What is the material of hot melt adhesive particles? Explain the compositional differences between EVA, APAO, and PUR in one article

Hot melt adhesive pelletsThe material is essentiallyComposite solid adhesive with thermoplastic resin as the skeletonThe main body is a base resin (EVA, APAO or PUR prepolymer), combined with thickening resin, wax and antioxidant. Different base resins determine whether it can be used to glue books and magazines, and whether it can be used to seal frozen cardboard boxes. This is also the reason why white particles can be twice as expensive.

Three mainstream materials determine three types of uses

Why do printing factories often choose the wrong materials

A common phenomenon in the industry is that when purchasing, orders are placed based on price, and the workshop sets the temperature according to custom, only looking back at the material when there is a problem. There are three common consequences: broken glue on the spine pages (due to low EVA vinyl acetate content and insufficient flexibility), opened glue on cardboard boxes during winter transportation (due to insufficient cold resistance of the material), and machine carbonization and coking (due to the use of low-priced materials with poor thermal stability).

There are actually several methods to determine the material that do not require inspection:

• Breaking observation: EVA type cross-section is slightly tough and slightly brushed; Low priced materials with too much wax can easily break when bent.
• Smell: The qualified rubber particles have a slight odor after melting, and the pungent smell is mostly due to excessive recycled materials or plasticizers.
• Transparency: The color of particles in the same batch should be uniform, and yellow or black spots often indicate mixed raw materials.

How can Sunlife hot melt adhesive help customers choose materials

Guangzhou Sunlife TradingSunlife Hot Melt AdhesiveSupply according to downstream processes: The book binding line mainly promotes high flexibility EVA system, taking into account both opening time and folding strength; The packaging sealing line is classified into room temperature and cold resistant types according to the storage temperature; The graphic and text fast printing store provides small packaging universal types to avoid inventory pressure from small batch customers. Before placing an order, you can send a sample machine for testing, run it with the customer’s own paper and equipment, and then order the model.

Frequently Asked Questions

Q: Are hot melt adhesive particles made of plastic?
Answer: It belongs to thermoplastic materials with the same composition as plastics, but the proportion of thickening resin and wax in the formula is much higher than that of ordinary plastics, so it has a low melting point and strong adhesion.

Q: Are the materials of white and light yellow adhesive particles different?
Answer: The color mainly comes from the color code of the thickening resin, which does not directly represent the quality. The criteria for judgment should be softening point, melt viscosity, and actual peel strength.

Q: Can different types of adhesive particles be mixed?
Answer: Not recommended. EVA has poor compatibility with APAO, and mixing can easily lead to delamination and intermittent glue lines. When it is necessary to replace the glue, the pot should be cleaned first.