1. What is the role of glue in producing plywood?
The quality and performance of plywood largely depend on the type of glue used in its manufacturing process.. We also can say it is the most important element of plywood. Together with the veneer material, glue determines the strength, quality, and durability of the plywood panels.
2. Many types of glue which Vietnam often use for manufacturing plywood
- Urea-Formaldehyde Glue (UF glue)
UF glue is the most common glue used in the plywood industry, it is a synthetic glue made from a reaction tank between Urea and Formalin at a suitable temperature with an additive that is a catalyst/reaction inhibitor such as formic acid and sodium hydroxide.
There are many UF glue types such as E0, E1, E2 glue types, in which E2 glue and mixed water glue are used popularly in Vietnam, which are usually used for exterior uses that do not have high requirements on formaldehyde emission and do not have strict requirements on quality.
- Melamine Glue (MUF glue)
MUF glue is a very popular WBP (Water Boiled Proof) glue in Vietnam, basically, MUF glue is produced the same as UF glue, it is a heat reaction process between Formalin and Urea under the catalysis/inhibition of Formic Acid and Sodium hydroxide. The difference between MUF and UF glue is that melamine is added during the reaction process of MUF glue.
MUF glue has diverse classifications from E0 to E2 types for local and export production. Depending on the melamine percent in the glue, the properties of the glue are also different. The more percent melamine includes the more water resistant plywood quality gain. The maximum level for water resistance is up to 72 hours boiling time.
- Phenolic glue (PF glue)
PF glue is a special thermoplastic glue combining Phenol and Formaldehyde used in the plywood industry. Because of the special bonds between Phenol and Formaldehyde molecules in the baze environment of the endothermic reaction, therefore, it’s very tight and durable chains.
In conclusion, different types of plywood glue are used for various applications, depending on their characteristics and properties. UF glue is the most common type of glue used in plywood manufacturing, while PF glue is commonly used in marine-grade plywood and exterior applications. MUF glue is a modified version of UF glue that emits less formaldehyde gas and provides better water resistance and bond strength.