Wood veneer panel - types and characteristics of traditional wood veneer

Plywood consists of three or more layers of veneer glued together. It is characterized by uniform material, good stability and mechanical properties, wide format, and high utilization rate of wood. According to Chinese standards, the water-resistance of plywood is generally divided into four categories: Category I is weather-resistant and boiling water-resistant plywood, which is glued with phenolic resin or its equivalent performance adhesive and can be used in outdoor conditions; Category II is water-resistant plywood, It is made of urea-formaldehyde resin glue, which can withstand cold water immersion or short-term hot water immersion, but is not resistant to boiling; class III is moisture-resistant plywood, made of blood glue, multi-filler urea-formaldehyde glue, etc., suitable for indoor use at room temperature; class IV It is not water-resistant plywood, and it is made of glue such as soybean glue. The plywood thickness ranges from 2.5 to 30 mm, the width is 915 to 1220 mm, and the length is 915 to 2440 mm. The quality of various types of plywood needs to be classified according to the use, surface material, and processing defects. The moisture content and bonding strength of plywood are the basic quality control indicators, and the specified values are shown in Table 1.