Why Do Hot Melt Glue Have Different Colors? | JCT Machinery

JCT provides hot melt glue production line turnkey project.

Factors affecting the color of hot melt glue

1. Raw material color: Some base resins (such as rosin modification, SBC, EVA) are slightly yellow or amber.
2. Tackifying resin: Phenolic modified resin or rosin ester is darker in color, which will cause the finished product to be yellowish.
3. Antioxidant: Added stabilizers such as BHT and IRGANOX are light yellow to brown at high temperatures.
4. Fillers are additives: Some plasticizers, waxes, and ingorganic fillers may make the colloid milky or opaque.
5. Whether it has been bleaches: Raw materials that have been bleaches or refined can improve transparency.

Color	Characteristics	Common uses
Transparent / white	Beautiful appearance, high purity	Electronic products, plastic packaging, fabric lamination, etc.
Yellow / amber	Strong viscosity, wide adaptability, relatively low cost	Corrugated boxes, book binding, labels, etc.
Milky white	Natural color of some APAO glues and polyolefin systems	Sanitary products, non-woven fabrics, baby diapers
Dark yellow / brown	High content of tackifier or general raw material grade	Woodworking, furniture edge bonding, jigsaw puzzles, etc.

Transparent ≠ Better quality. Yellow ≠ Poor performance

• Some high-performance hot melt glue (such as PUR hot melt glue, structural SBC adhesive) are amber or light yellow in color, with excellent bonding strength and heat resistance.
• Transparent adhesives are more suitable for products with high appearance requirements, but may not be resistant to high temperature or aging.

Before producing hot melt glue, the following should be considered:

Materials to be bonded (plastic, paper, metal, etc.)

Bond strength, curing time, temperature resistance

Are there any appearance or color requirements (e.g. white products require transparent adhesive)

Cost and process matching

** JCT can customize the hot melt glue formula for you according to your needs.