A compression-resistant antibacterial irradiation cross-linked polyolefin foaming material, a preparation method and application thereof

Abstract

The application belongs to the technical field of foamed materials, and particularly relates to a compression-resistant and antibacterial radiation crosslinking polyolefin foamed material and a preparation method and application thereof. The compression-resistant and antibacterial radiation crosslinking polyolefin foamed material comprises the following components in parts by weight: 60-80 parts of low-density polyethylene, 20-40 parts of high-density polyethylene, 3-10 parts of a foaming agent, 3-5 parts of an antibacterial agent, 2-4 parts of a compatilizer, 0-2 parts of a nucleating agent, and 0.2-0.5 parts of an antioxidant. The low-density polyethylene is used as a base resin, a certain amount of high-density polyethylene and an antibacterial agent are added for melt blending modification, and processes such as stepwise banburying, extrusion molding, radiation crosslinking and stepwise foaming are combined, so that the prepared compression-resistant and antibacterial radiation crosslinking polyolefin foamed material has high hardness and compression strength and excellent antibacterial performance, can meet the demand of the existing market for antibacterial crosslinking polyolefin foamed materials, and improves market competitiveness.

Description

Technical Field

[0001] This invention belongs to the field of foaming material technology, specifically relating to a pressure-resistant and antibacterial irradiated cross-linked polyolefin foaming material, its preparation method, and its application. Background Technology

[0002] Polyolefin foam materials are foamed materials made from polyethylene, polypropylene, etc., mainly cross-linked foam materials. Cross-linking methods can be divided into chemical cross-linking and radiation cross-linking. Compared with chemical cross-linking, which requires organic peroxides as cross-linking agents, radiation cross-linking does not require the addition of other substances. Through green and healthy radiation processing technology, the cross-linking produced by electro-ion radiation changes the original structure of polyolefins, forming a network of independent closed-cell foam structures. It has a series of properties such as light weight, good stability, non-toxicity, wear resistance, chemical corrosion resistance, and low temperature resistance. It has a wide range of applications, involving multiple industries such as daily necessities, packaging, construction, and medical materials.

[0003] Wood-plastic composite (WPC) is a novel material developed in recent years, organically combining the advantages of two different materials. It can be surface-glued and painted like wood, and can also be drilled, planed, and nailed; it can also be molded and processed like thermoplastics, showcasing the ease of processing of wood and the versatility and flexibility of plastic processing methods, resulting in a wide range of applications. Irradiated cross-linked polyolefin foam, as a crucial component of WPC flooring, plays a vital role in high compressive strength and high abrasion resistance under high-frequency angle wheelchair testing. Furthermore, WPC flooring is prone to mold growth and bacterial film formation in humid environments, thus requiring high antibacterial properties. However, currently available conventional polyolefin (LDPE) foam materials generally suffer from low hardness, low strength, and poor antibacterial properties, significantly limiting the applicability of WPC flooring. Therefore, there is an urgent need to develop a polyolefin foam material with good foaming performance, excellent mechanical properties, and antibacterial capabilities.

[0004] The invention patent with publication number CN103113653A discloses an HDPE / LDPE blended foam material and its preparation method. The method involves blending 100 parts of HDPE and LDPE according to a certain ratio, extruding and granulating the mixture, and then plasticizing it in a two-roll mill. Gradually add 0.5 parts by weight of crosslinking agent, 3-10 parts by weight of AC foaming agent, 1-2 parts by weight of zinc oxide, 0.5 parts by weight of stearic acid, 0.1 parts by weight of antioxidant, and 3-15 parts by weight of inorganic filler and other additives. After mixing evenly, the mixture is placed in a mold for foaming and molding. The above method utilizes the good compatibility between HDPE and LDPE. After blending, the good foaming properties of LDPE can improve the foaming properties of HDPE. However, directly plasticizing the additives with the base material requires strict control of the roll temperature of the two-roll mill (143-147℃), which is a harsh operating condition. Moreover, the additives, especially inorganic fillers, have poor compatibility with the base material, resulting in limited improvement on the performance of polyolefin foam materials. In addition, the prepared foam materials do not have antibacterial properties, which limits their application range. Summary of the Invention

[0005] To address the shortcomings of the existing technology, the present invention aims to provide a pressure-resistant and antibacterial irradiated cross-linked polyolefin foam material. This invention uses low-density polyethylene as the base resin and modifies it through melt blending with a certain amount of high-density polyethylene and an antibacterial agent, thereby imparting high hardness and compressive strength, as well as excellent antibacterial properties to the polyolefin foam material. It can be used as a carrier material for floor sound-absorbing mats.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A pressure-resistant and antibacterial radiation-crosslinked polyolefin foam material comprises the following components, by weight: 60-80 parts of low-density polyethylene, 20-40 parts of high-density polyethylene, 3-10 parts of foaming agent, 3-5 parts of antibacterial agent, 2-4 parts of compatibilizer, 0-2 parts of nucleating agent, and 0.2-0.5 parts of antioxidant.

[0008] As a preferred embodiment of the above technical solution, the low-density polyethylene has a melt flow rate of 0.8–2.0 g / 10 min at 190°C and a load of 2.16 kg, and a melting point temperature of 110–115°C; the high-density polyethylene has a density of 0.9–1.0 g / cm³. 3 The melt flow rate at 190℃ and a load of 2.16kg is 6.0~8.0g / 10min, and the melting point is 133~135℃.

[0009] As a preferred embodiment of the above technical solution, the foaming agent is any one of azodicarbonamide, 4,4-oxobisbenzenesulfonylhydrazine, and dimethylnitrospentamethylenetetramine. Preferably, the foaming agent is azodicarbonamide (ADC), with a gas emission rate of 200-230 mL / g, a particle size of 20-50 μm, and a pH value of 6-8.

[0010] As a preferred embodiment of the above technical solution, the antibacterial agent is one or more of zinc pyrithione (ZPT), sodium pyrithione (SPT), and copper pyrithione (CPT).

[0011] As a preferred embodiment of the above technical solution, the compatibilizer is one or more of PE-g-MAH, PE-g-GMA, and PE-G-AA.

[0012] As a preferred embodiment of the above technical solution, the nucleating agent is one or more of the following powders: calcium carbonate, talc, montmorillonite, mica powder, etc.

[0013] As a preferred embodiment of the above technical solution, the antioxidant is one or more of antioxidant 1010 and antioxidant 300. Preferably, the antioxidant is antioxidant 1010, namely pentaerythritol tetrakis(3,5-di-tert-butyl-4-hydroxy)phenylpropionate, with the molecular formula C1. 73 H 108 O 12 It has a melting point of 110–125°C and is a white powder.

[0014] In the above technical solution, the foaming agent used is a chemical foaming agent, which has a high decomposition temperature, generates a large amount of heat during decomposition, is difficult to release gas, and has an uneven cell structure. Therefore, as a preferred embodiment of the above technical solution, it also includes 0.5 to 0.8 parts of foaming aid. Adding a small amount of foaming aid to the polyolefin foaming raw material can act as an accelerator or activator to change the decomposition temperature of the foaming agent, thereby lowering the decomposition temperature of the foaming agent, increasing the decomposition rate of the foaming agent, increasing the number of bubbles, and ultimately leading to a decrease in the density of the foamed material and an increase in the foaming ratio. Preferably, the foaming aid is one or more of zinc stearate, zinc oxide, calcium stearate, and cadmium oxide.

[0015] Another object of the present invention is to provide a method for preparing the above-mentioned pressure-resistant and antibacterial irradiated cross-linked polyolefin foam material.

[0016] A method for preparing a pressure-resistant and antibacterial irradiated crosslinked polyolefin foam material includes the following steps:

[0017] S1. Internal mixing and granulation: Low-density polyethylene, foaming agent, and antioxidant are mixed in an internal mixer and blended at 120-130℃ for 9-12 minutes to obtain foamed particles; Low-density polyethylene, nucleating agent, and foaming aid are mixed in an internal mixer and blended at 120-130℃ for 8-10 minutes to obtain nucleated particles; Low-density polyethylene, antibacterial agent, and compatibilizer are mixed in an internal mixer and blended at 120-130℃ for 8-10 minutes to obtain antibacterial particles.

[0018] S2. Extrusion molding: The remaining low-density polyethylene, high-density polyethylene, foaming particles, nucleating particles and antibacterial particles are mixed evenly and then placed on a screw extruder for plasticizing and extrusion to obtain a blend sheet.

[0019] S3, Irradiation crosslinking: The blend sheet is irradiated and crosslinked using an electron accelerator to obtain the crosslinked sheet;

[0020] S4. High-temperature foaming: The cross-linked sheet is passed through the preheating section and the foaming section of the foaming furnace in sequence for foaming treatment. After foaming, a pressure-resistant and antibacterial irradiated cross-linked polyolefin foam material is obtained.

[0021] As a preferred embodiment of the above technical solution, before step S1, each component raw material needs to be dried at 60-80°C for 4-6 hours.

[0022] As a preferred embodiment of the above technical solution, in step S1, the amount of low-density polyethylene added to the foamed particles is 2.5 times that of the foaming agent; the amount of low-density polyethylene added to the nucleating particles is 3 times that of the nucleating agent; and the amount of low-density polyethylene added to the antibacterial particles is 5 times that of the antibacterial agent.

[0023] As a preferred embodiment of the above technical solution, in step S2, the screw extruder is a single-screw extruder, and the process conditions of the single-screw extruder are as follows: zone 1 temperature is 120-130℃, zone 2 temperature is 130-140℃, zone 3 temperature is 140-150℃, zone 4 temperature is 135-140℃, zone 5 temperature is 130-135℃, zone 6 temperature is 125-130℃, and zone 7 temperature is 125-130℃; the neck temperature is 124-128℃, the flange temperature is 128-132℃, the die temperature is 135-140℃, the die pressure is 10-14MPa, and the screw speed is 15-20 r / min.

[0024] As a preferred embodiment of the above technical solution, in step S3, the irradiation crosslinking process conditions are: energy of 2–2.5 MeV, irradiation of 2–4 sheet layers, scanning width of 800–1000 mm, and irradiation dose of 8–10 Mrad. The use of high-energy electron beam modification effectively improves the crosslinking degree of polyethylene resin, significantly enhancing the physical properties of the foamed material.

[0025] As a preferred embodiment of the above technical solution, in step S4, the process conditions of the preheating section are: zone 1 temperature 50-60℃, zone 2 temperature 60-70℃, and zone 3 temperature 80-90℃; the process conditions of the foaming section are: zone 1 temperature 250-260℃, zone 2 temperature 250-260℃, zone 3 temperature 240-250℃, zone 4 temperature 230-250℃, zone 5 temperature 180-210℃, and zone 6 temperature 160-180℃.

[0026] As a preferred embodiment of the above technical solution, in step S4 during the foaming process, the feeding speed is 2.5 to 5.0, the output speed is 5.0 to 13.0, and the ratio of the feeding speed to the output speed is 2.0 to 3.0.

[0027] In the above technical solution, steps S2 and S4 respectively use a single-screw extruder and a foaming furnace. Both processes employ a zoned heating method, with the temperature of each zone adjusted by heating and cooling. Compared to dynamic temperature adjustment in a single zone, this method offers the advantage of more stable temperature and avoids unnecessary errors caused by dynamic adjustment.

[0028] Another object of the present invention is to provide a carrier material for a floor soundproofing mat, which includes the above-mentioned pressure-resistant and antibacterial irradiated cross-linked polyolefin foam material.

[0029] In summary, the present invention has the following beneficial effects:

[0030] This invention uses low-density polyethylene as the base resin and modifies it by melt blending with a certain amount of high-density polyethylene and antibacterial agents. Combined with stepwise mixing, extrusion molding, irradiation crosslinking, and stepwise foaming processes, the resulting compression-resistant and antibacterial irradiated crosslinked polyolefin foam material has high hardness and compressive strength, as well as excellent antibacterial properties. It can meet the current market demand for antibacterial crosslinked polyolefin foam materials and enhance market competitiveness. At the same time, it overcomes the problems of low hardness, low compressive strength, and bacterial film formation in humid environments of traditional single low-density polyethylene crosslinked foam materials. Attached Figure Description

[0031] Figure 1 This is a flowchart illustrating the technical route of the pressure-resistant and antibacterial irradiated crosslinked polyolefin foam material of the present invention.

[0032] Figure 2 The graph shows the change in apparent density of the pressure-resistant and antibacterial irradiated cross-linked polyolefin foam materials prepared in Examples 1-4 of this invention as a function of the weight of high-density polyethylene (HDPE).

[0033] Figure 3 The melting temperature curves are shown for the blend sheets prepared in Examples 1-4 and Comparative Example 1 of this invention.

[0034] Figure 4 The crystallization temperature curves are shown for the blend sheets prepared in Examples 1-4 and Comparative Example 1 of this invention.

[0035] Figure 5 The complex viscosity curves are shown for the blend sheets prepared in Examples 1-4 and Comparative Example 1 of this invention.

[0036] Figure 6 The storage modulus curves are shown for the blend sheets prepared in Examples 1-4 and Comparative Example 1 of this invention.

[0037] Figure 7 Scanning electron microscope (SEM) images of the pressure-resistant and antibacterial irradiated crosslinked polyolefin foam materials prepared in Examples 1-4 of this invention. Detailed Implementation

[0038] The technical solution of the present invention will be further described below with reference to specific embodiments. However, the specific details of the embodiments are only for illustrating the present invention and do not represent all technical methods under the concept of the present invention. Therefore, they should not be construed as limiting the overall technical solution of the present invention.

[0039] Example 1

[0040] An anti-compression and antibacterial irradiated cross-linked polyolefin foam material comprises the following components in parts by weight: 80 parts of low-density polyethylene, 20 parts of high-density polyethylene, 3 parts of azodicarbonamide, 4 parts of zinc pyridinethione, 3 parts of PE-g-MAH, 1 part of calcium carbonate, 0.8 parts of zinc stearate, and 0.5 parts of antioxidant 1010.

[0041] The preparation method of the pressure-resistant and antibacterial irradiated crosslinked polyolefin foam material includes the following steps:

[0042] S1. Internal mixing and granulation: Low-density polyethylene, azodicarbonamide, and antioxidant 1010 are mixed in an internal mixer and blended at 130°C for 10 minutes to obtain foamed particles; low-density polyethylene, calcium carbonate, and zinc stearate are mixed in an internal mixer and blended at 120°C for 8 minutes to obtain nucleated particles; low-density polyethylene, zinc pyrithione, and PE-g-MAH are mixed in an internal mixer and blended at 120°C for 10 minutes to obtain antibacterial particles; in foamed particles, the amount of low-density polyethylene added is 2.5 times that of the foaming agent; in nucleated particles, the amount of low-density polyethylene added is 3 times that of the nucleating agent; in antibacterial particles, the amount of low-density polyethylene added is 5 times that of the antibacterial agent.

[0043] S2. Extrusion Molding: The remaining low-density polyethylene, high-density polyethylene, foamed particles, nucleating particles, and antibacterial particles are mixed in a high-speed mixer. The mixture is then plasticized and extruded through a single-screw extruder. The temperature is set in seven extrusion zones along the extrusion direction: Zone 1 temperature is 120℃, Zone 2 temperature is 130℃, Zone 3 temperature is 140℃, Zone 4 temperature is 140℃, Zone 5 temperature is 130℃, Zone 6 temperature is 128℃, Zone 7 temperature is 125℃, the neck temperature is 126℃, the flange temperature is 128℃, the die temperature is 135℃, the die pressure is 10MPa, and the screw speed is 15r / min, to obtain a blend sheet.

[0044] S3. The blended sheet was placed under an electron accelerator for irradiation crosslinking to obtain the crosslinked sheet. The process conditions were: energy of 2.0 MeV, number of irradiated sheet layers of 4, scanning width of 1000 mm, and irradiation dose of 80 kGy.

[0045] S4. The cross-linked sheet is subjected to a high-temperature foaming process, passing sequentially through the preheating section and the foaming section of a foaming furnace to produce a pressure-resistant and antibacterial irradiated cross-linked polyolefin foam material. The temperatures in the preheating section are 70℃ in zone 1, 80℃ in zone 2, and 90℃ in zone 3. The temperatures in the foaming section are 260℃ in zone 1, 260℃ in zone 2, 250℃ in zone 3, 250℃ in zone 4, 180℃ in zone 5, and 180℃ in zone 6. The sheet feeding speed is 4.0, the sheet output speed is 12.0, and the feed-output ratio is approximately 3.0.

[0046] Example 2

[0047] It is basically the same as Example 1, except that the 80 parts of low-density polyethylene and 20 parts of high-density polyethylene in Example 1 are replaced with 75 parts of low-density polyethylene and 25 parts of high-density polyethylene.

[0048] An anti-compression and antibacterial irradiated cross-linked polyolefin foam material comprises the following components in parts by weight: 75 parts low-density polyethylene, 25 parts high-density polyethylene, 3 parts azodicarbonamide, 4 parts zinc pyridinethione, 3 parts PE-g-MAH, 1 part calcium carbonate, 0.8 parts zinc stearate, and 0.5 parts antioxidant 1010.

[0049] Example 3

[0050] It is basically the same as Example 1, except that the 80 parts of low-density polyethylene and 20 parts of high-density polyethylene in Example 1 are replaced with 70 parts of low-density polyethylene and 30 parts of high-density polyethylene.

[0051] An anti-compression and antibacterial irradiated cross-linked polyolefin foam material comprises the following components in parts by weight: 70 parts low-density polyethylene, 30 parts high-density polyethylene, 3 parts azodicarbonamide, 4 parts zinc pyridinethione, 3 parts PE-g-MAH, 1 part calcium carbonate, 0.8 parts zinc stearate, and 0.5 parts antioxidant 1010.

[0052] Example 4

[0053] It is basically the same as Example 1, except that the 80 parts of low-density polyethylene and 20 parts of high-density polyethylene in Example 1 are replaced with 65 parts of low-density polyethylene and 35 parts of high-density polyethylene.

[0054] An anti-compression and antibacterial irradiated cross-linked polyolefin foam material comprises the following components in parts by weight: 65 parts low-density polyethylene, 35 parts high-density polyethylene, 3 parts azodicarbonamide, 4 parts zinc pyridinethione, 3 parts PE-g-MAH, 1 part calcium carbonate, 0.8 parts zinc stearate, and 0.5 parts antioxidant 1010.

[0055] Example 5

[0056] An anti-compression and antibacterial irradiated crosslinked polyolefin foam material comprises the following components in parts by weight: 78 parts of low-density polyethylene, 22 parts of high-density polyethylene, 5 parts of 4,4-oxobisbenzenesulfonyl hydrazine, 4 parts of sodium pyridinethione, 3 parts of PE-g-GMA, 1 part of talc, 0.6 parts of zinc oxide, and 0.5 parts of antioxidant 300.

[0057] The preparation method of the pressure-resistant and antibacterial irradiated crosslinked polyolefin foam material includes the following steps:

[0058] S1. Internal mixing and granulation: Low-density polyethylene, 4,4-oxobisbenzenesulfonyl hydrazine, and antioxidant 300 are mixed in an internal mixer and blended at 130°C for 10 minutes to obtain foamed particles; Low-density polyethylene, talc, and zinc oxide are mixed in an internal mixer and blended at 125°C for 7 minutes to obtain nucleated particles; Low-density polyethylene, sodium pyrithione, and PE-g-GMA are mixed in an internal mixer and blended at 120°C for 10 minutes to obtain antibacterial particles; In foamed particles, the amount of low-density polyethylene added is 2.5 times that of the foaming agent; In nucleated particles, the amount of low-density polyethylene added is 3 times that of the nucleating agent; In antibacterial particles, the amount of low-density polyethylene added is 5 times that of the antibacterial agent.

[0059] S2. Extrusion Molding: The remaining low-density polyethylene, high-density polyethylene, foamed particles, nucleating particles, and antibacterial particles are mixed in a high-speed mixer. The mixture is then plasticized and extruded through a single-screw extruder. The temperature is set in seven extrusion zones along the extrusion direction: Zone 1 temperature is 125℃, Zone 2 temperature is 135℃, Zone 3 temperature is 145℃, Zone 4 temperature is 140℃, Zone 5 temperature is 135℃, Zone 6 temperature is 125℃, Zone 7 temperature is 125℃, the neck temperature is 128℃, the flange temperature is 130℃, the die temperature is 135℃, the die pressure is 12MPa, and the screw speed is 18r / min, to obtain a blend sheet.

[0060] S3. The blended sheet was placed under an electron accelerator for irradiation crosslinking to obtain the crosslinked sheet. The process conditions were: energy of 2.2 MeV, number of irradiated sheet layers of 3, scanning width of 1000 mm, and irradiation dose of 90 kGy.

[0061] S4. The cross-linked sheet is subjected to a high-temperature foaming process, passing sequentially through the preheating section and the foaming section of a foaming furnace to produce a pressure-resistant and antibacterial irradiated cross-linked polyolefin foam material. The temperatures in the preheating section are 70℃ in zone 1, 80℃ in zone 2, and 90℃ in zone 3. The temperatures in the foaming section are 260℃ in zone 1, 260℃ in zone 2, 250℃ in zone 3, 240℃ in zone 4, 180℃ in zone 5, and 180℃ in zone 6. The sheet feed rate is 5.0, the sheet output rate is 13.0, and the feed-output ratio is approximately 2.6.

[0062] Example 6

[0063] A pressure-resistant and antibacterial irradiated crosslinked polyolefin foam material comprises the following components in parts by weight: 60 parts of low-density polyethylene, 40 parts of high-density polyethylene, 7 parts of dimethylnitrosopyramethylenetetramine, 4.5 parts of copper pyridinethione, 2.5 parts of PE-g-AA, 1.5 parts of montmorillonite, 0.6 parts of calcium stearate, and 0.4 parts of antioxidant 1010.

[0064] The preparation method of the pressure-resistant and antibacterial irradiated crosslinked polyolefin foam material includes the following steps:

[0065] S1. Internal mixing and granulation: Low-density polyethylene, dimethylnitrosopyramethylenetetramine, and antioxidant 1010 are mixed in an internal mixer and blended at 120°C for 12 minutes to obtain foamed particles; low-density polyethylene, montmorillonite, and calcium stearate are mixed in an internal mixer and blended at 130°C for 7 minutes to obtain nucleated particles; low-density polyethylene, copper pyridinethione, and PE-g-AA are mixed in an internal mixer and blended at 125°C for 8 minutes to obtain antibacterial particles; in foamed particles, the amount of low-density polyethylene added is twice that of the foaming agent; in nucleated particles, the amount of low-density polyethylene added is three times that of the nucleating agent; in antibacterial particles, the amount of low-density polyethylene added is five times that of the antibacterial agent.

[0066] S2. Extrusion Molding: The remaining low-density polyethylene, high-density polyethylene, foamed particles, nucleating particles, and antibacterial particles are mixed in a high-speed mixer. The mixture is then plasticized and extruded through a single-screw extruder. The temperature is set in seven extrusion zones along the extrusion direction: Zone 1 temperature is 130℃, Zone 2 temperature is 135℃, Zone 3 temperature is 140℃, Zone 4 temperature is 140℃, Zone 5 temperature is 130℃, Zone 6 temperature is 130℃, Zone 7 temperature is 128℃, the neck temperature is 128℃, the flange temperature is 130℃, the die temperature is 136℃, the die pressure is 14MPa, and the screw speed is 20r / min, to obtain a blend sheet.

[0067] S3. The blended sheet was placed under an electron accelerator for irradiation crosslinking to obtain the crosslinked sheet. The process conditions were: energy of 2.5 MeV, number of irradiated sheet layers of 2, scanning width of 800 mm, and irradiation dose of 100 kGy.

[0068] S4. The cross-linked sheet is subjected to a high-temperature foaming process, passing sequentially through the preheating section and the foaming section of a foaming furnace to produce a pressure-resistant and antibacterial irradiated cross-linked polyolefin foam material. The temperatures in the preheating section are 70℃ in zone 1, 80℃ in zone 2, and 90℃ in zone 3. The temperatures in the foaming section are 260℃ in zone 1, 260℃ in zone 2, 240℃ in zone 3, 240℃ in zone 4, 180℃ in zone 5, and 180℃ in zone 6. The sheet feeding speed is 3.0, the sheet output speed is 7.2, and the feed-output ratio is approximately 2.4.

[0069] Example 7

[0070] An anti-compression and antibacterial irradiated cross-linked polyolefin foam material comprises the following components in parts by weight: 65 parts low-density polyethylene, 35 parts high-density polyethylene, 9 parts azodicarbonamide, 5 parts zinc pyridinethione, 3 parts PE-g-MAH, 1 part mica powder, 0.4 parts cadmium oxide, and 0.5 parts antioxidant 1010.

[0071] The preparation method of the pressure-resistant and antibacterial irradiated crosslinked polyolefin foam material includes the following steps:

[0072] S1. Internal mixing and granulation: Low-density polyethylene, azodicarbonamide, and antioxidant 1010 are mixed in an internal mixer and blended at 120°C for 12 minutes to obtain foamed particles; Low-density polyethylene, mica powder, and cadmium oxide are mixed in an internal mixer and blended at 130°C for 7 minutes to obtain nucleated particles; Low-density polyethylene, zinc pyrithione, and PE-g-MAH are mixed in an internal mixer and blended at 120°C for 10 minutes to obtain antibacterial particles; In foamed particles, the amount of low-density polyethylene added is twice that of the foaming agent; In nucleated particles, the amount of low-density polyethylene added is three times that of the nucleating agent; In antibacterial particles, the amount of low-density polyethylene added is five times that of the antibacterial agent.

[0073] S2. Extrusion Molding: The remaining low-density polyethylene, high-density polyethylene, foamed particles, nucleating particles, and antibacterial particles are mixed in a high-speed mixer. The mixture is then plasticized and extruded through a single-screw extruder. The temperature is set in seven extrusion zones along the extrusion direction: Zone 1 temperature is 125℃, Zone 2 temperature is 140℃, Zone 3 temperature is 150℃, Zone 4 temperature is 140℃, Zone 5 temperature is 135℃, Zone 6 temperature is 130℃, Zone 7 temperature is 130℃, the neck temperature is 126℃, the flange temperature is 128℃, the die temperature is 136℃, the die pressure is 13MPa, and the screw speed is 16r / min, to obtain a blend sheet.

[0074] S3. The blend sheet was placed under an electron accelerator for irradiation crosslinking to obtain the crosslinked sheet. The process conditions were: energy of 2.0 MeV, number of irradiated sheet layers of 3, scanning width of 900 mm, and irradiation dose of 90 kGy.

[0075] S4. The cross-linked sheet is subjected to a high-temperature foaming process, passing sequentially through the preheating section and the foaming section of a foaming furnace to produce a pressure-resistant and antibacterial irradiated cross-linked polyolefin foam material. The temperatures in the preheating section are 70℃ in zone 1, 80℃ in zone 2, and 90℃ in zone 3. The temperatures in the foaming section are 260℃ in zone 1, 260℃ in zone 2, 250℃ in zone 3, 250℃ in zone 4, 180℃ in zone 5, and 180℃ in zone 6. The sheet feeding speed is 4.0, the sheet output speed is 12.0, and the feed-output ratio is approximately 3.0.

[0076] Comparative Example 1

[0077] It is basically the same as Example 1, except that the high-density polyethylene in Example 1 is replaced with low-density polyethylene, and the compatibilizer PE-g-MAH is not used.

[0078] A pressure-resistant and antibacterial irradiated crosslinked polyolefin foam material comprises the following components in parts by weight: 100 parts low-density polyethylene, 3 parts azodicarbonamide, 4 parts zinc pyrithione, 1 part calcium carbonate, 0.8 parts zinc stearate, and 0.5 parts antioxidant 1010.

[0079] Comparative Example 2

[0080] It is basically the same as Example 1, except that the low-density polyethylene in Example 1 is replaced with high-density polyethylene, and the compatibilizer PE-g-MAH is not used.

[0081] A pressure-resistant and antibacterial irradiated crosslinked polyolefin foam material comprises the following components in parts by weight: 100 parts high-density polyethylene, 3 parts azodicarbonamide, 4 parts zinc pyrithione, 1 part calcium carbonate, 0.8 parts zinc stearate, and 0.5 parts antioxidant 1010.

[0082] Comparative Example 3

[0083] It is basically the same as Example 1, except that the 80 parts of low-density polyethylene and 20 parts of high-density polyethylene in Example 1 are replaced with 20 parts of low-density polyethylene and 80 parts of high-density polyethylene.

[0084] An anti-compression and antibacterial irradiated cross-linked polyolefin foam material comprises the following components in parts by weight: 20 parts low-density polyethylene, 80 parts high-density polyethylene, 3 parts azodicarbonamide, 4 parts zinc pyridinethione, 3 parts PE-g-MAH, 1 part calcium carbonate, 0.8 parts zinc stearate, and 0.5 parts antioxidant 1010.

[0085] Comparative Example 4

[0086] It is basically the same as Example 1, except that the foaming agent zinc stearate in Example 1 is not used.

[0087] An anti-compression and antibacterial irradiated cross-linked polyolefin foam material comprises the following components in parts by weight: 80 parts low-density polyethylene, 20 parts high-density polyethylene, 3 parts azodicarbonamide, 4 parts zinc pyridinethione, 1 part calcium carbonate, and 0.5 parts antioxidant 1010.

[0088] Comparative Example 5

[0089] The method is basically the same as in Example 1, except that the preparation method of the pressure-resistant and antibacterial irradiated cross-linked polyolefin foam material is different.

[0090] The preparation method of the pressure-resistant and antibacterial irradiated crosslinked polyolefin foam material includes the following steps:

[0091] S1. Extrusion Molding: Low-density polyethylene, high-density polyethylene, azodicarbonamide, antioxidant 1010 foaming particles, calcium carbonate, zinc stearate, zinc pyrithione, and PE-g-MAH are mixed in a high-speed mixer. The mixture is then plasticized and extruded through a single-screw extruder. The temperature is set in seven extrusion zones along the extrusion direction: Zone 1 temperature is 120℃, Zone 2 temperature is 130℃, Zone 3 temperature is 140℃, Zone 4 temperature is 140℃, Zone 5 temperature is 130℃, Zone 6 temperature is 128℃, Zone 7 temperature is 125℃, the die neck temperature is 126℃, the flange temperature is 128℃, the die temperature is 135℃, the die pressure is 10MPa, and the screw speed is 15r / min to obtain a blend sheet.

[0092] S3. The blended sheet was placed under an electron accelerator for irradiation crosslinking to obtain the crosslinked sheet. The process conditions were: energy of 2.0 MeV, number of irradiated sheet layers of 4, scanning width of 1000 mm, and irradiation dose of 80 kGy.

[0093] S4. The cross-linked sheet is subjected to a high-temperature foaming process, passing sequentially through the preheating section and the foaming section of a foaming furnace to produce a pressure-resistant and antibacterial irradiated cross-linked polyolefin foam material. The temperatures in the preheating section are 70℃ in zone 1, 80℃ in zone 2, and 90℃ in zone 3. The temperatures in the foaming section are 260℃ in zone 1, 260℃ in zone 2, 250℃ in zone 3, 250℃ in zone 4, 180℃ in zone 5, and 180℃ in zone 6. The sheet feeding speed is 4.0, the sheet output speed is 12.0, and the feed-output ratio is approximately 3.0.

[0094] The performance of the above-prepared pressure-resistant and antibacterial irradiated cross-linked polyolefin foam material was tested, as follows:

[0095] Apparent density was tested according to GB / T 6342-1996; tensile strength was tested according to GB / T 6344-2008; Shore hardness was tested according to GB / T 6031-2017; compressive strength was tested according to GB / T 8813-2020; and antibacterial rate was tested according to ISO 22196-2011. The test results are shown in the table below.

[0096]

[0097] The results above show that the compressive strength and hardness of the antibacterial and pressure-resistant irradiated cross-linked polyolefin foam materials prepared in Examples 1-4 are much higher than those of the irradiated cross-linked polyolefin foam materials prepared in Comparative Examples 1-3. This indicates that the addition of high-density polyethylene can significantly improve the physical properties of the foam material, thereby obtaining an antibacterial and pressure-resistant irradiated cross-linked polyolefin foam material with excellent properties.

[0098] The embodiments of the present invention have been described in detail above. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various modifications can be made without departing from the spirit of the present invention. These are all non-inventive modifications, and are protected by patent law as long as they fall within the scope of the claims of the present invention.

Claims

1. A method for preparing a pressure-resistant and antibacterial radiation-crosslinked polyolefin foam material. The raw materials used to prepare the foamed material include the following components in parts by weight: 75-80 parts of low-density polyethylene, 20-25 parts of high-density polyethylene, 3 parts of foaming agent azodicarbonamide, 4 parts of antibacterial agent zinc pyrithione, 3 parts of compatibilizer PE-g-MAH, 1 part of nucleating agent calcium carbonate, 0.8 parts of foaming aid zinc stearate, and 0.5 parts of antioxidant 1010; The preparation method includes the following steps: S1. Internal Mixing and Granulation: Low-density polyethylene (LDPE), foaming agent, and antioxidant are mixed in an internal mixer and blended at 120-130℃ for 9-12 minutes to obtain foamed particles; LPE, nucleating agent, and foaming aid are mixed in an internal mixer and blended at 120-130℃ for 8-10 minutes to obtain nucleated particles; LPE, antibacterial agent, and compatibilizer are mixed in an internal mixer and blended at 120-130℃ for 8-10 minutes to obtain antibacterial particles; In foamed particles, the amount of LPE added is 2.5 times that of foaming agent; In nucleated particles, the amount of LPE added is 3 times that of nucleating agent; In antibacterial particles, the amount of LPE added is 5 times that of antibacterial agent. S2. Extrusion molding: The remaining low-density polyethylene, high-density polyethylene, foaming particles, nucleating particles and antibacterial particles are mixed evenly and then placed on a screw extruder for plasticizing and extrusion to obtain a blend sheet. S3, Irradiation crosslinking: The blend sheet is irradiated and crosslinked using an electron accelerator to obtain the crosslinked sheet; S4. High-temperature foaming: The cross-linked sheet is passed through the preheating section and the foaming section of the foaming furnace in sequence for foaming treatment. After foaming, a pressure-resistant and antibacterial irradiated cross-linked polyolefin foam material is obtained.

2. The method for preparing the pressure-resistant and antibacterial radiation-crosslinked polyolefin foam material according to claim 1, characterized in that, Before step S1, each component raw material needs to be dried at 60~80℃ for 4~6 hours.

3. A carrier material for a floor sound-absorbing mat, characterized in that, Includes pressure-resistant and antibacterial irradiated crosslinked polyolefin foam materials prepared by the method described in any one of claims 1 to 2.

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