Adhesion curtain coatings

Adhesives (qv) used to make plywood are classified as either the exterior adhesive or the lesser quaHty interior adhesive. The terms relate to the abUity of the adhesive to survive exposure to moisture and weather. PhenoHc resins (qv) are commonly used as adhesives to make plywood. The difference between interior and exterior phenoHc resin adhesive is the filler level. Exterior rated plywood uses higher resin content adhesives. Interior rated plywood uses either highly extended (below 24% resin soHds) or protein-based adhesives. The adhesive is appHed to the veneer by roU coating, spraying, curtain coating, or foam extmsion. 

Flow. In industry, adhesives are frequently applied to the wood by means of roll or spray applicators. Often the result is, initially, discrete strips or droplets of glue on the wood. These discrete areas of glue should flow or merge to form a continuous film. Some forms of application (e.g., curtain coating and hand brushing) produce a continuous film from the outset. Flow, as a separate step, would not be involved in this case. 

With respect to application methods, blood glues can be spread on wood surfaces by most conventional means. These include roller, knife, and extrusion but do not include curtain coating or spray, for which the glues must be thinned below practical film retention levels. The major advantage of alkaline-dispersed blood glues over all other wood glues except resorcinol-based synthetic resin adhesives is their sensitivity to heat, resulting in extremely... 

Latex adhesives replace solvent-based adhesives more easily than solution adhesives. Most latex adhesives are produced from polymers that were not designed for use as adhesives. This is why they require extensive formulation in order to obtain the proper appUcation and performance properties. Application methods for latex adhesives include brush, spray, roll coat, curtain coat, flow, and knife coat. The bonding techniques used for latex adhesives are similar to those used for solvent adhesives. The following techniques are popular ... 

If all these requirements are met, the adhesive film is even, smooth, and perfectly controlled in thickness, without bubbles or scratches, and of same thickness everywhere. Curtain coating may thus be used to bond thin plastic films without any defect. There is no loss of adhesive because the excess is recycled. 

Curtain coalers for hot melt adhesives and coatings and extrusion coating... 

Neoprene adhesives are conventionally applied by spraying, curtain coating, roller coating, brushing, or extrusion (i.e., by a caulking gun). Spraying is by far the most important industrial technique, as it permits rapid laydown of ad-... 

This flexibility has proven invaluable in the design of coater-ready aqueous adhesives which are specifically designed for a wide range of application techniques. These techniques include reverse roll coating, curtain coating, gravure coating, and spray application. Key characteristics built into the aqueous adhesives to permit such a wide variety of application techniques include ... 

Mention has already been made of Redux 775, the first structural adhesive film. Its manufacturing process has not changed since 1954. A film of phenolic resole is cast under a doctor knife, a considerable excess of the Polyvinyl Fluoride (PVF) powder is curtain coated onto the phenolic film, and the excess is then... 

Uses Defoamer, air release agent for 100% UV coatings, VOC-ftee systems, toller and curtain coating applies. food-pkg. adhesives defoamer in food-contact paper coatings/paper/paperboard... 

The viscosity of elastomeric adhesives determines their method of application. Typically, solvent-borne rubber compounds require low viscosities for application. Thus, viscosities lower than 0.6 Pas for spray, curtain or dip applications are required, whereas for brush application viscosities lower than 5 Pa s are generally used. Roll- coating technology requires viscosities between 5 and 15 Pa s. 

Flexible PVC resins and other dioctylphthalate-containing plastics and resins are used in a variety of industrial and domestic products plastisols for carpetback coating (EPA 1987b), film, wire, cables, and adhesives (HSDB 1995). Additional end-use products are automobile and furniture upholstery, wall coverings, window shades, garden hoses, shower curtains, tablecloths, rainwear, shoes, dolls, and toys (Mannsville Chemical Products Corporation 1989). 

Flow or curtain Use a head with a slot in the bottom through which the adhesive is poured or lowered onto the parts or surfaces as they pass beneath the head by a conveyor provides materials savings and ability to coat irregular surfaces uniformly... 

Methyl acrylate is combined with other monomers to produce copolymers used in the production of surface coatings (e.g., latex finishes, floor and fabric finishes), acrylic fibers (used in carpets, clothing, blankets, and curtains), plastics (e.g., medical and dental prosthe-ses), as well as adhesives, detergents, and sealants. 

MAJOR USES Used as a plasticizer for elastomers explosives nail polish solid rocket propellants nitrocellulose lacquers used in the manufacture of shower curtains raincoats food wraps bowls car interiors safety glass insecticides printing inks paper coatings adhesives. 

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