Ontario - Hitesh Sharma, president, International Federation of Knitting Technologists, Canada/US section, has published the technical details of a fine gauge fabric innovation that can be manufactured on superfine gauge circular knitting machines for facemask applications.
Knitted H-97 LoopCluster material, knitted with a higher gauge and lower pitch, uses a special type of sinker and additional interlocking loop casting-off technology to ensure maximum virus protection.
During research, the material also has limited possibilities for production on flat knitting technology due to the machines higher pitch value and limited gauge availability e.g. 18 other technical variations compare to circular knitting technology.
The LoopCluster material prevented the entry of glycoprotein spikes existing in coronavirus while breathing and stops these virus droplets spreading in the air when a mask is worn. These droplets and other small particles can easily land on other people, clothing and surfaces around them, but the LoopCluster material can easily control/hold the smaller particles in the air while sneezing and coughing.
The study shows that the virus can survive in droplets for up to 3 hours after being coughed out into the air. Fine droplets between 1-5 micrometres in size – about 30 times smaller than the width of a human hair can remain airborne for several hours in still air. However, copper surfaces tend to kill the virus in about four hours, although it can live on plastic and stainless steel (up to two to three days) and on cardboard (24 hours). This material can be produced along with 20 denier filament carbon, copper and silver filaments to enhance its antiviral properties.
This single layer mask material has to actually filter out the virus. The H97-LoopCluster is capable of filtering out about 97 per cent of particles of all sizes from the air. This includes something less than 0.1 microns in size. That’s the case with many types of fabric. Even when you use several layers of fabric, it may have too many holes. Usually, a layer of a handkerchief is only going to filter out less than 12% of particles. The filter material for H97-LoopCluster doesn’t just physically block viruses and other small particles as well. As the process goes, you can’t see it, it's electric.
During the manufacturing process, the fibres receive an electric charge. This electrostatic charge then attracts the virus so that it gets stuck on the fibres and loop cluster chambers itself. Coronavirus particles are spheres with diameters of approximately 0.125 microns (125 nm). The smallest particles are 0.06 microns, and the largest are 0.14 microns.
Particles filtered by mask material are =0.007µm. Coronavirus size=0.1µm, Bacteria =0.5µm
The activated-carbon material absorbs viruses. Polyacrylonitrile based activated carbon fiber are superior to pitch-based, cellulose-based, and Phenol resin-based activated carbon fibres for mechanical strength and absorbency.
Because of its conductivity, the carbon fibre absorbs and disperses electric charges accumulated from the environment or during mask on. Carbon yarn can prevent the electric charges from discharging on the body, therefore avoiding muscle contractions, cramps and fatigue. Carbon improves the electrical performance of the human body by promoting blood circulation and the regular supply of oxygen to the cells, offering an increase in resistance and reducing the sense of fatigue in the face muscles.
It speeds up the evaporation process, slows down the build-up of skin moisture created by droplets while sneezing and keeps the face at constant temperature, especially in the summer time.
Carbon also allows a quick dispersion of sweat, inducing sweat evaporation. The less sweat comes in contact with the skin, the greater the well being feeling, a comfortable wear that we can define “wellness even under pressure”. Another peculiarity of our yarn is the feeling of wellbeing, connected to the high level of conductivity of the yarn.
It protects the face from absorbing static energy, electro-smog, UV rays and control direct virus attack.
Technical Material Data: H97-LoopCluster
1. Air permeability=60.2 *tested on Frazier precision tester rating in cubic feet per square foot of fabrics per minute @30” of Murcury,70-degree F and 65% relative humidity.
2. Yarn Polyfilament (423.6 Micronaire)
3. Looping qty: 34x54= 1836/2 =918 LoopCluster per square inch
4. Mask size 6”x7” =42 Square inch. Then in each mask contain of: 42x918=38,556 Looping cluster
5. Looping height=2.65mm.
6. Material weight=14.15 ounce per square yard.
7. Material Thickness =0.44 mm (compare to 0.34 mm normal surgical mask)
8. Loop size=Front side 0.355mm and Backside 0.275mm