Hot melt adhesive properties

Compared with thermosetting adhesives, solvent based and water-based adhesives, hot melt adhesives have many advantages, mainly manifested in the following aspects:

1) Quick adhesion, can cure in seconds, suitable for continuous and automated high-speed operations, can effectively improve productivity and reduce costs.

2) Free of solvents, harmless to human health, pollution-free to the environment, green and environmentally friendly. There is no risk of poisoning or fire, nor is there any deformation, misalignment, or shrinkage of the adhesive caused by solvents. Transportation and storage are convenient and very safe.

3) No drying process is required, and the bonding process is simple. transport

4) It can be used to bond various materials, in addition to porous materials such as wood and paper, it can also be used to bond some non poly L-shaped materials (such as plastic, glass, and metal) as well as materials such as wax paper and carbon paper that are difficult to bond with other adhesives. The surface treatment is not strict, and the economic benefits are good.

5) It can be repeatedly melted and bonded. For example, if the hot melt adhesive applied to the object being bonded cannot be bonded due to cooling and solidification, it can be reheated for bonding operation. Therefore, it is particularly suitable for bonding components with special process requirements, such as the restoration of some cultural relics.

6) It can be made into blocks, films, strips, or granules, making packaging, storage, transportation, and use extremely convenient.

Of course, hot melt adhesive also has some drawbacks, mainly manifested in the following aspects:

1) The heat resistance is poor because the main component of hot melt adhesive is thermoplastic resin, so the heat resistance depends on its softening point. The heat resistance of hot melt adhesive commonly used for product end face bonding is less than 100 tons (usually 50-100 tons), so products after edge sealing should not be exposed to long-term sunlight or close to high-temperature places.

2) Special equipment such as a hot melt gun is required for melting and gluing.

3) Due to its high viscosity after melting, it has poor wettability and is difficult to apply evenly, making it unsuitable for large-area adhesive coating.

4) Affected greatly by climate, the wettability is poor in winter, the solidification slows down in summer, and the melting time is shortened due to strong winds. Hot melt adhesives are gradually replacing solvent based adhesives and receiving more attention due to their advantages of being pollution-free, suitable for automated production lines, fast operation speed, and low cost. The performance of hot melt adhesive is gradually improved and enhanced through techniques such as grafting modification, blending modification, and reaction curing. New varieties and processes of hot melt adhesive are also constantly developing, demonstrating a promising future.