Process of making plastic hinge for raceway

摘要

A U-shaped raceway having bottom and side walls formed as substantially rigid plastic panels, and flexible plastic hinges integrally joined between the lower edges of the side walls and the adjacent edges of the bottom wall. The plastic hinges are soft and flexible, and of substantially less hardness than the walls. The plastic hinges extend across the thickness of the walls. The raceway is formed as a dual extrusion so that the hinges are integrally joined to the rigid walls. During the extruding step, a rigid bridge structure is also extruded so as to span transversely across the hinge outwardly from one of the surfaces of the panels to maintain dimensional stability across the hinge. The bridge structure is severed from the panels following the extrusion operation.