Antifoam
A foam inhibitor or foam inhibitor is a substance or mixture of substances that is added to liquids in order to reduce or prevent undesired foam formation - usually when processing or filling liquids with low surface tension . In addition to the petrochemical industry, the term anti-foam is used almost exclusively in food technology to describe the polysiloxane derivatives used there. The similar term defoamer refers to - often similar - substances or mixtures that are intended to dissolve foam that has already formed. In principle, foam inhibitors and defoamers work identically in that they form a closed film at the interface of the liquid , which accelerates the outgassing or enables the gas bubbles to be destroyed.
In the food industry, as a food additive, they are supposed to prevent foam formation. For example:
- Mono- and diglycerides of fatty acids (E 471) (MDG)
- Polydimethylsiloxane (E 900) (see also Simeticon )
- Polyglycerol esters of fatty acids ( E 475 )
- Thermo-oxidized soybean oil , esterified with MDG ( E 479b )
In chemical reactions or fermentation processes , too, it may be necessary to prevent the formation of foam . An anti -foaming agent used for this purpose is 2-octanol . As an additive for lubricants foaming prevent the formation of surface scum by swirling of the lubricant with air in engines or transmissions.
Individual evidence
- ↑ a b Entry on anti-foaming agents. In: Römpp Online . Georg Thieme Verlag, accessed on August 15, 2015.
- ↑ a b Entry on defoamer. In: Römpp Online . Georg Thieme Verlag, accessed on August 15, 2015.
- ↑ ZZulV : Annex 7 (to Section 5, Paragraph 1) Additives for certain technological purposes .