Injection moulding process for plastics recycling - by injecting recycled plastics core into moulded plastics casing

摘要

A plastics recycling process involves (i) injecting virgin plastics (thermoplastics) for partially filling an empty nest mould and then injecting a gas (N2) to press the plastics against the mould wall and cause it to solidify; (ii) relieving the gas pressure and opt. (partially) evacuating the gas; and (iii) injecting recycled plastics as core material, by means of a second plasticising cylinder, into the residual cavity to fill the cavity using one or more gas blasts which, after feeder blocking, subject the core material to post-compression so that sepn. of the core material from the outer skin is avoided. In a modified process, a propellant is included in the virgin plastics, resulting in complete filling of the mould with a foam into which the recycled plastics is injected. ADVANTAGE - The process produces integral mouldings in which the recycled plastics core is hidden and bubbles are avoided.