| 摘要 |
<p>In the manufacture of lightweight extruded structural profile comprising a resin-bonded core of closely compacted particulate filler, loose filler is packed into an extrusion die (10) by means of applied vacuum (27). The filler is packed within a sheath of glass rovings (12) which is used to draw the packed filler through the die. As the sheath and packed filler are progressed through the die, a liquid bonding resin is introduced (44, 31, 33) to permeate and bond together the packed filler and the sheath. The filler comprises layer mineral foam in a coarse particulate form and a free-flowing relatively fine material (such as hollow silicate microspheres) as an additional filler, the additional filler being vacuumed in to occupy the interstices of previously packed foam filler.</p> |
