Low melt polyester staple fiber (LMPSF) is a type of polyester fiber engineered with a lower melting point than conventional polyester, typically ranging from 110°C to 180°C. Unlike regular polyester staple fiber (PSF) which softens around 250-260°C, low melt fiber is designed to melt and bond at a much lower temperature. This unique characteristic allows it to act as a thermal binder, fusing with surrounding fibers when heated, without requiring additional adhesives, glues, or chemical bonding agents.
Key Point: The fiber bonds materials together using only heat — no chemical adhesives required.
Low melt polyester staple fiber is typically produced through a bicomponent or co-polymer extrusion process. In bicomponent (sheath-core) construction, the outer sheath layer is made from a co-polyester with a lower melting point, while the core retains the higher-melting standard PET structure for strength. When the fiber is exposed to controlled heat during processing, only the sheath melts and softens, allowing it to flow and bond adjacent fibers together while the core maintains the fiber's structural integrity and shape.
Sheath
Low melting co-polyester layer
Core
High-melting PET for strength
Heat Activation
Sheath melts and bonds fibers
| Grade | Melting Point | Typical Use |
|---|---|---|
| LM110 | ~110°C | Fast, low-energy bonding |
| LM130 | ~130°C | General padding and wadding |
| LM150 | ~150°C | Cushioning and panels |
| LM180 | ~180°C | Higher-strength composites |
Low melt polyester staple fiber offers several notable benefits over traditional bonding methods. It eliminates the need for liquid adhesives, reducing chemical odor and environmental impact. The fiber provides excellent resilience, lightweight bulk, and good thermal insulation. Products made with low melt fiber tend to be softer to the touch, washable, and more durable over repeated use, since the bonding occurs at the molecular level rather than relying on a separate glue layer that can degrade over time.
This fiber blends easily with regular polyester staple fiber, cotton, or other natural and synthetic fibers in carding, garnetting, and needle-punching processes. After forming the desired shape or thickness through carding and lapping, the material passes through a heat oven, where the low melt component activates and binds the structure into a stable, self-supporting form.
Tip: Blending ratios of 20-50% low melt fiber are common, depending on the required firmness and bonding strength of the finished product.
Low melt polyester staple fiber is widely used in pillow and cushion filling, mattress padding, quilt batting, automotive interior panels, sound and thermal insulation materials, furniture cushioning, and nonwoven wadding products. It is also used as a binder fiber in composite panels, geotextiles, and filtration media, where consistent shape retention and chemical-free bonding are essential requirements.
