Low Melting Point Yarn (LMPY) selection is primarily governed by the thermal threshold of the carrier substrate and the specific energy requirements of the hot-press bonding cycle. The two most utilized specifications-85°C (typically Polyamide-based) and 110°C (typically Polyester-based)-serve distinct roles in textile lamination. The 85°C variant is engineered for heat-sensitive materials requiring low-temperature activation to prevent shrinkage or thermal degradation, while the 110°C variant provides higher thermal stability and enhanced tensile strength for heavy-duty industrial composites.
Technical Specification Comparison: 85°C vs. 110°C
The mechanical and thermal properties of these filaments dictate their deployment in high-performance textile manufacturing.
| Parameter | 85°C Low Melt Yarn (PA) | 110°C Low Melt Yarn (PES) |
| Polymer Base | Co-Polyamide | Co-Polyester |
| Melting Point Range | 85°C - 95°C | 110°C - 120°C |
| Standard D/F Specs | 20D/3F, 30D/10F, 75D/24F | 50D/18F, 100D/36F, 150D/48F |
| Peel Strength (N/cm) | 35 - 50 N/cm | 40 - 60 N/cm |
| Elongation (%) | 35% - 55% | 25% - 40% |
| Shrinkage (at 100°C) | < 3% | < 5% |
Direct factory sourcing for GRS-certified low-melt filaments.
Request Bulk Quote & Technical TDS
Thermal Sensitivity and Substrate Matching
Selecting the incorrect melting point results in either incomplete bonding (low temperature) or substrate damage (excessive heat).
1. The 85°C PA Advantage (Low-Temp Activation)
85°C Hot Melt Yarn is the industry standard for bonding heat-sensitive materials such as natural leather, ultra-thin TPU films, and delicate silk blends. Because activation occurs significantly below the glass transition temperature (Tg) of most synthetic carrier fibers, it preserves the macro-porosity and hand-feel of the fabric without causing "stiffening" outside the bond zone.
2. The 110°C PES Advantage (Thermal Stability)
For 110°C 110C yarn applications, the focus shifts to durability. This specification is preferred for polyester-based 3D fly-knit uppers and automotive textiles. The higher melting point ensures that the bond remains stable during subsequent high-temperature processes, such as sublimation printing or secondary heat-setting, which often exceed 100°C.
Energy Efficiency and Process Optimization
Energy consumption in Tier-1 footwear facilities is a critical KPI. Lowering the activation temperature from 110°C to 85°C can reduce the energy expenditure of a continuous lamination line by approximately 12-18%.
Dwell Time: 85°C yarn typically requires 10-12 seconds of dwell time at 2.5 bar pressure.
Dwell Time: 110°C yarn requires 15-20 seconds at 3.5 bar pressure to ensure full molecular diffusion into the substrate interstices.
Sustainability and Certification Compliance
Both WithTech 85°C and 110°C variants are Oeko-Tex Standard 100 certified, ensuring zero hazardous chemical migration. We also offer GRS certified recycled versions, enabling brands to meet circularity targets without compromising on the 50N+ peel strength requirements.
FAQ
Q1: What is the MOQ for custom-colored 110°C low melt yarn?
For raw white, the MOQ is 50kg. For dope-dyed custom colors to match specific footwear palettes, the MOQ is 500kg per specification to ensure color fastness and consistency.
Q2: Can I mix 85°C and 110°C yarns in the same knit structure?
While technically possible, it is not recommended for uniform bonding. The 110°C yarn would remain in a solid state when the 85°C yarn is fully activated, leading to inconsistent structural support and localized delamination.
Q3: How do I verify the GRS Transaction Certificate for my shipment?
All recycled polyester and nylon shipments from WithTech include a batch-specific Transaction Certificate (TC) issued by the certification body. This verifies the post-consumer or post-industrial waste content of the 110C yarn.
