Sewn Product Stitched Portion Thickness and Strength
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing sewing method using a flat seamer sewing machine results in stitched portions with increased thickness and noticeable unevenness due to six threads, compromising the aesthetic and strength of the sewn product.
Innovation Solution
A sewing method employing a bobbin thread interlocked with multiple needle threads to form zigzag seams, reducing the number of threads used and incorporating a vertical full rotation shuttle and swayable sewing needles to create a more compact and less noticeable stitched portion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If six threads are used to stitch material edges together with a flat seamer sewing machine, then the strength of the stitched portion is ensured, but the thickness of the stitched portion is increased
Solution Approach 1:
The stitching function is segmented into two independent parts: overedge stitching (using one needle thread and one bobbin thread) and seam stitching (using additional needle threads). This segmentation allows the overedge-stitched portions to be made thin while the seam stitching provides the necessary strength, resolving the contradiction between thickness and strength.
Solution Approach 2:
The invention merges overedge stitching and seam stitching into a single integrated process using one bobbin thread and multiple needle threads. The bobbin thread forms loops that are interlocked with multiple needle threads in sequence, combining the functions of edge finishing and seam construction while controlling overall thickness.
2Strength
If six threads are used to stitch material edges together, then the strength of the stitched portion is ensured, but the stitched portion becomes noticeable
Solution Approach 1:
The stitching is segmented into overedge stitching that creates thin, less visible edges and seam stitching that provides strength. The overedge-stitched portions have smaller thread thickness and are less noticeable, while the seam stitching between them provides the necessary strength without adding significant visibility.
Solution Approach 2:
Different parts of the stitched portion have different qualities: the overedge-stitched portions have thin threads for aesthetics and low visibility, while the seam stitching has sufficient thread density for strength. This local differentiation resolves the contradiction between visibility and strength.
3Strength
If material edges are stitched together with six threads, then the strength is ensured, but the unevenness in the stitched portion increases
Solution Approach 1:
The stitching process is segmented into overedge stitching that creates uniform, smooth edges and seam stitching that connects them. The overedge-stitched portions have consistent thread tension and spacing, reducing unevenness, while the seam stitching provides strength with controlled spacing between segments.
Data Source
AI summary
There is provided a sewn product in which one material edge and the other material edge are stitched together in an abutted state. The one material edge and the other material edge are stitched together with one bobbin thread and a plurality of needle threads, the plurality of needle threads being interlocked with the one bobbin thread to form a plurality of rows of zigzag stitched seams.