A retention agent is a process chemical that improves the retention of a functional chemical in a substrate. The result is that totally less chemicals are used to get the same effect of the functional chemical and less chemicals goes to waste

Chemical waste

Chemical waste is a waste that is made from harmful chemicals . Chemical waste may fall under regulations such as COSHH in the United Kingdom, or the Clean Water Act and Resource Conservation and Recovery Act in the United States...

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Applications

Retention agents (retention aids) are used in the papermaking

Papermaking

Papermaking is the process of making paper, a substance which is used universally today for writing and packaging.In papermaking a dilute suspension of fibres in water is drained through a screen, so that a mat of randomly interwoven fibres is laid down. Water is removed from this mat of fibres by...

 industry. These are added in the wet end of the paper machine to improve retention of sizing

Sizing

Sizing or size is any one of numerous specific substances that is applied to or incorporated in other material, especially papers and textiles, to act as a protecting filler or glaze....

, fine particles and fillers

Filler (materials)

Fillers are particles added to material to lower the consumption of more expensive binder material or to better some properties of the mixtured material...

 during the formation of paper

Paper

Paper is a thin material mainly used for writing upon, printing upon, drawing or for packaging. It is produced by pressing together moist fibers, typically cellulose pulp derived from wood, rags or grasses, and drying them into flexible sheets....

. Typical chemicals used as retention aids are: polyacrylamide

Polyacrylamide

Polyacrylamide is a polymer formed from acrylamide subunits. It can be synthesized as a simple linear-chain structure or cross-linked, typically using N,N-methylenebisacrylamide. Polyacrylamide is not toxic...

 (PAM), polyethyleneimine (PEI) or bentonite

Bentonite

Bentonite is an absorbent aluminium phyllosilicate, essentially impure clay consisting mostly of montmorillonite. There are different types of bentonite, each named after the respective dominant element, such as potassium , sodium , calcium , and aluminum . Experts debate a number of nomenclatorial...

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