Composite Polystyrene Particles and Methods of Making Same
AssigneeRapac
InventorsDennis W. Koerner, Michael Pate, David Wilson
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Abstract
Composite polystyrene particles have an average size less than 1200 μm and methods of making them are provided. The composite polystyrene particles can include recycled polystyrene obtained from a variety of sources. The composite polystyrene particles can be used in a variety of applications, including packaging materials and molded supports for the shipment of fragile objects.
Claims43
A composite polystyrene particle comprising a low molecular weight polystyrene component having an average molecular weight of less than 200,000 g/mol, wherein the composite polystyrene particle size is less than 1200 μm.
A composite polystyrene particle having a size of less than 1200 μm and comprising a nucleating agent.
A composite polystyrene particle comprising less than 3.5% blowing agent
A composite polystyrene particle comprising:
- at least one low molecular weight polystyrene component, and
- at least one high molecular weight polystyrene component,
- wherein the difference between the average molecular weight of the low molecular weight polystyrene component and the average molecular weight of the high molecular weight polystyrene component is at least 50,000 g/mol.
A method of making composite polystyrene particles comprising:
- a) heating at least one low molecular weight polystyrene component and at least one high molecular weight polystyrene component to form a composite melt in a tandem extruder having a first extruder operably connected to a second extruder;
- b) adding at least one blowing agent to the composite melt;
- c) extruding the composite melt from the first extruder to the second extruder;
- d) cooling the composite melt in the second extruder to form a polymer;
- e) pelletizing the polymer with an underwater pelletizer operably connected to the tandem extruder to form composite polystyrene particles;
- and
- f) recovering the composite polystyrene particles.
A method of making composite polystyrene particles having a particle size less than 1200 μm by extruding a polystyrene composition through an extruder.
Dependencies are inferred from the claim text.