Resin glue is a type of adhesive used in the construction industry that provides superior bonding capabilities. Because of its long curing time of as much as ten hours, it is ideal for woodworking applications, which require unhurried and careful assembly. It is manufactured in powdered, spray, emulsion, and liquid forms.
Also known as formaldehyde resin glue, this adhesive is one of the oldest synthetic polymers, first developed in 1872. As one of the least expensive glues, it is generally used to bond thin sheets of wood together to form plywood or wood chip to make particleboard. Polyurethane or epoxy adhesives have replaced phenolic resin glues in some applications over the last few decades. Advantages include superior adhesion to most substrates, good high temperature properties, water and weather resistance, resistance to burning, and high strength. Phenolic resins are sometimes used as a base resin or a modifier in an adhesive formulation.
This type is used to improve a product’s durability as well as to make it waterproof and resistant to solvents, heat, and flames. Applications include compression molding for hard plastic furniture and dishes, and to bond together cellulosics in the manufacture of Formica, Melmac, and similar products.
Commonly known as yellow glue or carpenter's glue, this adhesive is similar to plain white glue, but has been modified in structure to be stronger and more resistant to moisture. It is particularly effective on brown hardwoods and provides strong initial tack and fast setting to diminish clamping time. Unaffected by finishes, this adhesive may be fully sanded. Aliphatic resins may be used only on porous materials, dries quickly, and is easy to clean.
Available in powdered or liquid forms, urea resin glues are used for laminating and veneering. This glue is ideal for water- and heat-resistant construction applications. In liquid form, it has a powdered catalyst, while the powdered version has the urea and formaldehyde components already mixed. Respirators are generally recommended when mixing the powdered version as it is toxic. These glues usually do not need hardeners when mixed. One of the biggest advantages of urea resin glue is its long open life, meaning that the container can be left open for a long time while using the product without it drying or becoming rigid.
Resin glues are also used in construction applications that do not involved wood products. These include truck and cargo container flooring, adhesive for wood shop applications and furniture joints, and as a binder for feed pellets, foundry core and sand, plant fertilizer, and in wheels used to cut glass.