Plywood is a three-layer or multi-layer board-like material that is made of wood segments into veneers or sliced into veneers, and then glued with adhesives. The fiber orientations are glued perpendicular to each other. Plywood is often used in furniture production, fast packing, steel side box production, etc., because the use of a large amount of adhesive is likely to cause excessive formaldehyde emission, so the environmental protection of plywood is very concerned when people choose furniture. Plywood has great strength and good flexibility. MDF is well-proportioned and suitable for production and processing. It is one of the three major artificial boards.
So what causes the deformation of plywood?
- Deformation caused by the difference in water content in some internal areas.
In the production of plywood, such as particle board scraps and fiber parts of medium density fiberboard, the drying area is uneven, or uneven in the whole process of sizing. In the production of plywood, the veneer coating is uneven, etc. There are differences in water content, the curing of the glue and the evaporation of water content are different, and the stress is asymmetrical, resulting in deformation.
- Improper hot pressing process or deformation caused by the influence of the press itself.
During the whole pressing process of plywood, due to the conditions of the press itself, such as deformation of the pressing plate, insufficient temperature of individual hot pressing plates, or deformation caused by uneven pressure, or improper grasp of the hot pressing process, too high or too low temperature, Deformation caused by excessive pressure, etc.
- Deformation caused by structural asymmetry.
Structural asymmetry is a key factor that causes internal stress in the board. For example, the surface and back layers of medium density fiberboard and particleboard are different in size and size, and the upper and lower sides of the neutral layer of plywood are different in terms of tree species, veneer fiber arrangement orientation, thickness, moisture content, number of layers, and production methods. The board has twist lines, etc., which is also the key reason for warping deformation.
Technology of making high quality plywood from Sinoeuro Machinery
High quality board processing procedure and technology flow chart.
How to make quality furniture board?
Sinoeuro machinery solutions- board size: 1220*2440*3mm/5mm/9/12/18mm,
1. Veneer preparation Section Log sawing- 4ft log debarkder and peeling with auto stacker
Get veneer material Veneer after drying and selected,high quality board,material used is also higher. Core Veneer need to be selected and grade for different quality board.
2. Gluing Section Veneer gluing with 4ft glue spreader and veneer panel after core composing gluing.
3. Composing Core composer from 2ft veneer to 8ft veneer panel board, vertical side veneer composing with scraft jointing for edge grinding of veneer
/ (or directly 8ft veneer in some countries direct peel.)to ensure the veneer thickness is uniform and even.
- Assembly the veneer to be 3 layers 5/7/9/11 layers on your each order required spec.
5. Cold press- pre press for plain board
6. Repair/ Repatching/ Mending the board surface with glue tapes or plastic nails to ensure the surface is flat and even without sag.
7. Plain/base board Hot press
8. Putty and recheck the surface of the board
9.Calibration sanding for board thickness evenness and surface flatness
10.edge trimming saw for 4 sides trimming
11. Cold press again before veneer laminating
12. 2nd hot press- laminating press Put face veneer on the board and press
13. Board polishing and finishing for fine and shining surface for furniture.(Film faced plywood no need polishing sander,but furniture board needs)
14. Finished products inspection and packing,go to warehouse.
Finding one stop solutions,find Sinoeuro,we provide whole plant solutions with factory layout and processing technology for different types and quality of plywood .