| 摘要 |
PURPOSE: A ring for a lightproof covering of a ginseng cultivation house made by injection-molding polypropylene, ultraviolet absorbing agents, heat stabilizers, oxidants, colorants, plasticizers and the like is provided. The product has good hardness without cracking and can be effectively used in pulling the lightproof covering and hanging on a string. CONSTITUTION: Polypropylene is mixed with ultraviolet absorbing agents, heat stabilizers, oxidants, colorants, plasticizers, fillers, foaming agents, lubricating agents and antistatic agents and injection molded to give a ring for a lightproof covering of a ginseng cultivation house. |
