1. Field of the Invention
This invention relates to the forming of fibrous workpieces each comprised of a layer of randomly disposed fibers and adhesive material dispersed throughout the fibers for binding same upon heating and compressing the fibers and adhesive material and in particular to an improved apparatus for and method of forming such workpieces.
2. Prior Art Statement
It is known in the art to provide a pad construction or pad comprised of a layer of randomly disposed fibers with adhesive material dispersed throughout the fibers and binding same upon heating and compressing the fibers and the adhesive material. However, the previous practice has been to compress the layer of fibers and adhesive material between forming surfaces of a pair of molds which are supported between the platens of a standard forming press and the heating has been provided by either heating the platens themselves utilizing known heating techniques and relying on conduction through the molds to their forming surfaces or such heating has been provided utilizing hot dry air alone or in combination with conventionally heated platens of a press.
However, in forming apparatus and methods where the heating of a workpiece is achieved by heating the platens and relying solely on heat transfer through the molds and mold forming surfaces it is necessary to heat the molds for substantial time periods and use comparatively large forming pressures resulting in increased costs. Similarly, in apparatus and methods where the heating of a workpiece is either accomplished totally by or with the aid of hot dry air the time and forming pressures are still excessive, again resulting in increased costs; and, the use of hot dry air often results in substantial charring of the workpieces resulting in losses due to scrappage.