US3674600A - Apparatus for dispensing catalyst coated fibers and cementitious material onto a surface - Google Patents

Abstract

GLASS FIBER STRANDS COATED WITH A CEMENTITIOUS MATERIAL ARE FORCEFULLY PROJECTING FROM A SOURCE BY CENTRALLY ENTRAINING CONTINUOUS FIBER STRANDS ENSHROUDED BY A LIQUID CATALYST IN THE CEMENTITIOUS MATERIAL FOR DEPOSIT ONTO A RECEIVING SURFACE AS THE CATALYST MIXES WITH THE CEMENTITIOUS MATERIAL.

Description

United States Patent M US. Cl. 156-166 4 Claims ABSTRACT OF THE DISCLOSURE Glass fiber strands coated with a cementitious material are forcefully projecting from a source by centrally entraining continuous fiber strands enshrouded by a liquid catalyst in the cementitious material for deposit onto a receiving surface as the catalyst mixes with the cementitious material.

This invention relates to dispensing and use of cementitious material such as a resin and a fibrous material and, more particularly, to disposition of and transport by continuous fiber rovings of an auxiliary cooperating agent such as a liquid catalyst which is mixed with material such as a resin or the like as it is dispensed.

The present invention relates to improvements in the invention disclosed in US. Pat. No. 3,232,557, and application Ser. No. 722,678 now abandoned, filed Mar. 20, 1958. It is to be understood that the present invention is not limited to the environment of the specific disclosure in Pat. 3,232,557, and that it may be used generally to facilitate dispensing of fibrous material under pressure with dispensers for fluid cementitious material.

It is an object of the present invention to provide for coating and transporting of a catalyst coating by a continuous fiber roving such as fiber glass bundled together in continuous untwisted strands and to mix the cementitious material with the catalyst while contacting the fibers with resin.

The use of commercially available fiber rovings ordinarily packaged in spools has been found to introduce undesirable effects. It has been found to be diflicult to maintain a dispensing system in operation for extended periods by reason of the accumulation of unwanted debris which tends to foul the dispensing system. In addition, the movement of highly insulating fiber strands generates electrostatic charges which produce undesirable force fields.

Fibers suitably treated can be dispensed, avoiding the difliculties above mentioned. In Patent 3,232,557, continuous fibers are to be dispensed from a spool of rovings of continuous filaments.

In accordance with the present invention there is provided a liquid catalyst disposed as to enshroud the roving as it travels through the gun.

For a more complete understanding of the present invention and for further objects and advantages thereof, reference may now be had to the following description taken in conjunction with the accompanying drawings in which:

FIG. 1 illustrates a suitable system for dispensing a mixture of cementitious material with fibers enshrouded with an atomized liquid catalyst;

FIG; 2 is a top view of the gun of FIG. 1; and

FIGS. 3 and 4 illustrate modified forms of nozzle caps.

Referring now to FIG. 1, a dispensing gun is comprised of a nozzle 11 which is preferably in the form of a pair of coaxial elements, a nozzle 11a and a cap 11b. Nozzle 11b is flow connected to a pipe 12. Pipe 12 is coupled to a valve 13, the input of which leads by way of a line 14 to a fiber dispensing pot or container 15. A

3,674,600 Patented July 4, 1972 compressed air line 16 is connected to pot 15 in accordance with prior Pats. Nos. 3,232,557 or 3,305,150. Line 16 is also connected to a resin tank 17 and to an atomizer 18 leading from a liquid catalyst tank 19. Line 29 from atomizer 18 is connected by way of valve 21 and tube 22 to a lateral port 19 in one side of line 12.

The container 15 is provided for receiving a spool 40 of fiber rovings such as fiber glass rovings wherein the fibers are bundled and extend without being twisted throughout the entire spool. The container 15 comprises a chamber which can be pressurized. In the form shown it consists of a deep open topped receptacle onto which a lid may be secured in airtight relation. The compressor is connected to the chamber 15 by way of a line 28 whereby the interior of the container 15 may be maintained under pressure. An outlet port 41 is connected by way of the tubing 14 for delivery of the fiber rovings from the container 15 to the valve 13 in gun 10.

The details of construction of the container shown in FIG. 1 are found in Pat. 3,232,557, and thus will not be described further here. Alternatively, the container 15 may be of the form shown in Pat. 3,305,150. In either case, the spool 40 of glass fiber rovings is placed in the container. The fibers are then delivered through line 14, valve 13 and nozzle 11b to a mixing chamber in cap 11.

Resin from tank 17 is connected by line 30 to a valve 31 on the gun 10. Valve 31 is connected by tube 32 to a lateral port 33 in nozzle 11b. By this means the resin is delivered at a rate controlled by valve 31 to the mixing chamber. The resin flows around the central nozzle member as to centrally entrain fibers delivered to mixing chamber 11d through member 11c. Member 110 may be a rigid spout or it may be resilient so that it may fiap in chamber 11d upon flow therethrough.

Line 20 is employed in accordance with the present invention to inject into line 12 an atomized catlayst from tank 19 to cover or wet the fibers so that the catalyst will be distributed throughout the resin in chamber 11d and thereby accelerate curing of the resin with fibers therein as projected from nozzle cap 11a onto a form to be covered or coated with fiber reinforced resin.

One coating material that may be employed is a resin of the amine promoted type.

In use of such resin in accordance with the invention, liquid benzoyl peroxide catalyst is used Catalyst in amounts from 20% to 30% by volume of fiber has been found to be satisfactory. When this quantity is employed the benzoyl peroxide is ultimately delivered to and mixed with a polyester resin by reason of spraying the same along with the glass fibers such that there is from between 0.5 to 2.0 percent of benzoyl peroxide in the polyester, the ratio being by volume of benzoyl peroxide compared to the volume of the polyester. A representative resin that has been used is the resin made by Reichhold Chemical No. 32-175 under the trade name Polylite which is promoted by, or with dimethylane analine. Enough of benzoyl peroxide clings to the fiber to set this resin.

'It will be readily appreciated that the relative proportion of catalyst to polyester may be controlled by an operator in proportioning the amount of liquid benzoyl peroxide employed relative to the amount of fiber and resin employed in the given operation.

The system provides for the deposit of a glass reinforced resin body which Will set at room temperatures and, thus, is of enhanced value in connection with operations where resins are to be sprayed. Further, it has the distinct advantage in that all materials are mixed in cap 11a.

The catalyst-coated fibers, the resin and the compressed air are delivered to the nozzle 11 in controlled amounts.

Thus, there is provided a mixing chamber 11d within the nozzle wherein the fibers and the resin are thoroughly mixed before being ejected through the orifice 11e. Controlled amounts of air with catalytic agent can be introduced into the mixture to control the nature of the mixture to be ejected from the orifice 11e. It will be recognized that the gun can be used to dispense resin alone, fibers alone, compressed air alone, or any combination of the three. Thus, the nozzle 11 provides for prewetting the fibers with a resin which is responsive to the catalyst enshrouding the fibers so that when dispensed from the nozzle 11 the resin may be caused to set. The setting rate may be controlled by the amount of catalyst employed.

By atomizing the liquid catalyst in the air line the catalyst saturates the fiber before the fiber reaches the resin.

The atomizer is conventional, known in the art as a Nugent dripper, and may be located for convenience at the fiber pot or at compressor 26. The atomizer preferably is adjustable to meter the catalyst.

By this means, catalytic agents can be applied to a number of self-hardening, pumpable materials, such as methyl ethyl ketone peroxides, benzoyl peroxides, and the water impregnated polyesters. Also, foaming agents can be applied to a number of materials that cannot be premixed and pumped because a pump destroys the foam. More particularly, a gun such as shown in FIG. 1, but of larger capacity may be used to spray fiber reinforced portland cement. In such case, atomized caustic soda wetting the fibers will cause the cement to foam and thus permits formation of fiber reinforced concrete structures having characteristics attributable to foam therein but not possible under conventional practices. Magnesium chloride may be used with such cement, in the manner herein disclosed, to accelerate setting of the cement, a uniform mix of agent and cement being produced.

In this system, there is required only one source container or pot, reducing the clean-up problem. The pot life of the resins used is extended. Clean-up of the gun requires only removing the cap 11a and dipping the nozzle 11b and cap 11a in a solvent.

The foregoing discussion of resin systems has dealt particularly with the methyl ethyl ketone peroxide catalytic agent. There are several other catalyst agents that may be employed to produce the same end results. For example, some would be chosen to inhibit ultra violet light, some for fire protection, etc.

FIGS. 3 and 4 show variations in the cap 11a. Cap 50 would be employed when foaming agents are to be employed or where more mixing is required. Cap 51 would be chosen to control the mix or projection. Either may be used with a fixed or flopping action in spout 110, FIG. 1.

Having described the invention in connection with certain specific embodiments thereof, it is to be understood that further modifications may now suggest themselves to those skilled in the art and it is intended to cover such modifications as fall within the scope of the appended claims.

What is claimed is:

1. In a system where continuous fibers are to be dispensed from a spool or rovings of continuous fibers in a container for receiving said spool therein with a fiber line extending to a nozzle, the combination of (a) means to propel fiber entrained in air flow through said fiber line to said nozzle;

(b) means for introducing atomized liquid catalyst into said flow at a point adjacent said nozzle to enshroud the roving as it travels to said nozzle;

(c) structure forming a mixing chamber in said nozzle through which said fibers pass; and

(d) means for delivering a cementitious material to said chamber to coat said fibers and mix said catalyst with said material as the fibers and material are dispensed.

2. The combination set forth in claim 1 in which said catalyst is liquid benzoyl peroxide and said spool is fiber glass rovings.

3. The combination set forth in claim 1 in which said catalyst is methyl ethyl ketone peroxide and said spool is fiber glass rovings.

4. The combination set forth in claim 1 wherein the proportion of said liquid catalytic agent is adjustable in relation to the quantity of fiber being deposited into the mixture.

References Cited UNITED STATES PATENTS 3,296,051 1/1967 Harpfer et al l56285 3,329,543 7/1967 Arthur et a1. 156l66 3,480,498 11/1969 Paul 156285 3,393,109 7/1968 Dorst 156-279 BENJAMIN R. PADGETT, Primary Examiner S. J. LECHERT, JR., Assistant Examiner U.S. Cl. X.R.