EVA hot melt adhesive is a water-free, solvent-free solid thermoplastic polymer. Under normal temperatures, the hot melt adhesive remains a solid, melting into a flowable and adhesive liquid upon heating to a certain temperature.
The primary component of hot melt adhesive is a resin formed by copolymerizing ethylene and vinyl acetate under high pressure, which determines the fundamental properties of the adhesive. It is further enhanced with thickening agents (rosin) to increase bonding strength, wax to regulate the adhesive fluid's viscosity and solidification speed, and a small amount of antioxidant to slow down the aging process of the hot melt adhesive.
Key Features of Hot Melt Adhesives:
The small hot melt chamber contains no water or solvents. It is solid at room temperature and becomes a liquid with good flow properties at high temperatures, and is non-flammable. It is harmless to humans.
② Fast solidification rate. It solidifies within 7-30 seconds after leaving the adhesive pot, without the need for drying or additional curing agents. It fully meets the requirements of high-speed automation, thus becoming the adhesive material for the flat-bound wireless adhesive production line.
Hot melt adhesives are capable of bonding a variety of materials, with particularly strong adhesive power between porous homogenous materials. The cured adhesive film offers good flexibility.
④ Hot melt adhesive can be reheated and reused, and it is highly resistant to chemicals.
⑤ Non-absorbent, moisture-resistant, excellent water resistance, easy to hot press, adhesive bonding, and thermal insulation.
⑥ Excellent shock absorption and cushioning capabilities.
The adhesive features rapid curing, low pollution, strong adhesion, with a layer that offers a balance of flexibility, hardness, and tensile strength.
Standard EVA packaging bags are milky white and semi-transparent; the ones with higher transparency are due to the excessive addition of PE material within the material, which enhances the luster of the packaging. However, adding too much PE material greatly increases the difficulty of sealing the zipper bag with the zipper during heat pressing, making it easy to fail to seal properly. Moreover, some merchants to save costs may add some inexpensive PE raw materials to reduce production costs.
