Shanghai Daoqin Plastics Co., Ltd.

         in blow molding is will extrusion or injection molding tube/pipe 坯置于 mold in, in tube/pipe in pressure shrink gas will its 吹胀, make 之紧贴于 mold cavity upper, again cooling demolding to in products molding methods. this type of molding methods can production bottle, 壶, and other various packaging container, day commonly used product and toys and other.

         used for in blow molding plastics product types has polyethylene (PE), polyvinyl chloride (PVC), polypropylene (PP), polystyrene (PS), polyester, polycarbonate (PC), polyamide (PA), acid fiber and poly shrink aldehyde resin and other. its in high density polyethylene (PE) consumption amount 占首位. it widely used in food, chemical industry and liquid packaging. polymer/macromolecule amount polyethylene (PE) suitable for manufacturing large type material and and other.

         in blow molding classification

        1, according to molding methods different

         extrusion —— blow molding: production methods simple, output/production volume high, degree low, application relatively more.

         injection molding —— blow molding: degree high, quality good, price high, combined large amount product.

        2, according to molding process different

        普通 blow molding;

         tensile blow molding: product tensile, strong/high degree high, gas property good.

         extrusion — tensile — blow molding (简称挤—拉—吹)

         injection molding — tensile — blow molding (简称注—拉—吹)

        3, according to tube/pipe 坯层数 different classification

         mono blow molding;

         more blow molding: comprehensive property can good, production complex, suitable for packaging requirements high product packaging.

         blow molding plant/unit

        1, 针吹 method

        工序: 闭 combined ——穿破 type 坯壁——吹胀——吹针回 shrink —— melt material combined

         features: 适 combined 连续旋转 blow molding, small type container, belt/tape has 手柄.

        2, 顶吹 method

        工序: 闭 combined ——底部夹住——顶部开口—— type gas ——吹胀——旋转刀 tool remove material

         features: type as gas 芯轴, machine 构简化

         blow molding process effect/influence factors

        01, gas pressure

         blow molding in, pressure shrink gas has function, is make tube/pipe large 而紧贴 mold cavity 壁, formed need 形状;二 is cooling function. according to plastics product types and type temperature degree different, gas pressure 也不一样, generally control in 0.2-0.7兆帕 between, most is can make products in molding rear outer 形, and other table/sheet 露清晰 pressure.

        02, gas speed degree

         is shrink short gas time, 以利于 products obtain relatively uniform thick degree and relatively good surface, gas speed degree (mono time inner 流 空 gas 体积) need can can large 一, 但也不宜 large, 否则会 to products belt/tape defect effect/influence.

        03, ratio

         usually products dimensions and type dimensions ratio is ratio. type dimensions and weight 一定时, products dimensions large, type 坯 吹胀 ratio large. according to plastics product types, property 质, products and dimensions and type dimensions and other 决定吹胀 ratio large small. usually ratio control in 2, 4倍.

        04, mold temperature

         is ensure products quality, mold temperature degree distribution uniform, mold temperature generally maintain in 20-50℃. mold temperature low, make 夹口处 plastics property reduce, easy 吹胀, make products in separation add thick, meanwhile make molding difficult, products and and other 也不清楚. mold temperature high, cooling time long, production cycle add long. products demolding deformation, shrinkage increase large. mold temperature high low 取决于 plastics product types, plastics 玻璃化 temperature degree relatively high 时, can using/adopting relatively high mold temperature;反之, can can reduce mold temperature.

        05, molding cycle

         blow molding cycle extrusion type 坯, type 坯. clamping, gas, cooling, gas, 开横, products (its rear 修整, sleeve/set, packaging 另计) and other process.