Glass Fabric Properties and Selection Criteria for Technical Fabrics
Various characteristics are needed for choosing the most suitable fabrics for a particular need and, in most cases, a compromise between the following characteristics is needed to obtain maximum overall performance:
Technical Fabrics are manufactured in a large variety of thicknesses, from 0,02 up to 1 mm and more.
The weight varies from 20 g/m2 minimum to more than 1000 g/m2. A given weight can be achieved in several ways depending on the construction and yarn count used which, in turn, affect fabric performance; so particular attention has to be placed on the best fabric composition for the given application.
The number of warp and fill ends per cm; together with yarn count, construction may influence fabric stability, crimp and mechanical performance.
Yarn count refers to the weight of the yarn used in any particular fabric.
In the SI system, the main unit for defining glass count is the Tex (or dTex where Tex=10 dTex).
1 Tex is the linear mass in 1,000 m length.
I.E.: Tex 34 means that 1,000 m of that yarn weigh 34 g.;
Tex 34 1×2 yarn consists of 2 twisted strands Tex 34 plied together: 1,000 m yarns weighs 68 g.
It represents the way warp and fill yarns are interlaced. Weave Pattern covers an important role in fabric stability, crimp, drape-ability and, indirectly, on mechanical performance of the fabrics.
Plain weave, where warp fibers are interlaced each time they meet weft fibers, is the most common pattern used in the Technical Fabrics as it is the most stable and balanced; however, when fabrics must conform to sharp profile changes, lower crimp or some specific designs are required, Basket, Twill, Satin or UD Weave Patterns can be adopted.
Normally, if no other indication is given, this information is the minimal value of tensile strength based on untreated fabrics. Tensile strength largely depends on fiber type; within a given fiber type, yarn count, construction and weave pattern influence it.
For glass fabrics which have passed through a heat cleaning treatment (112 Finish) a loss of tensile strength is common and it varies from fabric to fabric. However, a subsequent Finish application helps fabrics to recover some of such tensile strength drop; such strength recovery depends from finish type and content.
Likewise, Technical Fabrics made of other fibers that are scoured or thermally treated, may show a drop in tensile strength from the original fiber strength.
Generally Technical Fabrics are used in conjunction with other materials. As a consequence it is necessary to study an adequate compatibility through the application of coupling agents or through fabric surface preparation by means of Finishing treatments.