US 12,083,718 B2 · Preparation method of high-rate foamed polylactic acid (PLA) sheet

Abstract

A preparation method of a high-rate foamed polylactic acid (PLA) sheet includes first-stage extrusion, second-stage extrusion, and foamed sheet extrusion. The method requires the following raw materials in parts by mass: 88 to 94 parts of PLA, 1 to 2 parts of a nucleating agent, 2 to 5 parts of a foaming agent, and 2 to 5 parts of an additive. The new method effectively solves the problems of low foaming rate, low strength, and the like in the industrial production using carbon dioxide, and a prepared PLA sheet with high foaming rate and excellent surface performance can be used in the fields of food packaging, disposable fully-degradable lunch boxes, and the like.

Claims9

Dependent claims

A preparation method of a high-rate foamed polylactic acid (PLA) sheet, comprising first-stage extrusion, second-stage extrusion, and foamed sheet extrusion, wherein the first-stage extrusion is conducted with the following raw materials in parts by mass:

88 to 95 parts of PLA, 1 to 2 parts of a nucleating agent, 2 to 5 parts of a foaming agent, and 2 to 5 parts of an additive;
and the foaming agent is a fluorine-containing compound, wherein the foaming agent is any one from the group consisting of difluoromonochloromethane, trifluorotrichloroethane, and tetrafluorodichloroethane, and wherein the high-rate foamed PLA sheet has a foaming rate of 13 to 16, a tensile strength of 80 Mpa to 88 Mpa, and a bending strength of 120 Mpa to 128 Mpa.

Dependencies are inferred from the claim text.

Facts

Application

17/419,308Filed 18 Jul 2019

Priority

CN 201811637504.929 Dec 2018

Published

US 2022/0088840 A124 Mar 2022

Granted

10 Sep 2024

Term ends

Not estimatedThe source records don’t support an estimate.

Classification34 codes

B29C 44/08
For articles of definite length, i.e. discrete articles: using several expanding or moulding steps
B29C 44/3415
Auxiliary operations: heating or cooling
B29C 44/50
Into an open space or onto moving surfaces, i.e. to make articles of indefinite length: using pressure difference, e.g. by extrusion or by spraying
B29C 44/5627
After-treatment of articles, e.g. for altering the shape: by mechanical deformation, e.g. crushing, embossing, stretching

Preparation method of high-rate foamed polylactic acid (PLA) sheet

Life of this patent

Preparation method of high-rate foamed polylactic acid (PLA) sheet

Life of this patent

Abstract

Claims9