Advances in coating technology are contributing to the proliferation of improved high-performance, weather-proof fabric. Textileglossary.com describes coated fabrics as “fabrics that have been coated with a lacquer, varnish, rubber, plastic resin of polyvinyl chloride or polyethylene, or other substance to make them longer lasting or impervious to water or other liquids.” Coatings are applied to garments and other fabric products for stain resistance, anti-bacterial properties, waterproofing, UV protection, and to condition fibers so that they feel softer. Polyurethane is a popular fabric coating to make lightweight, comfortable high-performance sports clothes and footwear. Polyurethane coatings are also used on imitation suede and man-made leather to make it similar in appearance and characteristics to real leather.
Structural fabrics—those used to make tents, awnings, and other outdoor structures—are coated with a variety of materials to impart greater strength and/or environmental resistance, depending on the application. These include polyester laminated or coated with polyvinyl chloride (PVC), woven fiberglass coated with polytetrafluoroethylene (PTFE) or silicone. An article on Fabric Architecture provides an overview of the the most widely used coating materials for structural fabrics:
Polyester: Polyester is the most frequently used base material because of its strength, durability, cost and stretch. Polyesters laminated or coated with PVC films generally are the least expensive for longer-term fabrications. For long-term exterior use, heavier materials such as polyvinyl fluoride (PVF) or polyvinylidene fluoride (PVDF) are used to protect against environmental degradation.
Vinyl-coated polyester: Vinyl-coated polyester is the most common fabric for producing flexible structures, such as custom-designed awnings, canopies, walkways, tent halls, smaller air-supported structures and light member-framed structures.
Vinyl-laminated polyesters: Vinyl-laminated polyesters are used for awnings, tents and low-tension frame structures.
Fiberglass: Another widely used base material is woven fiberglass coated with PTFE or silicone. The fiberglass has a high ultimate tensile strength, behaves elastically and does not undergo significant stress relaxation or creep.
The modification of fabrics with surface coatings to add or enhance properties or performance is one of the most enduring areas of surface technology, which can be used to analyze the coating to ensure a particular fabric performs as expected for the application.X-ray photoelectron spectroscopy (XPS) is a quantifiable surface sensitive analytical technique that is particularly well-suited to investigating the surface treatment of polyester fabric. XPS, also known as ESCA (electron spectroscopy for chemical analysis) is ideal for determining the areas where an invisible surface modification, such as a fabric protection coating, has been applied, and also for finding the amount of coating present. It can also be used for quality control of invisible coatings on fabrics and other materials to determine whether they have been applied uniformly.
Our next article will address the experiment of Using X-ray Photoelectron Spectroscopy to Investigate the Surface Treatment of Fabrics, involving a piece of polyester lint-free cloth that was sprayed with a soft furnishings protector. This sample was designed to simulate a possible production failure, where a transparent coating had not applied consistently to a fabric. to see test results using a sample designed to simulate a possible production failure to compare treated and untreated areas of fabric. Stay tuned to find out if XPS can be used for quality control of invisible coatings on fabrics.