Shanghai Daoqin Plastics Co., Ltd.

PVC （ polyvinyl chloride (PVC) ） injection molding processing process.

    injection molding process conditions:

    drying 处理: usually need drying 处理.

    temperature degree: 185~205℃

    mold temperature degree: 20~50℃

    injection pressure: can large to 1500bar

    holding pressure pressure: can large to 1000bar

    injection speed degree: is 避免材 material degradation, generally need use versus injection speed degree.

    runner and gate: has gate can use. if processing relatively small parts, most good use type gate or 潜入式 gate; for/regarding relatively thick parts, most good use gate. type gate or 潜入式 gate most small 直径应 is 1mm; gate thick degree can small 于1mm.

    chemical and material features

    rigid property PVC is use most plastics material 之一. PVC材 material is types non crystallization property material.

    PVC材 material in use in add stabilizer, lubricant, processing agent, color material, impact resistant agent and its it additives.

    PVC材 material tool has easy property, high strength, resistant gas 侯变化 property and excellent 良 几何 stability property.

    PVC for oxidation agent, also agent and strong/high acid has very strong/high resistant force. however it can by concentrated oxidation acid concentrated acid, concentrated acid and suitable and 芳香烃, chlorine 化烃接触 场 combined.

    PVC in processing 时熔化 temperature degree is non important process parameters, if parameters will 导致材 material separation understanding issues.

    PVC flow features versus 当差, its process scope/range very narrow. especially is large molecular weight PVC材 material more difficult processing （ this type of material usually need add lubricant improvement flow features ）, therefore usually use is small molecular weight PVC材 material.

    PVC shrinkage rate versus low, generally is 0.2~0.6%.

    PVC in molding process in easy 释放出 has gas 体

    type applications

    water pipeline, use pipeline, 房屋墙 sheet/plate, use machine housing/shell 体, electronics product packaging, medical devices, food packaging and other.

    pvc is polyvinyl chloride (PVC), true positive polyvinyl chloride (PVC) is 无毒. has is chlorine ethylene, polymer/macromolecule in has polymerization degree high low issues, polymerization degree high, chlorine ethylene content decline to value 时, is PVC!

    PVC is has 毒, is add heat stabilized agent, increase agent and other various has additives has 毒! has PVC sink marks is very large to 2%!

    PVC material time color;PVC for light oxygen hot good, very easy degradation,引起PVC products color 变化,变化顺序 is: white ---- powder color ----淡黄 color ----褐 color ----红棕 color -----红 black ---- black.

    PVC: formed formed product rear, 会发出 very 臭 味. 确实我 见 PVC odor very 差, belt/tape electrical easy 吸尘

    PVC in electrical 线\ cable \插头 and transparent type product its 砈?

    PVC (polyvinyl chloride (PVC)) -(CH2- CH2)- | CH3

    generally is 含15% below/following increase agent PVC称 is hard PVC, 而含15% above increase agent PVC称 is soft PVC, toys use PVC more is soft PVC, 35~90 degree

    @ plastics main/primary property can:

    a) non crystallization property plastics, transparent, color easy:

    b) material in increase agent content soft hard degree (generally in 55-90 degree) and force property can.

    @ injection molding process key points:

    a) raw materials must 乾燥(chlorine ethylene property separation easy water), temperature degree 85℃ left right, time 2 small above;

    b) material molding temperature degree separation understanding temperature degree, must control can can use relatively low temperature degree injection, meanwhile 亦应尽 can can shrink short cycle, decrease/reduce material in material inner time;

    material temperature parameters: front 160-170℃, in 160-165℃, rear 140-150℃. 由於PVC本身 heat resistant property 差, material in material inner long time hot, drop analysis chlorine hydrogen (HCL) make parts 变黄甚至 generate black spots, and chlorine hydrogen for mold cavity has function, therefore need 经常清洗 mold cavity and machine 头死角位;

    c) flow property very 差, injection molding gate ` runner can can coarse ` short ` thick made parts thick in 1.5mm above, decrease/reduce pressure loss make material fast type 腔, 总之宜 using/adopting high pressure temperature (injection pressure 200Mpa above, back pressure 取0.5-1.5Mpa, holding pressure pressure 20-30%);

    d) mold temperature degree can can low (usually water, control mold temperature in 30-45℃), shrink short molding cycle and decrease small parts rear deformation, necessary 时借助定 type 模` sink marks relatively positive control deformation;

    e) water material: 清洁良 good water material can separation 之百回 use;

    f) machine: 早10啤 front electrical 掣, machine rear use PE machine.

    use sheet/slice, bottle 子,人造皮, sheet/plate material, thin sheet/plate,胶 film, hot sleeve/set 馆,鞋子,线材, to water tube/pipe (UPVC),摥胶.

    blending modified plastics:

    a) PVC + EVA→ improve/increase impact strong/high degree (long increase function);

    b) PVC + ABS→ increase tough property, improve/increase impact strong/high degree