What is WBP glue – which is commonly used for plywood / film faced plywood
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 Marine plywood, 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.
What’s MR glue-which is commonly used for plywood / film faced plywood / blockboard
In plywood business, the words of ” MR glue ” is usually mentioned . A lot of people know that MR glue is cheaper than Melamine or Phenolic glue . But some people don’t know what the meaning of “MR” is . Then what on earth is ” MR glue ” ?
“MR” is the acronym of “Moisture Resistant” . MR glue means the glue is resistant to moisture . So The meaning of “MR” is different from that of “Melamine ” and “phenolic” . “Melamine ” or “phenolic” is the name of a specific glue . But Like the word of “WBP”, ” MR ” is only a kind of property/feature of glue . If a glue has MR property, the glue will can be called MR glue .
Plywood with MR glue is resistant to moisture . MR plywood are usually used for home interior application, such as furniture grade plywood / blockboard and so on .
MR glue can also be used for some exterior shuttering plywood / film faced plywood (formwork plywood) , too . MR plywood can be in cold water for some days without delamination . So MR shuttering plywood or MR film faced plywood can be used for some simple construction projects .
However MR plywood will delaminate in hot-water within short time (no more than 30 minutes) .