Shanghai Daoqin Plastics Co., Ltd.

　　 causes:

　　PBT separation in ring and ester formed large system, decrease small separation 子链 柔曲 property, make separation rigid property increase, and property ester 基, 羰基 存 in make separation function force increase large, separation rigid property 进一步 reinforcement, from tough property very 差.

　　 solution methods:

　　a) polymerization modified

　　 polymerization modified is through copolymer, grafting, 嵌段, crosslinked and other in polymerization process in in PBT separation in new flexible 链段, make its tool has good tough property.

　　b) blending modified

　　 blending modified is will modifier or high impact strong/high degree material and PBT blending or composite/compounding, make its as is dispersion versus distribution in PBT基体 in, utilizing separation separation versus property or interface function, improve/increase PBT impact property can. in PBT in add reaction property increase agent POE-g-GMA, through GMA and PBT 端羧基 原位 increase reaction, add strong/high interface function force, to toughened 效果.

  

thin electronics parts

　　 in electronics electrical appliances, automotive electronics industrial field/area, parts more thin is trend, this requirements material need more high flow property, can can can small versus 应浇注 device filling pressure or clamping force achieve type filling. utilizing low degree thermoplastic property polyester 组 combined material 也常常 can achieve more short ring cycle. another,良 good flow can force for/regarding quality separation ultra- 40% glass fiber and / or material high filling thermoplastic polyester combined material is non important.

　　 improvement methods:

　　1. selection low molecular weight PBT, is separation quality reduce effect/influence mechanical properties.

　　2.借助 flow promote agent hard acid ester or acid ester, can improvement PBT flow property,但 this category of low separation quality ester in product processing and use process in 渗出.

　　3. for/regarding need toughened PBT材 material, toughening agent add 入一定会导致 flow property decline, need selection for flow property effect/influence more small toughening agent.

　　4. add tool has structure type low separation polyester, 如CBT, CBT is types tool has large ring polyester structure function property resin, and PBT tool has very good versus property, less add amount,就 can large degree improve/increase resin flow property,而几乎不 effect/influence force property can.

　　5. add nano material, dispersion nano material in PBT in to types similar inner lubricated function, can improve/increase PBT flow property, nano filler dispersion is blending modified process in large difficulty/challenge.

　　 causes:

　　 warpage is material non-uniform shrinkage 结果. material in separation orientation and crystallization, injection molding using/adopting 不恰当 process conditions, mold design gate and 位置不 for, products design thick thick thin and other 都会造 formed products warpage. PBT/GF composite/compounding material warpage main/primary is glass fiber (GF) in flow direction upper toward made resin shrinkage, PBT in glass fiber (GF) 周围 诱导 crystallization also strong/high this type of 效果, make products toward (flow direction) shrinkage small toward (and flow direction direction), this type of non-uniform shrinkage 便导致 PBT/GF composite/compounding material warpage.

　　 solution methods:

　　一 is add material, utilizing material filler for property decrease light glass fiber (GF) orientation formed toward property;

　　二 is add non material, reduce PBT crystallization degree, decrease/reduce crystallization formed non-uniform shrinkage, add 入ASA or 者AS, is it and PBT versus property 差, need add compatibilizer;

　　三 is adjustment injection molding process, 如适当 improve/increase mold temperature degree, increase injection molding cycle.

　　 causes:

　　 fiber exposure generate causes comparison complex, simple 说, main/primary has below/following several 方面

　　(a)PBT and glass fiber (GF) versus property very 差, 导致二者无 method has adhesion in 一起;

　　(b)PBT and glass fiber (GF) viscosity very large, 导致二者 in flow process in formed separation trend, separation function large bonding force 时就会发生脱离, glass fiber (GF) toward outer outer 漏;

　　(c)剪切 force in, 既会导致 local viscosity has 差异, also bad glass fiber (GF) surface interface melt viscosity small, interface loss, glass fiber to adhesion force small,当 viscosity small to 一定程 degree 时, glass fiber 便会摆脱PBT resin 基体 束缚,逐渐 toward surface 累积而 outer 露.

　　(d) mold temperature degree effect/influence. due to mold type temperature degree relatively low, quality light cold fast glass fiber by 瞬間冻结,若不 can and by melt separation 包围,就会 outer 露而形 formed “ fiber exposure ”.

　　 solution methods:

　　1) add compatibilizer, dispersant and lubricant, improvement fiber exposure issues. use surface treatment glass fiber (GF), or add compatibilizer (如: SOG, types flow PBT modified compatibilizer,) through “桥梁” function, increase PBT and glass fiber (GF) adhesion force.

　　2) optimization molding process improvement fiber exposure issues. relatively high injection molding temperature degree and mold temperature degree, relatively large injection molding pressure and back pressure, relatively fast injection molding speed degree, relatively low screw speed, can 一定程 degree improvement fiber exposure issues.

 

glass fiber reinforced PBT surface fiber exposure 图

 

injection molding machine mold phenomenon

　　 causes:

　　模垢 generate is material small separation content high or material heat stabilized property relatively 差引起. PBT due to its poly material and small separation 子残留 rate usually in 1%～3%, versus for and other material easy generate 模垢. in glass fiber (GF) rear, more add obvious. this will in processing process in, need 定时清理 mold, formed production efficiency low lower.

　　 solution methods:

　　1) decrease/reduce small separation additives add amount (如 lubricant, coupling agent and other), amount selection polymer/macromolecule additives;

　　2) improvement PBT heat stabilized property, decrease/reduce processing process in thermal degradation generate small separation material;

　　5. PBT heat resistant hydrolysis property relatively 差

 

PBT heat resistant hydrolysis property relatively 差

　　 causes:

　　 effect/influence PBT hydrolysis main/primary factors is 端羧基 concentrated degree. due to PBT含 has ester 键, in high its 玻璃化转变 temperature degree temperature degree lower water in 会发生 ester fracture, hydrolysis formed acid property ring make hydrolysis accelerated reaction, property can decline.

　　 solution methods:

　　一 is add hydrolysis stabilizer, carbon 化二亚 amine, hydrolysis stabilizer consumption hydrolysis generate 羧基, decrease 缓PBT acid property hydrolysis speed degree, improve/increase PBT resin resistant hydrolysis property.

　　二 is is through add 封闭PBT端羧基 methods, reduce 端羧基 concentrated degree, improve/increase PBT resistant hydrolysis property, add belt/tape ring oxygen can additives (如SAG series, types styrene - acrylonitrile -GMA random copolymer), through can 团GMA and PBT端羧基 reaction 封端, from improve/increase PBT resistant hydrolysis property.