In plywood business , a lot of people sell / buy WBP plywood / film faced plywood . But only a few people know the real meaning of the word "WBP" . Thus, what is the real meaning of WBP ?
WBP stands for "Water Boiled Proof" . If you use WBP glue for the plywood / film faced plywood, the panel will can be exposed to weather, water and moisture for a long period (some maybe permanently ) without delamination . Like the word of "MR", WBP is not the name of a specific glue . WBP is only a kind of property/feature of glue . If a glue has WBP property, the glue will can be called WBP glue .
As a simple method of test for WBP plywood, you can put the plywood samples into the boiling water . If the samples have not delaminated in boiling water for a long period, then we will can say the plywood samples have WBP property and conclude that the samples are WBP plywood samples .
The common WBP glues are melamine glue and phenolic glue . Generally speaking, WBP(ordinary melamine) plywood can be in boiling water for 4-8 hours without delamination and WBP(better melamine) plywood can be in boiling water for over 10 hours or even 20 hours without delamination . WBP (phenolic) plywood can be in boiling water for 24-72 hours without delamination . The best WBP(phenolic) glue can be regarded as permanent adhesives .But the water boiled proof period of plywood is depended on not only the quality of WBP glue, but also the craftsmanship of production .
Usually , people like use WBP glue for exterior plywood , such as Marineplywood, film faced plywood (formwork plywood), structural plywood, plywood for signs and so on . But in practice, WBP glue is used for interior plywood as well, such as furniture plywood, cabinet plywood, plywood underlayment and so on , which are also required by customers to have water-boiled-proof(WBP) property.