In recent months, the northern regions of China, including Linyi, Xuzhou, and Henan, have experienced a significant increase in poplar and willow catkins (commonly known as “cotton fluff”) during April and May, accompanied by unusually high temperatures. This seasonal phenomenon has posed serious challenges to the production of film faced plywood, particularly affecting adhesive performance and overall product quality.
During this period, the rising temperatures accelerate the curing process of adhesives used in plywood manufacturing. Many factories failed to adapt their production schedules accordingly, leading to delays in pre-pressing and hot-pressing processes. As a result, the edges of plywood panels were exposed to prolonged heat before proper pressing, causing premature aging of the adhesive. This issue manifested in localized glue failure, resulting in delamination and weakened structural integrity of the final product.
Our quality inspections across multiple plywood factories revealed widespread defects, including core layer Delamination and Film bubbling. These defects were primarily attributed to the combined effects of high ambient temperatures and improper handling of plywood stacks before pressing. The extended exposure to heat caused partial curing of the adhesive before pressing, reducing its bonding strength and leading to inconsistent glue lines.
To mitigate these issues, manufacturers must optimize their production workflows during high-temperature periods. Key measures include reducing the interval between veneer core lay-up and pressing, improving workshop ventilation, and adjusting adhesive formulations to account for faster curing rates. Additionally, stricter quality control during pre-pressing and timely hot-pressing can help minimize adhesive aging and ensure consistent bonding performance.
In conclusion, the seasonal challenges posed by poplar catkins and elevated temperatures in April and May require proactive adjustments in plywood manufacturing processes. Addressing these factors is critical to maintaining product quality and preventing defects such as delamination and surface film bubbling in film faced plywood.
