Summary and Conclusions
The theory of water repellency of textile fabrics has been reviewed with special references to the more recent theory of the wetting of fabrics by water. A survey has also been made on the various testing methods that have been devised for measuring water repellency. The results of the present investigation lead to the following conclusions regarding the status of water repellency. There is a definite need for a comprehensive study of the role that the structure of a fabric plays in the phenomena of water repellency. Students can take these projects and develop the products in their workshops, chemical laborite and test them in the testing laboratory.
In the past, the emphasis has been on developing more efficient compounds. Data available indicate that a better understanding of fabric construction as it applies to repellency, coupled with the now available water-repellent agents, will lead to some more nearly idealized type of water-repellent garment. In regard to testing methods, it is required that correlation is established between the Water-Repellent Fabrics results of laboratory test methods and performance of fabrics.
As already stated, the contact angle is influenced by the following factors: The’ chemical nature of the solid surface, the porosity of the surface, and the presence of other molecules on the surface. Again, any one or all of these factors could diminish the contact angle during wetting of the fabric. The change will indicate moisture regain of the sample which will show that the rate at which a fabric absorbs moisture increases the proportion to the number of times the sample has been wetted. It is of interest to re-exam the surface factors that might be responsible for the increase in moisture absorption.
The loss in the repellent agent, the change in position of the fibers in the yarns, and the creation of new surface could all affect the rate of water absorption. The swelling of partially coated or uncoated fibers would also result to make available more hydrophilic surfaces (OH groups). Now, a team at MIT has come up with a promising solution: a coating that not only adds water-repellency to natural fabrics such as cotton and silk but is also more effective than the existing coatings.
The new findings are described in the journal Advanced Functional Materials, in a paper by MIT professors Kripa Varanasi and Karen Gleason, former MIT postdoc Dan Soto, and two others.
Closing Remarks
Now that you know that “water-repellent” is a characteristic, and understand the differences between water-resistance and waterproofness in fabrics, you should have a newfound sense of reassured confidence when purchasing the perfect product that meets your needs. Being mindful of label descriptions can greatly assist you in deciding whether a product will be suitable for the conditions that you expose it to.
Thank you for the detailed explanation Mr. Ashok Haboo. It has been very helpful for a new merchandiser like me. I have recently started a textile startup called
swagswami.comSwag Swami and we are in the process of developing new breathable activewear for the Indian Market. This article has helped me a lot!Thank you once again Sir!