Textiles Industry Guide for Universal Testing Machines
The global market for textiles is close to $1 Trillion dollars and is growing at about 5% per year. Over half of the world's production is in China, however many performance textiles are researched and developed here in the United States. The market is slowly returning and the industry has once again achieved growth as international manufacturers move back to southern states like the Carolinas and Georgia. In 2015, the United States Textile industry shipped about $20 Billion in product. There are an estimated 50-100 textile mills operating in America.
How to Configure a Universal Testing Machine for Textiles Testing
Many types of physical textile tests including puncture, tear and tensile can be performed on a Universal Testing Machine. Each ASTM procedure is slightly different and requires a specific grip, or grip jaw. Many technicians will find themselves switching grip jaws out frequently. Universal Grip offers Vise Grips with a special Quick Change carrier system. The carrier allows the user to switch the grip faces out easily and quickly.
Introduction to ASTM Testing for Textiles
ASTM D5035 - "Strip" Tensile Test - uses a pair of Vise Grips to pull the sample apart from two ends. The vise jaws much be wider than the sample. Usually a 1" wide sample is tested. Its important that the breakage does not occur adjacent to the grip jaws, the break must occur somewhere in the middle.
ASTM D5034 - "Grab" Tensile Test - also uses Vise Grips, however the grip jaws are slightly different because they must grab the middle of the sample. The grip jaw is usually 1x1" or 25.4x25.4mm smooth although in some cases testers will use 2" tall, 1 " wide grips. For stronger materials, serrated grip faces are used, however the smooth style are more common to avoid tearing of the sample.
ASTM D751 - Coated Fabrics - covers a series of tests for fabrics which are coated with an outer layer of material. There are over 10 different tests listed under this specification, so the configuration can be different depending on which test is being performed. The tests include those for tensile, puncture and tear strength.
ASTM D1388 - Fabric Stiffness by Cantilever Method covers a very basic bend test to determine the stiffness of a fabric under its own weight. The fabric is slowly slid out from a platform and allowed to bend until it hits the angled ledge. Once the fabric touches the ledge the measurement is taken.
ASTM D3787 or ASTM D6797 Ball Burst Test - uses the same puncture fixture. The diameter of the puncture plunger is 1" or 25.4mm and is attached to the top arm with a clevis pin style adapter. The base of the fixture has an opening of 44.45mm and is attached in the same way to the base of the machine.
ASTM D3822 - Single Fiber Tensile Test - uses a style of rope grip which wraps the single fiber around a winding drum. The breaking force as well as the total elongation at break can be measured with the Galdabini tensile tester automatically. This test is easy to perform and can come pre-configured on all new machines.
Software for Textiles Material Testing
Configuring a tensile testing machine takes about 10 minutes for an experienced user, and about 20 minutes for a beginner. The Galdabini tensile testing machines are extremely flexible and can handle everything from basic Constant-Rate-of-Extension (CRE) pull tests, to more advanced tear testing where averages of peaks and lows must be taken and calculated. Unlike other software control systems, The Galdabini Graphwork 6 software is 100% unlocked and ships complete with an extensive library of standard test methods. Universal Grip can also pre-program the machines for specific test methods that are not already contained in the test library. Check out the video below on how to set up a basic tensile test.