Transparent PE foam and preparation method thereof

Abstract

The invention relates to the technical field of PE foam, in particular to transparent PE foam and a preparation method thereof.The transparent PE foam is prepared from an AC foaming agent, zinc oxide, zinc stearate, an antioxidant, color masterbatch, sorbitol and PE, and the preparation method of the transparent PE foam comprises the steps that S1, granulation is conducted; s2, extrusion molding; s3, carrying out radiation crosslinking treatment; s4, foaming treatment; s5, cooling and sizing, compared with an existing common foam product, the transparent PE foam has the advantages that the light transmittance is greatly improved while the touch hand feeling and the comfort degree are good, the light transmission effect is more ideal, and use is convenient.

Description

Technical Field

[0001] The invention relates to the technical field of PE foam, and in particular to a transparent PE foam and a preparation method thereof. Background Art

[0002] PE foam, also known as bridge foam, is a new type of environmentally friendly material with the characteristics of non-toxic, odorless, sound insulation, sound absorption, and heat insulation. Its fine independent bubble structure can effectively reduce the energy exchange caused by air convection, and is suitable for making insulation pipes and insulation boards. It also has anti-condensation properties, making it extremely suitable for use as insulation materials in humid environments such as refrigerators, air conditioners, and cold storage. In addition, PE foam also has sound absorption and noise reduction functions, and is suitable for sound absorption and sound insulation materials in strong noise equipment and environments such as aircraft, railway vehicles, automobiles, and electric motors. It is made of semi-rigid foam, and it does not lose its original performance after being strongly impacted. It is mostly used in precision instruments, semiconductor packaging, and other fields. At the same time, PE foam can also be used for the production of sports protection products and leisure products by taking advantage of its easy formability.

[0003] As more and more electronic products are used in cars nowadays, in order to improve the feel and comfort of touch buttons, an ideal design solution is to pad PE foam on the buttons. However, the light transmittance of conventional PE foam is low, and the light of the button start / stop indicator light cannot be transmitted or the transmission effect is not ideal, resulting in the inability to determine whether the function is started or stopped. Therefore, it is imperative to improve the light transmittance of PE foam. Summary of the invention

[0004] In view of the shortcomings of the prior art, the present invention aims to provide a transparent PE foam with high light transmittance.

[0005] The object of the present invention can be achieved by the following technical scheme: a transparent PE foam, wherein the raw materials for preparing the transparent PE foam include: by weight, 10-15 parts of AC foaming agent, 0.2-1 parts of zinc oxide, 0.5-1.5 parts of zinc stearate, 0.2-0.5 parts of antioxidant, 2-5 parts of masterbatch, 3-5 parts of sorbitol and 72-84.1 parts of PE.

[0006] Preferably, the zinc oxide is transparent zinc oxide.

[0007] Preferably, the particle size of the transparent zinc oxide is ≥900 mesh.

[0008] Preferably, the masterbatch is a transparent masterbatch.

[0009] The present invention also provides a method for preparing a transparent PE foam, comprising the following steps: S1, granulation, firstly mix 10-15 parts of AC foaming agent and 0.2-0.5 parts of antioxidant and stir evenly, then pour into an internal mixer together with 0.2-1 parts of zinc oxide, 0.5-1.5 parts of zinc stearate, 2-5 parts of masterbatch, 3-5 parts of sorbitol and 72-84.1 parts of PE, mix evenly, add the mixture into a screw extruder, extrude and pelletize, and obtain functional masterbatch; S2, extrusion molding, adding the functional masterbatch obtained in step S1 into a single screw extruder, and extruding to obtain a masterbatch; S3, radiation cross-linking treatment, using an electron accelerator to perform radiation cross-linking treatment on the master sheet obtained in step S2 to obtain a radiation cross-linked master sheet; S4, foaming treatment, sending the radiation cross-linked mother sheet obtained in step S3 into a vertical furnace for foaming treatment to obtain a foamed sheet; S5, cooling and shaping, cooling and shaping the foamed sheet obtained in step S4, trimming and rolling, and obtaining transparent PE foam.

[0010] Preferably, in step S2, during the extrusion process, the processing temperature of the single screw extruder is: the temperature of zone 1 is 117℃±2℃, the temperature of zone 2 is 116℃±2℃, the temperature of zone 3 is 111℃±2℃, the temperature of zone 4 is 106℃±2℃, the temperature of zone 5 is 97℃±2℃, the temperature of zone 6 is 90℃±2℃, and the temperature of zone 7 is 90℃±2℃.

[0011] Preferably, the extrusion die temperature of the single-screw extruder: the temperature of zones one to five are all 120°C±2°C.

[0012] Preferably, in step S3, the irradiation parameters during the radiation cross-linking treatment are set as follows: 4 layers of sheet material, and a radiation energy of 1.85 MeV.

[0013] Preferably, in step S5, the vertical furnace includes a horizontal preheating zone and a vertical foaming zone, and the temperature of the horizontal preheating zone is: 115°C for preheating zone 1, 120°C for preheating zone 2, and 125°C for preheating zone 3; the temperature of the vertical foaming zone is: 260°C-265°C for foaming zone 1, 290°C-295°C for foaming zone 2, and 250°C for foaming zone 3.

[0014] Preferably, in step S4, during the foaming process, the net speed of the vertical furnace is controlled to be 5.2 m / min and the pulling speed is controlled to be 10 m / min.

[0015] The beneficial effects of the present invention are as follows: the present invention provides a transparent PE foam. After the finished product is prepared by using the components and the preparation method provided by the present invention, it is tested according to the GB / T 2410-2008 method A standard. Compared with the existing ordinary foam products, the light transmittance of the transparent PE foam of the present invention reaches 40.5%-42.3%. While ensuring the better touch feel and comfort, the light transmittance is greatly improved, the light transmission effect is more ideal, and it is easy to use. DETAILED DESCRIPTION

[0016] The technical solution of the present invention will be clearly and completely described below in conjunction with specific embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work belong to the protection scope of the present invention.

[0017] Example 1 A transparent PE foam, the raw materials for preparing the transparent PE foam include: by weight, 10 parts of AC foaming agent, 0.2 parts of zinc oxide, 0.5 parts of zinc stearate, 0.2 parts of antioxidant, 2 parts of masterbatch, 3 parts of sorbitol and 72 parts of PE. The zinc oxide is transparent zinc oxide, the particle size of the transparent zinc oxide is ≥900 mesh, and the masterbatch is a transparent masterbatch. Specifically, the addition of transparent zinc oxide has the following advantages: improving transparency, transparent zinc oxide particles with high mesh counts are finer and can be better dispersed in the substrate, reducing scattering and refraction, thereby improving the light transmittance of the product; enhancing performance, transparent zinc oxide particles with high mesh counts mean a larger specific surface area, and a larger specific surface area means that there are more contact areas and more interaction sites between zinc oxide particles and the substrate, which helps zinc oxide to be better dispersed in the substrate and form a more uniform distribution, thereby enhancing the bonding force between them, which helps to improve the physical properties of the product, such as tensile strength, tear strength and wear resistance; improving processing performance, transparent zinc oxide with high mesh counts can be more evenly dispersed in PE foam processing, reducing agglomeration, thereby improving product processing performance and increasing production efficiency. In summary, transparent zinc oxide with high mesh counts has significant advantages in improving product transparency, enhancing performance and improving processing performance. In addition, the addition of zinc stearate can enhance the physical properties of PE foam to a certain extent, improve its tensile strength and impact toughness; the addition of sorbitol can improve the transparency, surface gloss and other properties of PE foam.

[0018] The transparent PE foam is prepared by using the above raw materials. The preparation method of the transparent PE foam comprises the following steps: S1, granulation, firstly mix 10 parts of AC foaming agent with 0.2 parts of antioxidant and stir evenly, then pour into internal mixer together with 0.2 parts of zinc oxide, 0.5 parts of zinc stearate, 2 parts of masterbatch, 3 parts of sorbitol and 72 parts of PE, mix evenly, add the mixture into screw extruder, extrude and pelletize, and obtain functional masterbatch; S2, extrusion molding, adding the functional masterbatch obtained in step S1 into a single screw extruder, and extruding to obtain a master sheet; further, during the extrusion process, the processing temperature of the single screw extruder is: the temperature of zone 1 is 117℃±2℃, the temperature of zone 2 is 116℃±2℃, the temperature of zone 3 is 111℃±2℃, the temperature of zone 4 is 106℃±2℃, the temperature of zone 5 is 97℃±2℃, the temperature of zone 6 is 90℃±2℃, and the temperature of zone 7 is 90℃±2℃; further, the extrusion die temperature of the single screw extruder: the temperatures of zones 1 to 5 are all 120℃±2℃.

[0019] S3, radiation crosslinking treatment, using an electron accelerator to perform radiation crosslinking treatment on the master sheet obtained in step S2 to obtain a radiation crosslinked master sheet; further, the irradiation parameters during the radiation crosslinking treatment are set as follows: 4 layers of sheet material, and a radiation energy of 1.85 Mev.

[0020] S4, foaming treatment, sending the radiation cross-linked mother sheet obtained in step S3 into a vertical furnace for foaming treatment to obtain a foamed sheet; further, the vertical furnace includes a horizontal preheating zone and a vertical foaming zone, the temperature of the horizontal preheating zone is: 115°C for preheating zone 1, 120°C for preheating zone 2, and 125°C for preheating zone 3; the temperature of the vertical foaming zone is: 260°C-265°C for foaming zone 1, 290°C-295°C for foaming zone 2, and 250°C for foaming zone 3; further, during the foaming process, the network speed of the vertical furnace is controlled to be 5.2m / min, and the pulling speed is 10m / min.

[0021] S5, cooling and shaping, cooling and shaping the foamed sheet obtained in step S4, trimming and rolling, and obtaining transparent PE foam.

[0022] Example 2 The difference between this embodiment and embodiment 1 is that in step S1, the components are 11.25 parts of AC foaming agent, 0.275 parts of antioxidant, 0.4 parts of zinc oxide, 0.75 parts of zinc stearate, 2.75 parts of masterbatch, 3.5 parts of sorbitol, and 75.025 parts of PE, and the remaining steps are the same as those in embodiment 1.

[0023] Example 3 The difference between this embodiment and embodiment 1 is that in step S1, the components are 12.5 parts of AC foaming agent, 0.35 parts of antioxidant, 0.6 parts of zinc oxide, 1 part of zinc stearate, 3.5 parts of masterbatch, 4 parts of sorbitol, and 78.05 parts of PE, and the remaining steps are the same as those in embodiment 1.

[0024] Example 4 The difference between this embodiment and embodiment 1 is that in step S1, the components are 13.75 parts of AC foaming agent, 0.425 parts of antioxidant, 0.8 parts of zinc oxide, 1.25 parts of zinc stearate, 4.25 parts of masterbatch, 4.5 parts of sorbitol, and 81.075 parts of PE, and the remaining steps are the same as in embodiment 1.

[0025] Example 5 The difference between this embodiment and embodiment 1 is that in step S1, the components are 15 parts of AC foaming agent, 0.5 parts of antioxidant, 1 part of zinc oxide, 1.5 parts of zinc stearate, 5 parts of masterbatch, 5 parts of sorbitol, and 84.1 parts of PE, and the remaining steps are the same as those in embodiment 1.

[0026] The light transmittance of the transparent PE foams prepared in Examples 1-5 and the existing common foams was tested in accordance with GB / T 2410-2008 Method A. The test results are shown in the following table: In summary, after the finished product is prepared by using the raw material components and the preparation method of the present invention and tested according to the GB / T 2410-2008 method A standard, the light transmittance of the transparent PE foam of the present invention reaches 40.5%-42.3%, and the light transmittance of the existing ordinary foam products is about 23.4%. The transparent PE foam of the present invention greatly improves the light transmittance while ensuring a better touch feel and comfort, and the light transmission effect is more ideal, which is easy to use.

[0027] The present invention is further described above with the aid of specific embodiments. However, it should be understood that the specific description here should not be construed as limiting the essence and scope of the present invention. Various modifications made to the above embodiments by ordinary technicians in the field after reading this specification are all within the scope of protection of the present invention.

Claims

1. A transparent PE foam, characterized in that: The raw materials for preparing the transparent PE foam include: by weight, 10-15 parts of AC foaming agent, 0.2-1 parts of zinc oxide, 0.5-1.5 parts of zinc stearate, 0.2-0.5 parts of antioxidant, 2-5 parts of masterbatch, 3-5 parts of sorbitol and 72-84.1 parts of PE.

2. A transparent PE foam according to claim 1, characterized in that: The zinc oxide is transparent zinc oxide.

3. A transparent PE foam according to claim 2, characterized in that: The particle size of the transparent zinc oxide is ≥900 meshes.

4. A transparent PE foam according to claim 1, characterized in that: The masterbatch is a transparent masterbatch.

5. A method for preparing a transparent PE foam, characterized in that: The steps include: S1, granulation, firstly mix 10-15 parts of AC foaming agent and 0.2-0.5 parts of antioxidant and stir evenly, then pour into an internal mixer together with 0.2-1 parts of zinc oxide, 0.5-1.5 parts of zinc stearate, 2-5 parts of masterbatch, 3-5 parts of sorbitol and 72-84.1 parts of PE, mix evenly, add the mixture into a screw extruder, extrude and pelletize, and obtain functional masterbatch; S2, extrusion molding, adding the functional masterbatch obtained in step S1 into a single screw extruder, and extruding to obtain a masterbatch; S3, radiation cross-linking treatment, using an electron accelerator to perform radiation cross-linking treatment on the master sheet obtained in step S2 to obtain a radiation cross-linked master sheet; S4, foaming treatment, sending the radiation cross-linked mother sheet obtained in step S3 into a vertical furnace for foaming treatment to obtain a foamed sheet; S5, cooling and shaping, cooling and shaping the foamed sheet obtained in step S4, trimming and rolling, and obtaining transparent PE foam.

6. The method for preparing a transparent PE foam according to claim 5, characterized in that: In step S2, during the extrusion process, the processing temperature of the single screw extruder is: the temperature of zone 1 is 117℃±2℃, the temperature of zone 2 is 116℃±2℃, the temperature of zone 3 is 111℃±2℃, the temperature of zone 4 is 106℃±2℃, the temperature of zone 5 is 97℃±2℃, the temperature of zone 6 is 90℃±2℃, and the temperature of zone 7 is 90℃±2℃.

7. The method for preparing a transparent PE foam according to claim 6, characterized in that: The extrusion die temperature of the single screw extruder: the temperature of zones 1 to 5 is 120°C ± 2°C.

8. The method for preparing a transparent PE foam according to claim 5, characterized in that: In step S3, the radiation parameters during the radiation cross-linking treatment are set as follows: 4 layers of sheet material, and a radiation energy of 1.85 MeV.

9. The method for preparing a transparent PE foam according to claim 5, characterized in that: In step S4, the vertical furnace includes a horizontal preheating zone and a vertical foaming zone. The temperature of the horizontal preheating zone is 115°C for preheating zone 1, 120°C for preheating zone 2, and 125°C for preheating zone 3; the temperature of the vertical foaming zone is 260°C-265°C for foaming zone 1, 290°C-295°C for foaming zone 2, and 250°C for foaming zone 3.

10. The method for preparing a transparent PE foam according to claim 5, characterized in that: The light transmittance of the obtained transparent PE foam is 40.5%-42.3%.

Images