Shanghai Daoqin Plastics Co., Ltd.

tpu胶粒出模 rear left right easy what to do? this is very more tpu厂家 遇 to issues, this issues 我们应该 how to solution?

tpu胶粒 large separation orientation and crystallization degree for products structure, property can has obvious effect/influence, orientation and crystallization and injection molding process parameters has 关. in 实际工 as in, understanding tpu胶粒 orientation and crystallization 特征, for mold design and production in injection molding process has 一定 帮助.

一.tpu胶粒 in mold cavity in flow orientation features:

injection molding 充模时, tpu胶粒 melt in mold cavity in flow, generally mold cavity temperature degree ratio tpu胶粒 玻璃化 temperature degree low （ or melting point low ）, therefore melt from mold cavity 时刻起便开始 cooling, in and 模壁接触 一层 melt formed 不移动 outer housing/shell,而 its internal still is relatively hot melt. in process in, melt flow front in pressure function lower toward front 移动, meanwhile flow front is in toward direction generate toward flow, this type of flow process large separation 子 剪切 orientation, this type of flow direction very fast by cooling function solid lower. therefore, table/sheet generate very large orientation, in due to has speed degree 差, separation orientation degree most small, therefore in material material is toward property, table/sheet due to orientation function, orientation direction force property can obvious improve/increase.

二.tpu胶粒 in injection molding process in crystallization

usually crystallization type tpu胶粒 in crystallization process has important 特征: melt temperature degree Tm, most large crystallization speed rate crystallization temperature degree Tv-max, most large formed speed rate crystallization temperature degree Tc, 玻璃化 temperature degree Tg. crystallization type tpu胶粒 in high 于Tm时 performance is has melt, time long 晶核 数 amount less; melt in low 于TM temperature degree lower cooling, make its generate crystallization. effect/influence crystallization main/primary factors is cooling speed degree, density, production speed rate. cooling speed degree increase large, crystallization relatively fast. crystallization speed rate in very large degree upper and 晶核 存 in. temperature degree high 于Tg时, can generate most large density. injection molding 时, tpu胶粒 melt mold cavity rear, 因模壁 temperature degree low 于TM, crystallization in 接触模壁处开始, rear 逐渐想 in 心层进行. products thick degree direction, crystallization and degree 不一样; usually table/sheet is has formed di orientation structure, its is small structure, in 心层不受剪切 function formed random 则 点状晶核 structure, due to in temperature degree high, cooling speed degree slow, most formed relatively large crystallization.