Development of an innovative sewn-through joining technology of Spacer Stitching for 3D textile assemblies

• Applicant: Dr.-Ing. Hassan Saeed
• Subject Area: Lightweight Construction, Textile Technology
• Term: since 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 516003964

The sewn-through sewing method is the most commonly used joining method for the manufacturing of 3D textile assemblies. A major disadvantage to the sewn-through sewing method is that the 3D assemblies are compressed by the sewing threads along the stitch lines. These compression points are also commonly referred to as ‘cold spots’ in functional clothing. These points are present all along the stitch line and force the entrapped air present inside the insulation material to leave its structure. In this way, they act as a bridge to facilitate heat transfer. There is a general compromise on product functionality where joining with the sewn-through sewing method takes place and is taken as a byproduct of current sewing technology. Along with the insulation of functional garments, the compression along stitch lines is also relevant for industrial insulation products, medical textiles, spacer fabrics, and composites. Efforts are made for alternative complex material handling solutions, involving greater material usage and higher costs due to the absence of machine-based technological solutions. The project applicant has developed an innovative sewn-through sewing technology named ‘Spacer Stitching’ to address the problems related to material compressions along stitch lines for 3D textile assemblies. This machine-based technological solution has been granted a patent. With the help of patented spacer stitching technology, the 3D assemblies are successfully joined with the sewn-through method, and the compressions along stitch lines are avoided. Preliminary technology development has been performed with limited resources and the results of scientific studies have been published in peer-reviewed journals. The project applicant is convinced that there are deficiencies in the patented technology of spacer stitching that needs to be investigated for its further development. The current patented method offers lesser operational flexibility e.g. sewing of complex shapes, the crossover of stitch lines, and reproducible stitching when compared with conventional sewing methods are not possible. To address these problems and further development, the technology needs refinement and optimization. The proposed DFG project aims to improve the working principle of spacer stitching technology that addresses the identified weak areas, develop an experimental set-up and evaluate the technology with state-of-the-art testing methods for selected applications in the given project timeline. There are many unresolved issues related to sewing technology and the development of spacer stitching technology is a step towards addressing a pending issue related to the joining of 3D textile assemblies. The proposed DFG funds are considered very important to investigate the longstanding problem of compressions along the stitch line and to take a systematic approach to address this problem by developing the spacer stitching technology.

• DFG Programme: Research Grants