Superabsorbents

WHAT THEY ARE

Superabsorbents (also known as superabsorbent polymers or SAP) consist of a material which can absorb many times its own weight in aqueous fluids. They can absorb up to 300 times their weight in water and once absorbed, 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.

Superabsorbent material was first produced in the early 1970s in Japan and the US. It was introduced into baby diapers in the early 1980s and later that decade into adult incontinence pads. By the early 1990s superabsorbent material had become widely used in disposable baby diapers/nappies and incontinence products.

WHAT THEY ARE MADE OF

The majority of superabsorbent material available for today’s absorbent hygiene products market is made from sodium polyacrylate and is sold in granular form; some superabsorbent material is also available as a fibre.

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.

                                                               
Superabsorbent material           Adding a litre of water           The gel is formed                       No water is released

THEIR BENEFITS

  • 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.

For more information about the advantages of absorbent hygiene products, visit the Right for Hygiene website

THEIR SAFETY

Superabsorbents are safe for use in absorbent hygiene products. They have been extensively tested and researched. Scientists and doctors alike have reviewed the research and confirm that superabsorbent material is safe.

Superabsorbents have a proven history of safe use and their benefits have been widely recognised by experts in toxicology, general medicine, nursing and paediatrics. The use of superabsorbent polyacrylates in personal hygiene products has brought considerable health, hygiene, environmental and lifestyle benefits to the carers and people using these products.


HOW THEY ARE MADE

The main ingredients are acrylic acid, sodium hydroxide (or a similar neutralizing agent) and water plus a cross linker which forms the bridge that links one polymer chain to another.

This solution is mixed together and undergoes a polymerisation process to form the three-dimensional networks of polymer chains. This takes the form of an aqueous gel.

  

              The aqueous gel is chopped,
              crushed and then dried.





The granules are ground and sieved to the desired particle size. At this point the superabsorbent material can be further cross linked to give the material specific absorbency characteristics.



            The dried superabsorbent granules;
            ready for packaging into bags.

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