Super Absorbent Polymers and Fibers
Updated: Nov 22, 2021
What is Super Absorbent Polymer?
Super Absorbent Polymers are polymers that can absorb liquid more than a hundred times of their weight and do not release the liquid they withdraw under pressure. They are not toxic. These polymers are used in diapers, adult pads, feminine hygiene products, absorbent medical apparel, agricultural and other industrial applications.
Where, When, Why Was It Developed?
When we look at the history of superabsorbent polymer chemistry, it was not used commercially until the 1980s. Until the 1980s, we see that mostly cellulosics and cellulosic fiber-based products were used as water absorbing materials. Such materials, on the other hand, have the power to store liquids up to 20 times their weight. In the earlies of 1960s, a resin was developed in an agricultural engineering department (USDA) in the United States in the light of material discovery efforts to improve water conservation in the soil. This resin is obtained by grafting acrylonitrile polymer on molecules whose backbone is starch. This starch-acrylonitrile copolymer was able to absorb up to 400 times its weight in liquid when hydrolyzed. In addition, it has been observed that the gel-like structure that occurs when they are produced on a fiber basis does not release water or liquid. These polymers were first called “Super Slurper”.
USDA provided the necessary infrastructure information to the American companies in order to develop this technology. After this point, studies generally continued in the direction of acrylic acid, acrylamide and polyvinylalcohol combinations. Japanese companies that are aware of these studies have also continued their studies on starch, CMC, acrylic acid, polyvinylalcohol, isobutylenemaleicanhydride (IMA) structures independently of the USDA. Dow Chemical, Hercules, General Mills Chemical, DuPont, National Starch & Chemical, Enka(Akzo), Sanyo Chemical, Sumitomo Chemical, Kao, Nihon Starch and Japan Exlan companies introduced products with superabsorbent chemical structure to the market for the first time in the world.
Super Absorbent Fibers
SAF can be converted into a wide range of superabsorbent fabrics and spun yarns. When blended with other fibres – and fabric layers – the amount of different product variants that can be achieved is endless. Within these converted products, distribution of the SAF is homogeneous and uniform. The fibres are entangled and fixed in the structure with minimal migration, resulting in consistent absorption performance and no dusting.
In Which Areas Are Super Absorbent Fibers Used?
Super absorbent fibers are used in many products other than textile products. Below are some uses of superabsorbent fibers:
Industrial Cables: Water Blocking Telephone and Electric Cables
Medical: Wound Care and Dental Absorbent
Disposable Products: Female Hygiene Products
Textiles: Geotextiles, Protective Clothing and Filters
Gardening: Seed Planting Surfaces and Construction Fabrics
Food Packages: In Frozen Meat and Chicken Packages
Effect of Super Absorbent Fibers in Contact With Skin
Skin problems from absorbent hygiene products such as diapers, sanitary napkins and adult diapers are mostly caused by weather conditions and rubbing. If these conditions are dominant, irritating disorders on the skin and superficial skin infections may occur afterwards. Skin moisture and skin aging are the most important factors in the formation of skin diseases. People with sensitive skin and skin diseases should take care to choose high-quality products that contain super absorbent polymers, the outer surface of which is water vapor permeable, despite skin conditions. Covering the skin causes moisture to accumulate on the skin. This accumulated moisture is also an important factor in the formation of skin disorders. Other factors can be shown as temperature, friction, pH and pressure. Contrary to popular belief, there is very little allergy caused by diapers and their materials.
Developed Fibers, Yarns and Fabrics to Increase Clothing Comfort
This is a commercial fabric with high air and moisture transfer properties. It is produced from PES or PA. The fiber has a special micro-channel cross section. Thus, it gives the person less feeling of wetness caused by sweat compared to conventional PES and PA. Although it is washable, softener and chlorine should be avoided during washing.
It has been proven by the tests that Coolmax, which is superior to other fabrics, keeps body temperature and heart rate low. Its biggest feature is that it combines the properties of different fabrics. In this way, the sweat of the athlete in performance is transferred to the outside with the unique feature of the fabric before it dries on the body, preventing the jersey from getting heavy. Thanks to this feature, the performance of the athlete increases by getting rid of factors such as sweat and jersey weight. As seen in the figure, when the drying feature of Coolmax fiber is compared to other fibers, at the end of 30 minutes, the closest fiber is 86%, while Coolmax has become 100% dry.
This fabric has bi-component fiber structure, namely; polyamide is on the outside while polyester is on the inside. Thus, moisture on the skin can be quickly transferred to the outside atmosphere. Dryline fabric contains 63% Nylon, 25% Polyester and 12% Lycra fibers.
This is a double layer knit fabric. While one layer is in contact with the skin, the outer layer dries quickly by transferring moisture. This fabric is produced from polyester microfibres. The threads used on both sides are different. This fabric keeps the skin dry thanks to three complementary mechanisms:
The fabric has high air permeability and prevents sweat from staying on the body.
The fabric in contact with the skin absorbs the sweat on the body surface, then the moisture is quickly transmitted to the 2nd surface of the fabric. Polartec provides at least 30% more moisture transfer than Power Dry layered fabrics.
When the sweat rate in the outer layer of the fabric reaches its maximum, the outer surface expands to several times the normal surface area, thus drying more than 2 times faster than cotton.
Obtained from natural and synthetic fibers. Natural fiber absorbs moisture, while synthetic fiber quickly transmits moisture to the outside atmosphere. Fabrics made from these fibers have a drying rate 4 times faster than cotton.
UÇAR, Nuray. Örme Kumaşların Nem Alma Özelliklerinin Geliştirilmesi. Yüksek Lisans Tezi, İstanbul Teknik Üniversitesi Fen Bilimleri Enstitüsü, 2010.
Super Absorbent Fibre, https://www.exploresaf.com/?fibre
Emicilik Özelliği Geliştirilmiş Lifler 3.Bölüm. http://tekstilkutuphane.blogspot.com/2011/02/emicilik-ozelligi-gelistirilmis-lifler_9616.html