Shanghai Daoqin Plastics Co., Ltd.

        1, hydrolysis silver streaks

         hydrolysis silver streaks is plastics in material in hydrolysis formed silver streaks, its generate causes is due to material in molding front to separation drying, or already separation drying material in material in time long, material in also has 效 保 temperature measures, make its heavy new wet, water amount ultra- 规定 requirements, this type of water amount ultra-high material in material inner high temperature function lower water separation by 汽化, resin in melt process in degradation phenomenon, generate oxidation carbon gas 体.

        积存 in melt resin internal, 充模时随流 material mold cavity, formed hydrolysis filament. make parts strong/high degree significantly reduce, 质 变脆. this category of silver streaks 经常遇 to, but also comparison easy 识别, it usually is injection toward relatively uniform distribution, heavy 时密布 in 整 塑 parts surface.

        消 remove hydrolysis silver streaks methods is separation drying material 粒, molding use material water amount must control in 0.03% below/following. is 此, must control raw materials drying process conditions, in molding front in molding front for material 粒 含 water amount 进行测定.

         production in can using/adopting types 简便 检查 methods, use block small 玻璃, in 间夹一粒 by testing material 粒, rear to 280~300 degree add hot sheet/plate upper, material hot 渐熔时, in upper add pressure, will material pressure 扁, material in has bubbles, bubbles, is drying combined 格, can molding processing use, also need 继续进行 drying 处理.

        若 silver streaks is due to drying material in material in wet 致, according to specific 情况, in material in or add hot temperature plant/unit. control one-time material amount, 不致于导致 drying material in material in time long wet, generally, time most long 不

        宜 ultra- 30~60 separation 钟. currently, material add hot temperature plant/unit large is in material upper 部设置红 outer 灯泡, its rate large small can material 斗面积而定, generally 每平方米面积 upper 需设置25~30W add hot rate. in addition, can using/adopting 蒸汽夹 sleeve/set, electrical retardant filament add hot and other methods raw materials drying 处理.

        2, separation understanding silver streaks

         separation understanding silver streaks is molding process in resin hot separation understanding, generate oxidation carbon and other gas 体, make parts surface generate silver streaks.

        引起熔 material hot separation understanding specific causes very more, relatively to causes:

        一 is material temperature degree high;

        二 is material or nozzle in has material 死角;

        三 is material in material in time long;四 is resin molecular weight already reduce, therefore, parts impact strong/high degree reduce, 质 变脆, can meet/satisfy use requirements.

         this category of silver streaks generally can from appearance 进行识别, it in plastics parts surface distribution has 一定 规律, has 时呈现慧星状. in addition, separation understanding silver streaks 出现往往伴随 plastics parts color deep 甚至出现棕 color 斑痕, this in runner upper is obvious, this can as is separation understanding silver streaks main/primary based on.

         for/regarding separation understanding silver streaks, according to separation understanding causes versus measures. if is due to material certain temperature degree high formed, will temperature degree reduce; if is in material or nozzle in has material 死角, 则应清理滞 material 部位并修 remove 死角; if is due to material in material in time long, in ensure parts quality front lower amount shrink short molding cycle, still 不见效, 则应考虑换 use amount relatively small injection molding machine processing.

        3, structure silver streaks

         structure silver streaks is due to parts structure design combined 理, thick heavy non-uniform or 出现断面突变, make material in process in 急剧膨胀 or shrinkage, mold cavity in gas mixed material in formed silver streaks. this category of silver streaks main/primary is effect/influence appearance, for parts strong/high degree and impact tough property effect/influence large.

         structure silver streaks features is: process conditions solid 定时, silver streaks distribution and 位置也 is solid 定, but also generally is injection direction distribution, 发生 位置 more in 断面突变 部位之 rear. due to structure silver streaks is 由断面突变, parts thick heavy 不均 引起.

         therefore in parts surface meanwhile 出现凹陷 and shrinkage and other fault/failure, has 时甚至 in parts internal generate different degree bubbles.

         structure silver streaks generally can through injection speed degree methods troubleshooting. parts 截面变化不 large 时, can decrease slow injection speed degree, using/adopting slow speed injection 时, make material 平稳 充填 mold cavity, from make material 经 突变断面时不致 mixed gas, generate silver streaks. is, reduce injection speed degree also can can 出现欠注, this need through adjustment mold temperature and nozzle temperature degree and other its it process conditions solution. 当截面变化悬殊时, can use relatively high injection speed degree injection, combined improve/increase injection pressure, make gas from separation type strong/high made 排出.

         if improvement injection speed degree or improve/increase injection pressure still can remove fault/failure, 则应考虑改进塑 parts structure and improvement mold gas system.

        4, silver streaks

        浇道 silver streaks is due to system design combined or local 堵塞而引起 silver streaks. its generate causes and methods lower:

        (1), runner design large. if runner large, make material in injection 初期离开锥壁, generate 间隙, mold cavity 逐渐充满, gas mixed in material in mold cavity, formed silver streaks. this category of silver streaks main/primary is its distribution full injection direction 排列.

         troubleshooting this type of fault/failure 时, through for injection troubleshooting resin hydrolysis and separation understanding can can, again 检查主 runner large small is 否适当. 若A角 large is 1 0 degree has can can generate upper phenomenon. A角 and other 于4~6 degree is 宜, if A角取 太 small 则会引起 demolding difficult, material 不畅. silver streaks has 时也采取改变 injection speed degree methods remove, 但根本 methods also is or more gate sleeve/set, decrease/reduce runner 锥角.

        (2), gate design combined 理, if gate 截面积太 small, material through gate 时会形 formed or 喷注, make material and gas mixed, from in gate generate silver streaks. this category of silver streaks main/primary is gate is in injection direction 呈放射状 distribution. its remove methods is through expand large gate or gate 截面形状, make silver streaks 消失, in gate meanwhile if reduce injection speed degree, more easy 奏效.

        (3), nozzle cold material in injection process in formed system separation runner or local 堵塞. separation runner or gate local and gate small generate silver streaks mechanism versus 似, in identification this category of silver streaks in injection system in to cold material 痕迹. remove this category of fault/failure methods is add large mold in cold material and improve/increase nozzle temperature degree.

        5, silver streaks

         谓脉冲 silver streaks non silver streaks 呈脉冲状, is 指预塑 screw

         rear add material 时, non-uniform phenomenon, 犹似脉冲. this type of phenomenon main/primary is 反映 落 material positive 常, 此时, material in easy 进入空 gas, injection gas material mold cavity formed silver streaks.

         this category of silver streaks main/primary is generate and amount 无一定规律 property, has 时伴随发生欠注, sink marks and internal bubbles and other fault/failure. main/primary according to process in screw has 无脉冲跳动 phenomenon and injection 终 时 material is 否恒定 确定 silver streaks property 质.

        消 remove silver streaks methods is for phenomenon formed 因采取 versus measures.

         its generate causes and methods lower:

        (1), material rear temperature degree high, make material 口附近 material bonding in 一起, formed material positive 常. 应适当 reduce material rear temperature degree.

        (2), material temperature low, resin defect, 引起预塑 electrical machine negative large, screw speed 失常. 应适当 improve/increase molding temperature degree, add strong/high 塑化.

        (3), screw back pressure small, usually back pressure small injection pressure separation 之一.

        (4), material temperature plant/unit or use 不当. outer 灯泡离 material can or time long, make material in high temperature lower bonding formed block, effect/influence material.

         in positive production process in has 时突然出现脉冲 phenomenon, this is due to 别自控仪 table/sheet or material add hot plant/unit fault/failure, formed material rear temperature degree 失常 致, therefore, in adjustment temperature degree meanwhile, 应检查仪 table/sheet and electrical has 无异常.

        6, gas silver streaks

        封 gas silver streaks is material in process in gas can troubleshooting formed silver streaks. this category of silver streaks main/primary is has relatively obvious 熔接痕, but also silver streaks 往往出现 in 熔接痕附近, its it 部位没 has silver streaks.

        消 remove this category of silver streaks methods is gate and 形式, has 效 排 gas or 修改塑 parts structure, this need for mold relatively large 修改. in production or mold trial process in, 往往采取改 positive process conditions methods, adjustment injection pressure and injection speed degree, 改变定模 and temperature and other.