| 摘要 |
<p>Apparatus for cutting a body of rigid plastics foam material, such as polyurethane or poly-isocyanurate, comprises a bed for supporting the body and two sets of parallel cutting elements adapted to oscillate longitudinally out of phase with each other. The cutting elements may consist of helically twisted ribbons of electrical resistance alloy, twisted in such a way that the handedness of the twist varies at regular intervals along each element. The elements are heated to a temperature below the fusion temperature of the plastics material, and are passed through the body to sever it into a number of slabs.</p> |
