| 摘要 |
<p>PURPOSE:To prevent generation of dust at the time of forming grooves, by a method wherein a plurality of slits are formed in one side of a platelike heat insulation material, a space between the splits adjoining to each other is pressed alternately by a rotary roll or a projected mold and vent grooves are formed. CONSTITUTION:A plurality of slits 20 are formed in one side S1 of a platelike heat insulation material S possessing a foamed plastic layer 10, then spaces each among the slits 20 adjoining to each other are pressed alternately respectively by a pressing device 30 and vent grooves 40 are formed. Rigid urethane foam, phenolic modified urethane foam or polystyrene foam is used as a material of the foamed plastic layer 10. The foamed plastic layer 10 is made 10-150mm in thickness. The slit 20 is obtained by cutting the platelike heat insulation material S at a single stroke by making use of an edged tool such as a knife and cutter and a space between the slits 20 is made 5-100mm. A roll pressing device 30 smashes alternately the space between the slits 20, the vent grooves 40 are formed and pressing force is made at least 1.5kg/cm<2> by the rigid polyurethane foam.</p> |
