Production method of PLA foam sheet

Abstract

The invention provides a production method of a PLA (polylactic acid) foamed sheet, and the production method comprises the following steps of: pouring mixture formed by mixing 2-4% of nucleating agent, 1-3% of compound heat stabilizer, 0.3-0.5% of lubricating agent, 0.6-1% of dispersant and 1-4% of chain extender in mass ratio into 78.5-85.1% of a PLA material, mixing to be uniform, and conveying and melting by virtue of an extruder, wherein the nucleating agent is 3000-mesh talcum powder, the compound heat stabilizer is formed by mixing 80% of zinc stearate and 20% of calcium stearate in mass ratio, the lubricating agent is monoglyceride, the dispersant is sodium lauryl sulphate, and the chain extender is glycerine; then injecting 9% of butane with the purity of more than 98% at the pressure of 10-15 MPa to form a mixture at the temperature controlled to be 100-200 DEG C, and conveying the mixture to a moulding nose after being pressurized, mixed and cooled by virtue of a screw so as to be moulded into a foamed product. According to the invention, the PLA foamed sheet can be stably and reliably produced, the produced product has high foam density, small foam size, light mass and easiness in moulding, can substitute for most packaging material for food on the market and can be biologically degraded in nature, thus white pollution caused by the traditional macromolecule waste material to the environment can be greatly alleviated.

Description

technical field [0001] The invention relates to a production method of PLA foam sheet, the product is easy to shape, non-toxic and biodegradable, and is widely used in the food packaging industry. Background technique [0002] The advent of synthetic polymer materials and their rapid development have greatly improved human life, but their huge production and consumption have also produced two major problems: limited petroleum resources are consumed in large quantities and environmental pollution caused by waste polymers, these problems It has attracted global attention, and vigorously developing biodegradable polymer materials has been booming worldwide. Among the many biodegradable polymer materials that have been developed, PLA (polylactic acid) is known as one of the most promising varieties. Mainly because PLA is completely biodegradable and plant-derived with renewable resources as raw materials, and it is a material that maintains the balance of the natural carbon cyc...

AI Technical Summary

Problems solved by technology

[0003] The purpose of the present invention is to provide a production method of PLA foam sheet, which solves the difficult problem of stable foaming due to poor PLA melt strength, low viscosity, and high heat retention performance. It is a high-efficiency, energy-saving, non-toxic and pollution-free production method