Causes: 1. Poor quality of glue (e.g., mildew, etc.), 2. High moisture content.
Solution: 1. Large area, not easy to repair.Tear off the veneer, scrape off the glue, and re-glue;2. The water content of the veneer should be controlled between 12%-14%.
Causes: 1. The area is not coated with glue, 2. The pressing time is too long, the glue is coking 3, the moisture content is not even.
Solution: 1. Glue and press evenly;2. Use the sharp cutting knife to cut the wood grain or use the thick head syringe to inject the glue into the bubble, then press the iron flat;When the bubble area is large, it can remove the veneer, scrape the residual glue, choose the close single board, and close the patch, the water content of the single board or core should be uniform.
3.Film faced plywood common problem: the surface of adhesive plaster is uneven.
Causes: 1. The substrate itself is not smooth;2. The thickness of the adhesive layer is uneven, and the extra glue is not extruded when pressing.
Solution: 1. It is difficult to repair. When serious, the veneer can be re-planed and the surface of the part is trimmed.2. Press the excess glue to form a thick and uniform rubber layer.
Causes: 1. Excessive glue solution and excessive glue coating;2. The veneer thickness is not up to standard;3. Single board material structure (catheter is too large);4. High water content in single board;5. The adhesive pressure is too high.
Solution: 1. Adjust the viscosity and glue amount of adhesive2. Thin wood with a thickness of 0.6mm can be used to avoid the penetration of glue;3. Selected tree species with smaller catheters;4. The water content of the single board should not be too high. After the wet cloth is cleaned, it should be naturally dried and then paste.5. Extend the time of aging, the pressure of adhesive plaster should be controlled , and the light can be scraped or ground off by the knife;The serious man resection the veneer.
Causes: 1. Improper mixing ratio of adhesive;2. High pressure temperature and pressure;3. The veneer thickness is too thin and the quality is poor;4. The water content of the single board is too high, and shrinkage after drying.
Solution: 1. Adjust the mixture ratio of adhesive (increase UF, use curing agent) and improve the water resistance of glue solution;2. Reduce hot pressure temperature and pressure, spray water after discharge, and stack the plates face to face to reduce water evaporation;3. Use a slightly thick wood or a buffer layer between the thin wood and the base material (a layer of paper), and pay attention to the texture direction of the adhesive tape;4. The moisture content of thin wood should not be too high;5. Select the base material that meets the requirements.
Causes: the wood itself contains oil, lipid, waxy, tannin and pigment.
Solution: resin, grease can be used alcohol, ethyl ether, benzene and acetone etc. Solvent erasing, also can use 1% caustic soda or sodium carbonate to wipe with clean water first;The pollution of tannin, pigment and iron ions can be erased by hydrogen peroxide or 5% oxalic acid.
Causes: 1. The cutting knife is not fast when the plate is made, and it is not straight and tight;2. Large moisture content and drying shrinkage of thin wood;3. Improper viscosity of glue solution.
Solution: 1. The cutter must be sharp;The veneer is as tight as possible, but the central part is loose, not tight or joint.2. The water content should be controlled in a single board.3. Adjust the viscosity of adhesive (increase UF) and glue amount 4, reduce the hot pressure temperature.
Causes: 1. Improper mixing ratio of adhesive;2. Improper thermal pressure conditions;3. The surface of the table is not symmetrical;4. Large water content and drying shrinkage.
Solution: 1, the decrease of UF glue mixing proportion make rubber soft 2, moderate levels after hot pressing conditions, hot pressing and piled pressure heavy block 3, table on the back of the glue stick to use veneer should comply with the principle of symmetry and note glue stick texture direction of 4, moisture content of veneer is unfavorable and exorbitant.
Causes: 1. The veneer thickness is too thin;2. Uneven tone of base material.
Solution: 1. Apply a slightly thicker veneer or stick to the base material with the same color paper;2. Substrate coloring or adding a small amount of colorant to the adhesive.
10.Film faced plywood common problem: surface indentation.
Cause: the veneer surface has sundry or the base material surface has the glue mark and so on.
Solution: the sundries on the veneer should be cleaned in time and the board should be kept clean.
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Jiangsu Senso Building Materials Co.,Ltd. (SENSO) is one of largest manufacturer of plywood and related products in China, which was founded in 1995 with 6 subsidiaries. We are now enjoying 62 production lines of film faced plywood ,commercial plywood and LVL.......More information