Types of Fusing for Garments

Garment manufacturers use four principal fusing methods — single fusing, reverse fusing, sandwich fusing, and double fusing — to apply interlining to fabric. Each method addresses different production requirements based on garment type, fabric weight, and performance specifications. Selecting the correct fusing technique directly affects the quality, durability, and appearance of the finished garment.

Single fusing, the most straightforward method, places one interlining layer with the resin side facing the garment fabric. Beyond this foundation, advanced techniques like reverse fusing, sandwich fusing, and double fusing handle more complex garment construction requirements. This article covers the primary fusing methods used in industrial garment manufacturing, their specific applications, and how to avoid common defects.

Types of Fusing Methods Comparison

Types of Fusing

Garment manufacturers use four principal fusing techniques to apply interlining. The method selected depends on the garment type, fabric weight, interlining specification, and end-use performance requirements.

Reverse Fusing

• The interlining fabric is spread on the fusing bed with the resin side facing upward.
• The garment fabric is then placed on top of the exposed resin surface.
• Heat and pressure are applied from the top, bonding the resin to the garment fabric.
• The interlining footprint is intentionally cut smaller than the garment panel because aligning two components face-to-face presents handling challenges.
• Accurate spreading of both components is more difficult compared to single fusing.
• Flat-bed fusing machines where heat is applied from the heated upper platen are preferred for reverse fusing.
• Temperature control is critical within ±5°C of the specified setting to prevent resin migration.
• Reverse fusing is suitable for applying fusible web for appliqué materials where precise placement is required.

Sandwich Fusing

In continuous fusing machines, heat is applied from both the top and bottom platens simultaneously. This two-sided heating method requires careful coordination of machine parameters.

• Two interlining layers are positioned between two garment fabric layers, creating a layered construction.
• Both sides of the fabric assembly receive direct heat application at 130–150°C (266–302°F) for typical polyamide resin interlinings.
• Production output increases significantly compared to single-pass methods due to continuous feed operation.
• Strike-back defect occurs when resin penetrates the lower fabric layer due to excessive pressure exceeding 0.5 N/cm² or temperature above the interlining’s tolerance.
• Strike-through defect occurs when resin penetrates the upper fabric surface under similar excessive heat and pressure conditions.

Double Fusing

Double fusing joins two different interlining types to garment fabric in a single manufacturing step, eliminating a separate application pass.

• Two interlining types are bonded to the garment fabric simultaneously during one fusing cycle.
• This method is standard for collar construction in shirts and for front panels of tailored coats and jackets.
• Temperature must be maintained within the overlapping range of both interlining types’ activation temperatures—typically 120–140°C (248–284°F) for combined polyamide and polyethylene resins.
• Precise fabric cutting with computer-controlled fabric cutting systems ensures accurate panel alignment within ±1mm tolerance.
• Pressure settings of 0.3–0.5 N/cm² maintain adequate bond strength without causing surface delamination.

Fusing Defects and Their Causes

Two primary defects compromise fusing quality: strike back and strike through. Both result from improper heat and pressure control during the fusing cycle.

Strike Back

Strike back occurs when the resin from the interlining penetrates through the lower fabric layer during fusing. This defect results from uncontrolled heat exceeding the interlining’s activation temperature or pressure applied before the resin fully bonds. Standard fusing parameters that prevent strike back include maintaining temperature below 155°C (311°F) for polyamide-based interlinings and ensuring pressure does not exceed 0.6 N/cm² during the initial heating phase.

Strike Through

Strike through occurs when interlining resin penetrates the upper fabric surface. This defect appears as a shiny or sticky residue on the garment face fabric. The cause is identical to strike back—excessive heat or premature pressure application—but affects the top surface instead of the bottom. Prevention requires gradual temperature ramp-up over 3–5 seconds and pressure application only after the resin reaches its activation temperature of 100–120°C (212–248°F).

The Effect of Fusing on Fabric Stiffness

Fusing adds measurable stiffness to garment panels. The degree of stiffening depends directly on the type of fusible interfacing selected—nonwoven interlinings add 15–40% more stiffness compared to woven types at equivalent weight. This stiffening effect is desirable for permanent fabric stiffening in collar, cuff, and waistband applications where dimensional stability is critical.

Fusing Parameters Quick Reference

Defect Prevention Checklist

• Verify temperature calibration monthly—drift of ±5°C can cause strike defects in 10–15% of panels.
• Check pressure gauge readings before each production run.
• Allow 5-second preheat before applying pressure in continuous machines.
• Store interlining in controlled humidity (45–65% RH) to maintain consistent resin activity.
• Conduct peel-bond testing on sample panels every 2 hours of production.

References

• TextileTuts. (2020). Types of Fusing for Garments.
• Smith, B. & Jones, L. (Eds.). (2014). Garment Manufacturing Technology. Elsevier Science & Technology. (Chapter 12: Fabric Joining and Fusing).
• AATCC. (2021). Technical Manual of the American Association of Textile Chemists and Colorists. AATCC.
• Carr, H. & Latham, B. (1994). Technology of Clothing Manufacture (4th ed.). Wiley-Blackwell.