The largest use of SAP is found in personal disposable hygiene products, (such as baby diapers and sanitary napkins), but also in agriculture and horticulture retention agent, control of spill and waste aqueous fluid, products like air fresheners and crafts, or artificial snow for motion pictures and stage production. SAP is also used for blocking water penetration in underground power or communications cable. The first commercial use was in 1978 for feminine napkins in Japan and disposable bed liners for nursing home patients in the USA.
Also known as water crystals, water diamonds or soil polymers, SAP is a product 100% environmental friendly. The uses of SAP in agriculture and horticulture applications, are wide spread in seed germination, bedding plants, trees and shrubs, root dipping or transportation and transplant aid for turf. It is specially recommend adding SAP to container plants, like window boxes or hanging baskets. SAP will significantly reduce water depletion while dramatically improving plant survival and growth by reducing irrigation requirements up to 50%. It will also reduce water runoff and soil erosion, improving the quality of our natural water sources like lakes, streams and rivers.
Used by US Forestry Service and Recommended by Southern Living Magazine and HGTV
SAP is classified as hydro-gel when cross-linked, absorbing aqueous solutions through hydrogen bonding with water molecules. The ability of SAP absorbing water is a factor of the ionic concentration of the aqueous solution and it may absorb hundred times its weight and volume. It can become up to 99.9% liquid, but when put into a 0.9% saline solution, the absorbency drops to about 50 times its weight.
The total absorbency and swelling capacity are controlled by the type and degree of cross-linkers used to make the gel. Low density cross-linked SAP generally has a higher absorbent capacity and swell to a larger degree and also has a softer and more sticky gel formation.