims

1. A fluorine-free foamed board modified by blending recycled polyethylene, recycled EVA and recycled scraps, characterized in that: The composition comprises the following components in parts by weight: 30-40 parts of recycled polyethylene; 20-25 parts of recycled EVA particles; Recover 30-35 portions of variegated corner particles; 2 to 7.5 parts of alkaline agent; 10-15 parts of filler; 0.8 to 4 parts of stabilizing accelerator; 1.5 to 6 parts of foaming agent; Antioxidant 0.1-0.5 parts; Weathering agent 0.1-0.5 parts.

2. The fluorine-free foamed board modified by blending recycled polyethylene, recycled EVA and recycled scraps according to claim 1, characterized in that: The regenerated EVA particles are recycled granulated particles of regenerated ethylene-vinyl acetate copolymer.

3. The fluorine-free foamed board modified by blending recycled polyethylene, recycled EVA and recycled scraps according to claim 1, characterized in that: The filler is any one or more of variegated scraps, calcium powder, and talcum powder.

4. The fluorine-free foamed board modified by blending recycled polyethylene, recycled EVA and recycled scraps according to claim 1, characterized in that: The stabilizing agent and foaming agent are any one or more of ZNO, ZNST, BIBP, AS, OBSH and ADC.

5. The fluorine-free foamed board modified by blending recycled polyethylene, recycled EVA and recycled scraps according to claim 1, characterized in that: The antioxidants are BASF antioxidant 1010 and BASF antioxidant 168.

6. The fluorine-free foamed board modified by blending recycled polyethylene, recycled EVA and recycled scraps according to claim 1, characterized in that: The weathering agent is hexamethylphosphoric triamide.

7. The fluorine-free foamed board modified by blending recycled polyethylene, recycled EVA and recycled scraps according to claim 1, characterized in that: Alkaline agents include H powder, X powder, and A powder; in, H powder is: activated alumina; X powder is: calcium hydroxide Ca(OH)2; Powder A is: magnesium hydroxide Mg(OH)2.

8. A fluorine-free foamed board modified by blending recycled polyethylene, recycled EVA and recycled scraps. The preparation steps of the fluorine-free foamed board modified by blending recycled polyethylene, recycled EVA and recycled scraps according to any one of claims 1 to 7 are as follows: S1 single screw mixed color scraps Crushing-mixing-water ring cutting particles; S2 produces variegated corner particles and polyethylene recycled particles Twin-screw granulation - adding alkaline agent H powder, X powder, A powder - adjusting screw scale ratio speed ratio - making mixed granules, wherein, The spiral scale ratio speed ratio is 44:1; S3 Secret Refining The specific steps of internal mixing are as follows: Add recycled EVA, twin-screw granulation material, calcium powder, chemical additives, foaming agent, colorant, mix, knead and plasticize evenly.

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