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, such as a rotary pump, has its inlet connnected 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of the admixture to the dispensing apparatus upon de-activation of the dispensing apparatus and to return the admixture withdrawn from the reservoir by the pump to the reservoir.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.
Apparatus for spraying a mixture including resin and expanded thermoplastic spheres comprising a sprayer; a reservoir to contain the mixture, with means to maintain the mixture at a pressure insufficient to rupture the expanded thermoplastic spheres; a rotary pump adapted to produce low shearing force; means connecting the pump inlet to the reservoir; and variable fluid restrictor means connecting the pump outlet to the sprayer to remove the mixture from the reservoir and deliver it to the sprayer, said variable fluid restrictor means connecting the rotary pump to the sprayer including means to maintain the pressure in the connection at a value insufficient to rupture the expanded thermoplastic spheres; and a valve to initiate and terminate the flow of the mixture withdrawn from the reservoir by the pump to the reservoir.
Claim 2
Dependent Claim
131 words
Apparatus for spraying a mixture including resin and expanded thermoplastic spheres comprising a sprayer; a reservoir to contain the mixture, with means to maintain the mixture at a pressure insufficient to rupture the expanded thermoplastic spheres; a rotary pump adapted to produce low shearing force; means connecting the pump inlet to the reservoir; and variable fluid restrictor means connecting the pump outlet to the sprayer to remove the mixture from the reservoir and deliver it to the sprayer, said variable fluid restrictor means connecting the rotary pump to the sprayer including means to maintain the pressure in the connection at a value insufficient to rupture the expanded thermoplastic spheres; and a valve to initiate and terminate the flow of the mixture withdrawn from the reservoir by the pump to the reservoir.
Claim 3
Dependent Claim
23 words
Apparatus as set forth in claim 1 wherein the rotary pump adapted to produce low shearing force is a positive displacement gear pump.
Claim 4
Dependent Claim
32 words
Apparatus as set forth in claim 1 wherein said sprayer includes means to apply chopped fiber glass into the mixture of resin and expanded thermoplastic spheres and means to actuate the valve.