In world plywood industry, many business sell and buy WBP plywood. But really a few people know the meaning of the word “WBP”.
what is the real meaning of WBP in Plywood
WBP stands for “Water Boiled Proof”. If you use WBP glue for the plywood / film faced plywood, the panel will can be exposed to humid or moisture for a long time without delamination. Like the word of “MR”, WBP is not the name of a specific glue, WBP is a kind of property of glue . If a glue has WBP property, the glue will can be called WBP glue. The melmaine formaldehyde and phenolic formaldehyde can be regarded as WBP glue as the plywood made from these are water boil proof.
As a simple method of test for WBP plywood is to boil plywood sample. 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 test results can be 10 hrs, 24 hrs, 48 hrs, 72hrs etc.
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 phenolic can be regarded as permanent resin. But the water boiled proof period of plywood is depended on not only the quality of WBP glue, but also the craftsmanship of production of core and face.
Manufacturers use WBP glue for exterior plywood, such as Marine plywood, film faced plywood (formwork plywood), structural plywood, plywood for signs packing 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 property.