Two days ago, a client said that many of the plywood he got were delaminated in the middle and the quality was very poor. He was consulting me about how to identify the plywood. I replied to him that the products are worth every penny, the price is too cheap, and the quality will not be much better.
I gave that client a list of frequently asked questions about plywood and analyzed the production of plywood.
The following is part of the content
1. Cracks: Reasons: panel cracks, glued board has cracks. Preventive measures: When screening (when selecting boards), pay attention to pick them out, screen non-destructive plastic boards, and arrange them neatly.
2. Overlap: Reason: plastic board, dry board, the filling is too large (the interval is too large (too small). Preventive measures: fill the hole according to a certain size, and cannot exceed the original hole.
3. White leakage: Reason: It is not uniform enough when the red oil is passed once or twice. Preventive measures: During the inspection, manually add red oil.
4. Explosion board: Reason: wet board (plastic board) is not dry enough. Precautions: Inspect wood core boards when shipping.
5. The board surface is rough: Reason: fill the hole, the wood core board knife tail is thinner. Preventive measures: try to choose a flat wood core board.
The board core (single board) is generally divided into: 4A grade (whole core and whole board), 3A board core with a small number of holes and rotten board. The veneer should pay attention to the uniform thickness, so that it is not easy to warp (slope), and the dry and wet properties are good, so it is not easy to peel (bubble). The dough is generally 50-60 filaments, less than 30 is easy for the board to peel. The thicker the dough, the smoother the surface of the board, the less transition (carbonization), and the plywood is not easy to be torn when demoulding, and the surface effect is good, and the number of turnovers can also be guaranteed.
The pressure of the press is generally about 180-220, the hot pressing is more than 13 minutes, and the temperature is 120-128 degrees. If the pressure of the press is not high enough, the adhesion of the plywood is not good, and cracked, not well glued. The amount of glue for a single layer should be close to 0.5kg, and the amount of glue is small, and the plywood is easy to burst and delaminate.
There are many holes in the core of the sawing plywood. On the one hand, the raw materials are inferior, and the bad board is used as a good board. On the other hand, the production workers are not skilled in typesetting, and the gap between the veneer is too large.
The advantage of poplar core board is that the price is relatively cheap. Disadvantages: The density of the veneer is small, the hardness is average, and the board quality is average.
The advantage of eucalyptus core board is better quality (more flexible). Disadvantage: slightly expensive
The south is rich in eucalyptus, and Guangxi concentrates on the production of eucalyptus core plywood
The north is rich in poplar, and there are many poplar core plywood in Shandong and Jiangsu.
Related parameters of our products:
Flour content 25%-35%
A single layer (2 sides) contains about 0.5kg of glue
A single piece of dough is 50 silk, and the one above 13mm is 60 silk. (pine veneer)
Melamine content 12%-13%
Cold Press 1000 seconds, 16.7 minutes
1.3 Hot pressing for about 800 seconds 1.4 Hot pressing for more than 800 seconds 13.3 minutes
Processing method: hot pressing
The press is three (cylinder) top 600 tons, pressure 200-220, boiler steam
Hot pressing temperature 120-128 degrees divided into three sections
Raw material 2mm-2.2mm, whole core board
Post time: Aug-01-2022