Film faced plywood is a wood based panel coated with phenolic film. Its veneers are bonded together by adhesive glue. While plywood manufacturers use mostly phenolic resin to produce formwork plywood, Chinese plywood manufacturers have more options than their counterparts. The glue creates the bonding strength between each layers of the wood veneers in the plywood. The main contents of the glue is formaldehyde and urea. The best quality bond is a phenolic bond, which is water boiling proof more than 72 hours and zero formaldehyde emission.
Glue used by plywood mill in China
MR Glue
The MR glue means moisture resistant. Its material is Urea-Formaldehyde. Thus MR glue is also UF glue. It is the cheap kind of glue. The plywood made with MR glue is suitable for projects in dry climate countries such as Middle East and North China.
WBP Melamine Glue
Melamine glue is more moisture resistant compared with the UF glue. It was added with melamine which can keep some water away from the board. It is a cheaper kind of WBP glue which is suitable for humid and tropical countries.
WBP Phenolic Glue
The WBP phenolic glue is the best in the industry. It is water boiling proof and gives the plywood extra strength in the concrete shuttering works. The formaldehyde emission grade is very low. This high quality bond usually comes with a hardwood core and good quality film on the phenolic board.
| GLUE TYPE | SHORT NAME | CHACRATERISTIC OF THE GLUE |
|---|---|---|
| Urea Formaldehyde | UF C-bond | Moisture Resistant (MR) |
| Melamine Fortified Urea Formaldehyde | MUF B-bond | WBP (Weather and boiling proof) |
| Phenolic Urea Formaldehyde | PUF A-bond | WBP (Weather and boiling proof), Waterproof, Increasing structural strength |
Glue Difference
It is important to know what your plywood suppliers are using for your plywood. The three types of bond are different in performance and price.
- Price Comparision: PUF > MUF > MR
- Water Resistant Capacity: PUF > MUF > MR
- Cost: PUF > MUF > MR
How to tell the glue used in plywood?
If you have no professional chemical analysis equipment, you can tell the glue type by boiling the plywood samples in a pot.
- MR glue can withstand no more than 2 hours of hot water boiling.
- WBP Melamine can withstand at most 5 hours boiling.
- WBP phenol bonded plywood can be boiled for at least 24 hours. At high as 72 hours without delamination.