| 摘要 |
<p>Plastic mouldings to be fired as targets for e.g., clay pigeon shooting, are prepd. from two different matls. under conditions which generate an interfacially sensitive aggregate. Target strength is controlled to have sufficient cohesion longitudinally to withstand ejection by a ballistic cannon, e.g., with a thrust of ca. 20 kg./cm2, but to readily shatter radially or transversely if struck by shotgun pellet(s). Specif., a blend of two matls. is charged to the mould using a brief injection cycle and with the melt temp. rapidly cycling sinusoidally. The mould tool may incorporate 'windows' permitting local radiation of the moulding surface. Articles may be ejected while hot and malleable, and set after ejection.</p> |
