Waterproof footwear is an essential part of personal protective equipment (PPE) and outdoor equipment, providing protection for the wearer’s feet from water while providing a waterproof, safe barrier in a wet environment. While the waterproof membrane and materials are the focus when thinking of waterproof footwear, perhaps the least thought about aspect of waterproof footwear, the thread, holds an integral lock to the waterproof barrier. Common threads wick water, providing a passage for water into the footwear, thus providing a failure to the footwear. This is where anti-wicking (or hydrophobic) threads come in and play a critical role in stopping the passage of water in footwear. The anti-wicking thread will improve the waterproof footwear performance.
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Understanding Wicking and Its Impact on Waterproof Footwear:
Wicking is the capillary action that draws liquids through narrow spaces between fibrous materials. With footwear, this means water can be drawn up through the thread, infiltrating the stitches and compromising the waterproof membrane. This can cause multiple issues:
- Water Infiltration: Wicking allows water to enter the footwear, making your feet wet and uncomfortable.
- Reduced Insulation: Wetness diminishes the insulation abilities of footwear, causing cold feet in cold weather.
- Increased Drying Time: Water held in the seams and materials increases drying time, compromising the practicality of continued use.
- Material Degradation: Extended periods of moisture can lead to material degradation, including waterproof layers and inner linings.
- Increased Infection: Prolonged wetness increases the risk of fungal and bacterial growth and foot infection.
The Role of Anti-Wicking Threads:
An anti-wicking sewing machine thread is designed to reduce or eliminate capillary action that allows water to travel along the thread. Anti-wicking threads are essential to keeping footwear waterproof in demanding environments.
Types of Anti-Wicking Threads:
There are several different types of anti-wicking threads, and each has its own characteristics and benefits.
- Hydrophobic Threads:
These threads are treated with a hydrophobic coating that will repel water off the coated thread. The coating establishes a layer that will not allow water to stick to the surface of the thread. PTFE (polytetrafluoroethylene) coatings are primarily used due to their excellent water repellency and durability, and silicone-based coatings are also used.
2. Bonded Threads:
Bonded threads are made by bonding the individual filaments together, creating a solid, non-porous structure. This process eliminates the holes between filaments so that water cannot wick through the thread. Bonded nylon thread can be found in waterproof footwear.
3. Encapsulated Threads:
Encapsulated threads are over-coated with a waterproof polymer that creates a protective area around the thread. The encapsulation eliminates all contact of water and the interior core of the thread. The encapsulated method exhibits excellent water resistance and durability.
4. Threads with Modified Fiber Structures:
Engineered threads with modified fiber structures can reduce wicking.
This can be done by changing the fibers’ cross-sectional shape to reduce the surface area that water can travel along.
Changing the fiber twist and how many fibres are in the thread also changes wicking properties.
Key Properties of Anti-Wicking Threads:
In order to truly prevent wicking, threads must be engineered to have several fundamental properties:
- Hydrophobicity: The ability to repel water and prevent it from adhering to the thread.
- Low Capillarity: The ability to minimize or eliminate the ability for liquid to travel down through the threads.
- Durability: Ability to withstand repeated exposure to water and other environments.
- Strength and Abrasion Resistance: Ability to resist structural collapse as a result of stress or friction.
- Sewability: The Ability to be sewn smoothly and efficiently while maintaining performance.
- Chemical Resistance: The Ability to withstand various chemicals the footwear may be exposed to.
Testing and Evaluation:
It is important to complete thorough testing and evaluation to prove that anti-wicking threads will perform.
Some common tests include:
- Water Wicking Tests: Measured how quickly water travels along the thread.
- Hydrostatic Pressure Tests: Measured the ability of the thread side to withstand water pressure.
- Immersion Tests: The performance of the thread once placed into the water after a specified time.
- Abrasion Tests: ability of the thread to resist wear.
- Chemical Resistance Tests: The performance of the thread when exposed to a variety of chemical agents.
Benefits of Using Anti-Wicking Threads in Waterproof Footwear:
Anti-wicking threads come with several important advantages:
- Enhanced waterproof performance: Keeps water out and maintains the integrity of a waterproof barrier.
- Increased comfort: Feet remain dry and comfortable, even in a wet environment.
- Improved insulation: Insulating properties of the footwear remain intact, keeping feet warm in cold conditions.
- Reduced drying time: Limits water absorption and helps promote drier footwear and faster drying time.
- Extended life of footwear: Protects the materials from moisture damage, extending the life of the footwear.
- Reduced risk of infections: Provides a drier environment, promoting less fungal and bacterial growth.
- Increased safety of the user: For safety footwear, the safety properties are not impacted other than normal wear.
Application of Anti-Wicking Threads:
The application of anti-wicking threads is applicable to many waterproof footwear applications:
- Outdoor footwear: Hiking boots, rain boots, and other outdoor footwear designed for grey and wet feet.
- Safety footwear: Industrial boots, work boots, and safety shoes for wet and dangerous conditions.
- Military footwear: Combat boots and other military footwear designed for extreme work.
- Medical footwear: Footwear in medical settings whereema may be found.
- Sportswear: Footwear used in water sports or other activities where moisture is highly likely present.
Future Trends and Innovations:
The development of anti-wicking threads will continue to evolve as advancements are made in material science and manufacturing processes.
Advanced Hydrophobic Coatings – where more durable and environmentally friendly coatings will be created. Another trend is the incorporation of nanomaterials to improve water and durability repellency characteristics.
Research will be conducted into bio-based anti-wicking threads as an alternative to traditional synthetic threads. Smart threads will be made with sensors that are conductive in order to monitor moisture levels and feedback in real time.
Lastly, it is expected that improved manufacturing processes will help to increase consistency and quality for all anti-wicking threads.
Conclusion
In conclusion, anti-wicking threads are integral to the waterproof footwear experience, and not only are anti-wicking threads added to parts of waterproof footwear, but they are also an essential feature to keep the wearer dry for comfort, safety, and longevity of waterproof footwear. Anti-wicking threads mitigate the effects of capillary action by preventing water from wicking through the seams and through the waterproof membrane, as seen with traditional threads.
The wide selection of anti-wicking threads (hydrophobic, bonded, encapsulated, and modified fiber structure threads) shows significant technological progress in this area. Each thread is unique and has its own advantages and disadvantages that differentiate them in fulfilling a specific need and/or environment. In addition, the detailed testing and evaluations demonstrate not only the quality and performance but also the performance in adverse conditions.
Given the advancements in material science and manufacturing technologies, it may be fully expected that we will see continued innovation and technology development in anti-wicking threads in the near future. In fact, with the ideas for new durable, sustainable hydrophobic coatings and advances incorporating nanotechnology and biological alternatives practices, new waterproof footwear product development is in its infancy. Smart threads with moisture monitoring sensors also hold the potential to enhance user experience and safety.
In summary, high-quality anti-wicking threads represent an important consideration in developing waterproof footwear that is comfortable and reliable. From the outdoor athlete to the industrial worker to the military participant, anti-wicking threads provide a reasonable level of dryness, comfort, and safety in damp conditions.