External mix spraying system

An external mix, plural component spraying system comprising:

• a first source of first component;
• a second source of second component;
• a hand-held spray gun for mixing said first and second components and for directing mixed first and second components at a substrate;
• liquid delivery means for providing a flow of said first component from said first source to said spray gun;
• a source of compressed air;
• air delivery means for providing a flow of compressed air from said compressed air source to said spray gun;
• and
• mixing means coupled to said second source and to said compressed air source for introducing said second component into said compressed air, said mixing means being coupled to said spray gun for delivering a flow of compressed air and second component to said spray gun,
• said spray gun including an airless liquid nozzle for forming the first component flow into a fan-like film with edges expanding from a liquid orifice, and a nozzle assembly for directing a flow of compressed air and second component at the fan-like film closely adjacent to the airless liquid nozzle and for further directing a flow of compressed air at the expanding edges of the fan-like film downstream of the impingement of the second component, said flows of compressed air and second component interacting with the fan-like film of the first component and its expanding edges to capture the particles of the second component and to incorporate and to mix and distribute the particles of second component with particles of first component formed from the fan-like film of first component.

A method of forming an article from a plurality of mixed components, comprising:

• delivering a flow of a first component to a spraying means;
• delivering a flow of compressed air to said spraying means;
• introducing a second component into a flow of compressed air to said spraying means;
• forming the first component flow into a fan-like film with expanding edges extending from the spraying means;
• dividing the flow of compressed air and second component into at least two air-second component flows and directing the at least two air-second component flows at the fan-like film of said first component from opposite sides of the film within a fraction of an inch of the spraying means;
• dividing the flow of compressed air into at least two air flows directed at the expanding edges of the fan-like film downstream of intersection of the air-second component flows with the fan-like film of first component;
• atomizing the first component and mixing the first component and second component with the flows of compressed air;
• and
• directing the atomized and mixed first and second components at an article-forming substrate where the first and second mixed components harden to form an article.

A nozzle for use with an airless spray nozzle in an external mix, plural component system, comprising:

• a body forming an opening in its face permitting the body to be positioned adjacent an airless spray nozzle that is adapted to project a first component material in a plane forwardly of the body, said body having a plurality of means to direct combined flows of compressed air and a second component material forwardly of the body in a direction to intersect the plane of the first component material projected from the airless spray nozzle a fraction of an inch forwardly of the face of the body, and a plurality of means to direct flows of compressed air forwardly of the body, generally parallel to each other and generally in the plane of the first component material projected from the airless spray nozzle, said plurality of means to direct combined flows of compressed air and a second plural component material comprising a pair of air-catalyst spray nozzles centered upon and equally spaced on opposite sides of the body opening and oriented at an acute angle in the face of the body and said plurality of means to direct flows of compressed air forwardly of the body comprising a pair of passageways forming orifices centered upon and equally spaced on opposite sides of the body opening and further being generally equally spaced from each of the pair of air-catalyst spray nozzles, each of said passageways including a portion lying along lines perpendicular to the face of the nozzle body adjacent the face of the nozzle body, and each of said orifices being encompassed by a small cavity formed in the face of the nozzle body.

A method of forming an article from a plurality of mixed components, comprising:

• delivering a flow of a first component to a spraying means;
• introducing a second component into a flow of compressed air and delivering the flow of compressed air and introduced second component to said spraying means;
• forming the first component flow into a fan-like film with expanding edges extending from the spraying means;
• directing the flow of compressed air and second component at the fan-like film of said first component closely adjacent the spraying means;
• directing a pair of flows of compressed air to intersect the flows of first component and of compressed air and second component downstream of their intersection to assist atomization and mixing and to substantially contain the first component and second component;
• and
• directing the atomized and mized first and second components at an article-forming substrate in a spray pattern substantially without the escape of said components.

Means for forming an article from a catalyzed, resinous material, comprising:

• a first source of resin;
• a second source of catalyst for said resin;
• spraying means to mix said catalyst with said resin and to direct mixed catalyst and resin at an article-forming substrate;
• liquid delivery means to provide a flow of resin from said first source to said spraying means;
• air delivery means to provide a flow of compressed air to said spraying means;
• and
• injection means to introduce catalyst in a flow of air from said air delivery means,
• said spraying means comprising a liquid nozzle for forming the resin flow into a fan-like resin film with expanding edges extending from a liquid orifice, and a nozzle assembly directing compressed air and catalyst particles at the fan-like resin film, said nozzle assembly having a central opening in which a liquid nozzle is positioned, a pair of air-catalyst nozzles for directing compressed air and catalyst particles at the fan-like resin film from opposing sides thereof to impinge upon the fan-like resin film a fraction of an inch forwardly of the liquid orifice, and a pair of air passageways for directing compressed air at the expanding edges of the fan-like resin film to intersect the expanding edges of the fan-like film at a distance farther from the liquid orifice than the directed compressed air and catalyst particles,
• said liquid nozzle and said nozzle assembly being adapted so that the compressed air and catalyst particles interact with the fan-like resin film and its expanding edges to provide a spray pattern with mixed catalyst and resin particles substantially uniformly distributed throughout the spray pattern.