SAP or Superabsorbent polymers is a material which can absorb up to 300 times their weight in aqueous fluids. Once absorbed, they do not subsequently release it. They are therefore an ideal material for use in products which are designed to contain fluids such as baby diapers/nappies, incontinence products, and feminine hygiene pads and liners.

The benefits of superabsorbent polymers
✓ They help keep the skin dry. This is done by drawing the liquid away from the skin and absorbing and retaining it in the core of the product. This creates greater comfort for the user.

✓ They help protect against skin irritation in diaper users by reducing skin wetness. If skin becomes too wet it is more vulnerable to irritation because the natural balance of the skin, which helps protect against harmful bacteria, can be compromised. This is especially so in the presence of faeces and associated enzymes.

✓ They help prevent the spread of infections. The containment of fluid in the superabsorbent core reduces leakage. It also reduces the risk of urine mixing with faecal material and becoming contaminated with microorganisms which can cause the spread of diseases such as diarrhoea and gastroenteritis.

✓ They offer improved quality of life and personal dignity. Many people suffer from a lack of bladder or bowel control as a result of illness, disability or age. Disposable products with superabsorbents help many of these individuals and their care-givers maintain a quality of life with greater mobility and independence.

Industry	Application
Foundries, Asphalt Plants, Cement Plants	Air/water scrubbers, settling ponds
Food Processing, Vegetable Canning, Sugar Cane Processing, Fruit Preparation	Flotation and Settling Tanks, Clarification, Wash Water Systems, Biological Treatment Systems.
Metal Plating or Finishing	Treatment for Heavy Metals Removal, Copper, Zinc, Iron, Nickel, Cadmium, Chromium Removal, etc., and Oil Recovery.
Sand & Gravel Plants, Coal Preparation, Limestone Quarries, Iron Ore, etc..	Mineral Washing and Water Recycling Operations, Dewatering
Primary Metal	Oil Recovery, Influent Clarification, Scrubber Systems, Thickening, Biological Treatment Systems.
Paper	Biological treatment, Influent Clarification, Dewatering.
Other Industrial Operations, such as Glass Plants, Chemical Plants, Refineries, etc.	Water Recycling, Oil/water Separators, etc.
Municipal Potable Water Plants	Drinking Water Clarification, Filtration
Thickening, Centrifugation or Flotation	Sludge Dewatering

Problem:	Polymer usage benefit / application
Adhesives	Replacement of animal glues Gummed paper tapes and labels
Aluminum anodization and surface treatment	Chemical treatment of effluent Sludge treatment
Aluminum smelters	Water recycling
Aluminum sulfate	Impurity removal during process
Asbestos plate	Improvement of filtration rates
Borax production	Process

Brewing industry	Effluent
Brine clarification	Ca and Mg removal
Ceramic industry	Effluent treatment Centrifugation aid
Chemical industry effluent	Organic chemicals and inorganics Biological treatment sludge handling Physio-chemical treatment
Clay and china clay production	Water recycling Concentration
Coagulant	Under certain circumstances polymers Replace/partially replace inorganic coagulants
Coagulant aid	i.e. flocculant reduction of 50% of alum
Coal washeries	Settling of coal slurries Settling of tailings Filtration of coal Filtration of concentrated tailings Centrifugation of tailings
Cyanidation	Gold mining

Dairy and milk industry	Biological treatment of effluent Sludge handling
Dicalcium phosphate	Wet process
Dredging and land reclamation	Hopper dredges (slit settling) Soil stabilization
Electroplating industry	Treatment of hydroxides
Drying beds	Reduction of drying time
Filter aid	Sludge conditioning prior to filtration
Floatation aid	Improvement of particle size prior to flotation
Food processing industry
Hydraulic back-fill	In mining operations
Industrial raw water treatment	As a coagulant aid during treatment of river or underground water Dewatering of settled sludge
Iron ore	Filtration of fines Settling
Iron and steel industry	Steel works blast furnace gas washing Clarification in steel rolling mills Clarification of pickling water
Latex and synthetic rubber effluent treatment	Effluent treatment
Leaching	Uranium mining Copper mining Other mineral processing
Lithophone	Process
Magnesia from sea water	Sedimentation of magnesium hydroxide
Meat processing	Waste water treatment
Motor industry	Waste water treatment
Municipal sewage	Primary sludge treatment Digested sludge treatment Drying beds Sleeve belt presses Physio-chemical treatment Phosphate removal
Oil production	Treatment of drilling water Drilling Muds Secondary oil recovery
Petroleum refineries	Effluent treatment
Pharmaceutical industry	Effluent treatment
Phosphate ore	Water recycling
Phosphate removal	In municipal effluent
Phosphoric acid wet process	Acid clarification Filtration rate Reduction of P2O5 losses in gypsum
Potato industry	Effluent treatment
Potable water	Improvement of process efficiency Treatment of hydroxide sludge Reduction of alum consumption
Potash mining	Impurity removal in salt cold and hot processes
Pulp and paper	Treatment of incoming water Filler fiber retention aid Drainage aid Flotation aid on save-all Effluent treatment
Sand and gravel	Water recycling Clay removal
Settling aid	Improvement of settling rates through use of flocculant Design of compact units
Sugar processing	Cane or beet sugar clarification Water recycling in beet sugar industry
Tailing disposal	In mining for environmental purposes or water economy
Tannery	Effluent treatment
Textile industry	Effluent treatment
Titanium dioxide manufacturing	Clarification of “black liquors” Processing of titanium dioxide slurries
Zinc electrolysis	Acid leach Natural leach

The majority are made of sodium polyacrylate and available in granular form or as fibers. The granular material is a polymer made up of millions of identical units of sodium acrylate formed into a chain-fence like structure. These are then linked together to make the material into a three-dimensional network. In their dry state the long polymer chains are coiled. When they absorb liquid, they uncoil, and the network expands. The liquid is then stored in the spaces in the molecular network and the material forms a gel which locks the liquid in.