Patent ID: 9009942
Filing Date: 2015-04-21
Classification: B60J,E06B,Y10T

Abstract:
1. A method for making a reinforced panel of thermoplastic material for a roll up door assembly comprising: blow molding a hollow panel with a thermoplastic material in a mold cavity to form hollow, elongated channels along top and bottom portions of the panel, the channels being closed at their ends, and further to form a relatively flat outside wall and a ribbed inside wall, the inside wall having longitudinal ribs formed by open-sided longitudinally extending channels that extend toward the outside wall and at least some of which are fused to the outside wall, and transverse ribs that intersect the open-sided, longitudinally extending channels; trimming the panel to open the elongated channels at one end thereof; inserting a stiff reinforcing member into each channel, each reinforcing member having a cross-sectional shape that approximates the cross-sectional shape of the channel into the elongated channel; and retaining the reinforcing member in the hollow elongated channels.