Selection and Judgment Method of Wood based Panel and Wood Glue
Guide: The direct way to judge the advantages and disadvantages of wood-based panels and wood adhesives is to make tests and comparisons. Wood panel and wood glue are required for wood splicing, furniture, wood doors, wood appliances manufacturing, assembly, bonding, etc.
At present, there are many fake and inferior wood-based panels and wood glue on the market. The price of inferior wood-based panels and wood glue is low, and they are often misused by some manufacturers. Once inferior wood-based panels and wood glue are used, they often cause significant losses or the price of glue is low but the comprehensive cost is high.
The direct way to judge the advantages and disadvantages of wood-based panels and wood adhesives is to test and compare them.
1： It seems that the glue with good appearance is even both inside and outside during the shelf life, and the colloid is fine without particles and roughness. Poor quality glue often has water sample delamination on the surface or a large amount of mud like sediment at the bottom, and the colloid has obvious roughness. It is normal for glue to occasionally appear a small amount of water like substance or a small amount of precipitation.
2： It can be seen that the bulk wood-based panels and wood adhesives are mainly composed of high molecular polymers, polyvinyl alcohol (PVA), fillers, additives, water, etc. Low price wood-based panels and wood adhesives will use a small amount of high molecular polymers, and use a large number of fillers to reduce costs. Because the density of fillers is far greater than the polymer density, the volume of glue with the same weight will be much less. For example, if a standard ton packaging tank is also 1200 kg, the low price glue will appear insufficient, and the upper part of the tank is very empty. Glue painting is volume. The larger the glue volume is, the larger the painting area will be. The more fillers, the greater the resistance of glue after the reaction between glue and cross-linking agent, and the poorer the leveling property. The wood grain can be covered by rolling coating for many times, and the amount of glue will be significantly increased, as we often say, “It is cheap to buy, but expensive to use”.
3： In order to increase the sales of wood-based panel and wood glue, or to solve the problem of high filler precipitation, merchants with poor viscosity added thickeners in wood-based panel and wood glue, and lied to customers that the higher the viscosity, the better the filling effect and the better the quality. In fact, water-based wood-based panel and wood glue basically have no filling effect. The panel and assembly surface must fit together to make a good product. If the gap exceeds ± 0.1mm, even the best glue will fail to bond. The more viscous the glue is, the more it will be used. Some glue will thicken quickly after reacting with the cross-linking agent, and the more glue will be used and wasted.
4： It seems that the better the glue coating thickness is, the lower the glue coating resistance of wood-based panel and wood glue is, and the glue coating is smooth and smooth. Basically, it can be rolled in place at one time, and the glue coating surface is smooth and wet. The coating resistance of low-quality wood-based panels and wood glue is large, which requires repeated roll coating. The glue is thick, not smooth and dry. Good assembly or tooth bonding glue is easy to be applied into the tenon or tooth position. The machine can adjust the gear clearance to a small size without missing coating. On the contrary, the gear clearance needs to be adjusted to a large size to ensure that the glue is full.
5： Take the same weight of glue for test, compare the actual size of glue coating area, and calculate the glue coating amount per unit area. Good splicing glue can paint more splicing areas. If the glue price is 10% different, the glue coating amount per unit of glue coating area will be 10~40% different, which is what we often say, “It’s expensive to buy, but it’s fairly used.”.
6： Detection of glue solid content The effective solid content of water-based wood-based panels and wood adhesives is determined by the number of high polymer. Bad businesses will reduce costs and increase solid content by using a large number of fillers. They falsely claim that the higher the solid content, the better the glue quality. The solid content produced by the filler is false solid content. Therefore, it is not said that the higher the solid content, the better the glue.
7： For the wood with higher density of glue water resistance and weather resistance, the boards spliced with glue shall withstand blistering or boiling in the morning and evening when the humidity changes greatly, and then be baked for testing. Otherwise, the splicing surface is easy to crack, causing serious losses, which is the biggest waste of factory costs. The high polymer used in good glue has excellent water resistance and baking resistance. The price of raw materials required must be higher than that of those that are not resistant to water and baking. The synthesis process is also complex and the processing cost is also high. Water resistance and weather resistance can be evaluated according to Japanese JAS standard, European EN204/205D4 standard and cold and hot cycle test.
8： After testing the solvent resistance of glue and spraying paint on the assembled plate, the seam or tooth joint may be uneven, which is because the glue is not solvent resistant and is swollen. The spliced boards can be soaked in Tianna water (banana water) to see if they are swollen to test the solvent resistance of glue. The solution resistance of low-end wood-based panels and wood adhesives is poor. 9： The raw materials used for wood-based panels and wood adhesives with good glue environmental protection indicators are high value, environmentally friendly, and safe for sizing workers and consumers. In particular, preservatives and plasticizers are environmentally friendly. Low quality glue uses cheap formaldehyde anti-corrosion and plasticizer harmful to human body, not to mention the problem of exceeding the standard of total organic volatile matter. How do you choose? It mainly depends on the valuable environmental protection certificates of glue, such as the national standard inspection report, the “China Environmental Labeling Product Certification Certificate” issued by the State Environmental Protection Administration, which is commonly called the “Green Ten Rings” sign. When purchasing, ask for the certification report from the manufacturer’s sales personnel, or check the authenticity through official channels through the certificate number, or take samples from the production glue, and entrust a third-party testing agency to test the environmental protection and harmful substance content of the glue. In addition, when selecting wood-based panels and wood adhesives, we also need to see whether the product packaging is standardized and whether it is “three no products”. After knowing the above information, will you just choose the products with low prices?
