Waterproof garments are intended to keep the wearer dry and shield against rain, moisture, wind, and difficult outdoor circumstances. Sewing thread is given less focus, but it is equally vital to the performance of a garment. If seams aren’t waterproof, the waterproofing material won’t work.
That makes the choice of thread more critical when it comes to rain jackets, outdoor clothing, protective workwear, hiking apparel, ski wear, and other technical clothing. Selecting the right thread isn’t just a matter of choosing its color and strength. All of these properties—including water resistance, seam construction, abrasion resistance, flexibility, temperature performance, and compatibility with seam-sealing processes—must be taken into account.
Importance of Thread Selection For Waterproof Garments
Each needle hole makes tiny holes in the textile. Although a high-performance waterproof material is used, these openings can become potential water penetration points.
It’s a problem that’s routinely solved with a technique called “seam sealing.” These openings are then closed with a sealing tape or suitable coating. The thread, however, will have to maintain its reliability beneath the sealed seam.
The appropriate thread should include:
- High and consistent seam strength
- Good resistance to moisture and chemicals
- Flexibility when moving garments.
- Excellent abrasion resistance
- Resistance to temperature changes
- Compatibility with seam-sealing processes
Wrong thread selection may cause the thread to break, the seam to stretch, leak, and/or lead to the failure of the garment
Think About the Thread Material
The first is the material to be used for the thread. Polyester nylon is mainly used as a technical fabric in a garment application due to its strength and durability.
Polyester has good dimensional stability, moisture and UV resistance, and resistance to many chemicals. It can be used for various kinds of outdoor and performance wear.
Nylon has a high strength and flexibility, suitable for use where seams are subject to repeated movement and mechanical stress. The particular grade and finish must be determined for the specific use, however.
When it comes to waterproof garments, it’s not just the tensile strength that should be the criterion for choosing a material.
Assess Water and Moisture Resistance
Waterproof garments come in contact with moisture, condensation, rain, and possibly washing or immersion for extended periods. The thread then should withstand wet conditions without undergoing significant changes in its physical properties.
When choosing thread, factors to take into account include:
- Moisture absorption
- Strength retention when wet
- Resistance to hydrolysis
- Not washing repeatedly
- Long-term exposure to humidity
A thread that works great on dry cloth but weakens or goes soft when repeatedly exposed to moisture may have a negative impact on the garment’s usefulness.
Match Thread with Seam-Sealing Technology
Thread and seam-sealing compatibility are among the most significant factors to take into account.
Various types of waterproof garments are available and may employ different technologies such as heat-applied seam tapes, liquid seam sealants, coatings, or specialized bonding processes. The recycled sewing thread should not shrink, melt, or lose strength under the heat and processing conditions used.
The manufacturer should do production trials to check if the selected thread is suitable for the selected sealing system.
Technical performance is not always the best thread to use if it hinders the sealing process.
Consider Thread Size and Seam Construction
The size of the thread will also affect the waterproof garment’s effectiveness. Too thick of a thread can cause larger holes in your needlework, and a too fine of a thread may not have enough body to hold a heavier fabric together at the seam.
The correct size of thread should therefore be chosen according to:
- Fabric thickness
- Seam type
- Stitch density
- Garment construction
- Expected load
- Needle size
- Required appearance
The idea is to establish a balanced seam sufficient in strength but not add too many or large openings in the fabric.
Flexibility and Stretch Recovery
Clothing for the outdoors and performance often has large amounts of movement. Jackets flex over the shoulder and elbow line, sportswear stretches when in use, and workwear can be subjected to repeated mechanical stress.
The thread should be sufficiently flexible to allow the thread to move without breaking or harming the seam.
An over-tightened thread can put a great deal of tension at one stitch, and a properly flexible thread can spread out the tension over the seam.
It is particularly important in clothing made for climbing, bicycling, hiking, skiing, and other tasks in which a person is using his or her body extensively.
Abrasion and Chemical Resistance
Waterproof clothing is frequently subjected to harsh conditions. Seams can chafe against backpacks, equipment, other layers of clothing, or rough surfaces.
High abrasion resistance helps prevent the thread from wearing down during use.
Industrial and protective garments should also be considered for chemicals. Cleaning products, detergents, oils, and other chemicals can impact thread performance. In these types of applications, manufacturers should choose threads that have the right chemical resistance and test them out.
Color and Appearance Still Matter
Technical performance is the main consideration, but thread appearance is still important. Visible decorative or functional stitching is frequently employed in the waterproof garments, especially in pockets, hoods, zippers, and intersections of panels.
The color of the threads should match the fabric and be consistent during production.
If you’re buying top-tier outdoor gear, a slight variation in thread color or shine can impact how good the clothing looks. Hence, the manufacturer needs to consider technical performance along with visual uniformity.
Test Before Large-Scale Production
Always do not choose a thread according to a specification chart provided by the supplier. Laboratory and production testing is of critical importance.
Manufacturers can evaluate:
- Seam strength
- Water penetration
- Thread breakage
- Abrasion resistance
- Flexing performance
- Washing durability
- Heat resistance
- Seam-sealing compatibility
Testing the entire fabric/thread/seam-sealing assembly is more representative than testing the thread alone.
Sustainability Considerations
Technical clothing manufacturing is more and more being driven by sustainability. In some cases, recycled polyester thread could be used if that is suitable for the context and performance requirements.
But sustainability should not be compromised by lack of durability. A longer-lasting, waterproof garment will be less likely to need to be replaced and use less material.
The best strategy is to choose a thread that is both durable and high-performance with responsible materials.
Conclusion
Selecting the right thread for seam sealing and for waterproof garments is a complex engineering problem and not a straightforward buying decision. The thread must be coordinated with the fabric, needle, stitch pattern, sewing machine, and seam-sealing method.
When deciding on a thread, manufacturers should consider material resistance, moisture resistance, flexibility, abrasion resistance, thread size, heat performance, chemical resistance, and sealing compatibility.
The end goal is that the seams will remain strong, flexible, and waterproof during the service life of the garment. With the evolution of waterproof garments into more technical and performance-oriented, proper thread selection will remain a critical aspect for ensuring successful, long-lasting, and quality products.
