Shanghai Daoqin Plastics Co., Ltd.

foaming plastics is thermoplastic property or hot solid property resin is 基体, its internal tool has micro small gas plastics. foaming is plastics processing important methods 之一, plastics foaming to foam plastics has gas solid 两项 - gas and solid 体. gas 体以泡孔 形式存 in foam in, and 泡孔互 versus 隔绝 称 is 闭孔, 连通 称 is 开孔, from has foam plastics and foam plastics separation. foam structure or is Raw Materials property can and its processing process 决定.

    plastics foaming technology 渊源久远. most is 20 year 代初期 foam 胶木, use similar manufacturing foam methods made 取; 30 year 代出现 hard polyurethane ester foam and polystyrene (PS) foam; 40 year has polyethylene (PE), polyvinyl chloride (PVC), ring oxygen resin, aldehyde foam; 50 year has can property polystyrene (PS) foam and soft polyurethane ester foam. in, basic upper has plastics, thermoplastic property and hot solid property can foaming is foam plastics. industrial upper made methods has: extrusion foaming, injection molding foaming, foaming, calendering foaming, powder foaming and spray coating foaming and other and other. its in, injection molding foaming is most important molding methods 之一, in this focus/key point injection molding foaming.
        
    foaming molding principle
        
    plastics foaming methods according to use foaming agent different can separation is material foaming method and chemical foaming method large type. in this 里首先 simple introduction lower foaming agent.
        
    ◆ foaming agent
        
    foaming agent can simple coarse separation is material foaming agent and chemical foaming agent type. for material foaming agent requirements is: 无毒, 无臭, 无腐蚀 function, 不燃烧, heat stabilized property good, gas lower 不发生 chemical reaction, gas in plastics melt in expand dispersion speed degree low in gas in expand dispersion speed degree. commonly used material foaming agent has gas, nitrogen gas, oxidation carbon, carbon hydrogen combined material, fluorine and other; chemical foaming agent is types hot can 释放出 gas 体诸如 nitrogen gas, oxidation carbon and other material 质, for chemical foaming agent requirements is: its separation understanding 释放出 gas is 无毒, 无腐蚀 property, 不燃烧, for products molding and material 理, chemical property can effect/influence, gas speed degree can control, foaming agent in plastics in tool has good dispersion property. application comparison has machine foaming agent carbon acid hydrogen and carbon acid 铵, has machine foaming agent nitrogen amine and nitrogen 二异丁腈.
        
    ◆ material foaming method
        
    simple 讲, is utilizing material methods make plastics foaming, generally has types methods:
        
   （1）先 will inert property gas in pressure lower solvent plastics melt or material in, again decrease pressure 释放出 gas 体, from in plastics in formed gas foaming;
        
   （2） through for solvent polymer melt in low liquid 体进行蒸发 make 之汽化而 foaming;
        
   （3） in plastics in add 空心球而形 formed foaming foaming and other.
        
    material foaming method use material foaming agent cost versus for relatively low, especially is oxidation carbon and nitrogen gas cost low, also can flame retardant, 无污染, therefore application value relatively high; but also material foaming agent foaming rear 无残余 material, for foaming plastics property can effect/influence large. is it need specialized injection molding machine and equipment, technology difficult degree very large.
        
    ◆ chemical foaming method
        
    chemical foaming method is utilizing chemical methods generate gas make plastics foaming: for add plastics in chemical foaming agent add hot make separation understanding 释放出 gas foaming; another can utilizing plastics separation between versus 互发生 chemical reaction 释放出 gas foaming.
        
    using/adopting chemical foaming agent foaming plastics injection molding process basic upper and generally injection molding process same. plastics add hot rise temperature, mixed combined, and large separation foaming 膨胀都 is in injection molding machine in formed.

    总之, 不论选取哪一 types plastics raw materials, 也不论 using/adopting types foaming methods, its foaming process generally need 经 形 formed bubbles 核, bubbles 核膨胀, solid type and other stage/phase.

structure foaming molding
        
     structure foaming method (Structral Foam Molding) belongs to chemical foaming method, it is injection molding process technology in revolutionary. it 保留 传统 injection molding process many advantages, also 避免 传统 injection molding process in to issues, products strong/high degree 不够, production cycle long, rate low and other. another, using/adopting structure foaming technology also can large type complex products, use low cost mold, more mold cavity can meanwhile as, from reduce products production cost. structure foaming products is types tool has table/sheet 层 连体 foaming material, its mono weight strong/high degree and rigid degree ratio types foaming material high 3～4倍.

    structure foaming method most large features is can use increase equipment, use injection molding machine can injection molding production, using/adopting mold cavity expand large method foaming high pressure structure foaming injection molding machine and injection molding machine versus ratio, increase clamping holding pressure plant/unit. currently, company already formed development 出CJ1000M3 machine used for structure foaming molding, already 服务于客户, to good 评.

    in recent years, structure foaming injection molding technology to very development, molding methods very more, nano can separation is types: low pressure foaming method; high pressure foaming method （注: low pressure and high pressure mold mold cavity inner pressure ）; di separation foaming method.
        
    ◆ low pressure foaming method
        
    low pressure foaming method injection molding and injection molding difference in its mold mold cavity pressure relatively low, 约2～7Mpa, 而普通 injection molding in 30～60Mpa between. low pressure foaming injection molding generally using/adopting method, will amount （不注满 mold cavity ） plastics melt （含 has foaming agent ）注入 mold cavity, foaming agent separation understanding gas make plastics 膨胀而充满 mold cavity. in injection molding machine upper low pressure foaming injection molding, generally is will chemical foaming agent and plastics mixed combined, in machine inner 塑化, must using/adopting 自锁式射嘴. injection 时, due to gas expand dispersion speed degree very fast, formed products surface coarse 糙, therefore injection molding machine injection speed degree need fast. generally using/adopting increase pressure device improve/increase injection speed degree and injection amount, make injection as in 瞬间完 formed.
        
    ◆ high pressure foaming method
        
    high pressure foaming method injection molding mold cavity pressure in 7～15Mpa between, using/adopting methods, one-time injection amount positive good and other mold mold cavity 容积. is make made parts to foaming 膨胀, can using/adopting strong/high made expand large mold cavity, or make separation plastics separation mold cavity. generally relatively more using/adopting mold cavity expand large method. using/adopting expand large mold cavity method injection molding machine and injection molding machine versus ratio, increase clamping holding pressure plant/unit, plastics and foaming agent melt mixed combined material by to mold cavity rear 延时一段 time, rear clamping machine 构 动模 sheet/plate toward rear 移动一 small 段距离, make mold and 定模稍 is separation 开, mold cavity expand large, mold cavity inner plastics foaming 膨胀. products cooling rear in its surface formed table/sheet 皮, due to plastics melt foaming 膨胀受 to sheet/plate control, therefore, can for products table/sheet thick degree control. sheet/plate can is overall 移动, can is separation make local foaming, from to different density products. high pressure foaming method for mold manufacturing degree requirements high, mold use high, and for injection molding machine has 二次锁模 holding pressure requirements.
        
    ◆ di separation foaming method
        
    di separation foaming injection molding is types high pressure structure foaming injection molding methods, it using/adopting di separation injection molding machine. this type of injection molding machine has sleeve/set injection molding plant/unit: sleeve/set use injection molding products 芯部, sleeve/set use injection molding products table/sheet 层. in injection molding 时, 先注入皮层 material material, rear through gate again mixed has foaming agent 芯部材 material. due to 芯部材 material 呈层流状态 flow, this ensure 芯部材 material uniform in internal, make type to full filling. material type rear, again a small amount of has foaming agent material, make gate 封闭. products rear, again gate to tool has foaming table/sheet and has foaming light products.
micro foaming molding
        
     micro foaming molding belongs to material foaming method. foam plastics 泡孔直径 generally large 于50mm, density (mono 位体积 inner 泡孔 数 amount) small 于106 /cm3. this large dimensions 泡孔受 force 时常常 formed is cracks 发源, reduce material mechanical properties. is meet/satisfy industrial upper requirements reduce certain plastics product cost reduce its mechanical properties requirements, 20世纪80 year 代初期, USA 麻省理工 large (MIT) 学者J.E.Martini J.Colton以 and N.P.Suh and other 以CO2, Ｎ2 and other inert property gas as is foaming agent made 出泡孔直径 is micron grade foam plastics, will 泡孔直径 is 1mｍ～10mｍ, density is 109～1012 /cm3 foam plastics is micro plastics (Microcelluar Plastics).
        
     injection molding is micro plastics products main/primary molding methods 之一. plastics raw materials add injection molding machine material rear, in screw force and add hot outer add hot function lower 塑化, foaming agent 直接注入 injection screw melt and melt uniform mixed combined, rear high pressure high speed mold cavity. in mold cavity inner drop pressure, make melt in a large amount of saturated and gas 体离析出, foaming, 膨胀, molding, type formed micro plastics products. another, can using/adopting temperature degree methods formed 泡核, and pressure method versus ratio, comparison easy control, for/regarding gas solvent understanding degree for temperature degree 不敏感 plastics suitable.
        
    development micro plastics injection molding technology difficult degree comparison large, is and foam plastics versus ratio, dimensions need small more, need to good micro plastics products, must need ensure for machine melt in ultra- 临界流体精确计 amount, requirements plastics melt must separation mixed combined, 均化, dispersion, formed versus mixed combined 体, ensure melt in formed 核点必 must more 于109 /cm3, and control formed bubbles and other and other. this for equipment and injection molding process parameters requirements non high.
        
    using/adopting technology features is:
        
    ● products weight decrease/reduce 50％;
    ● injection pressure reduce 30～50％;
    ● clamping force reduce 20％;
    ● 循 ring cycle decrease/reduce 10～15％;
    ● using/adopting sleeve/set belt/tape amount control plant/unit gas 体输入 equipment.
        
    据报道, outer injection molding machine production already formed development micro plastics injection molding machine, ratio USA Trexel company, Germany Arburg company, 奥 利Engel company and other. currently also has Milacron, Husky, Battenfeld and other company positive in add development micro plastics injection molding equipment. inner 华南理工 large from 1995 year research micro plastics, in upper 取 一定进展, already in 实验室 made multiple Model/Grade micro plastics. rear, its it high versus 继进行 micro plastics research. micro plastics industry also has 一段距离, currently inner also has micro plastics injection molding equipment product.
        
    结语: foaming plastics due to has bubbles in, therefore tool has light, material, can absorption impact 载荷, thermal insulation and property can, ratio strong/high degree high and other features, especially is can 节省材 material, decrease small can consumption, reduce cost 方面, make can large force application. micro foaming plastics remove tool has upper generally foam plastics advantages outer, also has more add excellent force property can. therefore, foam plastics application scope separation 广泛, especially is in made as automotive, machine and various device and other field/area has application value. can expected, foaming injection molding especially is micro foaming injection molding will is plastics processing machine and products processing hot 点.