Process for expanding small diameter polystyrene beads for use in cementitious board
AssigneeNational Gypsum Company
InventorMarie-Andrée Mathieu
Life of this patent
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Abstract
A process for expanding small diameter polystyrene beads is disclosed. The process comprises applying a steam pressure of about three to seven pounds per square inch at a temperature of about two hundred twenty degrees Fahrenheit to two hundred forty degrees Fahrenheit to a plurality of expandable polystyrene beads until each of the plurality of expandable polystyrene beads has expanded to a diameter of about 0.030 inches to 0.125 inches, wherein each of the plurality of expandable polystyrene beads has an unexpanded diameter of about 0.015 inches to about 0.028 inches.
Claims10
A process for expanding small diameter polystyrene beads, the process comprising:
- applying a steam pressure of about three to seven pounds per square inch at a temperature of about two hundred twenty degrees Fahrenheit to two hundred forty degrees Fahrenheit to a plurality of expandable polystyrene beads until each of the plurality of expandable polystyrene beads has expanded to a diameter of about 0.030 inches to 0.125 inches;
- wherein each of the plurality of expandable polystyrene beads has an unexpanded diameter of about 0.015 inches to about 0.028 inches.
A process for expanding small diameter polystyrene beads comprising the steps of:
- feeding a plurality of small diameter expandable polystyrene beads into a heated expander, wherein the heated expander applies a steam pressure of about three to seven pounds per square inch at a temperature of about two hundred twenty degrees Fahrenheit to two hundred forty degrees Fahrenheit to the plurality of polystyrene beads until each of the plurality of expandable polystyrene beads has expanded.
Dependencies are inferred from the claim text.