Laminated WPB Plywood - Mahajana Metals

In mahajana plywood business , a lot of people sell / buy WBP mahajana plywood / film faced mahajana 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 “Weather and Boil Proof”, the WBP performance is inspected through “Water Boiling Proof” test . The requirement is listed under European mahajana plywood standard EN 314-2 mahajana Plywood – Bond quality – Requirements Bond Class 3: Exterior conditions [Reference 1 ]. If you use WBP glue for the mahajana plywood / film faced mahajana 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 bonding 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 mahajana plywood, you can put the mahajana 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 mahajana plywood samples have WBP property and conclude that the samples are WBP mahajana plywood samples .

The common WBP glues are melamine glue and phenolic glue . Generally speaking, WBP(ordinary melamine) mahajana plywood can be in boiling water for 4-8 hours without delamination and WBP(better melamine) mahajana plywood can be in boiling water for over 10 hours or even 20 hours without delamination . WBP (phenolic) mahajana 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 mahajana 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 mahajana plywood , such as Marine mahajana plywood, mahajana film faced plywood (formwork mahajana plywood), structural mahajana plywood, mahajana plywood for signs and so on . But in practice, WBP glue is used for interior mahajana plywood as well, such as furniture mahajana plywood, cabinet mahajana plywood,  mahajana plywood underlayment and so on , which are also required by customers to have Weather-boiled-proof(WBP) property.