A new, simple water foamed injection moulding process to allow class A polymer surface finish

到2020年，全球结构泡沫塑料市场预计将达到319亿美元，2015-2020年间的年化增长率约为6%。结构泡沫塑料明显比固体塑料轻，具有高强度重量比和较低的模具成本。汽车行业是结构泡沫塑料增长的主要驱动力，因为终身能源和二氧化碳节约推动了对轻质部件的需求。结构泡沫塑料生产中通常使用的化学发泡剂会导致臭氧消耗，并将根据《蒙特利尔议定书》逐步淘汰。丁烷和戊烷等气体是固有的火灾风险，而氮气和二氧化碳的使用成本相对较高，需要与模具M/C一起储存。同样使用这些工艺的结构泡沫部件的表面光洁度都相对较差，特别是在使用低注射压力时。泡沫塑料是一种制造结构泡沫成型轻质零件的新工艺，表面光洁度为A级。这一想法结合了新的发泡技术--超热注水技术(SHWI)，该技术使用自来水来发泡聚合物，该聚合物是通过源自共轨柴油喷射系统的新型注射技术实现的。这与我们新颖的熔体流分离阀阵列结合在一起，使我们能够保持‘泡沫’部分与‘表面’部分分离，以获得A级表面光洁度。“

"The global structural foam market is expected to reach $31.9 Billion by 2020, with annualized growth of ~6% between 2015 & 2020\.Structural foam is significantly lighter than solid plastics, with high strength-to-weight ratio and lower cost tooling. The automotive sector is the main driver to structural foam growth as lifetime energy & CO2 savings drive the need for light weight components.Chemical blowing agents normally used in structural foam production cause ozone depletion & will be phased out under the Montreal Protocol. Gases such as butane & pentane are an inherent fire risk, while N2 & CO2 are relatively expensive to use, require storage alongside the mould m/c. Structural foam parts also using these processes all suffer from relatively poor surface finish especially when low injection pressure is used. Foamtech is a new process to make structural foam moulded light-weight parts, with a Class A surface finish. The idea combines novel foaming technology - Super Heated Water Injection technology (SHWI) that uses tap water to foam polymer achieved using a novel injection technology derived from a common rail diesel injection system. This is combined with our novel melt stream splitting valve array that enables us to keep the 'foamed' fraction separate from the 'skin' fraction to achieve a class A surface finish."