How to Select Threads for Recycled and Regenerated Fabrics in Apparel

The apparel industry is increasingly adopting recycled and regenerated fabrics to reduce waste, conserve resources, and support more sustainable manufacturing practices. Fibres, like recycled polyester, recycled cotton, viscose, lyocell, and also other fibres, that are regenerated, are gaining popularity for clothing manufacturing. These fabrics are not necessarily equivalent in strength, extensibility, texture or even in the manner in which they need to be sewn, however.

There is a critical need to choose the appropriate sewing thread with these fabrics to assure strong seams, quality, and productivity during sewing.

Understanding Recycled and Regenerated Fabrics

Recycled fabrics are made by recycling and reprocessing existing materials like used clothes, textile waste, plastic bottles and more. Recycled polyester and recycled cotton are examples of this.

Regenerated fabrics are produced by treatment of natural raw materials, such as wood pulp, to regenerate fibres for textile use, including viscose, modal and lyocell.

There are both positive and negative environmental aspects to both categories, and they perform differently when they’re cut up, sewn together, washed, and treated. The diversity of fabrics, therefore, requires a range of options for thread selection, and it will not be possible to have one solution for all the sustainable textile options.

Key Factors in Thread Selection

Evaluate Fabric Strength and Structure

It’s important to know the qualities of the fabric’s tensile strength, thickness, how many times it was woven, and how it will feel in the needle. As per the recycling process, recycled cotton fibres can have a different length, and lightweight regenerated fabrics may need to be handled very delicately.

Fabrics that are stronger or heavier can obtain stronger/heavier threads which will have a higher range of tensile strength and abrasion resistance to provide successful seaming. For lightweight fabrics, finer threads can help reduce fabric damage and the bulk of seams, which might be desirable.

Match Thread Strength to Garment Requirements

The strength of threads needs to be equal to the purpose of the garment, the type of seams and how it will be under stress while worn. The seams of sportswear, denim, workwear or some types of outerwear can be stitched with higher strength than light shirts or dresses.

Abrasion, consistent stitching and durability are some of the reasons why recycled polyester threads can be a viable option in certain applications. When using regenerated fibres, manufacturers should verify the seam strength of the thread used in the garment to not cause any undue distortion or damage.

Consider Thread Elasticity

Fabric and thread should move, stretch and be repeated over the materials during their use. If the thread is not sufficiently elastic to be used, seams will tear when the garment is stretched. If there is excessive elasticity or an insufficient balance of elasticity, then the seam will look bad.

The performance of the thread should be researched in connection with other fabric properties like stretch and recovery in stretch garments with recycled fibre content. Use of the correct thread helps to hold seams open and to use it to hold seams open and to ensure the comfort of the garment.

Assess Surface Finish and Sewability

Smoothness and consistency of thread and lubrication have an impact on sewing performance. Finishing helps to minimise friction that occurs between the needle, fabric and machine components, while the thread passes through them.

High thread quality leads to consistent thread quality, which reduces stitch irregularity and limitations such as thread breaks, skipped stitches and machine down time. This is especially crucial during the fast-paced process of making clothes; even small variations can make a difference in productivity in the apparel manufacturing industry.

Supporting Sustainable Apparel Manufacturing

Check Environmental Credentials

Any manufacturer looking to take steps to make the production of apparel more environmentally friendly is welcome to incorporate threads consisting of recycled fibres or those from responsibly managed sources. When done right, recycled polyester sewing threads can play their part in promoting material circularity.

But recycled content is not the only thing to consider for judging the sustainability of a thread. Other considerations include the end-of-life requirements of the garment, manufacturing processes, energy and resource use, certification, and traceability.

Consider Dyeing and Finishing Processes

Post stitching may include chemical finishes, heat setting (or heat extremes), dyeing or washing. All of these processes can have an impact on thread colour, strength, dimensions, and dimensional stability.

The selection of thread should take into consideration anticipated processing conditions to reduce colour variation, withstand high temperatures (flame-resistant sewing thread, para-aramid thread), distortion of the seams and reduced strength. When linen and clothing are being tested in combination, this is especially crucial in instances of certain laundry requirements or unique finishing processes.

Conduct Sewing and Performance Trials

Manufacturers should test the selected thread in actual operating conditions prior to scale-up production. Trials should test whether or not there are consistent stitches, strength of seams, thread breakage, puckering, and post-washing performance.

When testing the finished garments, it is tested to see if the thread/fabric combination is able to withstand the wear and care situations it is likely to encounter. This also enables manufacturers to tweak the size of the needle, the tension at which it is used and the stitch density of the cloth prior to the start of manufacturing.

Conclusion

Choosing recycled and regenerated fabric threads should consider fabric structure, seam strength, stretch, and surface finish, as well as finishing needs. When assessing environmental attributes of the thread and suitability with the article, manufacturers should focus on the constant sewing performance.

Apparel manufacturers can leverage an understanding of the right thread choices alongside targeted testing and quality control measures to create more durable, comfortable, and well-finished items while helping to move towards more responsible textiles.