METHOD OF DISPENSING A MIXTURE OF RESIN AND EXPANDED THERMOPLASTIC SPHERES

• US 3,780,942 A
• Filed: 10/02/1972
• Issued: 12/25/1973
• Est. Priority Date: 10/02/1972
• Status: Expired due to Term

• Current Assignee: Glas Craft Incorporated (Graco Incorporated)
• Original Assignee: James A. Scharfenberger
• Inventors: Scharfenberger, James A.
• Primary Examiner(s): Wood, Jr., M. Henson
• Assistant Examiner(s): Love, John J.
• Application Number:
  US05/293,809
• Time in Patent Office: 449 Days
• Field of Search: 118/DIG.2 117/105.5,14B,27,16 239/8,11,1,127,336
• US Class Current: 239/1
• CPC Class Codes: B05B 7/1431 comprising means for supplying an additional liquid B05B7/1418 takes precedence
• CPC Class Codes: Y10T 428/29 Coated or structually defined flake, particle, cell, strand, strand portion, rod, filament, macroscopic fiber or mass thereof

Abstract

A system for and a method of dispensing an admixture including a thermosetting or thermoplastic resin and expanded thermoplastic spheres. The system includes a reservoir for the admixture. A pump, which as a rotary pump, has its inlet connected to the reservoir and is adapted to withdraw the admixture from the reservoir. The length of time that the admixture is subjected to such pressure of the pump is insufficient to either cause harmful rupturing of the expanded spheres or to cause generation of heat of sufficient magnitude to cause harmful curing of the resin. A dispensing apparatus is connected to the outlet of the pump and is adapted to spray the admixture when activated. A valve may be connected between the outlet of the pump and the reservoir. The valve is adapted to terminate the flow of the admixture to the dispensing apparatus upon de-activation of the dispensing apparatus and to return the admixture withdrawn from the reservoir by the pump to the reservoir. The system may include a pressure balancing device to regulate the pressure of the system so that the system experiences little, if any, pressure differences when the system is cycled.

Claims

1. A method for dispensing an admixture including a resin and expanded spheres having a particle size of up to about 200 microns, the method including the steps of providing a reservoir with the admixture including the resin and the expanded spheres, withdrawing the admixture from the reservoir at a pressure sufficient to displace the admixture from the reservoir, the admixture withdrawn from the reservoir being subjected to the withdrawal and movement pressure for a period of time insufficient to cause harmful rupturing of expanded spheres and insufficient to generate the amount of heat necessary to cause harmful curing of the resin, prior to being sprayed, and dispensing the admixture from a dispensing apparatus as converging streams that intersect prior to impinging upon a deposition surface.

2. The method of claim 1 including the further step of terminating the flow of the admixture to the dispensing apparatus upon de-activation of the dispensing apparatus and returning the admixture withdrawn from the reservoir to the reservoir.

3. A composite material of thermosetting resin and expanded thermoplastic spheres fabricated using the method of claim 1.