Traditional hot melt sealing technology

The edge part processing methods of the panel parts mainly include the Finishing method, the Edge method, the Folding method and the Edge banding method, and the Edge banding method is most widely used in the production of panel furniture. The edge banding method is to press edge sealing strip on the edge of plate component by adhesive, which not only protects the sheet from moisture intrusion, but also increases the visual aesthetic of the panel furniture, which is practical and aesthetic.

The traditional edge-sealing technology uses a linear edge banding machine or a curved edge banding machine to uniformly apply the adhesive heated to the molten state to the edge of the sheet by a rubberizing roller, and then press the edge strip on the sheet by a pressure roller. After the adhesive is cured and hardened, the bonding of the sheet and the edge strip is achieved. Most edge banding machines currently use hot melt adhesives. The glue is solid in a normal temperature state, is a fluid in a heated and molten state, and is rapidly hardened in a cooling state, thereby achieving edge sealing. The traditional edge-sealing technique uses a roll coating or a spray coating method to apply hot melt adhesive between the panel and the edge strip to complete the edge sealing of the panel. The hot melt adhesives used in traditional edge-sealing technology include Polyamide hot melt adhesive, EVA hot melt adhesive, Polyolefin hot melt adhesive, PUR hot melt adhesive, etc. The two most commonly used ones are here: EVA hot melt adhesive and PUR hot melt adhesive.

EVA hot melt adhesive edge banding

EVA (ethylene-vinyl acetate copolymer) base material hot-melt adhesive edge sealing is the most common and the most mature edge-sealing technology in the country. This glue has strong versatility and can bond almost all edge-sealing materials. It is praised by the industry as “universal edge banding glue”.

However, EVA glue has some defects, and the environmental requirements are relatively high when used, and the quality of the edge-sealing product also has hidden dangers. EVA adhesives have poor heat resistance, and the ambient temperature cannot be higher than 120 °C when used. EVA glue is limited to physical solidification, has a small viscosity, and has the risk of falling off the edge strip in subsequent use.

PUR hot melt adhesive edge banding

In addition to EVA glue, another common use is polyurethane (PUR glue). It has better solubility, cold resistance and water resistance relative to EVA glue. Because PUR glue has physical solidification and chemical solidification, That is, the glue will not only form a physical solidification by cooling to reach the initial strength, but also chemically react with the moisture in the air, the moisture on the surface of the plate and the moisture on the surface of the edge band to form a molecular polymerization between the edge strip and the plate. Therefore, it will not dissolve under the action of cold, heat and water.

The technology is widely used at home and abroad, but there are inevitably some problems. For example, the curing time of the glue is long. Generally, the physical solidification takes only a few seconds in the cooling stage, but chemical solidification generally requires 2 to 5 days to fully cure, to achieve the final bonding strength, and this glue storage requirements are high, must be stored in a sealed container, once exposed to air, it will chemically react with the moisture in the air, thus affecting the quality of the edge .

#KNOW MORE#

More Hot melt PA adhesives Choices