Formable cellulose-based webs enabled by foam forming technology

The opportunity to replace water with foam as a carrier medium in paper and board making has been studied since the early 1970s. The main reported benefits of foam forming technology have been related to increased process efficiency, improved formation (especially with long fibers), widening of the raw materials base, better control over the web structure, and high layer purity in stratified forming. In addition to the benefits for paper and board products, the possibility to utilize foam forming technology to produce other fiber-based products, such as foam-laid nonwovens, alternatives for plastic bags, insulation materials, and growth media have been investigated. In this paper, we introduce two recent development works related to foam forming technology, in which the goal is to produce highly formable cellulose-based, webs. Our first approach. The effects of different fibers, refining strategies, bonding solutions and web compaction were studied. As a result, we obtained higher than 30% extensibility of fiber network with several recipes, enabling the manufacturing of a wide range of packaging solutions. In the second approach, a web containing short cut fibers, cellulose fibers, and thermoplastic polymers were produced using foam forming technology to obtain high fiber length in the final product. In traditional composite manufacturing processes, such as extrusion processes, the fiber length is typically reduced to 1 mm or below, and injection molding below 0.5 mm, independent of the original fiber length. However, using foam forming technology, fiber length was maintained during the composite manufacturing process. As a result, strong and lightweight cellulose-based composite materials were successfully produced. This study shows again that foam forming technology opens up new and interesting opportunities for current and new fiber-based products.