The key to the firm bond between interlining and fabric lies in the hot-melt adhesive coated on its surface and its coating morphology.
1. Common Types of Hot-Melt Adhesives
- PA (Polyamide / Nylon Adhesive): Most widely used, offering excellent dry-cleaning resistance, a soft handfeel, and a moderate bonding temperature.
- PES (Polyester Adhesive): Features outstanding wash resistance, making it exceptionally suitable for workwear or outdoor apparel that requires rigorous industrial laundering.
- HDPE (High-Density Polyethylene Adhesive): Offers relatively low cost, primarily used for standard non-woven interlinings.
- EVA (Ethylene-Vinyl Acetate Copolymer): Features a lower melting point and fast bonding speed, but has weaker high-temperature and wash resistance.
2. Coating Forms and Processes
- Scatter Coating (Powder Scatter): Hot-melt adhesive powder is scattered directly onto the base fabric and heat-cured. The adhesive dots are randomly distributed with a heavier handfeel, mostly applied in non-woven interlinings or mid-to-low-grade woven interlinings.
- Double-Dot Coating: An advanced international process. A layer of base paste (undercoat) is first printed onto the base fabric, followed by a layer of hot-melt adhesive powder superimposed on top.
- Core Advantages of the Double-Dot Process：
- Completely prevents hot-melt adhesive from bleed-through (strike-through) to the front side of the fabric during fusing.
- Features highly uniform adhesive dots, a soft handfeel, high peel strength, and exceptional dry-cleaning and washing performance.