The present application relates to a supercritical fluid injection foaming polylactide foam material and a preparation method therefor. The method includes: first obtaining a surface-modified cellulose nanofiber aqueous solution; then melting and blending the cellulose nanofiber aqueous solution and a polylactide twice; passing same through extrusion, cooling under water, and granulation so as to obtain a polylactide/cellulose nanofiber composite material; then plasticizing and melting the polylactide/cellulose nanofiber composite material in a microporous foaming injection molding machine; uniformly mixing same with a supercritical fluid foaming agent in the injection molding machine; injecting same into a mold cavity; and subjecting the resultant to post-treatment so as to obtain a polylactide foam material. The polylactide foam material has a sandwich structure, in which two outer surface layers are solid layers that do not contain any foam, and the sandwiched layer is a foam layer having a cellular structure.

A method of manufacturing a product includes forming a first mixture of PVC fragments and cellulosic fragments, heating the first mixture at a temperature and duration sufficient to melt at least a portion of the PVC fragments, and cooling the first mixture until the melted PVC fragments resolidify.