TENSILE SHADE FABRICS

Today's architectural fabrics are composites of woven substrate fiber protected by an applied coating. New fibers, primarily nylon, polyester, polyethylene and fiberglass, have been developed to fill the need for materials with high strength, longer life spans and a high modulus of elasticity. The woven substrate provides the basic tensile strength of the material and its resistance to tear. The finish coating applied to the substrate material seals the fabric against weather and dirt, provides resistance to ultraviolet light, functions as a medium for joining panels and, in some cases, incorporates fire-resistant chemicals.

Fabric manufacturers report that architectural fabrics can be manufactured to vary in translucency from 1% to 80% and, in thermal resistance, from a single pane of glass to that of a conventionally insulated structure, while still maintaining adequate day lighting. The roof can be a source of light at night by directing artificial light on its highly reflective surface.

A variety of fabrics with varying degrees of transparency pave the way to new architectural dynamics. Modern fabrics combined with high-performance materials can be utilized for their specific properties such as UV resistance, low maintenance, and non-combustibility. These materials and fabrics are used to create shade within an aesthetically pleasing form while retaining excellent engineering properties.

The performance of today's architectural fabrics depends upon the weaving pattern, choice of substrate, and coating. Each type of composite has unique properties and characteristics that suit it to different applications. The proper selection of membrane material is based on the proposed structure's size, form, function, project economics, and desired longevity.

 Structural fabrics in common architectural use today include:
  • Teflon Coated Fiberglass (PTFE)
  • Vinyl Coated Polyester (PVC)
  • High-density Polyethylene (HDPE) woven mesh - Shade cloth
HIGH-DENSITY POLYETHYLENE (HDPE)

HDPE or Shadecloth is a mesh material manufactured and used in a variety of ways. This material can be made for agricultural shading or engineered and woven for structural purposes. Shadecloth comes in a variety of styles, colors and shade factors.

HDPE membranes are not waterproof. This material is sewn using industrial sewing machines. Typically, High Density Polyethylene carries a warranty for up to 10 years.

VINYL COATED POLYESTER (PVC)
 PVC is the most cost effective material membrane material and therefore an ideal choice for both temporary and permanent tension structures. The fabric came into prominent use in the 1960's replacing nylon, which had been used almost exclusively until that point. The material is soft, pliable and less expensive than PTFE. It is available in a variety of types to meet a wide range of structural requirements. It has a minimum of stretch and shrinkage in a wide range of temperature and humidity conditions and the coating process prevents mildew, stain and streaking.

PVC material has a life span of 5-10 years. It comes in a variety of colors and textures. This material is sealed using radio frequency (RF) equipment. Most PVC fabric producers have 5-10 year warrantees on their material.

TEFLON COATED FIBERGLASS (PTFE)

PTFE is used worldwide as the preferred material for large-scale permanent structures or structures with specific construction code compliance requirements. PTFE has excellent weather, temperature and chemical resistance in addition to its durability and strength. This material has a life span of over 25 years, varies in translucency from 7% to 15% and reflects between 68%-75% of incident sun-light. The quality of light transmitted is color balanced, diffused and free of shadows and glare.

Before installation, PTFE has an irregular off white or slightly brown color, which is caused during the manufacturing and fabrication process. Once exposed to direct sunlight, the external surface of the membrane bleaches to a milky white within a matter of days. PTFE is the obvious option if long life and low maintenance are the most important factors in selecting a fabric. This material requires heat-sealing at the seams to joint fabric pattern sections. Warranties for PTFE range from 10 to 15 years.