GSM means grams per square meter. Fabric weight is expressed by GSM. It has no limits but does affect the many of the fabric properties. Fabric weight is a fundamental property that needs to be controlled during the manufacturing process in order to avoid economic loss, for example, by buying heavier fabric than is necessary for the product being manufactured.
Fabric weight, that is, GSM, influences other fabric properties such as thickness, flexural rigidity, bending rigidity, drape, air permeability and thermal properties. For example, the lighter the fabric, the lower its bending rigidity.
GSMis an important parameter of knitted fabrics which is very essential for a textile engineer for understanding and production of fabric. In order to satisfy the quality demands of consumers the engineers have to control fabric GSM. Yarn count is very crucial parameter for variation of GSM. By this we can compare the fabrics in unit area which is heavier and which is lighter.
The GSM of knitted fabric can be adjusted very easily by varying yarn count, without altering the stitch density or loop length.
Mass per unit area (weight) of the fabric sample is determined by using the GSM cutter. In order to determine the weight per unit area of the fabric samples of 113 mm diameter are prepared from different places by the help of GSM cutter. Five random samples are prepared and the weight is determined by the help of weighing balance. Sample weight is determined in grams; it is divided by the constant (0.01) in order to determine the gram per square meter. Gram / square yard can also be determined by this method.
Fig” Measuring GSM of knitted fabric
Apparatus & Sample:
GSM cutter
Electric balance.
Knitted fabric
Working Procedure of Measuring GSM of Knitted Fabric:
For Measuring GSM, fabric sample is cut by GSM cutter.
Now weight is taken by electric balance.
By this way we get the weight in gram per one square meter fabric.
Here GSM of the fabrics by the GSM cutter is obtained by the multiplying the sample weight with 100.
How to Control GSM in Knitted Fabrics? GSM is broadly dependent on stitch density (cpi × wpi), loop length and yarn count. In general, if the stitch density is high, if the yarn diameter is large, or if the yarn is heavy, the GSM will increase proportionally. However, if the loop length is high then the GSM will decrease, as stitch density decreases at a higher rate to the increase in loop length. For double jersey fabric, the additional factors of knitting timing and the gap between the two beds can also cause variation.
GSM is affected by variation in a large number knitting parameters. Therefore, in order to control GSM, these parameters need to be controlled. Depending upon the requirements of the consumer, GSM is mainly controlled by changing the stitch cam setting, the yarn input tension and the yarn count.
Founder & Editor of Textile Learner. He is a Textile Consultant, Blogger & Entrepreneur. He is working as a textile consultant in several local and international companies. He is also a contributor of Wikipedia.
