Adhesive Dispensing System And Method

What is this patent about?

’887 is related to the field of adhesive dispensing systems, specifically those used for applying multi-component adhesives in construction applications like roofing and carpeting. Traditional systems either use high-pressure sprays, which are expensive and messy, or low-pressure beads, which provide non-uniform coverage. The patent addresses the need for a system that can apply adhesives uniformly without the drawbacks of high-pressure systems.

The underlying idea behind ’887 is to introduce pressurized air into the adhesive components *before* they are mixed , creating an aerated, low-pressure spray. This aeration serves two purposes: it provides additional pressure to propel the adhesive, and it introduces air bubbles into the mixture. This results in a more uniform, 'splattered' application of adhesive across the work surface, covering a larger area than a bead but without the atomization and overspray associated with high-pressure systems.

The claims of ’887 focus on a dispenser head and system that allows for the controlled mixing of adhesive components with pressurized air. Specifically, the independent claims cover a dispenser head with separate fluid passages for each component, an air passage that intersects one of the fluid passages to create a mixing point, and valves to regulate the flow of both the fluids and the air. The key is the air/fluid mixing passage which allows for aeration *before* the components combine.

In practice, the system uses a proportioning pump to deliver the adhesive components to the dispensing head. Pressurized air is then injected into one or both of the component streams *before* they reach the mixing tip. By adjusting the air pressure, the operator can control the degree of aeration and the resulting spray pattern. With no air, the system dispenses a bead; with air, it dispenses a low-pressure aerated spray. This allows for a single system to be used for different application requirements.

The differentiation from prior art lies in the method of aeration and the resulting adhesive structure. Unlike high-pressure systems that atomize the adhesive, this system creates a low-pressure aerated spray with larger droplets , reducing overspray and improving control. Furthermore, the aeration process leads to a cured adhesive with a finer, more uniform cell structure, resulting in improved adhesion compared to traditional bead applications and comparable performance to high-pressure sprays, but with a simpler and more controllable system. The system also allows for air purging of the lines to prevent clogging.