Laboratory Tests and Methods for Seams

Visual inspections are important, but laboratory tests provide a more complete seam strength and performance analysis. These tests evaluate tearing, bursting, and tensile strength, which includes tension, breaking strength, elongation, and recovery. They also assess slippage resistance, wash resistance, dimensional change, failure and needle damage, and stitch resistance.
Combining these laboratory tests with visual inspections gives you a comprehensive understanding of seam quality and functionality. That allows you to identify potential weaknesses, optimize sewing parameters, and ensure that your garments meet the desired performance standards.
Here are some basic yet critical laboratory tests and methods utilized to examine sewing seams:

Laboratory Tests And Methods For Seams

1. Seam Strength Testing:

It is the most fundamental test for sewn seams. It measures the force required to break the seam, indicating its overall strength and ability to withstand stress during wear.

Methods: 

– Grab Test: This is a standardized test method in which fabric strips are gripped on either side of the seam and pulled by a tensile testing machine until the seam breaks. The force required to achieve this breakpoint is recorded as the seam strength.

– Burst Strength Test: This test measures the force required to push a diaphragm through the fabric at the seam point, simulating pressure applied during wear.

Laboratory Tests and Methods for Seams

2. Seam Slippage Testing:

This test evaluates the stitching’s resistance to yarn slippage within the seam. Excessive slippage can lead to seam puckering, loss of shape, and potential seam failure over time.

Methods: 

– Fixed Load Method: A fabric strip with a seam is clamped in a device, and a constant load is applied. The yarn slippage within the seam is measured over a specified time.

– Needle Clamp Method: A specific section of the seam is clamped, and a needle-like probe is inserted into the seam. The force required to pull the needle through the seam is measured, indicating the yarn’s resistance to slippage.

3. Seam Appearance Testing:

While not strictly a performance test, evaluating seam appearance is crucial for garment aesthetics and quality perception.

Methods: 

– Seam Smoothness Testers: These automated devices measure the smoothness and evenness of the seam surface, providing objective data on seam aesthetics.

Laboratory Tests and Methods for Seams

4. Additional Tests for Specific Applications:

Depending on the garment type and intended use, additional tests might be employed:

Washing Resistance Testing:

Seams are subjected to simulated washing cycles to evaluate how well they maintain strength and appearance after laundering.

Abrasion Resistance Testing:

For garments exposed to friction (like backpacks or jeans), tests assess the seam’s ability to withstand wear and tear.

Seam Security Testing:

This test, particularly relevant for safety gear or workwear, evaluates the seam’s ability to hold under high stress or heavy loads.

This information is a part of the extensive research conducted for our third book, Strong Seams, a seam catalogue focused on garment durability and quality. 
We couldn’t include all the research in the book. However, we believe it’s worth sharing with people like you who are also interested in quality and long-lasting garments.

We hope the material is helpful. If you want to know more about our book Strong Seams, please visit the following link: book Strong Seams (link)

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