Shade has been a requirement for human beings since ancient times, but very little technological development related to shade occurred until the last 30 to 40 years, said Andrew Nasarczyk, senior manager—research and development, GALE Pacific Ltd., Braeside, Victoria, Australia.
Nasarczyk explained the design and development of world-class knitted shade fabrics in an educational session at IFAI Expo in Orlando, Fla.
HDPE (High Density Polyethylene) knitted shade fabric offers high strength, good UV resistance and is recyclable. The fabric lends itself to shade structures with interesting shapes and colors, and it’s durable and easy to clean. As the market matures, shade fabricators will push the limits of design, Nasarczyk said.
In the presentation’s manufacturing overview, Nasarczyk walked attendees through the processes of fiber extrusion, warping, knitting and heat setting of two HDPE types, monofilament and tape yarn, along with the advantages and disadvantages of each type.
Common testing parameters include fabric weight, tensile strength, tear resistance, burst force, biaxial stability and flame retardancy. The fabric’s Achilles heel, Nasarczyk said, is that because it is an oil-derived product, its inherent flammability isn’t ideal. Different jurisdictions have different requirements for flammability tests, which makes it challenging to figure out if a fabric is in compliance with local codes. Flame retardants are also a “tricky additive,” he said. The retardants themselves are an environmental contaminant, impact UV life, and affect color, so manufacturers have to adjust their own pigment to account for that fact.