Materials Abstracts



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Materials Abstracts

Short Polymer Fiber Technology – World’s Smallest Fibers for Textile Finishing Enable Previously Unrealizable Surface Modifications – Murray Height, HeiQ Materials AB, Switzerland

HeiQ, through its research partnership with Deakin University, Australia, has developed an innovative process for the synthesis of Short Polymer Fibers (SPF), a revolutionary, patented process for the manufacture of micro-fibrous polymer structures with diameters of 0.1 to 5 μm and lengths of 1 to 1000 μm – currently the smallest fiber size for the textile finishing market in the world. SPF may be made from many materials, the wide choice of functional SPF ingredients opening new opportunities for innovative textile surface functionalization (e.g. our Real Silk which covers “common” materials like cotton or polyester with minute silk fibers). The high degree of interaction of linear filamental structure of the SPF materials with fabric substrates offer increased durability compared to particles with point-wise interaction only.

Cellulosic for New Fashions – Gregory R. Kiggins, Eastman Chemical Company

Eastman Chemical Company is introducing a cellulosic yarn, the new name in fashion apparel. What is new?

– Dyeing blends at high temperature that include an elastomer
– Heat transfer printing
– Optimizing wet fastness

Applications and properties for Naia include:

– Expanded fashions from ladies’ intimates to casual wear.
– The hand is very soft and luxurious and wrinkling is minimal.
– Jet dyeing with disperse dyes at 100-130 C is the preferred method of dyeing knits.
– Fabrics include this fiber alone or with polyester, nylon and elastomers.
– A new application is heat transfer printing much the same as polyester.
– Studies will show wet fastness with and without an after scour. Comparisons of standard wash fastness testing vs actual home laundry methods will be presented.

Spider Silk Fibers from Bolt Threads – Scalable Fiber Production and Silk-like Properties – Lindsay Wray, Bolt Threads

At Bolt Threads we are making fibers for the textile industry that are inspired by natural protein polymeric materials. The myriad of unique properties and inherent environmental compatibility of these polymers is our motivation for developing a molecular biology platform that is capable of manufacturing these materials via large-scale fermentation. With genetic-level control over the amino acid sequence, we are capable of fine tuning the polymer processing windows and functional material properties. Today, we are capable of producing a recombinant spider silk protein at commercial scale and spin this material into filament and staple yarns. These filaments exhibit spider silk biomimicry and can be generated with high consistency and at large volumes. This first fiber demonstrates the baselined capability of our designer protein polymer pipeline.

Breathable and Conformable Piezoelectric PVDF/ZnO Nanofibrous Membrane Sensor for Wearable Applications – Minji Kim, Cornell University

Piezoelectric ceramic and polymer composites have been shown to have remarkable piezoelectric constant. However, such composites lack flexibility and breathability and sometimes have health issues for application in wearable fashion. The said limitations can be alleviated by electrospinning piezoelectric polymers containing non-toxic piezoelectric ceramics into porous membranes. Here we report on a novel breathable piezoelectric membrane which has zinc oxide (ZnO) nanorods grown on the surface of electrospun polyvinylidene fluoride (PVDF) nanofibers using a hydrothermal method. Significant improvements in the piezoelectric response of PVDF membrane was achieved without compromising breathability, conformability, or health risk of the material. PVDF is one of the most frequently used piezoelectric polymers due to its high piezoelectric coefficient values, and unlike many piezoelectric ceramics containing heavy metal, ZnO is a non-toxic material which has been widely used in many fields of applications including cosmetics. The fabrication process is simple and economical due to no additional poling process needed for PVDF membranes after electrospinning in a high electric field, and ZnO growth temperature being lower than water boiling temperature in aqueous solution. 

Leveraging Textile Technology for Robotic Apparel – Vanessa Sanchez, Harvard University

The rapidly emerging field of soft robotics presents a new opportunity to develop wearable assistive technology optimized for the needs of individuals with residual capacity as well as for augmenting human performance. Unlike their rigid counterparts, soft wearable robots are lightweight, intimately conformal to the body and can more easily fit a range of sizes. The hierarchical structure and flexible/conformal nature of textiles provide an ideal platform to construct these wearable robotic systems. Textiles impart the ability to tune mechanical properties for use in inflatable actuation profiles or to anchor to the body and distribute and route forces through attachment points in cable driven systems. Looking forward, additional functionalities will be embedded into the textile beyond structural needs including sensing, and flexible electronic routing.

Preparation and Characterization of Flexible Piezoelectric Textiles for Energy Harvesting – Suraj Sharma, University of Georgia

coated nylon filament as inner electrode, a PVDF (polyvinylidene fluoride} electroactive layer prepared by electrospinning deposition process followed by PVDF solution coating, and a 60 nm silver outer electrode applied by electron beam physical vapor deposition. The resultant filament exhibited a more even and durable structure compared with two piezoelectric filaments developed using PVDF solution coating and electrospinning deposition process. Under a cyclic compression of 0.02 MPa at 1.6 Hz, a 3-cm long filament can produce an average peak-to-peak open-circuit voltage of 0.76V. The high-performance, durable and flexible piezoelectric filament showed a great potential to be used as wearable energy harvester to scavenge mechanical energy of human movements.

Wearables and Electrical Safety – George Poulos and Michael Sakamoto, Underwriters Laboratories

As the wearables categories expands to integrate electronics and batteries into their design, it becomes critically important that basic electrical safety requirements are designed into the wearables to keep consumers from risk of shock, burns, and other related risks. UL, with its extensive knowledge and experience in electrical safety science, testing, certification will discuss the risks associated with this developing wearable category and how the industry and manufacturers can pursue a path toward safer products in the marketplace.

Design and Development of an Active Compression Treatment System for Vascular Disease Using a Series of Silicon Based Inflatable Mini Bladders – Gayani Nandasiri, Nottingham Trent University, United Kingdom

Venous disease in lower limb can range from minor asymptomatic incompetence of venous valves to chronic venous ulcers. The established gold standard of treatment is graduated compression using compression bandages or stockings. However, these conventional methods are incapable of delivering required pressure profiles. The aim of present research is to revolutionize the compression therapy by using a novel active compression system to deliver accurate pressure profiles using a series of inflatable mini bladders. Two types of commercially available silicones were tested for the application, and the inflation/deflation heights and pressure transmittance characteristics of mini bladders were analyzed experimentally. The results showed 70-80% of inlet pressure transmittance onto treated surface. Further, FEM simulations of inflatable mini bladder showed a 60-70% agreement with the inflation/deflation experimental heights.

Preparation of Biocidal Textiles for Prevention of Disease Transmission – Gang Sun, University of California-Davis

Transmissions of deadly diseases such as Ebola and Methicillin-resistant Staphylococcus aureus (MRSA) have been known and are public threats due to frequent outbreaks.  With the current personal protective equipment (PPE) and practices, infection rates of healthcare workers by the most contagious diseases are still very high, and some of drug resistant diseases have been spread to communities. Thus, novel textiles that can provide increased protection for healthcare workers and the public from transmission of the contagious diseases should be developed. So, what type of textiles can provide such desired functions?  This presentation will discuss the biocidal functions of textiles and proper technologies that can meet the requirements from protection of publics from these biological agents, as well as future directions in the research area.

Structure/Function Relations of Hemostatic Nonwoven Dressings Based on Greige Cotton –J. Vincent Edwards, Southern Regional Research Center, USDA

A variety of natural and synthetic fibers are employed in hemostatic dressings. Here we demonstrate the use of greige cotton as a functional fiber, which when combined with hydrophilic and hydrophobic fibers in hydroentangled nonwoven materials, promotes accelerated clotting.  A biophysical approach was developed to identify fiber compositions that promote hemostasis.  The structure/function characterization of greige cotton-based dressings was based on the relationship of material electrokinetics to the rate of fibrin and clot formation. When coupled to material absorption capacity and wicking determinations, materials that promote a rapid onset of clotting were identified.  In vitro assessment of whole materials that promote hemostasis was completed using the Lee White Clotting assay to provide a structure versus function profile of hemostatic activity for selection of leads.

The Preparation of Bionic Structural Antibacterial Finishing Agent and Its Application on Fibers – jindan Wu, Zhejiang University, China

The existing antibacterial wound dressing has some disadvantages, e.g. short-term antibacterial effect, high possibility of causing bacterial resistance and poor biocompatibility. In this paper, PDMAEMA-co-PtBA was polymerized through ATRP using EBiB as initiator. DMAEMA units were partially quaternized to obtain antibacterial properties. The obtained copolymer QPDMAEMA-co-PtBA was hydrolyzed to produce carboxyl groups which reacted with dopamine later. The structure of the copolymer was characterized by means of NMR, gel permeation chromatography and infrared. By introducing dopamine structure to the copolymer segment, the polymer could be used as a kind of reactive antibacterial finishing agent for various types of fibers, including cotton, silk, Dacron, nylon and polyethylene fibers. The results of antibacterial experiments suggested that all of the fibers after finishing have good antibacterial efficiency.

Effects of FR Clothing Materials on Sweat Absorption and Comfort in Wildland Firefighter Protective Clothing – Roger Barker, North Carolina State University

Clothing wear comfort is a high priority need of wildland firefighters whose work often requires strenuous sweat generating activity in thermally stressful environments. This presentation describes a study that determined the effects of FR clothing materials and base layers on the amount and location of sweat absorbed in the wildland firefighter clothing. It examines relationships between measured moisture management properties and perceived human comfort response in laboratory wear trials designed to simulate wildland firefighting conditions. It shows the effect of single and double layer protective clothing systems and the effect of a high wicking FR t-shirt material on moisture absorption and comfort in wildland firefighter clothing. It shows the correlations between moisture management tests and wearer perceived moisture sensations in wildland firefighter FR clothing.

Assessing the Needs of Greenhouse and Farm Workers Engaged in Pesticide Application for Improved Personal Protective Equipment (PPE) Design – Sanjay Guria, Cornell University

Appropriate personal protective equipment (PPE) is a basic risk mitigation tool that provides an effective barrier to humans engaged in pesticide application. To validate this concept, a multi-method approach was adopted to record user issues and functional limits to the effective performance of PPE. Eight greenhouse pesticide applicators (4 males and 4 female) and eight farm workers (4 males and 4 female) from upstate New York participated in the study. Information was collected regarding (1) participants’ demography (2) work dynamics and work environment, and (3) issues and concerns related to the use of the PPE. Findings of this study highlighted four key issues related to the existing PPE (i) heat stress (ii) mobility (iii) integrity of the interface and contamination and (iv) behavioral responses.

Assessment of Ventilated Athletic Uniforms for Improved Thermal Comfort and Human Performance – Meredith McQuerry, Florida State University

Due to disproportionate rates of football players experiencing heat illness injuries, there is a need to focus on the thermal comfort of athletes. Clothing ventilation in athletic uniforms may significantly improve thermal comfort. These improvements are especially important for football athletes as they perform intense physical activity in thermally stressful environments. The purpose of this research was to investigate the thermal comfort of different ventilated football uniform designs. Air permeability testing and a human wear trial were conducted to determine thermal comfort properties. Three ventilated football uniforms (mesh, laser micro-perforated, and combination) were evaluated.  Heart rate, perceived exertion, perceived comfort, and thermal sensation were analyzed. Findings illustrate significant differences in air permeability and perceived thermal comfort amongst the three ventilated uniform types.

Development of Holistic Assessment for the Firefighter Protective Hood – Bryan Ormond, North Carolina State University

Chronic exposures to toxic combustion products in the fireground environment are believed to contribute to higher rates of cancers experienced by firefighters.  When used during fire suppression and overhaul stages, the self-contained breathing apparatus protects the highly susceptible respiratory tract from the toxicants in smoke and soot.  However, the simple knit protective hoods that firefighters wear provide minimal protection from particulate deposition on the skin of the face and neck.  Newly developed particulate blocking hoods are available on the market, but the impacts of these additional layers on the thermal protection, thermal burden, mechanical properties, and situational awareness have yet to be fully investigated.  This presentation provides an explanation of the holistic assessment of the protective hood that is being developed at NC State University.