Why do boards sometimes come unglued? What are the reasons for this?

What causes wood panels to come apart? Wood panels are a crucial component of most furniture. Different types of wood panels have different physical properties. However, all wood panels used in furniture face the problem of delamination.

Delamination is a key factor affecting the quality of wood panels, which is an important indicator of furniture quality. Therefore, only by understanding the specific reasons for delamination can unnecessary losses be avoided. The main factors influencing delamination include the moisture content of the wood panels, drying process, adhesives, and the external environment.

First, the moisture content of the wood-based panels is a key factor affecting bond strength. Plywood, particleboard, and medium-density fiberboard (MDF) all contain moisture. Freshly felled timber has a higher moisture content, while timber that has been air-dried for a long time has a lower moisture content. Generally, the moisture content of wood-based panels is between 8% and 12%, which is the national standard. However, due to differences in climate and air humidity, the moisture content of wood-based panels varies from region to region, and therefore, the control of moisture content also differs from region to region. Methods for controlling the moisture content of wood-based panels include natural drying and machine drying.

Secondly, drying is an important process in the production of boards. The drying process allows the boards to reach the required standards more quickly and evenly.

Third, the adhesives used in the sheets can also affect delamination. If the bond strength is insufficient, delamination will subsequently occur. For example, early urea-formaldehyde adhesives used a 7:3 urea-formaldehyde ratio for environmental reasons. However, later, the urea-formaldehyde ratio was changed to 3:7 to increase bond strength, which is why many boards using urea-formaldehyde adhesives exceed formaldehyde emission standards.

Finally, the external environment can also affect delamination. Even if the boards are well-controlled, unnecessary losses, including delamination, can occur if they are exposed to dark and humid environments for extended periods. Sunlight exposure can cause the boards to crack, and prolonged dampness can affect the overall adhesive strength. Therefore, to avoid unnecessary losses caused by delamination, it is necessary to choose suitable boards and maintain the furniture properly.