Foam forming revisited. Part II. Effect of surfactant on the properties of foam-formed paper products

3D-oriented fiber networks made by foam forming

“…Recently, foam forming was studied extensively to develop the understanding of foam-fiber interactions (Al-Qararah et al 2012Lappalainen and Lehmonen 2012;Lappalainen et al 2014;Mira et al 2014) and also to find the potential applications of this technology in papermaking Lehmonen et al 2013;Poranen et al 2013) as well as other specialty products, e.g., filters and insulators (Cervin et al 2013;Jahangiri et al 2014). Foam was introduced to the paper industry already in the mid-1960s.…”

A unique microstructure of the fiber networks deposited from foam–fiber suspensions

“…Moreover, no wet pressing was applied in either process so as to leave a maximal trace of the foam-fiber interactions in the resulting network structure. Here the word "interaction" means any mutual influence between the two phases (foam and fibers) [12][13][14][15][16]. This influence may also be of geometric origin so that the bubble structure limits the orientation and movement of the fibers and vice verse.…”

Foam forming of fiber products: a review

“…Besides the most common anionic sodium dodecyl sulfate (SDS, C 12 H 25 SO 4 Na), [90] there are also many other options for foaming agent. [91][92][93][94] Industrially interesting examples are nonionic polyoxyethylene (20) sorbitan monolaurate (Tween 20), nonionic alkyl glucosides or alkyl polyglucosides (APGs), and nonionic polyvinyl alcohol (PVOH or PVA). The advantage of SDS is that it enables achieving high air content at low concentration due to its small molecular weight.…”

“…In laboratory-scale studies, the dosage of surfactant typically varies in the range of 0.3-4.0 g/l. [21,91] In the pilot and at the industrial scale, the surfactant level could be somewhat lower.…”