Artificial boxwood sizing
Includes veneer coating, shavings and fiber sizing. Veneer gluing still uses traditional roller gluing in Europe. Since the 1970s, many plywood factories have switched to laminating. Chinese plywood factories also use roller coating. The leaching method is suitable for the process of sizing the intermediate plate and the automated slab. Shavings and fiber sizing are now mainly used by spray glue.
In the late 1970s, some countries in Europe and the United States studied the non-adhesive gluing technology. The more advanced is the activation of lignin molecules, the use of lignin glue under certain conditions; or the use of hemicellulose in wood or other materials, processed to transform Gluing the cemented material. In the early 1980s, Canada successfully used steamed slag to make glueless particleboard. Research institutes and universities in China are also conducting research on glueless bonding technology, and preliminary results have been achieved.
Artificial boxwood forming and pressing
The bundling of the plywood, the slab forming and pressurization of the particleboard fiberboard are all the molding processes of the artificial board manufacturing. The study of wood structure by wood science reveals that the arrangement of wood fibers in natural wood is hierarchical and directional, and thus can withstand a certain amount of external force exerted by nature on wood. The evolution of the manufacturing process of wood-based panels is undoubtedly affected by this understanding: the slab level of particleboard and fiberboard is changed from a single layer to a three-layer structure and a multi-layer structure; the arrangement of shavings and fibers in the slab also tends to be oriented from a random type; The orientation of the adjacent layers of the plywood fibers perpendicular to each other improves the anisotropy of the wood under natural growth conditions and improves dimensional stability.
Pressurization is divided into pre-pressure and hot pressing. It is necessary to pre-press the slab when using a padless system. It keeps the slab from being damaged when it is pushed into the hot press. The hot pressing process is the key process to determine the production capacity and output of the enterprise. The hot pressing equipment commonly used in the wood-based panel industry is mainly a multi-layer hot press. In addition, single-layer large-format hot presses and continuous hot presses are gradually being adopted. The single-layer hot press is used in the particleboard factory. The single-layer laminator in the manufacture of medium-density fiberboard can realize the combined heating of high frequency and steam, which is beneficial to shorten the pressurization cycle and improve the uniformity of the product section density.
Artificial yellow boxwood final processing
After the sheet is discharged from the hot press, it is subjected to the stage of cooling and moisture content balance, that is, sawing and sanding, and the hard fiber board is subjected to heat treatment and humidity control. In the past, the sawing edges of the plates were cold sawing. Now, the hot sawing method is also used, but the hot sanding method must not be used. The hot sand will damage the surface quality of the finished product. According to the requirements of use, some plates need special treatments such as dipping, painting, laminating and edge sealing.
