Shanghai Daoqin Plastics Co., Ltd.

in recent years, already again meet/satisfy sheet/plate electrical use function, for its appearance product and green environmental protection requirements 越 越 high. due to that type of injection molding electrical machine machine housing/shell, rear again spray coating methods, environmental protection, quality unstable, more 国际国 inner electrical 视厂商如三星, 夏普, long and and other 纷纷摒弃 老 methods, using/adopting types new type molding process ——免 spray coating high light injection molding technology. technology can make sheet/plate electrical sheet/plate surface gloss degree high weld lines, flow marks and shrink and other defect, and rear spray coating 工序, from for environmental protection and reduce cost is has 利. due to spray coating high light injection molding technology 实施离不开 high gloss plastics material, high light injection molding mold, mold temperature temperature equipment and injection molding machine and injection molding process 紧密配 combined, therefore will from this several for technology 进行阐述.

免 spray coating high gloss plastics material

need achieve spray coating high light injection molding,首先 need selection high gloss plastics material. for/regarding types material features requirements generally 包括: material flow property relatively high, more good made mold surface, reduce and improvement weld lines; has resistant scratch property, surface hardness need good, generally hardness in H above; material heat stabilized property need good, easy generate material. especially is for/regarding flame retardant grade material, improve/increase heat resistant property and decrease/reduce material can anti 止腐蚀 mold and decrease/reduce product surface generate; material gloss degree need good; tool has excellent tough property and rigid property, can through home appliances requirements testing and other function testing.

currently, spray coating sheet/plate electrical frame injection molding production main/primary using/adopting PMMA/ABS, PC/ABS or high light ABS材 material. its in, high light ABS hardness most low, PMMA/ABS hardness most high, hardness can 达1H or above （如图1 示）. high light PMMA/ABS also can formed semi 透效果, from achieve more appearance and LED light function. very more company launch PMMA/ABS, 如三星第一毛织 BF-0677F, Shanghai Kumho day HAM8541以 and LG Chem XG569C and other. if requirements use flame retardant material,则 can selection flame retardant PC/ABS, Kumho day HAC8250NH, or selection flame retardant high light ABS, Shanghai Kumho day HFA705G. electrical machine can according to product different requirements selection different Model/Grade material. forecast, in will, electrical machine will more toward selection used for ultra- thin LED electrical high rigidity reinforcement material, Kumho day HCG25X0FR. is this can meet/satisfy thin type design rigid property requirements, also can maintain high light appearance.
 
high light injection molding mold

high light injection molding mold from design, selection to mold processing need ratio mold has more high requirements. mold design need high temperature resistance design, suitable water design and 安装匹配 and other factors. water ensure fast speed rise temperature and drop temperature, make mold temperature degree uniform, generally using/adopting type 腔 随形 water 道, in increase thermal insulation or utilizing thermal insulation （如图2 示）. mold gate design need can can decrease/reduce weld lines, has 利于排 gas and decrease/reduce 剪切. for using/adopting add hot mold temperature machine mold, gate dimensions need comparison large, for other 行位, combined and toward and other need high temperature requirements, attention/notes thermal insulation or cooling and combined. due to mold inner surface requirements to non high light degree （镜面效果）, mold need selection light property good, high pure degree, high degree and hot deformation small excellent 质钢, 如瑞典ASSAB S136, Japan large NAK80. if molding flame retardant high light material, mold also corrosion resistant property good, most good use S136 SUP or and other grade 钢材.
 
for/regarding high light mold maintenance, need attention/notes in use in and 时清洁 mold separation type and gas 槽, 以免造 formed gas defect. in addition, 应该不定时 use specialized 清洁布 or 纸清洁 mold 镜面部 separation, especially is injection molding flame retardant high light material 时, must remove viscous in 模面 析出 material, 以免出现白雾 and other appearance defect. injection molding formed rear also need use specialized agent type 腔, specialized anti 锈油.
mold temperature control technology
精确 control mold temperature is achieve spray coating high light injection molding large key/critical, currently use relatively more temperature technology has lower types:
1． use add hot high temperature mold temperature machine. mold temperature can by 始终维持 in temperature degree, advantages is cost low, use 方便, in mold design upper need good weld lines 处理, meanwhile for material flow property requirements versus for more high. types mold temperature machine main applications for appearance requirements low product.

2．蒸汽 add hot fast speed technology. this is relatively used for plastics high light molding types technology, its process principle is: in clamping front and clamping process in for mold 进行蒸汽 add temperature, clamping formed rear, temperature degree to setting conditions can injection; injection process in mold 继续维持 high temperature, this can make material in process in maintain very good flow property; injection formed, in holding pressure cooling 时, use low temperature water for mold drop temperature 处理, shrink short products cooling time, improve/increase production efficiency.

该 process need fast speed generate amount 蒸汽, can and injection molding machine 信号互锁, achieve ring control, also requirements material heat resistant property and versus property good. using/adopting technology, mold temperature can to very high temperature degree, in weld lines issues, meanwhile can improve/increase product surface hardness. due to 锅炉投入 relatively large, made technology use. is 此, currently market upper 出现 无需锅炉 fast cold fast hot machine.
3． electrical add hot fast speed technology. this technology Korea NADA company E-MOLD（Electricity Mold） system is table/sheet （如图4 示）, can achieve ultra-high temperature mold temperature degree control, is fast speed add hot cooling molding technology most new 进展. technology utilizing electrical add hot in short time inner mold surface temperature degree add hot to very high, rear in 几十秒之 inner also can temperature degree decline to 50℃ below/following, from 而帮助 high light injection molding 顺利完 formed.
E-mold technology use 方便, control device control mold temperature, utilizing cold water mold cooling.
当 mold mold opening products 时, type 芯开始 add hot. add hot temperature degree is 始终如一, is according to gate and other design 决定. mold 关闭时, add hot formed, meanwhile injection molding 开始. through add hot, rise high mold temperature, make 射胶时 solvent flow property large large improve/increase, from can relatively low pressure molding. relatively low injection molding pressure reduce products internal stress, make products heat resistant property and rear processing property to improve/increase. more important is, resin flow property improve/increase, pressure drop decrease/reduce, make product easy cold material 而导致 surface weld lines, flow marks and other defect, large large improve/increase product quality.
E-mold technology currently already by used for home appliances product outer housing/shell molding, especially for/regarding sheet/plate electrical front frame, decoration frame, base/seat and rear frame molding, already day formed is 主流.

4． other mold temperature control technology. high frequency electrical magnetic add hot system, outer add hot system and using/adopting Korea TITAN technology high pressure water temperature machine in inner other mold temperature control system, in high light injection molding in to application. it although add hot methods different, control principle large small 异, has excellent disadvantages.

injection molding machine and injection molding process

免 spray coating high light injection molding technology for injection molding machine requirements high, for machine reaction degree and stability property requirements relatively high, can 够实时 fast speed 反馈信号, and mold temperature control equipment 协调工 as. injection molding machine most good 配备塑化 can force strong/high screw, meanwhile requirements screw for material 剪切尽 can can small.

high light injection molding process control according to different product and mold structure and mold temperature equipment different has relatively large 差异, generally 应遵循 below/following 原则: amount using/adopting high mold temperature degree, using/adopting add hot mold or E-MOLD technology 时, mold local can to 150℃ or more high; is more good made mold surface, molding temperature degree 应适当 high 一, injection molding pressure can can large 一点; is 顺利排 gas, need using/adopting more grade injection molding speed degree; process adjustment screw speed, different stage/phase injection molding speed degree and other, need decrease/reduce material 剪切.  

is 此, spray coating high light injection molding technology will to more more application, plastics material, mold and injection molding equipment and molding technology development to 不断完善.