Odour formed due to perspiration or sweating is the daily problem faced by all humans. This causes discomfort to the wearer, physically as well as mentally. The consumer demands of fabric which absorb as well as release moisture effectively increases day by day along with the problem of heat rising. To make sure that the wearer is in a good environment, aroma finishes are applied to the fabrics. When the finish applied fabric is abraded, the aroma capsules burst and produce fragrance. (Suganthi, 2010)
Introduction to the finish
Our country has a rich culture of inventing varieties of medicines using herbs to cure various diseases for the welfare of the human community. In recent years, there is a shift seen their use due to their properties of low toxicity, economic viability and pharmacological activities. The awareness of natural products has increased, as they are not harmful, are more biodegradable and have multiple health and wellness benefits as compared to the chemical and non-sustainable products. (Cerempei, 2016)
Multiple finishes are being applied in the field of textiles on the fabrics for numerous reasons. The aroma or fragrance is a pleasant smell or odour present in food, spices, oils and essential oils. They are known as ‘aroma compounds’. Fragrances in form of essential oils and aromatic compounds, when applied on textile materials, give the textile a pleasant odour that gives the wearer maximum beneficial effects. This process is known as Aroma Finish or Aromatic Finishes.
In 1982, the term ‘aromachology’, a study of the relationship between psychology and fragrance technology which bring forth a variety of specific feelings and emotions such as relaxation, happiness and well-being came into existence.
There are many textiles materials that come in contact with microorganisms which cause bad odour, and they don’t remain fresh for long. The aroma finish when applied to these materials add value to the products for use. Aromatic textiles makes the user feel fresh and infuses a feeling of well-being. These textiles are also used in medical and alternative healing fields.(Uzzal, n.d.)
Agents used in finishing
The agents commonly used for Aroma Finishes include essential oils like lavender, basil, rose, clove, jasmine, etc. which have the aromatic compounds. They are applied on the fabric with the assistance of Chitosan in microencapsulation method. Similarly, silicone softener is used in padding method of application. The oils aren’t soluble in water thus, propylene glycol is used to make them soluble in water. (Avernita Srivastava, n.d.)
Mechanism of the finish
The essential oils are oil-based compounds which require a binding agent to link them with the fabric surface. The mechanisms commonly used are pad-dry-cure method and microencapsulation method.
- PAD-DRY-CURE METHOD:
The fabric piece is dipped into the solution of the essential oil and water, passed through the padding mangle. Squeezing of the treated sample between two rollers for penetration of the finish which is followed by air drying and curing. The solution only penetrates in the fibre surface.
Microencapsulation is defined as a process by which individual particles or droplets of solid or liquid material (the core) are surrounded or coated with a continuous film of polymer material (the shell) to produce capsules.
Process of finishing
PREPARATION OF THE RECIPE
The fragrance agents with the binder was formed with a solution with alcohol and water ratio (1:3). The solution is emulsified with a mixer at speed of 10,000 rpm for 5 minutes. The fragrance solution is added to the emulsified solution for 30 minutes and stirred for 2 hours at 400C temperature.
The finish is applied on the fabric with exhaustion method, where the fabric is kept in the solution for 20-30 minutes with the ML ratio – 1:10 at 400C in water bath. The fabric is then squeezed and dried in the oven for 5 minutes at 1000C and cured at 1200C for 2 minutes. (D. Vasanth Kumar, n.d.)
Washing of the aroma treated fabric in domestic washing machine is carried out to find how long lasting the fragrance is on the surface. The durability of the fragrance should last up to 7-8 washes.
Testing the treated fabric with a perspiration treatment between two laundering cycles, simulating a daily wear condition. This gives a proper understanding of the working of the fabrics performance in wash-use-wash conditions. (Snehal, March 2007)
- Subjective Evaluation of Aroma Finish
The subjective evaluation of the finish is done under the Odour Intensity Referencing Scale (OIRS). Its criteria is as follows:
- No odour,
- Very Faint odour,
- Faint odour,
- Distinct odour,
- Strong odour,
- Very Strong odour,
- Extremely Strong odour(Suganthi, 2010)
Health and environmental issues
The skin is the most sensitive organ of the human body. It is the entry point for many materials into the body. Aroma compounds can be irritants, or allergens and can have many negative effects on the skin.
Aroma compounds can worsen or induce respiratory problems, triggering asthma, allergies, sinus, and many others caused due to irritants.
- Systemic effects
The compounds can enter the body through many ways as inhalation, ingestions, olfactory paths as well as absorption from skin causing an impact to any organ or system of the human body. (Bridges, 2002)
Uses-end user based
- Home Textiles such as bedsheets, curtains, rugs, quilts, carpets, etc.
- Apparel such as socks, undergarments, gloves, etc.
- Sports Wear
- Aromatherapy Textiles – When aroma finish on textiles is used for healing purposes, the textiles is categorized as Aromatherapy Textile. (Priyanka, 2007)
The aroma or fragrance is a pleasant smell or odour present in food, spices, oils and essential oils. Fragrances in form of essential oils and aromatic compounds, when applied on textile materials, give birth to aromatic finishes on textile materials. These are used in our daily utilization products with multiple benefits.
Article written by:
Arwa Aamir Kalawadwala
M.Sc. in Textile and Fashion Technology
College of Home Science, Nirmala Niketan.
Textile Value Chain Intern.