Plywood QC Inspection Checklist : Part 24 Differences among phenolic, melamine and urea-formaldehyde adhesives
What is the difference between phenolic, melamine and urea-formaldehyde?
Urea-formaldehyde adhesive is mainly made of urea and formaldehyde.
Phenolic resin is a general term for the formation of resins by phenols and aldehydes under the action of catalysts. It is the earliest synthetic polymer material in industrialization (Bakelite, Germany, 1910). In the past century, it has been used in many industrial fields and is still an important synthetic polymer material. Phenolic resin is one of the most widely used adhesives in the field of wood processing, and its dosage is second only to urea-formaldehyde resin. Especially in the production of water and weather resistant wood products, phenolic resin has special significance.
Phenolic resin adhesives are widely used because of their good heat resistance, high bonding strength, good aging resistance, excellent electrical insulation and low cost.
Melamine glue (melamine formaldehyde resin) is mainly made of melamine and formaldehyde.
Among them, a certain amount of free formaldehyde phenolic adhesive and urea formaldehyde adhesive are used to produce raw materials, which have formaldehyde bonding properties, corrosion resistance, low cost of urea formaldehyde adhesive, mechanical strength and other aspects of phenolic adhesive is superior, the price is also high, which has great harm to human body, and is widely used in wood-based panel production.
Although formaldehyde resin adhesives have the advantages of high bonding strength, water resistance, heat resistance, wear resistance and chemical stability, phenolic resin adhesives are the preferred adhesives in the production of weather-resistant and heat-resistant wood products, their application is limited due to their low wear resistance, high cost, high curing temperature and long hot pressing time. For this reason, many people adopt various ways to modify it.
The modification of phenolic resin can mix flexible linear macromolecule compounds (such as rubber, polyvinyl acetal, polyamide resin, etc.) into phenolic resin, or make graft or block copolymers of some High-adhesive or heat-resistant macromolecule compounds or monomers and phenolic resin by chemical methods, so as to obtain adhesives with various comprehensive properties.