| 摘要 |
<p>An electrostatic foaming process for producing foamed components, esp. rounded components such as sponges, from plastics contng. expanding agents or reacting plastics, esp. from salt or hard polyurethane foam based on polyester and/or polyether, utilises an energy source in the mixing head - discharge pipe-spray head region; an applied d.c. voltage produces an electrostatic field, in which the liquid or creamy reacting components are charged and then strike the mould wall at high speed in the field, the wall forming the counter-pole; this forms a film of reaction mixture on the mould wall which assists the mixing effect, so that foaming occurs from all points on the mould wall inwards. Specif., a layer of parting agent may first be projected onto the mould surface, followed by a projected layer of flakes, fibres or similar materials forming a carpet to bond the parting layer to the body of the foam.</p> |
