| 摘要 |
PURPOSE:To obtain a sheet in continuous form, the commercial value of which is not lowered at the joint, by a method wherein the ends of expandable thermoplastic resin sheets are overlapped up each other under the state of being heated up to a predetermined temperature so as to be pressed to each other. CONSTITUTION:The final end and the starting end of two expandable sheet to be joined are heated up to a temperature, which is higher than or equal to the melting point or softening point of at least one thermoplastic resin out of thermoplastic resins, of which each expandable sheet is made, and is below the decomposition temperature of heat decomposition type expanding agent contained in the expandable sheet. The overlapped part consisting of said final end and the starting end is pressed so as to be bonded by fusion. As a result, a favorable strength and external appearance are obtained at the joint. When the thicknesses of two expandable sheets are denoted by X and Y, the thickness Z or the joint after pressing preferably satisfies the following formula: 0.35(X+ Y)<=Z<=0.65(X+Y). If Z fills out of said range, unstable expanding operation results and, in some cases, the stable taking-off of a foam sheet becomes difficult. |
