Shanghai Daoqin Plastics Co., Ltd.

chemical foaming agent is types can generate gas chemical product, generate gas usually is nitrogen gas, oxidation carbon, water separation and its it a small amount of its it gas 体. generate gas nitrogen gas is 佳, property low, 无味无毒, can generate property can good, uniform foam. 　　 in processing process time, it 即会放出 gas 体, make plastics in formed 泡孔. foam formed generally can separation is stage/phase. stage/phase, foaming agent must full uniform dispersion in polymer inner, polymer usually liquid or melt 态. foaming agent in polymer in can formed true positive solvent liquid, or is uniform dispersion in polymer in, formed versus system. foaming agent and polymer/macromolecule material mixed combined usually is using/adopting or 开炼形式 add 入, selection foaming agent 时, must 考虑炼胶 temperature degree low foaming agent separation understanding temperature degree. 　　第二 stage/phase, a large amount of mono bubbles formed rear, system 即转变 formed gas dispersion in liquid in system. system in need add nucleating agent, promote a large amount of small bubbles formed. 否则, will generate is non-uniform 泡孔. nucleating agent generally is fine inert property pellets, carbon acid 钙, high carbon and other additives can as is nucleating agent. 　　第三 stage/phase, most formed in 不断涨 large, this is is has more more gas expand dispersion polymer 进入 泡孔. if this time long, mono 泡孔就 will versus 接触并 melt combined. if main/primary is through 泡孔互连而形 formed foam, 则称之 is 开孔式 foam. if is 由互不 versus 连 泡孔形 formed foam, 就叫闭孔式 foam. if 允许泡孔 melt combined made lower, that foam 就会塌陷. stage/phase, polymer viscosity increase, foaming agent separation understanding basic full, 泡孔不 can again growth 时, foam stability 住, formed is type product. using/adopting cooling, crosslinked or its it methods can increase polymer viscosity. foaming process rear stage/phase, from time 看, can short separation 之一秒, most long 也不会 ultra- 几秒钟. 　　 foam plastics quality good bad, and production process in foaming agent separation understanding and polymer/macromolecule material 凝胶（ polymer/macromolecule material viscosity ） is related. usually requirements foaming agent separation understanding process and polymer/macromolecule material process 一致, or 凝胶稍早于 foaming agent separation understanding. if upper process 不匹配, will can obtain property can good foam. process if rear foaming process, formed 泡孔壁 viscosity low, will 会导致 foam soft, heavy can foam material 而出现塌陷; versus 反, 泡孔壁 strong/high degree high, make internal pressure high, make 孔壁撕裂, will in foam in 心出现 large cracking.