Breathable Performance Research Articles

Changing Breathability of Polyethylene Composite Films with Different Porous Structures Depending on Stretching Processes

ABSTRACTThe aim of this work is to investigate the effects of different stretching processes on breathability performance of linear low‐density polyethylene (LLDPE)/coated calcium carbonate (CaCO3) composite films under the same conditions. Coated calcium carbonates and powdered LLDPE were physically mixed and dried in a high shear mixer, and polymer compounds containing 45 and 55 wt% coated calcium carbonate were generated using a twin screw extruder. Cast films were produced and then they were stretched 3.5 times in machine direction at 25°C by using stenter and interdigitation stretching methods. It was revealed that not only the CaCO3 type and loading amount but also the stretching type has an enormous effect on breathability performance. In addition, the quality of porosity, that is, the amount of interconnecting pores, was determined to play an important role in breathability. And, the interdigitation stretching process offers the potential for a better breathability at reduced processing costs.

Carbon Nanotubes Enhanced Fluorinated Polyurethane Macroporous Membranes for Waterproof and Breathable Application.

Waterproof and breathable macroporous membranes that are both completely resistant to liquid water penetration and easily allowable to vapor transmission would have significant implication for numerous applications; however, fabrication of such materials has proven to be tremendously challenging. Herein, we reported novel electrospun composite fibrous membranes with high waterproof and breathable performance, which consisted of polyurethane (PU), terminal fluorinated polyurethane (FPU), and carbon nanotubes (CNTs). Benefiting from the utilization of FPU and CNTs, the fibrous membranes were endowed with superhydrophobic surface, optimized pores size and porosity, along with enhanced fibers, which resulted in excellent waterproof, breathable and mechanical properties. Significantly, the relationship among waterproofness, pore structure and surface wettability has been confirmed finely accordance with Young-Laplace equation. Ultimately, the resultant membranes presented high waterproofness with hydrostatic pressure up to 108 kPa, good breathability with water vapor transmission rate over 9.2 kg m(-2) d(-1), as well as robust mechanical properties with bursting strength of 47.6 kPa and tensile strength of 12.5 MPa, suggesting them as promising alternatives for a number of potential applications, such as protective clothing.

Fluorinated polyurethane macroporous membranes with waterproof, breathable and mechanical performance improved by lithium chloride

The waterproof, breathable, and mechanical properties of the FPU/PU fibrous membranes could be dramatically improved at the same time simply by regulating the polymers solutions conductivity.

Parameters of High-Density Soft Breathable and Anti-Velvet Fabric Technology

At present, there are still drilling soft velvet jacket fabric, breathable, coated thick and many other issues, the clothing brand's lack of guidance on the technical parameters of the purchase fabric, so that the domestic high-end brands in soft single layer anti-velvet products domestic market share is far behind foreign brands. Based on the above situation, this paper on the international market of high-end brands such fabrics for data analysis, according to research data to buy produce like cloth, sewn jacket kind of clothing to complete the work and try to verify their anti-velvet, breathable performance, research findings provide proof fabric for further research fellow basic data, reference may be fabric or garment production company's procurement offer.

The nature of mass masonry granite walling and the potential for retrofit internal wall insulation strategies

Traditional buildings constructed of solid granite walling that have timber framing with lath and plaster internal finish are not thermally efficient when compared with modern constructions. They are also termed ‘hard-to-treat’ as they need special care and attention to historic detailing, breathability and hygrothermal performance. These traditional buildings were originally constructed with lime mortar but during the period of mass Housing Disrepair Notices, many of these buildings were re-pointed using OPC-based cement/sand mortar. While the ‘whole house’ needs to be considered in any thermal improvement strategy, granite walling presents a particular characteristic which demands a different approach to that of sandstone or limestone walling when considering internal wall insulation. This paper explores the main issues to consider when contemplating a thermal improvement strategy from the material perspective. The buildings identified in this paper are in the North-East of Scotland.

Designing waterproof breathable materials based on electrospun nanofibers and assessing the performance characteristics

To develop waterproof breathable materials for diverse consumer applications, we used electrospinning to fabricate layered fabric systems with varying composite structures. Specifically, we developed layered fabric structures based on electrospun nanofiber webs with different levels of nanofiber web density, as well as different substrates and layer structures, and then examined the breathability and waterproofness of the material. The breathability and waterproofness of the layered fabric systems were compared with those of traditional waterproof breathable fabrics, including densely woven fabric, microporous membrane laminated fabric, and hydrophilic nonporous polyurethane coated fabric. Different breathability and barrier performance levels were achieved by varying the layer structure and substrates in the electrospun nanofiber web layered fabric systems. The uniformity of the nanofiber web and lamination process also affected the barrier and comfort performances. The comparison of waterproofness and breathability performances between the new materials and the traditional waterproof breathable materials revealed that the layered structures based on electrospun nanofiber webs provide a higher level of resistance to water penetration than densely woven fabrics and a higher degree of moisture vapor and air permeability than microporous membrane laminates and coated fabrics, with a proper selection of layer structure, substrate fabric, and lamination process.

Precision Placement of Thin Polymeric Silicone Films Within Fabrics

This unique patented technology allows for the precision place ment of thin polymeric films around fibers, crossover points, and filling in or leav ing open interstitial spaces within fabrics. The choice of polymer, substrate, and placement of polymer allows for improvement of properties, such as breathable barrier performance, controlled porosity, resistance to fluids, and adhesion/release behavior. This technology has found applications including apparel, automotive, aerospace, and medical. The benefits in these applications are delivered in a process that has no Volatile Organic Compounds (VOC) and yields inert residual materi als. Examples of materials and comparative performances will be discussed