Shanghai Daoqin Plastics Co., Ltd.

         terephthalic acid type plastics main/primary terephthalic acid ester (PET) and terephthalic acid ester (PBT). PET, separation structure high degree for 称, tool has crystallization orientation can force, tool has relatively high formed film property. PET tool has very good optical property can and weather resistance, non PET tool has good optical transparent property. another PET tool has excellent wear resistant consumption scratch property and dimensional stability and electrical insulation property. PET做 formed bottle tool has strong/high degree large, transparent property good, 无毒, anti 渗透, quality light, production efficiency high and other 因而受 to application.

         in plastics classification in, PET is 1号, function 广泛:

         can formed polyester fiber, 即涤纶;

         can made formed film used for 录音, 录像, electrical sheet/slice and other sheet/slice, insulation film, product packaging and other;

         as is plastics can made formed various bottle, can bottle, water bottle and other;

         can as is electrical appliances parts, bearings, gears and other.

        PBT and PET separation structure versus 似, large separation property is 一样, is separation 子主链由两 亚甲基变 formed 四, therefore separation more add 柔顺, processing properties more add excellent 良.

         terephthalic acid ester other thermoplastic polyester property can versus 近, its chemical and material property 质亦近似: and terephthalic acid ester (PET) versus ratio, terephthalic acid ester strong/high degree and rigid degree relatively low, for 撞击 抵 resistant relatively 佳, 而玻璃化转变 temperature degree relatively low. PET and PBT均 for ultra- 60 °C hot water 敏感. types plastics for outer 线敏感, therefore can in outer long use, add additives, can 帮助两 types plastics resistant outer 线

        PET

         polyethylene terephthalate (PET)

         typical applications scope/range

         automotive industrial (structure device parts light box/case, electrical parts 如车头灯反 light and other), electrical appliances parts (马达 housing/shell 体, electrical device, electrical appliances, 开关, micro internal device parts and other). industrial application (泵 housing/shell 体, device and other).

         injection molding process conditions

         drying 处理: processing front drying is must, is PET wet property relatively strong/high. drying conditions is 120~165℃, 4 small drying 处理. requirements wet degree small 于0.02%.

        熔化 temperature degree: for/regarding non filling type type: 265~280℃; for/regarding filling type type: 275~290℃.

         mold temperature degree: 80~120℃.

         injection pressure: 300~1300bar.

         injection speed degree: in 不导致脆化 front lower can use relatively high injection speed degree.

         runner and gate: can use has type type gate. gate dimensions is parts thick degree 50~100%.

         chemical and material features

        PET 玻璃化转化 temperature degree in 165℃ left right, material crystallization temperature degree scope/range is 120~220℃. PET in high temperature lower has very strong/high wet property. for/regarding glass fiber reinforcement type PET材 material 说, in high temperature lower also non easy bending 形变. can through add crystallization reinforcement agent improve/increase material crystallization degree. use PET processing transparent products tool has gloss degree and hot temperature degree. can toward PET in add and other additives make bending deformation decrease small to most small. if use relatively low mold temperature degree, that use non filling PET材 material can obtain transparent products

        PBT

         polybutylene terephthalate (PBT)

         typical applications scope/range

        家 use device tool (food processing sheet/slice, true 空吸尘 device parts, electrical 风扇, drying machine housing/shell 体, device and other), electrical appliances parts (开关, electrical machine housing/shell, filament box/case, machine 键盘按键 and other), automotive industrial (dispersion hot device 格窗, 车身嵌 sheet/plate, cover/cap, 门窗部 parts and other).

         injection molding process conditions

         drying 处理: this type of material in high temperature lower very easy hydrolysis, therefore processing front drying is very important. in gas in drying conditions is 120℃, 6~8 small 时, or 者150℃, 2~4 small 时. wet degree must small 于0.03%. if use wet drying device drying, conditions is 150℃, 2.5 small 时.

        熔化 temperature degree: 225~275℃, temperature degree: 250℃.

         mold temperature degree: for/regarding reinforcement type material is 40~60℃. need very good design mold cooling 腔道以 decrease small parts bending. hot amount dispersion 失一定 need fast uniform. mold cooling 腔道 直径 is 12mm.

         injection pressure: in and other (most large to 1500bar).

         injection speed degree: use can can fast injection speed degree (因 is PBT solid very fast).

         runner and gate: use runner increase pressure 传递(experience 公式: runner 直径=塑 parts thick degree +1.5mm). can use various type gate. can use hot runner, need attention/notes anti material and degradation. gate 直径应该 in 0.8~1.0*t between, this t is parts thick degree. if is 潜入式 gate, most small is 0.75mm.

         chemical and material features

        PBT is most tough engineering thermoplastic material 之一, it is semi crystallization material, has non good chemical stability property, machine strong/high degree, electrical insulation features and heat stabilized property. this material in very ring conditions lower has very good stability property. PBT吸 wet features very low. non reinforcement type PBT force strong/high degree is 50MPa, additives type PBT张 force strong/high degree is 170MPa. additives more will 导致材 material 变脆. PBT; crystallization very speed, this will 导致因 cooling non-uniform formed bending deformation. for/regarding has additives type type material, process/workflow direction shrinkage rate can decrease small, and process/workflow direction shrinkage rate basic upper and 普通材 material has difference. generally material shrinkage rate in 1.5%~2.8% between. 含30%玻璃 additives material shrinkage 0.3%~1.6% between. melting point (225℃) and high temperature deformation temperature degree ratio PET材 material need low. Vicat softening temperature large is 170℃. 玻璃化转换 temperature degree (glass trasitio temperature) in 22℃ to 43℃ between. due to PBT crystallization speed degree very high, therefore it viscous property very low, parts processing cycle time generally relatively low.

         terephthalic acid ester used for electrical engineering, main/primary as insulation use; another in automotive manufacturing process in, used for made as connectors. in day 常 家居 use product in, in or 熨斗 手, selection this type of material. terephthalic acid ester can formed filament, used for made as or use powder 刷 刷毛.