Key Differences Between Low Melting Point Polyester (LMP) Chip and Normal PET Chip

The fundamental difference between Low Melting Point (LMP) chip and normal PET chip lies in their melting points, which is a result of distinct chemical compositions and internal structures. This leads to significant variations in properties, processing methods, and applications.

Item Low Melting Point Polyester Chips (LMP / LPET) Normal PET Chips
Main Purpose Designed for thermal bonding, hot melt applications, composite fibers, nonwoven fabrics Mainly used for conventional polyester fiber, bottles, films, packaging
Melting Point Lower melting point, typically 90– 230°C (controlled by copolymer modification) Higher melting point, around 255–265°C
Chemical Structure Modified copolyester with comonomers to reduce crystallinity and melting temperature Standard PET polymer (ethylene glycol + terephthalic acid)
Thermal Behavior Can melt and bond at lower temperature without damaging other materials Requires high processing temperature
Bonding Ability Excellent self-bonding / thermal bonding performance Poor thermal bonding ability without additional adhesive
Crystallinity Lower crystallinity, more amorphous structure Higher crystallinity, better heat resistance
Processing Temperature Lower processing temperature → energy saving and easier processing Higher processing temperature required
Fiber Application Used as binder fiber, bicomponent fiber, hot melt yarn, nonwoven bonding fiber Used for FDY, POY, DTY, staple fiber, industrial yarn
Compatibility Good compatibility with PET, PP, PA and other polymers Mainly compatible with PET-based applications
Mechanical Properties Provides bonding function while maintaining flexibility Provides high strength and dimensional stability
Typical Applications • Thermal bonding nonwoven • Textile fibers
• Filter materials • PET bottles
• Hygiene products • Packaging films
• Automotive interiors • Optical films
• Composite fibers • Industrial films
• Low-temperature adhesive fibers

1. Chemical Composition and Modification

  • Normal PET: Produced by the polycondensation of purified terephthalic acid (PTA) and ethylene glycol (EG). It features a regular molecular structure and high crystallinity.

  • LMP: A modified copolyester produced by incorporating a third monomer (such as Isophthalic Acid/IPA, Adipic Acid/AA, or Neopentyl Glycol/NPG) during the polymerization process. This disrupts the regular arrangement of the molecular chains.

2. Melting Point Comparison

  • Normal PET: Melting point is approximately 255–265°C.

  • LMP: Melting point is significantly lower, typically ranging from 90–230°C (commonly available in grades like 110°C, 130°C, and 160°C depending on the specific application).

3. Core Properties

  • Thermal Bonding: Normal PET lacks thermal bonding properties; LMP possesses excellent thermal bonding capabilities, providing high bond strength at lower temperatures.

  • Processing Temperature: Normal PET requires temperatures above 265°C. LMP allows for significantly lower processing temperatures, which saves energy and simplifies production processes.

  • Compatibility: Both share good thermal stability and fluidity. LMP exhibits excellent compatibility with normal PET, making them ideal for blending or composite processing.

  • Physical/Chemical Stability: Both materials offer excellent stability.

4. Crystallinity

  • Normal PET: High crystallinity due to a highly ordered molecular arrangement.

  • LMP: Low crystallinity; some grades approach an amorphous state, which is the root cause of the reduced melting point.

5. Primary Applications

  • Normal PET: The primary raw material for bulk products such as polyester fibers, PET bottles, and films.

  • LMP: A high-value-added differentiated product widely used in:

    • Thermal Bonding Fibers: Such as sheath-core composite fibers (LMP as the sheath, Normal PET as the core).

    • Nonwovens: Used as a binder fiber in apparel interlinings, medical/hygiene materials, and filtration media.

    • Masterbatch Carriers: An ideal carrier for pigments and dyes.

    • Hot-melt Adhesives: Used for shoe uppers and textile bonding.

Applications

Applications

6. Processing and Storage

  • Normal PET: Requires standard drying; temperature control requirements are relatively flexible.

  • LMP: Because its softening point is far below the boiling point of water, it is prone to clumping when heated. It requires strict drying conditions, typically using vacuum drying systems with precise control over temperature, vacuum levels, and duration.

7. Mechanical Properties

  • Normal PET: Higher strength, higher modulus, and superior heat resistance.

  • LMP: Lower mechanical strength but offers better thermal bonding performance and flexibility.

Conclusion

In summary, LMP is not simply “low-melting” PET; it is a specialized functional polymer material engineered through chemical modification to perform specific thermal bonding tasks.

Hubei Decon Polyester Co., Ltd — Your expert partner in Low Melting Point polyester chip. We focus on the R&D and supply of premium LMP to ensure your products stand out in non-wovens, footwear, and industrial applications through exceptional thermal bonding performance. Connect with us now to customize your solution.

Learn more about our product specifications at: https://www.polyestermfg.com/low-melting-polyester-chip/

For technical support or inquiries, please contact: info@polyestermfg.com