This article is a study of methylene chloride as a substitute for trichloro-fluoromethane in producing flexible polyurethane foam.

讨论了用二氯甲烷替代一氟三氯甲烷进行软质聚氨酯的生产。

Plastics -- Methods for determining the density of non-cellular plastics -- Part 1: Immersion method, liquid pyknometer method and titration method

.非的密度测定方法.第一部分:浸渍法、液体比重瓶法和滴定法.

A foamable phenolic resin was prepared,through addition,condensation,in the presence of alkali.The resin was foamed with surfactant, foamer,solidifying agent , then the foam phenolplast was given .

苯酚与甲在碱性条件下经加成、缩合制得可性酚树脂，该树脂和表面活性、、固化一起即得酚。

The characteristic, structure, raw materials, equipment, process, cost and applications of arched colour plated roofing are introduced. The foams act as insulator, seal and waterproofer in roofing.

简要介绍了用保温、密封、防水的拱形彩钢屋面的特点、构造、材、设备、施工工艺、生产成本和应用。