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injection molding property plastics performance
Date: 2019-11-25 03:40
Views: 2571
Source: Internet
is what need lower plastics property can 呢? rigid rigid 开始接触 molding very understanding! is it what use, less can fast speed has solution products 异常, can as time long, is it important. simple 举 例子, commonly used resin ABS in production generally use 210摄氏 degree left right processing temperature degree, that is what 呢? using/adopting 200 can can? can, can can, is this temperature degree is according to equipment, mold and products quality requirements to. has versus 差5摄氏 degree 都不行, in use POM resin 时常遇 to similar phenomenon. this 一点, has experience process 人员应该遇 to 吧! therefore 说“科学 is very 严禁 ”一点错都没 has. need 想继续 understanding molding technology, for plastics property can or more or less 知道一 is very has 益处, is must.
polymer/macromolecule formed
一 polymer/macromolecule formed
carbon and hydrogen in conditions lower formed structure structure, formed 呈现一定 features separation 子, 如甲烷, 乙烷, and other; this quality large separation also can 进一步 reaction formed quality more large separation structure, ethylene and propylene and other. therefore can is, polymer/macromolecule is below/following in material formed:
1, 甲烷, 乙烷, 丙烷, 丁烷, and other.
2, this 基体首先必 must is: 亚甲基, ethylene and propylene.
this in material is or mono 体, in polymerization reaction process in, formed separation quality more is large separation 子. if ultra- 500 this mono polymerization, 结果就会形 formed polymer/macromolecule, or is polymer.
由一 types mono polymerization formed polymer is homopolymer, polyethylene (PE), polypropylene (PP) and other, has types or types above mono polymerization formed polymer/macromolecule, 如ABS resin is propylene 氰, butadiene and styrene formed terpolymer.
this is polymer/macromolecule simple formed process, is polymer/macromolecule 名称 由. formed polymer/macromolecule mono different, 排列 链状 structure different, formed plastics different, 因而呈现出 different material and chemical property can.
二 polymer/macromolecule quality
polymer/macromolecule is mono amount ultra- 500 or more more mono formed separation 子链, has separation can can same amount mono 体, is, can through control polymerization process control separation structure and long degree. polymer can through separation quality separation, this generate micro separation quality distribution.
large more mono is gas 体, short separation small separation is liquid 体, large separation polymer is solid 体. therefore, 甲烷, 乙烷, and other separation is gas 体, ethylene, propylene is liquid 体, formed polymer rear polyethylene (PE), polypropylene (PP) is solid 体.
separation quality large, plastics strong/high degree and rigid degree large, is large separation plastics degree large. therefore, large separation melt filling is need pressure high; separation quality large, plastics molding difficult degree high; ultra- large separation plastics is can through injection molding process molding.
large separation plastics degree generally very high, is reduce degree, must improve/increase plastics processing temperature degree, is this 会引起 polymer/macromolecule plastics degradation. therefore, in processing polymer/macromolecule plastics 时, to plastics heat stabilized property, generally processing temperature degree and plastics melt time. therefore, polymer/macromolecule plastics in injection molding machine mono in time has 一定 限 made, if ultra- 出 this time, plastics can can degradation, 我们也 formed is separation understanding.
polymer/macromolecule in 状态
polymer/macromolecule in 状态
玻璃态, viscous 流态, melt is polymer/macromolecule in types material 理状态. polymer/macromolecule 不象空 gas 一样存 in gas 体状态, in day 常 工 as in, due to resin in screw in time large temperature degree maintain time therefore has 时候我们 can can to in nozzle has 烟雾喷出, this is separation understanding 致, is it can in 状态.
一, 玻璃态 处于玻璃态 plastics separation 子, basic upper 处于停止状态, separation in 自身 位置 upper 振动, separation 子链缠绕 formed or 卷曲状, versus 互无序交错连接, 锻段仅 as micro small shrink and 键角改变. plastics tool has rigid property and strong/high degree （ resistant strong/high degree, resistant strong/high degree ）. in this type of lower, plastics parts can by use or machine processing, 如切削, and other and other.
in 玻璃状态 lower, plastics use property can, is it force 学, physical properties and for ring 境 忍受 property can, 取决于 separation 子链 构 formed, 形状, 序列, property and versus 互位置, density and other.
although plastics in 玻璃态时像玻璃 that tool has non versus solid type material property 质, 但并不 and other cold liquid structure 玻璃. in property 方面就 has relatively large 差异, make is easy polystyrene (PS) transparent parts, its tough property relatively 普通 玻璃 large, hardness also very 远.
当然, plastics has 脆如玻璃 时候. in upper has 一 脆化 temperature degree T, ultra- this temperature degree below/following, separation 子链段 自我振动 by “冻结” lower, can tensile, 扭转, method absorption and dispersion outer force. in outer force function lower, very fast fracture, plastics products will obvious 像普通玻璃 that easy 于破碎.
in 实际 工 as in, has types phenomenon table/sheet this issues true property. due to molding machine machine has will screw in material injection 出, or is short time machine, in machine production 时候没 has screw 清扫, that generally lower in products injection to mold 时候就会 to strong/high degree non low products. if material in screw separation understanding comparison heavy lower, products color 发生变化如 is color resin, can can formed color; if is white resin can can formed color; if is black resin separation understanding rear also is black. in this type of lower injection products in color upper can 判定OK or NG（不 combined 格）, in products in ejection 时发生破裂, this resin material in inner （ screw ） inner separation understanding.
high temperature and low temperature different ring 境, time use rear screw color 会发生变化.
thermoplastic property injection molding engineering in and plastics （ rear understanding ） main/primary physical properties has: force property can, thermal properties, electrical property can, optical property can and aging property can. thermal properties is injection molding in key/critical, is process adjustment, mold design 人员必 must and understanding related Knowledge.
1, features
ratio and density, ratio is density 倒数. in processing process in, due to plastics 形态转化（玻璃态, high elastic 态, viscous 流态） 结果, plastics ratio or density its versus different 发生变化. generally lower, relatively large ratio density versus for relatively small; 玻璃态 plastics is separation poly relatively is 密实, ratio 体积也 versus for relatively small. crystallization property plastics ratio and density in melting point 附近发生跳跃式 变化, this is crystallization property plastics and non crystallization plastics obvious difference.
2, hot features
specific heat capacity or quality hot 容, will mono quality plastics improve/increase 1℃ need hot amount. this parameters is amount plastics temperature degree is easy degree amount. specific heat capacity high, plastics absorption hot amount more; specific heat capacity low, plastics absorption hot amount 也就越 less.
hot expand dispersion rate is amount hot amount from high temperature low temperature speed degree, is temperature degree fast slow performance 形式. 钢材质 mold in rise temperature or drop temperature process in, temperature degree speed degree relatively slow, aluminum 模无论 is rise temperature also is drop temperature speed degree very fast.
melt hot and crystallization hot is versus hot. melt hot table/sheet will mono quality plastics solid 态转化 is liquid 态 需 hot amount; crystallization hot crystallization property plastics in process in hot amount. melt hot is use dispersion plastics separation structure can amount. due to crystallization property plastics separation structure non 常紧密 and 结实, 打断晶体 structure need can amount very large, therefore need melt hot comparison large.
3, versus temperature degree
it is polymer types 状态 转变 temperature degree. its in temperature degree is crystallization property polymer from polymer/macromolecule structure has 序状态转变 formed viscous 流态时 temperature degree. 转变点Tm for/regarding low separation material 说, process is non narrow, is 0.2K, has obvious melting point; for/regarding crystallization property polymer 说, has to can and rear, 晶体才会一边熔化一边 rise temperature, therefore low separation and polymer/macromolecule ratio and temperature degree has obvious different; front obvious; rear 者则走一 “S” type 曲
