Metal corrosion inhibitor

Excerpt: WET processing of garments is gaining importance now-a-days. Apart from washing and cleaning, it can impart artistic and innovative look to the garments

WET processing of garments is gaining importance now-a-days. Apart from washing and cleaning, it can impart artistic and innovative look to the garments. Today innovative processing of garments such as antimicrobial, wrinkle-free, water resistant, moisture management finishes leads to their value addition. Besides, different effects viz., distressed or worn-out looks, stone-washed, soft handle, creasing can be imparted. There are various types of effects achieved by different garment washing methods, such as bleach wash, stone wash, enzyme wash, sand wash, etc. These effects attract the immediate attention of consumers and are in demand by fashion industry. Aesthetic value addition by the application of a fashion treatment make a garment more appealing. Garment processing is an emerging technology which is governed by the latest trends in fashion and provides higher earnings.

Fashion industry utilizes metal trims such as buckles, zippers, eyelets, rivets, buttons, or snaps to impart a contemporary look to a garment. These metal accessories, on contact with concentrated chemicals during processing, can get corroded, eventually affecting aesthetic properties of the garment. Metal corrosion may cause staining on the adjacent fabric or material and also affect the function and appearance of the metal trim, e.g. buckle, metal hook. Corrosion is the destruction of metal materials resulting from chemical or electrochemical reactions during processing or with the environment. Rusting, the formation of iron oxides, is a well- known example of electrochemical corrosion.

This type of damage typically produces oxide(s) or salt(s) of the original metal, and results in a distinctive orange colouration. Corrosion can also occur in materials other than metals such as ceramics or polymers. Corrosion degrades the material's strength, appearance, and functionality.

Such rusting, discoloration of fabric and impaired functionality of metal accessories is unacceptable at customer end. It is important to realize that corrosive attack on a metal can only occur at the surface of the metal, hence any modification of the surface or its environment can change the rate of corrosive reaction. Corrosion processes, being surface reactions, can be controlled by products known as inhibitors which adsorb on the reacting metal surface.

With the development of the garment industry, the new materials, new techniques as well as the washing process and post-treatment of the ready-to-wear products have witnessed increasing diversification. A wide range of products are developed for garment wash to achieve various effects. However, garment washing may have an adverse effects on the quality of metal accessories attached to them if special care is not taken, making them fail to reach the standards as expected and reduce their service life regardless of the superior quality materials they are made from. The copper alloy will react with such chemicals as the acid, alkali, oxidizing agent, reducing agent and sulfide, which will result in the discoloration and rusting of metal.

Keeping in view the customer's problem, Sarex has developed Heflor-CI (Conc) which is a passive inhibitor for metal corrosion when it comes in contact with chemicals. This product protects metal from corrosion during processing/dyeing of garments with metal buttons/zips, especially made up of alloy.

Unique Features

  • Protects zippers/buttons from corrosion during garment washing.
  • Prevents stain formation on garments due to metal accessories.
  • Wide pH stable (stable from pH 3 - 13). Corrosive and passive inhibitor for metal. - Does not affect shade of dyed garments.

Recommended procedure

0.5-1.0 g/I Heflor-CI (Conc) to be added at room temperature before addition of dye.

Note

  • Heflor-CI (Conc) can be directly dosed in machine.
  • Heflor-CI (Conc) not to be used with chlorine- based oxidizing products.

Test Methods

The corrosion resistance properties can be assessed by below testing methods.

  • ASTM B117:2009 - Standard practice for operating Salt spray(Fog) apparatus
  • ASTM D2059 - Standard test method for resistance of zippers to salt spray(Fog)
  • ISO 9227:2006 - Corrosion test in artificial atmospheres: Salt spray tests
  • ISO 7384:1986 - Corrosion tests in artificial atmosphere: General requirements

Author Details

Dr. Naresh Saraf

Sarex Chemicals

A division of Saraf Chemicals Ltd., Andheri (W), India