Can’t cut it, can’t pierce it, can’t puncture it

Imagine a material that you can’t cut, can’t pierce and can’t puncture. It sounds like a material that might be so thick you would never be able to bend it. Think again. SuperFabric is a new material developed in the US by Higher Dimension Research that also retains the ability to flex, bend, and stretch. Other properties, such as elasticity, can also be incorporated into it either through its structure or through the choice of chemical materials used in the manufacturing process.

SuperFabric can be made from a variety of materials. The basis of the design of the fabric is not due to the material properties of a specific family of chemical materials. Specific material properties such as dielectric strength, tensile modulus, flexural strength, coefficient of friction that are required for particular applications of SuperFabric dictate the choices of materials used to make specific products. Metals, plastics, ceramics, and composites can be used to make SuperFabric depending on the target applications.

The material can also be made in a variety of thicknesses. For example, material that is about 1mm thick can be used for products that require the highest degrees of dexterity and tactility. Potential applications in this category include surgical gloves, and even space suits for Shuttle astronauts. Robust SuperFabric, several millimetres thick to many inches thick can also be made.

Other types of properties that can be controlled by the material include air barrier and fluid barrier effectiveness. One version can prevent the passage of needles and other sharply pointed objects while simultaneously permitting free air-flow through the fabric. Another version can provide cut, tear, pierce, and puncture resistance with bio-hazard fluid protection.

Similar in cost to other high-performance protective fabrics, it can be produced in large sheets or rolls to complement conversion processes. It can be sewn into pockets in a cut and sew product or laminated to a variety of substrates.

The physical and cosmetic properties of SuperFabric can be custom engineered and optimised to give the desired combination of cut/puncture protection, durability, tactility, and dexterity, for each particular application.

To demonstrate the mechanical protection which can be achieved, HDM conducted tests at a reputable independent testing facility. TRI/Environmental, Austin, TX, served as the independent laboratory to determine the puncture and cut resistance of the material.

The puncture resistance of a fabric is conventionally measured by the ASTM D1342 test. This measures the maximum base required to face a sharp probe completely through the fabric. The standard probe used is much wider than a needle; it resembles a nail but is subjected to strict constraints in material, sharpness, and angle of the conical tip.

To measure puncture resistance to a surgical needle, the normal test was modified by replacing the standard probe with a B-D 21G1 Precision Glide needle. Compared to three competitive glove products, SuperFabric was up to 17 times more puncture resistant than current available leather glove products which use Spectra or Kevlar liners, and nearly six times more puncture resistant than the Kevlar gloves with coated fingertips.

The cut resistance performance of each of the samples was determined by the standard ASTM F1790 test using the Ashland CPP Cut Test Device. In this test, the measured quantity is the grams of force placed on a razor-type blade that will cause a cut through the fabric with 1in of blade travel. The SuperFabric glove has a cut resistance which rivals the very best glove products on the market.

SuperFabric contains macroscopic, zig-zag shaped pores which span the thickness of the fabric. This enables both gases and liquids to easily pass through the structure. Structurally, this is quite different from fabrics which have a microporous structure and actually are `air trapping’ when stacked in layers. Thus protective garments constructed from the material have the ability to cool the body via evaporative cooling.

Further clues to the design can be gleaned by examining the patents that are referred to on the company web site at www.superfabric.com. The company patent refers to a puncture and cut resistant fabric comprised of identical platelets and rivets arranged into an array whereby the tops of adjacent platelets are reversed so that tabs on each platelet slidably engage with tabs of each adjacent platelet. These are held in engagement by hooks from each tab and the rivets placed through apertures formed by the edges of the tabs.

SuperFabric can be custom engineered and optimised for each product application. Thus performance properties can be controlled. The specific SuperFabric design parameters and choice of materials will determine the thickness and aereal density.

Information: HDM Tel:+1 (651) 730-6203