CASE STUDY

Overcoming Challenges in Developing an Advanced Waterproof, Breathable Laminate with Enhanced Chemical Resistance

Solutions and Material Innovations for Reliable Military-grade Laminates

Introduction

Protective garments, e.g., garments used by emergency workers, utility workers, or military personnel, are generally made of fabrics that protect the wearer from the conditions the wearer expects to encounter, such as heat and flame in the case of firefighting garments, or chemical or biological exposure. The fabrics used in such garments are typically waterproof from the outside but allow water vapor to pass from inside to outside the garment to provide comfort to the wearer during periods of exertion. This case study delves into a collaboration between Shawmut and a Fortune 50 company that was facing a unique set of challenges when developing a waterproof, breathable laminate with enhanced chemical resistance for military applications. Shawmut’s commitment to pushing the boundaries of materials technology driven by an unwavering passion for discovery and problem-solving played a pivotal role in overcoming the complexities of this challenging project.

The Challenge

The challenge presented to Shawmut was to create a laminate that effectively bonded a highly moisture vapor transmissive, selectively permeable, and chemical-resistant film to military-grade apparel fabric. However, certain chemically-resistant breathable films are relatively brittle and may fracture easily when flexed under certain conditions. This brittleness may render fabrics that include such films to show a decrease in chemical impermeability after laundering, due to the impact of the wet environment of laundering on the physical properties of the film. Some chemically resistant breathable films are also subject to a decrease in their impermeability as a result of flexing under dry conditions. Adding to this already difficult challenge, an internal liner for abrasion resistance needed integration into the composite fabric as well, all while conforming to an extensive list of critical military performance specifications. These specifications included moisture vapor transmission (MVT) rate, wash durability, Gelbo flex (measuring the flex durability of flexible barrier materials), hydrostatic performance, and chemical resistance, requiring a solution that could withstand the rigorous demands of military use.

Innovative Approach

To find a solution, Shawmut conducted multiple lamination trials and utilized thorough third-party testing. Through testing, the key issues identified were the chemical-resistant layer’s susceptibility to flexural fatigue during laundering and its diminished resistance to chemical challenges. After examining the test results, Shawmut’s engineering and technical team developed and introduced a closely guarded trade secret into the lamination process, specifically engineered to eliminate flexural fatigue and offer enhanced fracture resistance to the film.

The application of this proprietary trade secret brought about a groundbreaking change. The revamped lamination process not only addressed the challenges faced by the client but propelled the waterproof, breathable laminate to surpass all critical military performance requirements. Recognizing the nature of the solution, Shawmut secured a patent for the technology and subsequently licensed it, ensuring broader accessibility to this transformative innovation.

Results and Impact

The benefits derived from Shawmut’s materials innovation, expertise in lamination technologies, and problem-solving approach were multi-faceted, yielding impressive results:

Enhanced Chemical Resistance: The incorporation of Shawmut’s trade secret significantly bolstered the chemical resistance of the laminate, fortifying its efficacy in demanding military environments where exposure to various chemicals is commonplace.
Flexural Fatigue Elimination: The application of the proprietary trade secret successfully eliminated flexural fatigue in the chemical-resistant layer, contributing to increased durability during laundering and, consequently, an extended product lifespan.
Exceeding High-spec Military Standards: Shawmut’s solution not only met but exceeded critical military performance requirements, proving the capacity of their materials innovation to navigate complex specifications and deliver high-performance solutions.
Patented Technology: The successful patenting of the proprietary process recognized Shawmut’s ingenuity and provided legal protection for this unique solution, reinforcing its expertise in lamination process innovation.
Licensing Success: Acknowledging the transformative nature of the technology, Shawmut pursued licensing opportunities, ensuring wider access to the innovative waterproof, breathable laminate technology within the industry.

Conclusion

The successful development of the military-grade laminate illuminates how Shawmut’s profound knowledge across materials development and laminated solution technologies empowers it to design custom solutions that address unique needs. Shawmut’s collaboration with this Fortune 50 company underscores its core values of discovery, problem-solving, and materials innovation. Furthermore, Shawmut’s willingness to license the technology aligns with its purpose of materials innovation for a better world by offering others an opportunity to use the patented technology for the greater good. Shawmut’s legacy in materials innovation continues to shape the future of industries by providing solutions that redefine standards and exceed expectations.

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Project Details

Project:

Developing a waterproof, breathable laminate with enhanced chemical resistance

Capabilities Applied/Processes:

A patented, proprietary lamination process, specifically engineered to eliminate flexural fatigue and enhance fracture resistance.
Adhesive and thermal lamination
Encapsulation

Industry for Use:

Military and Defense
Protective

Materials Used:

Hydrophilic Film
Membrane
NyCo (nylon-cotton fabrics)
Nomex jersey knits

Equipment Used:

Adhesive Laminator
Thermal Laminator

In Process Testing/Inspection Performed:

Moisture Vapor Transmission (MVT) Rate
Wash Durability
Gelbo Flex (Flexural Fatigue)
Hydrostatic Performance
Chemical Resistance
Flame Retardance

Width:

Variable Widths

Length:

Continuous Rolls

Standards Met:

Customer Requirements
ASTM F392 Gelbo Flex Test