Shanghai Daoqin Plastics Co., Ltd.

PC通称 polycarbonate (PC), due to its excellent mechanical properties, anti elastic 胶. PC tool has machine strong/high degree high, use temperature degree scope/range 广, electrical insulation property can good （但 anti electrical property can 不变）, dimensional stability good, transparent and other features. in electrical product, electrical outer housing/shell, electronics product structural parts upper by use. PC modified product relatively more, usually has add glass fiber, material filler, chemical flame retardant, its it plastics and other. PC flow property relatively 差, processing temperature degree relatively high, therefore its many grade modified material processing need 专门 塑化 injection structure.
一, plastics 处理
PC water absorption relatively large, processing front need preheating drying, pure PC drying 120℃, modified PC generally use 110℃ temperature degree drying 4 small above. drying time can ultra- 10 small 时. generally can use for extrusion method drying is 否足够.
recycled material use ratio/proportion can 达20%. in certain lower, can 100% use recycled material, 实际份 amount need products quality requirements 而定. recycled material can meanwhile mixed combined different color masterbatch, 否则会严 heavy loss bad formed product property 质.

二, mold and gate design
Common mold temperature degree is 80-100℃, add glass fiber (GF) is 100-130℃, small type products can use gate, gate deep degree has most thick 部位 70%, its it gate has ring and long 方形.
gate large good, decrease low plastics by degree 剪切而造 formed defect.
排 gas deep degree small 于0.03-0.06mm, runner amount short 而圆.
demolding degree generally is 30′-1° left right.

三, injection molding machine selection
现 in PC products due to cost and its it causes, more use modified material, especially is electrical product, also must increase anti property can, in flame retardant PC and its it plastics alloy product molding 时, for injection molding machine system requirements is mixed combined good, corrosion resistant, 常规 塑化 screw difficult to, in 选购时, need 预先说明. 华美达 company has specialized PC screw 供客户 selection.

四, temperature degree
can use for injection method processing temperature degree high low. generally PC processing temperature degree is 270-320℃, has modified or low molecular weight PC is 230-270℃.

五, back pressure
10bar left right back pressure, in has gas marks and mixed color lower can reduce.

六, injection speed degree
more use fast injection speed degree molding, electrical appliances parts. Common is slow speed → fast speed molding.

七, time
in high temperature lower time long, material material drop 质, 放也CO2, formed color. use LDPE, POM, ABS or PA清理 machine 筒. application PS清理.

八, precautions
has modified PC, due to recycling 次数太 more （ molecular weight reduce ） or various formed separation mixing/compounding 不均, easy generate deep color liquid 体泡.

燃烧产 material and plastics types type has 关
  generally 说, plastics 燃烧产 material and plastics types type, carbon upper 含基团 property and other has 关. in in, plastics 燃烧产 material main/primary has 烟雾, has gas 体, can gas and 燃烧熔滴.

 烟雾如 polystyrene (PS), polyurethane ester foam, in in 燃烧会迅 speed generate a large amount of 烟. plastics 发烟规律 is: large more types type plastics hot separation understanding, generate very concentrated 烟雾, using/adopting methods can remove separation 烟雾, can large degree reduce concentrated degree; can polymer in hot conditions lower and in 会冒烟, concentrated degree relatively low; aldehyde foam plastics has 无火焰, need by add hot can generate concentrated 烟, but also speed degree very fast.

has gas in conditions lower, plastics 燃烧都会 generate has gas 体, its has formed separation main/primary is oxidation carbon. types type plastics remove generate oxidation carbon outer, also generate other gas 体, this gas and oxidation carbon mixed combined property more large. chemical formed separation different plastics 燃烧时 generate has gas types type different: carbon, hydrogen or carbon, hydrogen, oxygen is main/primary formed plastics generate has gas is oxidation carbon, in 火势猛烈时, this type of gas most tool property; nitrogen plastics, poly amine aldehyde and polyurethane ester and other, 燃烧时 can generate oxidation carbon, oxidation nitrogen and hydrogen, this type of mixed combined gas property large; chlorine plastics, polyvinyl chloride (PVC), in in or separation add hot generate chlorine hydrogen, to concentrated degree 时会致人死亡; fluorine plastics, PTFE, in in or separation hot generate fluorine hydrogen gas 体, gas tool has property, property.

 燃烧熔滴 generally lower, has thermoplastic property plastics products in hot 时熔化 and flow, generate can 燃烧 熔滴, hot solid property plastics products 燃烧不 generate 熔滴, polyurethane ester foam outer. 燃烧熔滴 出现, accelerated 火势蔓延, for safety hydrophobic dispersion and 灭火都 has effect/influence. 燃烧熔滴 can can belt/tape types 结果: is plastics from 火焰区熔化 outer retardant again 燃烧, is 熔滴燃烧并 generate 柏油一样 滴落 material. rear types 结果出现 can can property more large.

  can gas plastics or hot separation understanding material in can gas 体, oxidation carbon, hydrogen and other and gas mixed combined material, in conditions lower 会燃烧 or 爆炸, 当火场 oxygen gas concentrated degree 改变时, can can more 猛烈 燃烧 or 爆炸发生. PC俗称 polycarbonate (PC). easy 燃, outer strong/high add 燃烧时, 冒黑烟, has small pellets 析出, 花果腐臭味. material good bad tough degree good bad generally sheet/plate material is polymer/macromolecule PC(good material), need attention/notes coating (use surface, 如刮出 is very powder is has coating)现国 inner has remove coating use 户, need 算人工费,   price need low.   generally product material 都· is in separation or high or low, product need 而定, this category of poly carbon most Common,   lamp covers (has coating)游戏 machine inner transparent parts, optical sheet/slice and electrical appliances outer housing/shell and other, transparent and its it color or black has 一定差距. low separation 子PC——般见于唱 sheet/slice material (VCD, CD and other), this type of material low.
    has used as plastics polycarbonate (PC) has di 酚. 鉴定时 it and for -甲 amine 基苯甲 aldehyde color reaction or Gibss靛酚 experiment/testing to positive 结果.

    polycarbonate (PC) in 10％ hydrogen oxidation alcohol solvent liquid in add hot separation 钟就会完 full 皂化. reaction has carbon acid 钾钾沉淀析出, use dilute acid acid 化沉淀, 就会放出二 oxidation carbon gas 体. add hydrogen oxidation solvent liquid 时就会 generate carbon acid 钡沉淀.