Edge sealing hot melt adhesive is a kind of adhesive specially used for artificial plate edge sealing. It is a solvent-free thermoplastic adhesive. Hot melt adhesive is heated to a certain temperature, that is, from the solid state into the molten state, when coated to the wood-based panel substrate or edge material surface, cooling into a solid, edge material and the substrate bonded together.
1, sealing edge hot melt adhesive base material
(1)EVA (ethylene – vinyl acetate copolymer resin) base material hot melt adhesive, this hot melt adhesive can be divided into two types with packing and no packing. EVA as the base material is a common edge sealing hot melt adhesive production technology, its main limitation is poor heat resistance. The ambient temperature of panel furniture sealed with EVA hot melt glue can not be higher than 120°C;
(2) Pol YAMIDE(polyamide) base material hot melt adhesive, this hot melt adhesive has the characteristics of good heat resistance and fast curing, the main disadvantage is that the price is expensive.
(3)HMPU(polyurethane) base material hot melt adhesive, it is a kind of hot melt adhesive with good performance, is the guarantee of high quality plate edge sealing. It is expensive and requires special methods of use.
2, the viscosity of sealing hot melt adhesive
The viscosity of the sealing hot melt adhesive does not directly reflect the performance of the adhesive. In general, the higher the viscosity of the edge hot melt adhesive, the better its initial adhesive strength, but the worse the coating performance. Low viscosity hot melt adhesive coating amount is small, wettability can be better. Some hot melt adhesives with low viscosity and fast curing speed may also have high initial adhesive strength. For the particleboard with poor quality, the edge sealing needs to choose the hot melt adhesive with high viscosity. This is because the hot melt adhesive with high viscosity has poor fluidity and is not as easy to enter the pore of the edge of the particleboard as the hot melt adhesive with low viscosity when coating, so that the hot melt adhesive can be fully coated on the edge of the board.
3, sealing edge of the density of hot melt adhesive
The density of sealing hot melt adhesive is generally 0.95-1.6g/cm 3, the size of the density depends on the amount of filler (the more the filler, the greater the density). Because the plate edge sealing requirements to achieve a certain area of glue, so the density of small filler without hot melt glue per unit length glue quantity is less than the filler hot melt glue. And because of the good bonding performance of the filler hot-melt adhesive, to achieve the same edge sealing effect, the amount of the filler hot-melt adhesive is less than that of the filler hot-melt adhesive is possible. In order to reduce the amount of glue, the edge sealing machine must have a good glue system.
4. Softening point and use temperature of sealing hot melt adhesive
The softening point is an indicator of the heat resistance of the edge hot melt adhesive. The higher the softening point, the less easy the edge hot melt adhesive is to melt. At the same time, softening point is also an important aspect to measure the temperature resistance of panel furniture. In Europe, to the heat-resistant performance of plank seal edge already had a method of detection, also put forward a standard to the heat-resistant sex of board type furniture. France, Germany and Italy and other countries have not large-scale production of low softening point sealing hot melt adhesive, but domestic manufacturers (including Taiwan manufacturers) still produce and supply the domestic market, the reason is that domestic furniture manufacturers and consumers on the panel furniture, especially the heat resistance of kitchen furniture did not pay enough attention. The softening point range of EVA hot melt adhesive is generally between 90-135℃.
The use temperature of hot melt adhesive refers to the temperature of the glue on the cots of the edge sealing machine. Only at this temperature can the hot melt adhesive achieve the best adhesive strength. There is a considerable error between the temperature displayed on some edge banding machines and the actual temperature, so the temperature of the machine should be checked regularly. Edge sealing machine temperature is too high, will make the glue carbonization, smoke phenomenon; Too low, will make adhesive strength drop.
5, edge sealing hot melt adhesive opening time and edge sealing machine feeding speed
The opening time of edge sealing hot melt adhesive refers to a period of time before the edge sealing machine from the beginning of the glue to the edge sealing tape pressed to the substrate, the opening time varies with the different kinds of glue. Edge banding machine feeding speed and opening time is closely related, the two are very important in the choice and use of hot melt adhesive. The fast feeding edge sealing machine must choose the hot melt adhesive with short opening time, otherwise, the hot melt adhesive with long opening time is selected.
For most manual edge banding machines, due to the manual operation of the workers, it requires the opening time of the hot melt adhesive to be long enough to facilitate the edge banding of curved parts. Hot melt adhesive is generally coated on the edge sealing belt. In order to ensure the quality of the edge sealing, the domestic manual edge sealing machine also has the method of double-sided glue coating. Manual edge sealing machine glue tank temperature is generally controlled below 180°C (Germany BRANDT manual edge sealing machine can be heated to more than 200°C), so the use of hot melt adhesive temperature below 180°C. If the manual edge sealing machine is below 0.2mm thick PVC edge sealing strip, then the use of hot melt adhesive temperature must be about 120°C.
Post time: Mar-30-2021