Detailed explanation of several types of laminating processes for customized wardrobe boards!
Introduction: Veneer decoration is a very important process in the production of panel furniture, which can cover the defects of the material surface and improve the physical properties of the substrate. Veneer decoration is a very important process in the production of panel furniture, which can cover the defects of the material surface and improve the physical properties of the substrate.
The veneering materials include veneer veneers (veneer veneers, wood veneer veneers), wood grain paper veneers, PVC plastic film veneers, and melamine board veneers. Let’s learn about artificial panel cosmetic surgery – veneer technology – through the following detailed introduction to veneer veneers, PVC veneers, and decorative paper veneers!
1、 Veneer veneer is the most important decorative method for panel components, and it is a technology for gluing veneer (plain or various types of mosaic) onto the surface of various substrates (artificial board, solid wood edge board, solid wood panel, etc.). The process includes sanding before and after the veneer, and sanding with fixed thickness before the veneer. After thickness correction, it is generally required that the thickness difference of the same batch of plates should be controlled within 0.2mm, and the surface of the plates should be free of obvious sand marks and wavy lines, and there should be no obvious surface irregularities when drawing with hand or chalk. However, a certain deviation between the plate thickness and the nominal thickness is allowed, usually controlled within ± 0.5mm. The common equipment for surface sanding after veneering is a broadband sanding machine, usually with three sanding frames, and uses a rubber sanding wheel or airbag type sanding pad with lower hardness as the sanding head, and installs fine sanding paper tapes of 150 to 240 sizes. The one-time sanding amount for surface sanding should be controlled between 0.1~0.2mm, and 80%~90% of the surface adhesive paper should be sanded off. For plates with slight bending, the amount of sanding should be reduced to ensure that the maximum amount of sanding is not broken by sand; Wideband sanders cannot be used to work on panels with severe warping, and narrow band hand pressure sanders are usually used.
2、 Thin wood hot pressing veneering technology Thin wood veneering usually uses a hot pressing veneering process, which includes specific processes such as sheet gluing, assembly, and hot pressing. 1. Prefabrication technology, hot pressing veneer technology Prefabrication: When using rapid curing glue for hot pressing veneer processing, after applying glue, directly cover the veneer onto the board surface, and then send it to a hot press for pressing processing. The veneer size should generally be about 10mm larger than the base material. 2. Cold pressing veneer technology assembly: After the panel is coated with glue, it is usually required to have a period of aging time before pressing, so that the glue can fully contact and moisten the veneer, improving the veneer quality. 3. Hot pressing veneer technology, equipment: multi-layer hot press or short cycle single layer hot press. The multi-layer hot press is mainly suitable for the gluing operation of most small and medium-sized furniture enterprises or small size panels. Short cycle hot presses are suitable for enterprises that produce in large quantities. Hot pressing parameters: hot pressing pressure (P), temperature (T), and time (t), commonly known as the three elements of hot pressing; Pressure: usually 0.6~1.2MPa; Hot pressing temperature and time: Generally, the UF glue temperature should not be lower than 110 ℃ (usually 120~130 ℃). The higher the temperature, the shorter the hot pressing time, and the higher the production efficiency; However, if the temperature is too high, it will easily crack the adhesive layer of the veneer. Modified PVAc is commonly used for low-temperature hot pressing, and the general temperature should not be higher than 100 ℃ (typically 90~105 ℃). The thicker the base material is, the slower the heat transfer is, and therefore the hot pressing time requirement is correspondingly extended. In actual production, the specific time is usually determined through experiments, subject to the basic curing of the glue after hot pressing.
3、 Printing and decorative plastic veneer Currently, the plastic films used for veneer of panel components mainly include polyvinyl chloride (PVC), polyethylene (PVE), polypropylene (PP), polyester (PET), and other categories. PVC is the most widely used, commonly referred to in practical production as PVC, which is a generic term for printing and decorative plastics.
4、 PVC Veneering Technology for Flat Panels There are two methods for PVC veneering of flat panels: flat pressing and roller pressing. Flat pressing method is generally cold pressing method, which is rarely used in actual production due to its low production efficiency. The most commonly used method for surface veneering of planar components is the roller pressing method. The specific working process is as follows: the substrate is first subjected to brush roller dust removal, roller type gluing machine for gluing treatment, and roller pressing gluing. The gluing pressure is 1.0~2.0MPa. PVC vacuum cladding technology, commonly known as soft molding veneers, is used for PVC cladding of surface molded panels. This method has uniform pressure and good veneering effect, but requires special equipment and low production efficiency. The basic working process is: placing the workpiece after spraying glue on the workbench; After the glue finger is dried, the surface is covered with a PVC film and clamped firmly to allow the workbench to enter the heating plate, the upper pressing plate is closed, and the upper and lower working cavities are sealed; The upper working chamber is vacuumized to remove cold air from the chamber, and the PVC film is brought into contact with the upper heating plate to soften during heating; Vacuumize the lower working chamber and inject compressed hot air into the upper working chamber to make the PVC film tightly adhere to and closely adhere to the substrate; After the glue has solidified, remove the positive and negative pressure from the upper and lower working cavities, and turn on the press to complete the adhesive bonding of the membrane pressing surface components; After the workpiece has cooled down, use tools or sandpaper to remove excess PVC film from the edges.
