Background
House wrap sales in North America are projected to exceed $3 billion by 2022. Legislation of new and more stringent building energy codes, along with increasingly dramatic climate situations are driving the market. The function of a house wrap is to avoid the intrusion of water (or liquid, dirt) into a structure, and to promote the respiration of vapor and transmission of air (or gas) from a structure (Figure 1).
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- Vapor barriers or vapor retarders exhibit a degree of permeability that allows the building to “breathe”, are usually applied in the building interior, for example, on walls and floors. These membranes need to combine high mechanical strength and low weight with ease of installation
- Underslating breathable membranes are usually applied to exterior surfaces, allowing vaporization of residual moisture in the insulation material, on which they can be laminated.
By adding durable “breathable moisture repellent” functionality to the substrate, preferably in a one-step process, the resulting membrane should have the same or superior mechanical properties and weight (preferably in the range of 100 grams per square meter) with additional hydrophobicity and vapor transmission functionality. An efficient manufacturing process would provide a valuable asset in the industry.
Adding further functionality such as infrared reflectivity, heat insulation or acoustic performance, liquid transport, energy storage and smart connectivity (for instance including sensor functions for temperature or humidity) would also be desirable.
Detailed Solution Description
The preferred solution would offer at least the following typical breathable membrane performance characteristics:
- Air Penetration: 0.005 l/s∙m2 (0.001 cfm/ft2) at 75 Pa, when tested in accordance with ASTM E2178. Type I per ASTM E1677. ≤0.20 l/s∙m2 (0.04 cfm/ft2) at 75 Pa, when tested in accordance with ASTM E2357.
- Water Vapor Transmission: 19 metric (28 US) perms, when tested in accordance with ASTM E96, Method B.
- Water Penetration Resistance: Minimum 280 cm when tested in accordance with AATCC Test Method 127.
The preferred solution would not reduce the tensile properties of the substrate. Increasing the tensile properties of the substrate is acceptable.
The preferred solution would retrofit into existing manufacturing operations with little to no alterations to the existing equipment or process.
The preferred solution would meet workplace safety requirements consistent with OSHA standards.
Possible Routes To Investigate
Topical coatings and laminates are commonly used to affect surface functionality to textile substrates. While not preferable, these options are not outside the scope of this request.
Anticipated Next Steps with Respondents
- Upon identification, company would seek to create prototypical samples from a variety of substrates to demonstrate the efficacy of the process and determine the physical properties of the prototypical samples.
Other Comments / Important Considerations
- Solution would need to be compatible with maintaining a safe working environment for employees and equipment. Solutions would need to be compatible with temperatures associated with melt extrusion processes, and with the other thermoplastics used in manufacturing the products.
- Upon identification, company would seek to create prototypical samples from a variety of substrates to demonstrate the efficacy of the process and determine the physical properties of the prototypical samples.
Type of Outcome expected
- Proven technology ready for commercial implementation
Company Demographics
- Industry: Industrial Textiles
- Annual Revenue: > 500m €
- Years in Business: 100 Years
- Headquarters Area: Europe
