光洁的

C-timber has no knots in it.

洁的木料没有节疤。

Compared with that of furane resin bonded sand,the feasibility of phenol resin bonded sand in forming a uniform coating layer in the inside mould surface is studied as well.

本文分析究了砂在铸中的成条件洁面的形成机理，并对比究了覆膜和呋喃自硬砂在铸面形成均匀覆砂层的可行性。