초록 ▼

To produce a panel of variable thickness, a stratified assembly of a layer of fibers containing a non-polymerized binder and at least one cover sheet is placed between the mold and mold-backing of a molding press. The stratified assembly is caused to conform to the interior surface of the mold or mo

To produce a panel of variable thickness, a stratified assembly of a layer of fibers containing a non-polymerized binder and at least one cover sheet is placed between the mold and mold-backing of a molding press. The stratified assembly is caused to conform to the interior surface of the mold or mold-backing by forcing the cover sheet against the mold or mold-backing interior. Hot air is blown into the fiber layer from the mold surface opposite the cover sheet, into at least the region that will correspond to the area of greater thickness. The direction of the heated air is reversed after a period of time, the blowing of the air being maintained and adjusted in order to secure polymerization of the binder. At the same time, the portions of the panel corresponding to areas of lesser thickness, generally the edges of an acoustical panel, are cured (the binder polymerized) by contact heating means. To effect cross-over blowing, both the mold and mold-backing are provided with ports through which heated air may be blown or passed.

대표청구항 ▼

A one step molding process for the production of a composite panel of variable thickness comprising a fiber backing and a cover sheet, said panel having at least one area of greater thickness and one area of lesser thickness, said process comprising: placing a stratified assembly comprising a first

A one step molding process for the production of a composite panel of variable thickness comprising a fiber backing and a cover sheet, said panel having at least one area of greater thickness and one area of lesser thickness, said process comprising: placing a stratified assembly comprising a first layer of fibers and a non-polymerized binder and a second layer comprising an air permeable cover sheet thereover between a mold and mold-backing which are mutually shaped to define said areas of greater and lesser thickness; conforming said stratified assembly to the shape of said mold or mold-backing by applying said assembly thereagainst; blowing heated air by cross-over blowing into the assembly only in the area corresponding to said area of greater thickness, said air being blown into said assembly from side opposite said cover sheet; thereafter reversing the direction of said blown air, said blowing being maintained for sufficient time and at sufficient temperature to polymerize said binder; and contact heating the areas of said assembly corresponding to said area of lesser thickness.