| 摘要 |
There is disclosed a form liner having a thickness no greater than 0.5 inch and having planar dimensions of approximately 2 feet by 4 feet, with one of its planar surfaces having a molded negative impression of a desirable surface relief pattern for a concrete wall. The form liner is manufactured by processing pre-formed sheets or panels of expanded plastic foam, typically expanded polystyrene foam. These stock panels are obtained in approximately 3/8 inch thickness and a positive pattern of the desired relief is pressed into the panel under sufficient heat, about 200 degrees F. and pressure, about 2500 psi, to mold one of the smooth surfaces of the panel into a negative impression of the desired surface relief pattern. The molding can be accomplished in a standard compression equipment with cycle times of approximately ten seconds. This permits the inexpensive and facile manufacture of these panels at sites removed from the polystyrene foam expander plant.
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