Hot melt adhesive is actually a large category. Basically, all adhesives that are solid at room temperature and need to be heated to melt into a liquid state can be called hot melt adhesives. Hot melt adhesive has fast bonding speed, does not contain solvents, is harmless to the human body, is easy to transport and store, can be melted and bonded repeatedly, can bond a variety of materials, has strong chemical resistance and good electrical properties, so it is widely used in all walks of life. According to the classification of ingredients, hot melt adhesives are mainly divided into 5 types as following:
Polyethylene hot melt adhesive is a hot melt adhesive made by polymerizing ethylene with a small amount of α-olefin or other monomers. It is characterized by good bonding performance, low price, and easy bonding to porous surfaces. It is widely used in carton and carton packaging, food packaging container sealing, non-woven fabric production, carpet patchwork, automobile carpet backing, clothing interlining bonding, etc.
Polypropylene hot melt adhesive is a thermoplastic resin polymerized from propylene, mainly atactic polypropylene. Its characteristic is that it has good adhesion to the surface of low surface energy materials. It is often mixed with low molecular polyethylene or crystalline polypropylene to improve the curing speed and temperature resistance. Mainly used for bonding paper packaging, carpet backing, paper lamination, polypropylene plastic, etc.
EVA hot melt adhesive is an ethylene-vinyl acetate copolymer hot melt adhesive, which is produced by high-pressure bulk polymerization or solution polymerization of ethylene and vinyl acetate enzyme. It has excellent adhesion, softness, heating fluidity, cold resistance, chemical resistance, weather resistance and other characteristics. It is widely used in book binding, wood processing, packaging, canning, shoemaking automation operations, paper product processing and other industries.
Polyester hot melt adhesive: Polyester is the general name for polymers containing ester groups in the main chain. It is divided into unsaturated polyester and heat saturated polyester. As a hot melt adhesive, it needs to be prepared with saturated polyester. Polyester hot melt adhesive has excellent electrical insulation and good bonding strength, and has good impact resistance, water resistance, heat resistance, cold resistance, medium resistance and elasticity, and can bond a variety of materials. Widely used in clothing, electrical appliances, shoemaking, and construction industries.
Polyamide hot melt adhesive is a polymer with repeated amide groups as its molecular backbone. It has excellent heat resistance, cold resistance, electrical properties, oil resistance, chemical resistance and medium resistance. It is odorless and colorless, can be quickly cured, and can bond a variety of metals and non-metals. In addition, the hot melt adhesive is very stable at high temperatures (149°C).
How to choose the appropriate adhesive for application? There are 4 steps:
1. Determine the bonding method, potting or bonding, large area bonding or small area bonding, that is, determine the specific form of bonding.
2. Determine the bonding material. Bonding materials include metal, plastic, wood, fabric, etc. For pure plastics, there are also high-surface materials and low-surface energy materials. In addition, it is also necessary to determine whether the surface of the material needs to be treated. Different glues have different bonding strengths and will bond differently to different surfaces. You need to choose the appropriate glue based on the material.
3. Determine the process requirements. In the current process steps, if there are any changes that need to be bonded, whether enough curing time has been reserved, etc. Different glues have different opening times and curing times, and the appropriate product needs to be selected based on the process.
4. Determine the application environment of the terminal, whether it is an outdoor application or an indoor application, what kind of aging resistance requirements are required, whether it needs temperature resistance, flame retardancy, etc.
Here is our EVA hot melt glue sticks for your reference, which diameter is 7mm-11mm, and the length could be customizable, and it could be super transparent and soft. Besides, we also could provide hot melt glue gun.
Post time: 2023-12-29 15:10:42