When a fabric enters the market for the use of end consumer, there are several factors that are taken care of prior to that. The fresh and tidy feel of the fabric is attributed to the process of finishing. Finishing involves several processes and treatments that a fabric undergoes after it has been made and dyed or printed. Finishing is the final process that a fabric has to go through. Wrinkle free, smooth surface, stiffer, improved fall and drape of the fabric, water proof, the process of finishing brings to the market fabrics with combination of various properties.


The finishing is broadly classified by the designers and merchandisers as aesthetic finishes, which transform the appearance and feel of the fabric, and functional finishes that improve the performance of the fabric under the specific conditions. Those involved in textile processing categorize finishes as chemical finishes and mechanical finishes, also known as wet finishing and dry finishing, respectively. On degree of permanence, finishes are grouped as permanent, durable, semi-durable and temporary finishes.


These days the demand from the markets pertaining fabrics requires fresh and innovative approach. The textile industry has worked on novel finishing methods. These latest finishing techniques can be textile industry's most powerful tool and a key driver of value. There are several companies that are pursuing these new ideas that help the fabric reach its full potential.


Nanotechnology in finishing adds value to the process. Nanotechnology covers a wide range of technologies concerned with structures and processes on the nanometre scale. Nanotechnology is regarded as an important technology that will influence technological development in near future and will have economic, social, and ecological implications.


tf2.jpgThe technology is suitable to engineer required textile attributes, like fabric softness, durability, and breathability, water repellence, fire proof fabric, antimicrobial resistance, etc. in fibres, yarns and fabrics. The applications and scope of nanotechnology in the area of textiles are widespread. The nano processed garments have protective coating and the protective layer remains almost invisible to the naked eye. The nano finish saves time and laundering cost. The structure of the clothing that involves nano finishing signifies that the size is manipulated to 100 nanometres, thus making the clothing stain and dirt free.


Under the nano finishing, antimicrobial finish is gaining popularity. The intrinsic properties of the textile fibres can induce the growth of micro organisms. These microbes cause cross infection by pathogens and develop odor when the fabric is worn next to skin. In addition, the staining and loss of the performance properties of textile substrates are the results of microbial attack. Basically, with a view to protect the wearer and the textile substrate itself antimicrobial finish is applied to textile materials.


There are some requirements that need to be satisfied to obtain maximum benefits out of the antimicrobial finish. The durability to washing, dry-cleaning and hot pressing should be maintained. The process and the fabric should not have any harmful effects either to the manufacturer, user or the environment. It should comply with the statutory requirements of regulating agencies and should be attuned with the chemical processes. Resistant to body fluids and resistant to disinfections or sterilization are a must requirement.

There are several methods to apply the antimicrobial agents to the textile substrates. It can be done by exhaust, pad-dry-cure, coating, spray and foam techniques. The substances can also be applied by directly adding into the fibre spinning dope. It is claimed that the commercial agents can be applied online during the dyeing and finishing operations. In order to improve the durability of the finish it is recommended that the fibre is treated with resin, condensates or cross-linking agents and insolubilisation of the active substances in or on the fibre is required.


Another popular finish is UV protective finish. A garment must protect the wearer from the weather. However it is also to protect the wearer from harmful rays of the sun. The UV-blocking property of a fabric is improved when a dye, pigment, delustrant, or ultraviolet absorber finish is present that absorbs ultraviolet radiation and blocks its transmission through a fabric to the skin. Metal oxides like ZnO as UV-blocker are more stable when compared to organic UV-blocking agents. Hence, nano ZnO will really enhance the UV-blocking property due to their increase surface area and intense absorption in the UV region. For antibacterial finishing, ZnO nanoparticles scores over nano-silver in cost-effectiveness, whiteness, and UV-blocking property.


These days, the manufacturers also prefer odour fighting finishes. A natural substance tourmaline is used in such finishes. The tourmaline comes in contact with oxygen, carbon dioxide and water molecules that allow an electrolytic dissociation which in turn create negative ions. The negative ions are responsible for creating a magnetic field that fights back the bacteria so the fabric stays odour free. Also there we see another occurrence of infra red consumption that destroys bacteria to make the fabric odour free.


There is another finishing technology - micro encapsulation, which imparts an array of unique characteristics to a garment. Particles filled with active ingredients are applied to the fabric for long lasting effects. Micro encapsulated particles are anchored onto the fibre. With the movements of the wearer, the capsules are activated producing a slow release of the active ingredient. These ingredients include moisturizers, aloe, vitamin E, therapeutic smells and insect repellent. Micro encapsulation technology is also being used to create garments with built-in temperature control systems. Micro encapsulation technology can also be used to cover up odours with fragrances.


The stain resistant finishes are also being used now on a regular basis. It is no longer considered a niche market. Antistatic finishes are also applied to the fabric by chemical means these days. They check the formation of static electricity that can occur due to friction between electrically-insulating fibres. Static electricity can cause serious problems in the aerospace and geotextiles market sectors, where it can cause sparks, possibly leading to fires. Antistatic finishes increase the conductivity of fibres, thus preventing the build-up of static charge.


Today apart from the look and feel, the durability and performance of the fabric are also significant in raising its demand. Textile finishing methods can impart unique traits to the fabric and this can work wonders for the textile industry and also the consumers.


References:


1. Mytextilenotes.blogspot.in

2. Textilelearner.blogspot.in

3. Techexchange.com


Image Courtesy:


1. Asme.org

2. Asknature.org