You can also visit my other blog http://www.chineseplywoodsource.com/what-is-wbp-glue-how-they-used-in-the-plywood-production/ ,We are making the WBP glue plywood now ,from the face/back film to the inside every layers of the plywood,all WBP glue .We can call it WBP glue ,but not just the film ,or the inside every layers .
When making the WBP glue plywood,please check with your Glue suppleirs,what these WBP glue will be used for ,the wood species of the core veneer is poplar or pine or hardwood ,the glue suppliers will supply different kinds of glue to you .
Also you need tell the glue suppleirs how much boilding test will be 4 hours or 24 horus or 72 hours,the quality of the glue are much different .
If normal WBP glue Melamine ,the plywood cold pressing is very simple like MR,you can make the cold pressing within 12 hours to 24 hours .But if WBP phenolic Glue ,the cold pressing are much complicated ,need make the cold pressing within 2 hours or 4 hours maximum to make sure the veneer core platform are solid ,then would make the hot pressing immediately .
WHEN YOU USE WBP GLUE ,THE ORIGNAL COLOR IS LIGHT YELLOW BROWN ,AFTER SPRAYIN THE GLUE TO THE WOOD veneer ,the color will be changed to dark brown color ,see these color changes from these pictures I took the Phenolic WBP glue ( 72 hours boiling test ) .Some of the factories using fake or low quality WBP to mixed with color pigment to make the color like WBP glue color .That is cheating and play games .
Glues used in exterior and marine plywood that will be exposed to water and weather is described as WBP (Weather and Boil Proof). This only means that a plywood sample glued with this adhesive does not delaminate after a prolonged period of boiling. It is NOT a description of the type of glue. WBP only describes its characteristics. Several glues have proved to be WBP.
Most WBP glues are either melamine or phenolic glues. Lower quality melamine plywood can sustain 4-8 hours boiling without delaminating. Higher end melamine can last between 10-20 hours in the boil test.
Phenolic plywood is considerably more resistant (24-72 hours). The best phenolic glue can be regarded as essentially permanent adhesives and are used in the higher grades of Marine Plywood.
It is likely that under sustained boiling, plywood plies glued with high end phenolic adhesive, will fail before the glue. It is therefore important to consider the ply quality and manufacture quality along with the quality of the adhesive. No amount of quality WBP will keep a poorly manufactured panel made with inferior plies together.
When one is looking for the ultimate in weather resistant plywood, it is important to look for WBP. This abbreviation stands for “Water Boil Proof” or “Weather and Boil Proof;” a standard used to determine the water resistance of the plywood products . In actuality, this is more arating of the glue used in the manufacture of the plywood, than it is in the wood itself.
WBP testing consists of immersing a sample piece of the plywood in boiling water, and leaving it there for an extended time. If the plywood doesn’t delaminate from the heated water, then it is considered WBP. Boiling water is used because many adhesives are softened by heat. On top of that, the moving air bubbles from boiling agitate the plywood, making it more like to delaminate .Since water boils at 100°C or 212°F, using boiling water provides for consistent testing.
There is no one glue that is considered to be WBF glue. Rather, WBP is a property that is determined by testing. A number of different types of glues can be WBF. However, different types of glues provide for different levels of protection against water. Therefore, the WBP rating is only a minimum; often, the specific plywood carries an additional rating of how long it can withstand the WBP test. The most common WBP glues used in plywood are melamine and phenolic. Ordinary melamine plywood can withstand the WBP test for 4 to 8 hours, without delamination. There is also a better grade of WBP melamine plywood, which can withstand the test for over 10 hours, in some cases up to 20 hours. However, phenolic WBP plywood outperforms melamine, surviving WBP testing for 24 to 72 hours.
Please note: When we refer to WBP phenolic adhesive it isn’t the same as phenolic plywood. Standard phenolic plywood is not WBP, as the phenolic resin is only applied to the face laminations. The interior laminations use a different adhesive, which is not WBP. However, WBP phenolic plywood would use phenolic as the adhesive on all laminating layers, in addition to having the face layers impregnated with it, making it highly water resistant.
WBP plywood can be used as exterior grade plywood for construction. However, it is more commonly used as Marine plywood, especially for interior applications. The difference between WBP and standard marine plywood is that marine plywood is guaranteed 100% void free, without any knotholes and cracks, while other WBP plywood may not be.
In construction, WBP plywood provides for a more weather resistant structure than using normal exterior grade plywood. It can also be used for signage, as it is highly weather resistant. A number of types of interior plywood are also rated WBP, such as many types of cabinet plywood , even though they are not used in an application where they are exposed to the weather.
In plywood business,Most of people producing and sell or buy WBP plywood.But only a few people know the real meaning of the word of WBP.
What is the real meaning of WBP?
WBP stands for or it is full name of “water boiled proof”.if you use WBP glue for the plywood, film faced plywood or other types of plywood. The panel can be exposed to weather, water and moisture for long period without delimitation. 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 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 delamination 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 wanter for 4-6hours without delamination and better melamine plywood can be in boiling water for over 10hours or even 20hours without delamination.WBP phenolic plywood can be in boiling water for 24hours -72hours without delamination.The best WBP phenolic glue can be regarded as permanent adhesives.But the water boild proof period of plywood is depanded on not only the quality of WBP glue.But also the craftsmanship of production.
Most of the manufacturers use color-pigment to mixed together with MR or Melamine Glue to make it like real WBP glue ,just matched the color but not the real WBP characteristic .This way to reduce the manufacturing costs .If no special request or special quality requirement,the manufacturers normally use this way to make WBP glue plywood .
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-boild-proof property.