Shanghai Daoqin Plastics Co., Ltd.

        polyethylene (PE) foam plastics sheet/plate used for construction use drop 缝, frame structure sheet/plate, mixed 凝土公路伸 shrink 缝之接缝 sheet/plate;  道桥接缝止 water sheet/plate;   water engineering 堤坝, 护坝, force 坝, 护坡, retardant 墙之伸 shrink sheet/plate;   water electrical, electrical, engineering, water 塔底部止 water sheet/plate;   construction use drop 缝, frame structure sheet/plate;  生 active use water and water 处理厂 water water sheet/plate;   machine 场跑道之接缝 sheet/plate;  港口, 码头, mixed 凝土之接缝 sheet/plate;   water 洞, mixed 凝土之 water sheet/plate;   iron, lower mixed 凝土止 water sheet/plate.
        positive is polyethylene (PE) foam plastics sheet/plate its excellent property, rate strong/high, water property, resistant water impact property, resistant gas property, chemical resistant product property, resistant aging property is its it material has, polyethylene (PE) foam plastics sheet/plate application areas 越 越广泛.

and “二次投 material ” process different, “ one-time material ” method will types different polyethylene (PE) raw materials mold, types is powder polyethylene (PE), 而另一 types is mixed has foaming agent small polyethylene (PE). powder polyethylene (PE) and mold viscous small polyethylene (PE) 继续循 ring flow 并不断受 hot, rear formed parts table/sheet housing/shell 层接 进行 foaming reaction. this type of has 别于传统“二次投 material ” rotational molding process new in 哪里

    is 改进传统“二次投 material ” rotational molding process 突出局限 property, Polivinil Rotomachinery company development “ one-time material ” rotational molding new process, use production polyethylene (PE) structure foam plastics sheet/plate. for field/area research in can in sheet/plate between filling types can sheet/plate 材各项 property can material, this property can main/primary has chemical? physical properties （ 如 thermal insulation property, specific gravity, property and other and other ） or mechanical properties （ 如 resistant property, structure strong/high degree and other ）. remove can to can foaming polyethylene (PE) structure foam plastics product outer, for its 感兴趣 另一 causes is material material recycling use.

    传统 “二次投 material ” process 开始于 will 必需 一定 amount material material mold molding parts outer 层（ “ table/sheet housing/shell 层” ）, 一旦该 material material in add hot inner melt will mold from inner 取出并 add foaming agent （ 如: types mixed in polyethylene (PE) in powder additives ）, 并立即 heavy new add hot inner formed molding cycle （ 第二次熔 melt, cooling and other ）. process in safety issues, is for high temperature mold 人工操 as make molding cycle long, long time long short and mold large small formed positive ratio, but also in table/sheet housing/shell and toward lower material material solid front must in as process （ mold large this type of phenomenon heavy ）.

    and “二次投 material ” process different, “ one-time material ” method will types different polyethylene (PE) raw materials mold, types is powder polyethylene (PE), 而另一 types is mixed has foaming agent small polyethylene (PE). powder polyethylene (PE) melting point ratio foaming agent separation understanding temperature degree low, pellets dimensions large small different, use molding parts outer table/sheet 层. （ powder polyethylene (PE) pellets dimensions in 500~1000 micron, small 球状（ mixed has foaming agent ） polyethylene (PE) pellets dimensions is 3~4 mm ）. powder polyethylene (PE) and mold viscous small polyethylene (PE) 继续循 ring flow 并不断受 hot, rear formed parts table/sheet housing/shell 层接 进行 foaming reaction.

    material material in 210℃ lower through stage/phase melt, powder material material viscous in mold upper, has formed parts surface housing/shell toward temperature degree is 265℃ 第二 stage/phase melt 推进, polyethylene (PE) soft formed 球壁. due to foaming agent separation understanding generate inner pressure, this process 一直持续 to inner pressure and gas large gas pressure versus balanced is 止. small polyethylene (PE) pellets foaming large, most rear 充满整 type 腔, through cooling rear polyethylene (PE) solid. process is 2 types material material in stage/phase full separation 离, for foaming material control through adjustment processing temperature degree, melt and cooling time, speed degree and gas 口位置. more 进一步说, must need is in table/sheet housing/shell in bonding has small polyethylene (PE) pellets, in usually conditions lower, due to foaming agent separation understanding generate pressure, small pellets uniform hot soft 化, foaming. therefore, if parts table/sheet housing/shell has melt, remove non small full 包裹, small polyethylene (PE) pellets can can lower 沉（ 几乎不 can 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 （ 此处 is rear 屈服点 ）, in parts surface lower can 见 痕迹.

    foaming process is 一 连续 process, small polyethylene (PE) temperature degree high mold inner foaming agent separation understanding temperature degree, inner pressure high has 空间允许模 inner material material 发生膨胀, foaming 开始发生, material material will inner gas from gas 口排出. and foaming process related issues can can has foaming agent 泡壁 破裂, and increase large. thin foaming parts for mold combined method has 害且造 formed demolding difficult.

    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 solid property, from formed tool has large 泡 区域（ 空洞 large 泡不受欢迎 ）. foam plastics in high temperature lower long 久停留 increase process time, generate long large 危险. foaming agent for for 泡孔泡壁施 add force 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 第二熔 melt stage/phase time formed positive ratio, and foaming sheet/plate thick degree formed positive ratio （ high temperature lower in sheet/plate 材芯部 obtain and other temperature foaming agent separation understanding reaction add hot control more add difficult ）.

    is has this 情况 发生, must can can increase cooling speed degree, 实践证明仅此 also 不够, also need decrease/reduce 第二熔 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 and （ or ）不 positive 常, generate 不受欢迎 large gas 囊区, polyethylene (PE) small distribution 不一致, increase large retardant and （ or ） retardant or gas 孔 不足 can 导致出现此 types phenomenon. polyethylene (PE) small distribution 不一致 is certain separation small amount 不足, therefore can mold type 腔（ 即 make full foaming ）, therefore 旋转必 must adjustment. if inner in foam growth 运动 障碍 material, foaming material material can mold type 腔, especially is in high temperature lower and 第二熔 melt stage/phase time short more is 如此. more has 甚者, 当泡孔 can can uniform distribution positive good gas dimensions small will gas and 密闭, in 一定程 degree upper, gas pressure lower inner internal pressure versus retardant 碍泡孔 进一步 long large. therefore, gas must need has positive dimensions large small 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 （ 导致 production must in 断 ）, 同样也造 formed mold loss bad.

    already formed table/sheet 明, 第一熔 melt stage/phase temperature degree must can can low, 以保护 has small 珠开始 soft 化时 完整. in Logica PRM 3000 8C machine in use most low temperature degree is 215℃. remove non has 特殊 美观 requirements, foaming sheet/plate table/sheet housing/shell thick degree generally is 2～3 mm. is small 球冒出, table/sheet housing/shell thick degree can increase 至3～4 mm, 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. must using/adopting relatively high speed degree reduce has small and table/sheet housing/shell 层接触 time. in design stage/phase, use “ one-time material method ” production structure foam sheet/plate is this types sheet/plate, 空孔保留 in sheet/plate internal, ensure gas can from certain flow to 邻近 一 孔, gas can easy 排出. 另一方面, must in 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 熔 melt temperature degree must 仅考虑 add solid material material to mold in this process temperature degree （ 没 has foaming small 珠 ）. through temperature degree is 200～230℃ decrease/reduce time is can 取. must based on use table/sheet housing/shell thick degree 确定第一 stage/phase melt time. in melt stage/phase already mold used for made as table/sheet housing/shell 层 材 material and foaming small in 一起时, in mold 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 combined 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 is 不足, it can in material material foaming 时观察 its foaming property can. most rear, product can in 紧邻闭模 method key/critical 处切开以观察 its structure. this key/critical also has gas 口处, gas large 泡区域 and 泡孔撕裂区域.