Shanghai Daoqin Plastics Co., Ltd.

　 in blow molding (also blow molding 模塑) is 借助于 gas pressure make combined in mold in hot type 坯吹胀形 formed in products methods, is types most commonly used plastics processing methods, meanwhile is development relatively fast types plastics molding methods. blow molding use mold has anionic (凹模), and injection molding versus ratio, equipment relatively low, property relatively strong/high, can molding property can good (如 low force), can molding tool has complex 起伏曲线 (形状) products. blow molding 起源于 19 世纪 30 year 代. to 1979 year rear, blow molding 才进入广泛 application stage/phase. this stage/phase, blow molding grade plastics 包括: polyolefin, engineering plastics and elastomer; blow molding products application and to automotive, office equipment, use electrical appliances, medical and other 方面; small can production 6 万 bottle can manufacturing large type blow molding parts (parts heavy 达 180kg), more blow molding technology to relatively large development; blow molding equipment already using/adopting micro machine, solid electronics ring control system, machine CAE/CAM technology day formed 熟; blow molding machine more 专业化, more tool color this main/primary blow molding (also blow molding 模塑) is 借助于 gas pressure make combined in mold in hot type 坯吹胀形 formed in products methods, is types most commonly used plastics processing methods, meanwhile is development relatively fast types plastics molding methods. blow molding use mold has anionic (凹模), and injection molding versus ratio, equipment relatively low, property relatively strong/high, can molding property can good (如 low force), can molding tool has complex 起伏曲线 (形状) products.
　　 blow molding 起源于 19 世纪 30 year 代. to 1979 year rear, blow molding 才进入广泛 application stage/phase. this stage/phase, blow molding grade plastics raw materials 包括: polyolefin, engineering plastics and elastomer; blow molding products application and to automotive, office equipment, use electrical appliances, medical and other 方面; small can production 6 万 bottle can manufacturing large type blow molding parts (parts heavy 达 180kg), more blow molding technology to relatively large development; blow molding equipment already using/adopting micro machine, solid electronics ring control system, machine CAE/CAM technology day formed 熟; blow molding machine more 专业化, more tool color.
　　1 blow molding methods
　　1.1 molding methods
　　 different blow molding methods, due to raw materials, processing requirements, output/production volume and its cost 差异, in processing different product in tool has different advantages. detailed blow molding process can 参考文献. this from macro degree introduction blow molding features.
　　 in products blow molding 包括三 main/primary methods: extrusion blow molding: main/primary used for by type processing; injection blow molding: main/primary used for metal type 芯支撑 type processing; tensile blow molding: extrusion tensile blow molding, injection tensile blow molding types methods, can processing di orientation products, large reduce production cost and products property can.
　　 in addition, also has more blow molding, pressure made blow molding, coating blow molding, foaming blow molding, blow molding and other. blow molding products 75 ％ use extrusion blow molding, 24 ％ use injection blow molding, 1 ％ use its it blow molding; in has blow molding product in, 75 ％ belongs to di toward tensile product. extrusion blow molding advantages is production efficiency high, equipment cost low, mold and machine selection scope/range 广, disadvantages is waste product rate relatively high, waste material recycling, utilizing 差, products thick degree control, raw materials dispersion property made, molding rear must 进行修边操 as. injection blow molding advantages is processing process in has waste material generate, can very good control products thick and material material dispersion, fine product molding degree high, product surface light 洁, can 经济 进行 small amount production. disadvantages is molding equipment cost high, but also in 一定程 degree upper combined small blow molding products. in blow molding process conditions, requirements mold in type pressure shrink gas must dry 净. injection blow molding gas pressure is 0.55 ～ 1MPa; extrusion blow molding pressure is 0.2l ～ 0.62MPa, tensile blow molding pressure need high 达 4MPa. in plastics solid in, low pressure make products generate internal stress low, force dispersion relatively uniform, low force can products tensile, impact, bending and other property can.
　　1.2 products types type
　　 blow molding products has container, industrial made parts type.
　　 its in container 包括: packaging container, large 容积储桶 / 储罐, and can container. blow molding process formed 熟, industrial made parts blow molding products 越 越 more, application scope day 益广泛. currently, container 约占 80 ％ market 份额, year growth 4 ％ left right; industrial and structure use products amount 20 ％, year growth speed degree is 12 ％. container consumption amount growth in can plastics container application scope expand large, industrial use products consumption amount growth main/primary is new type processing technology 改进 致, more type extrusion, di extrusion, non for blow molding and other.
　　1.3 blow molding 进展
　　(1) Raw Materials polymer in molding process in, through 口模时受 high force function, rear material material extrusion and shrink phenomenon, in formed lower type 坯时, its rate is 零. type by 吹胀紧贴 in mold upper, this 时呈现 low rate. degree 口模膨胀会 generate waste product. degree shrink made parts to 底部壁 thick thick degree non-uniform, heavy 甚至不 can molding. therefore, in selection combined blow molding polymer 时, must its and viscous elastic features.
　　HDPE due to heat stabilized property good, also has multiple modified product, formed is blow molding in application most plastics. through copolymer and blending function, for blow molding use Raw Materials research in extrusion blow molding grade resin 方面也取 一 进展, PA6, PP and PET. 间歇式 type blow molding, upper suitable for structure sheet/plate and large type made parts processing, requirements use engineering plastics, flame retardant type ABS, reinforcement PVC, modified PPO and PC and other, this category of extrusion type plastics high temperature resistance property can generally relatively 差, has less resin can in equipment upper blow molding large type made parts. in poly 萘二甲 acid ester (PEN)/PET blending material blow molding 时, will anti oxygen and anti water gas resin (ethylene / 乙 acid ethylene alcohol) copolymer (EVOH) and HDPE and PET formed composite/compounding 层, generate 锚联层, improvement PEN/PET material property and heat stabilized property. currently positive research will HDPE and PA6 using/adopting more blow molding, production 燃油油箱.
　　(2) equipment and process technology blow molding machine equipment already has very large 改进.
　　 relatively new formed has: ① using/adopting type outer add hot technology again blow molding; ② non high speed 旋转挤塑 pressure, main applications in bottle production upper; ③ mold in pressure machine upper 以补偿喷流 phenomenon; ④ more 层连续 extrusion blow molding anti property container; ⑤ through for orientation crystallization and hot crystallization, molding and mold temperature, gas pressure, and type in mold cavity inner time control, 进行连续 property hot PET bottle production.
　　 due to market for complex, 曲折 输送 pipe/tube made parts demand, 推动 偏轴 extrusion blow molding technology development, this type of technology 笼统称 is 3D or 3 维 blow molding. upper, 该工序十 separation simple, type extrusion rear, by local 吹胀并贴 in mold upper, extrusion machine or mold 转动, already 编 2 轴 or 3 轴程序转动. difficulty/challenge in requirements tool has non large property amount large type blow molding machine in high speed clamping 时误差 need low 于 10 ％. more blow molding process used for processing anti property container, its process is increase 设一 阀门 system, in extrusion process in can more plastics raw materials, can production hard and soft products. production large type made parts 如燃油箱 or automotive outer structure sheet/plate 材时, in cooling process in reduce mold cavity inner pressure adjustment processing ring cycle. solution methods is will material in extrusion screw front 端 熔槽 in, again in versus high speed lower extrusion type 坯, most large degree decrease/reduce type thick 变化, from ensure remove shrink and extrusion phenomenon. material machine 头改进, make can extrusion hot property plastics ABS — R, modified PPD and PVC. but also, heavy new design machine 头, in production in can fast speed 装拆以方便清理 plastics, meanwhile, for plastics features analysis and machine runner analysis can design type runner, 以便于 hot property plastics molding.
　　(3) control and blow molding type 坯 程序 control already has year experience. main/primary issues is type can 拉坯变 thin most thin degree (如 bottle 颈部位), increase thick type 坯拉坯 most large degree (如 container bottle or 边角部位), and design 一 壁 thick degree 变化部位, 例如凹边 and bottle and other. its as focus/key point in in use plastics viscous elastic property features upper. for tube/pipe 状 预 molding thick forecast, is design tool has anti function type most thick thick degree selection based on. this is molding crystallization degree, use plastics and temperature degree related force 一应变 elastic property features, and injection molding processing formed 冻结应 force degree and distribution and other 情况 决定.
　　1980 year, GE company is hot molding and blow molding development: PITA design. type blow molding control soft parts must comprehensive 考虑如 lower factors: non-uniform type thick; type 坯截坯口 and ring type blow molding pipe/tube 截口; in clamping front 预先吹胀 type 坯; process control and 截坯口开设 部位; and structural parts blow molding in for type 坯边缘 裁切定位 and other.
　　 currently, 商业化 blow molding soft parts main/primary has USA ACTech company C — PITA, ratio POLYFLOw and other. value difficult degree in 于: large 应变, non property material is, issues and process in material non stability property, this complex property will generate series need 迭代求 understanding non property 方程. its in, material, blow molding mechanism research is research difficulty/challenge, hot 点, tensile blow molding by application, for process need force crystallization 数学描述, to currently is 止尚无 combined methods. extrusion blow molding type 坯, is polymer melt ring 形模头时形 formed, ring pipeline 几何形状 and material viscous elastic property will effect/influence type 胚膨胀, has viscous elastic property Knowledge also method this process. and versus for formed injection molding CAE technology versus ratio, blow molding soft parts currently positive development stage/phase.
　　1.4 blow molding development trend
　　 blow molding will market for its products demand, in material, machine 械, equipment, control system, soft parts and other has lower development trend.
　　(1) Raw Materials is meet/satisfy blow molding products function, property can (医药, food packaging) requirements, blow molding grade raw materials will more add 丰富, processing properties more good. PEN type material, not only strong/high degree high, heat resistant property good, gas retardant property strong/high, transparent, resistant outer 线照射, can suitable for made various plastics bottle 体, and filling temperature degree high, for oxidation carbon gas 体, oxygen gas retardant property can excellent 良, chemical resistant product.
　　(2) products packaging container, industrial products will has relatively large growth, but also injection blow molding, more blow molding has fast speed development.
　　(3) blow molding machine and equipment blow molding machine precision high 效化; production (操 as) equipment 自动化. “ precision high 效” not only machine equipment in production molding process in tool has relatively high speed degree and relatively high pressure, but also requirements production product in appearance dimensions and parts heavy 波动方面均 can to relatively high stability property, is production products 各 部位 dimensions and outer 形几何形状精 degree high, deformation and shrinkage small, products appearance and inner in quality and production efficiency and other indicators need to relatively high water 准. 辅助操 as flash, 切割, heavy, 钻孔, and other, its process 自动化 is development trend 之一.
　　(4) blow molding blow molding mechanism research more add in-depth, blow molding 模拟 数学模 type combined 理构建, value method fast speed, is key/critical, blow molding will in products quality forecast, control in 发挥越 越 important function.
　　2 effect/influence blow molding products quality factors and Common defect troubleshooting
　　2.1 blow molding effect/influence factors lower from blow molding process analysis stage/phase molding parameters.
　　 blow molding process can separation is stage/phase:
　　(1) type formed stage/phase polymer in extrusion machine in 输送, melt, mixing/compounding, molding is type 坯 形 formed stage/phase; in this stage/phase, effect/influence thick distribution main/primary process parameters has: ①材 material molecular weight distribution, molecular weight; ② blow molding machine temperature degree control system and screw speed, its in temperature degree control system material temperature degree, material 筒 1 区, 2 区, 3 区, 4 区 temperature degree, method temperature degree, and material 模头 1 区, 2 区, 3 区, 4 区 temperature degree.
　　(2) type lower material stage/phase type from and 模芯 间隙 in extrusion is lower material stage/phase. 此时, type 坯离模膨胀 and type 坯垂伸 this types phenomenon effect/influence type molding. effect/influence thick distribution main/primary process parameters is blow molding machine 模头直径 and thick control system, its in control system 包括轴 toward thick control system and toward thick control system, adjustment and 模芯 间隙.
　　(3) type 坯预吹 stage/phase is type inner surface 接触, viscous 附, improvement products thick uniform property, need for type 坯进行预吹胀. in type 坯预吹 stage/phase, from type lower type inner gas, 以护持 type 坯, decrease small its 垂伸. in this stage/phase, effect/influence thick distribution main/primary process parameters has: pressure, time.
　　(4) type high pressure stage/phase high pressure type 坯, make 之贴紧 mold type 腔, achieve product property molding stage/phase. stage/phase, effect/influence product molding is type high pressure deformation, type and mold cavity deformation. effect/influence thick distribution main/primary process parameters has: material shrinkage rate; gas pressure, time; mold material, structure, mold gas system and mold cooling system, cooling water distribution, cooling water water temperature degree and other. tube/pipe effect/influence blow molding products quality factors relatively more, production conditions, products requirements rear, adjustment blow molding process parameters can has improvement products quality. optimization process parameters can improve/increase production efficiency, reduce Raw Materials consumption, optimization product comprehensive property can.
　　2.2 blow molding process conditions setting
　　 process conditions adjustment is, in meet/satisfy product most small thick requirements upper, product thick can can uniform, product parts heavy can can small (decrease/reduce material consumption). process parameters setting combined methods is, will experience and value analysis technology combined. basic process is:
　　① utilizing already 建立 计算 machine type, blow molding mold, lower material type 坯, material sheet/plate and other 状态;
　　②输入各 stage/phase for type thick distribution effect/influence parameters;
　　③ for to 模拟结果进行 analysis, through machine 模拟显示 which 部位壁 thick to requirements, which 部位壁 thick ultra- thick;
　　④ utilizing experience, adjustment parameters, heavy 复①～③ process, ensure product 各部位 in to most small thick front lower, can can decrease small product 各部位壁 thick.
　　⑤ for more process solution/scheme analysis, comparison, most 终确定 optimization process parameters. tensile blow molding also di orientation blow molding, is in polymer high elastic lower through machine methods toward tensile type 坯, use pressure shrink gas toward (tensile) type molding packaging container methods. tensile blow molding has method, method.
　　2.3 blow molding Common products defect and its this to extrusion blow molding, injection blow molding, tensile blow molding Common issues, generate causes and solutions.
　　(1) extrusion blow molding extrusion blow molding is extrusion molding most main/primary molding methods. has extrusion and 不连续 extrusion types methods.
　　(2) injection blow molding injection blow molding is use injection method made formed has type 坯, again will it 吹移至 blow molding mold in molding in products. injection blow molding can for products 进行精确 control, can production 无刮痕, degree high, surface light slip products, 无需二次 processing; its in products parts heavy can control in ± 0 ． 1g, 螺纹 精 degree can is ± 100 μ m.
　　(3) tensile blow molding
　　3 结语 blow molding technology is plastics industrial, machine manufacturing and other multiple technology 进步而不断 development, in blow molding product design, production process in, melt 人现代 design 思想, design tool, engineering technology 人员应充 separation utilizing design 理念, combined experience, make products design, manufacturing step/link efficiency improve/increase, from improve/increase blow molding products quality and market competition can force.