Shanghai Daoqin Plastics Co., Ltd.

plastics molding process has very multiple, main/primary has pressure shrink 模塑, extrusion molding, injection 模塑, 传递模塑, blow molding, 铸塑, lamination, calendering, coating, reaction injection and rotational molding and other and other. currently type has plastics molding processing process 文献资 material in for rotational molding process introduction more, for plastics rotational molding molding new process introduction more less, 本文拟 for rotational molding molding and its new process introduction. 　　 rotational molding process process 　　 rotational molding is 旋转模塑 or 旋转浇铸 molding, basic process process is will powder or liquid poly material in injection molding parts mold 里, add hot meanwhile 围绕两 垂直轴旋转, rear cooling. in add hot stage/phase most 初, if use is powder 末状材 material, will injection molding parts mold surface formed table/sheet housing/shell 层, rear ring process 渐渐熔 melt, formed uniform thick degree versus 层; if use Raw Materials is liquid 体; flow and coating in injection molding parts mold surface, to 凝胶点时则完 full flow. injection molding parts mold rear cooling stage/phase, through strong/high made or water cooling, rear by 放置于 demolding as 区, in this injection molding parts mold by 打开, molding parts by 取出, in lower cycle ring molding as. 　　 rotational molding process development 　　本 process in 二十世纪四十 year already 出现, most is use polyvinyl chloride (PVC) through rotational molding molding methods production plastics type toys and other product. year 代, development low density polyethylene (PE) powder resin is raw materials polyethylene (PE) rotational molding molding process, production polyethylene (PE) 贮槽, large type pipe/tube and other industrial product, from large large promote rotational molding process development. rear, nylon, polycarbonate (PC), ABS and other multiple plastics versus using/adopting rotational molding process molding, to year rotational molding already formed is tool has production plastics molding process. 1971 year, in UK already has 50余家 company from rotational molding products production, rotational molding thermoplastic property plastics injection molding parts processing 家约70余家; in Europe large has 20余家 company from rotational molding molding processing, its in has Germany, France, Switzerland, 挪威, 奥 利, and other company. year 代初, UK already can provide can production amount 达18000L container rotational molding machine; Netherlands already production 出直径2.1m, long 4.8m large type 圆柱形贮 water 槽, 该贮槽540Kg, thick 25mm. 1970 year, Europe rotational molding products amount already 达15000t above, its in UK 约7000t. 1970 year, USA already has 500余家 mono from rotational molding products production, has 500余台 rotational molding machine, rotational molding made container amount already ultra- 10000L拥 has rotational molding machine can production most large plastics made parts is 4.6×4.6×2.1m. 二十世纪六十 year 代, rotational molding molding process therefore to speed development, and resin property can and rotational molding equipment 改进息息 related. its development less rotational molding molding specialized plastics, 例如联 combined carbon company development PE P-320, Raychem Flamolin 771 and other polyethylene (PE) resin. FE P-320 is types low density polyethylene (PE), it has low density polyethylene (PE) resin good flow molding property can and high density polyethylene (PE) resin low temperature impact tough property, chemical resistant product parts and resistant force cracking property Raychems Flamol in 711 is types rotational molding use crosslinked polyethylene (PE) resin, it remove can crosslinked outer, also tool has self-extinguishing property. force company rotational molding grade crosslinked polyethylene (PE) resin Marlex c1-100也 is in this time development 出. 　　 is made large type rotational molding products need, year 代末期 development many can rotational molding molding large type made parts ． can has utilizing 占 面积 and hot can machine. 1970 year, rotational molding machine in semi above rotational molding machine, its 回转直径 scope/range ultra- 1.75m. in addition, machine control water to different degree improve/increase, 例如三臂式 rotational molding machine McNeil Auronjsmodel 3000-200 can separation control add hot, cooling cycle, meanwhile rotational molding molding different dimensions and different material material products, its 回转直径达5m, 每 臂 can injection molding parts mold and resin weight 约13500N; hot good. 占 面积 small sleeve/set machine in this time design, manufacturing 出. is from 二十世纪六十 year 代开始 rotational molding development research, to year rear 期, Shanghai toys industry already utilizing rotational molding molding methods year soft polyvinyl chloride (PVC) small 球; Shanghai plastics injection molding parts processing already formed 功 试 made 出容积200L and 1500L rotational molding polyethylene (PE) container; year in 期, 北京玻璃钢研 made development formed rotational molding nylon container in 森林灭火 bottle and other product in to application. true positive large industrial production, also is in year in, rear 期, from outer 引入先进 rotational molding equipment and technology rear. currently, already can made container amount 20000L, above chemical industry 贮槽以 and full 塑游艇 and other large type plastics products. 　　 rotational molding process main/primary advantages 　　适于模塑 large type and large type made parts 　　绝 large more plastics molding processing process, in molding process in, plastics and injection molding parts mold 均处于 versus high pressure lower, ratio application is injection molding parts, pressure shrink 模塑, extrusion, blow molding and other, therefore application this molding process production large type plastics made parts 时, not only must use can 够承受 very large pressure injection molding parts mold, make injection molding parts mold 变 笨 heavy complex, but also plastics molding equipment must design, manufacturing separation solid, machine and injection molding parts mold processing manufacturing difficult degree versus increase large, cost increase. and versus 反, due to rotational molding molding process requirements machine strong/high degree 足以支承 material material, injection molding parts mold and machine 架自身 weight, and anti material material clamping force, therefore make rotational molding large type and large type plastics made parts, 也无需 use separation heavy equipment and injection molding parts mold, machine and injection molding parts mold processing manufacturing separation 方便, manufacturing cycle short, cost low. from upper 讲, use rotational molding molding process molding made parts, in dimensions upper 几乎没 has upper 限. production this large plastics container, using/adopting blow molding, use separation 昂贵而庞 large blow molding equipment is can can. 　　 suitable for more product types ． small amount plastics products production 　　 due to rotational molding molding use injection molding parts mold outer force function. injection molding parts mold simple, price low 廉, manufacturing 方便. another, rotational molding equipment tool has relatively large machine property, rotational molding machine, can 安装一 large type injection molding parts mold, can more small type tool it not only can large small different made parts, but also can meanwhile molding large small and 形状均极不 same products, need rotational molding products using/adopting raw materials same, products thick degree versus 当, can meanwhile rotational molding molding, therefore rotational molding molding process other molding methods has more large machine property. 　　 rotational molding molding easy products color 　　 rotational molding molding will material material add to injection molding parts mold in, this make material material full 部进入 products. products from injection molding parts mold in 取出以 rear, again add lower molding need material material, therefore 当我们 need products color 时, 既不致浪费点滴 raw materials, need consumption time machine and injection molding parts mold. 当我们 in use more injection molding parts mold rotational molding molding types plastics products 时, also can in different injection molding parts mold in add different color material material, meanwhile rotational molding different color plastics products. 　　适于 molding various complex in made parts 　　 rotational molding molding process in, material material is coating, to injection molding parts mold inner surface upper, products for/regarding injection molding parts mold type upper and other fine structure has very strong/high made can force. meanwhile due to injection molding parts mold in molding process in outer pressure, can using/adopting precision and other methods made tool has fine structure, complex injection molding parts mold. 　　节约 Raw Materials 　　 rotational molding products thick comparison uniform 且倒角处稍 thick, can separation material material can, has 利于节约 Raw Materials. in addition, in rotational molding molding process in, has runner, gate and other waste material, debugging good rear, production process in 几乎没回炉 material, therefore process for/regarding material material utilizing rate high. 　　 structure foam plastics rotational molding new process 　　 structure foam plastics rotational molding process is “二次投 material ”投 material process, process 开始于 will 必需 一定 amount material material injection molding parts mold molding parts outer 层. 一旦该 material material in add hot inner melt will injection molding parts mold from inner 取出并 add types mixed in is powder polymer （如 polyethylene (PE)) in powder additives, 并立即 heavy new add hot inner formed 第二次烘 melt and cooling and other. process has molding cycle long, product quality and other issues, is for high temperature injection molding parts mold dry make molding cycle long, long time long short and injection molding parts mold large small formed positive ratio, but also in one-time 塑化形 formed surface housing/shell and rear add material material can can has formed overall phenomenon. new development “ one-time material ”旋转模塑 new process use production polyethylene (PE) structure foam plastics sheet/plate, this 不足, but also production sheet/plate 材 两壁 between can filling modified material, from 而改进 sheet/plate 材 各项 property can, thermal insulation property, specific gravity, property, resistant property, structure strong/high degree and other and other. 　　 and "二次投 material " process different, " one-time material " process is will types different polyethylene (PE) raw materials one-time injection molding parts mold, types is powder polyethylene (PE), 而另一 types is mixed has foaming agent polyethylene (PE), mixed has foaming agent polyethylene (PE) is small 球状. powder polyethylene (PE) tool has ratio foaming agent separation understanding temperature degree low melting point pellets dimensions large small different, it use molding parts outer table/sheet housing/shell 层. powder polyethylene (PE) pellets dimensions in 500-1000 micron, small 球状(mixed has foaming agent) polyethylene (PE) pellets dimensions is 34 mm, powder polyethylene (PE) in inner hot and injection molding parts mold viscous 附, small polyethylene (PE) in inner ring flow 并不断受 hot, rear in formed parts table/sheet housing/shell rear foaming reaction. 　　 material material hot 经 两 stage/phase ． material material in 21OC lower through stage/phase melt, powder material material viscous injection molding parts mold formed table/sheet housing/shell 层, formed table/sheet housing/shell rear, temperature degree rise is 265C, 即进行第二 stage/phase melt, foaming is in 第二烘 melt stage/phase 进行. due to foaming agent separation understanding generate inner pressure, this process 一直持续 to inner pressure through gas large gas pressure versus balanced 而结束, small polyethylene (PE) pellets foaming long large, most rear 充满整 type 腔, through cooling stage/phase polyethylene (PE) solid. processing process is in processing temperature degree, speed degree lower and gas 口处．两 types material material in stage/phase and foaming control, melt and cooling stage/phase in full separation 开. more 进一步说, must in table/sheet housing/shell in mixed combined has small polyethylene (PE) pellets, in usually conditions lower, due to foaming agent amount separation understanding generate pressure, small uniform hot soft 化直接 foaming. therefore, if parts table/sheet housing/shell has melt, remove non small full 包裹, small polyethylene (PE) pellets can can lower 沉, difficult 以避免, add hot make housing/shell and small pellets 接触处达 to soft 化点但 also has 发生膨胀, foaming agent in housing/shell and small 球接触处 separation understanding this in parts surface lower obvious 痕迹. 　　 foaming process is 一 连续 process. small polyethylene (PE) temperature degree high injection molding parts mold inner foaming agent separation understanding temperature degree 时, inner pressure high has 空间允许模 inner material material 发膨胀, foaming 开始, material material will inner gas from gas extrusion. foaming agent in gas 口附近 generate positive in long large process in bubbles can by and 撕破, decrease small processing product machine strong/high degree, from formed for plastics products quality has 害 空洞 large structure. foam plastics in high temperature lower long time increase process time, from has generate long large. foaming agent generate gas for 泡孔泡壁 generate pressure 会引起泡孔 坍塌, 结果导致泡孔 poly combined 并, make 泡孔变 越 越 large. growth large small and 第二烘 melt stage/phase time formed positive ratio, and foaming sheet/plate thick degree formed positive ratio, need in high temperature lower sheet/plate 材芯部位 obtain and other temperature foaming agent separation understanding reaction, for add hot control process requirements very high, as more is difficult. 　　 is this 情况 发生, must can can add fast cooling speed degree, 实践证明仅此 also 不够, also need decrease/reduce 第二烘 melt stage/phase time. 此膨胀 process can is is polyethylene (PE) small pellets macro long large 运动, small from table/sheet housing/shell toward pressure relatively low 区域(排 gas 口区域) long large, if growth non-uniform or positive 常, generate for product quality has large gas 囊区, polyethylene (PE) small distribution 不一致, increase large retardant or gas 孔 数 amount can 导致出现此 type phenomenon. polyethylene (PE) small distribution 不一致 is certain separation small amount 不足, therefore can injection molding parts mold type 腔(即 make full foaming), therefore 旋转情况必 must versus adjustment. if inner in foam growth factors, foaming material material can injection molding parts mold type 腔, especially is in high temperature lower and 第二烘 melt stage/phase time short more is 如此. more has 甚者, 当泡孔 can can uniform distribution gas dimensions small 而引起排 gas 不畅, in 一定程 degree upper, gas pressure and internal pressure versus make 泡孔不 can 进一步 long large. therefore, gas must need has combined dimensions or has 足够 数 amount, let gas 体顺利排出. 当膨胀 material material 堵塞排 gas 口时, inner pressure increase large, in certain lower material material through method toward outer 溢出, remove method outer (this 会导致 production must in 断), 同样也 can can formed injection molding parts mold loss bad. 　　 already has table/sheet 明第一烘 melt stage/phase temperature degree must can can low, 以保护 has small 珠开始 soft 化时 完整 property, time still need can can in positive production cycle inner, rear 续第二烘 melt stage/phase in 265℃, in certain equipment in, temperature degree fast speed decline 至210℃ below/following. also has, remove non has 客户规定 requirements, foaming sheet/plate table/sheet housing/shell thick degree can is 2-3mm outer, is small 球冒出, table/sheet housing/shell thick degree generally can is 3—4mm, is tool has more add strong/high complex 形状. foaming sheet/plate thick 则第二 stage/phase melt time long, is table/sheet housing/shell hot defect. speed degree must high reduce has small and table/sheet housing/shell 层接触 time. in design stage/phase, for " one-time material method " process production structure foam sheet/plate is this types sheet/plate, 空孔保留 in sheet/plate internal, is foam, gas can easy 排出. 另一方面, must in injection molding parts mold upper design 一定数 amount gas 口, material material foaming can ensure 顺利排 gas. versus 反, in process in, for/regarding formed table/sheet housing/shell 层 烘 melt temperature degree must 仅考虑 add solid material material to injection molding parts mold in this process temperature degree. 不考虑 has foaming agent material material. through will temperature degree is 200-230℃ decrease/reduce time is has 害. therefore, must table/sheet housing/shell 层 期望 thick degree 确定第一 stage/phase melt time (maintain temperature degree scope/range). in melt stage/phase already injection molding parts mold used for made as table/sheet housing/shell 层 材 material and foaming small in 一起时, in inner time will increase 10％, is hot amount need foaming small absorption. in 此情况 lower, has necessary material material and foaming agent mixed 台 理论 amount, need 考虑没 has table/sheet housing/shell type large small and foaming density. most good is 第一批 product can use relatively low foaming agent material material production, large foaming small 球20-25％. versus for/regarding use amount, this use amount 不足, it can in material material foaming let production as can its foaming property can. most rear, product can in 紧邻闭模 method key/critical 处(has material material 溢出)切开以观察 its structure. this key/critical also has gas 口处, gas large 泡区域 and 泡孔撕裂区域. through can product quality is 否符台 requirements. product to production requirements, can according to to process production, has issues again for process 进行适当 adjustment to combined requirements is 止. 　　 above for rotational molding molding process and use process production structure foam plastics new process simple introduction. in recent years rotational molding process in already relatively large development, main/primary is use production container type product, process production structure foam plastics new process in industrial upper application also has 待进一步 development.