A kind of foamed rotomolded product prepared by one-step rotomolding and foaming polyethylene and its preparation method

Abstract

The invention relates to the technical field of the polyethylene material modification and in particular to a polyethylene composition for one-step process rotational moulding foaming and an application method thereof. The composition comprises a crosslinkable polyethylene surface layer, a transition layer and a foamable core layer. The crosslinkable polyethylene surface layer comprises the following raw materials in parts by weight: 100 parts of a polyethylene mixture, 0.1-2 parts of a crosslinking agent, 0.1-2 parts of a crosslinking assistant, and 0.1-1 part of other assistants; the transition layer is thermosetting crosslinked polyethylene recycled powder; and the foamable core layer comprises the following raw materials in parts by weight: 100 parts of the polyethylene mixture, 0.1-1part of the crosslinking agent, 0.1-1 part of the crosslinking assistant, 1-15 parts of a foaming agent, 0.1-1 part of a foaming assistant, 1-8 parts of a nucleating agent, and 0.1-1 part of other assistants. The composition is capable of solving a problem that production efficiency of the rotational moulding foaming is low, improving the production efficiency, wherein the transition layer formedby the crosslinked polyethylene recycled powder can prevent hole channeling of an outer layer, ensuring quality of the outer layer, and recycling a crosslinked polyethylene waste material, and has animportant practical application value.

Description

technical field [0001] The invention relates to the technical field of polyethylene material modification, in particular to a foamed rotational molding product prepared from polyethylene for one-step rotational molding foaming and a preparation method thereof. Background technique [0002] Rotationally molded products are hollow and have a light specific gravity. Filling the hollow with foam material not only maintains its light specific gravity, but also gives it good sound insulation and thermal insulation properties, and is widely used in the market. At present, the main method of commercialization is to fill PU foam material, but there are disadvantages such as poor adhesion between the foam core layer and the rotomoulding surface layer, and high material cost; while using PE foam core, in order to obtain a smooth surface, dense outer layer and The foaming material of the foamed inner layer has undergone intermittent rotomolding foaming, two-step method, multi-step metho...

AI Technical Summary

Problems solved by technology

At present, the main method of commercialization is to fill PU foam material, but there are disadvantages such as poor adhesion between the foam core layer and the rotomoulding surface layer, and high material cost; while using PE foam core, in order to obtain a smooth surface, dense outer layer and The foaming material of the foaming inner layer, rotomolding foaming has experienced intermittent rotomolding foaming, two-step method, multi-step method and other production methods, not only the process is complicated, the production efficiency is low, and the mold and equipment must be modified

The one-step method does not require a lot of modification of molds and equipment, and has high production efficiency, but it puts forward higher requirements for rotational molding materials.

[0003] At present, the one-step rotomolding foaming mainly uses the difference in density, powder particle size, melting point and other differences between foamed resin and non-foamed resin to form a dense outer layer and foam core, but because foaming is a process that generates pressure , it is easy to have various adverse effects on the surface due to pressure, and the yield is low

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