Production and Characterization of Liquid and Solid Foams

In the current context of sustainable development and the depletion of fossil resources, finding bio-based and biodegradable alternatives to synthetic plastic foams, such as expanded polystyrene (EPS), has become more necessary than ever. Cellulose, in contrast, is a bio-based, biodegradable, abundant material that is not required for food. Replacing petroleum-based materials with cellulose-based counterparts is therefore of scientific, commercial, and societal interest.

Objectives

Within the framework of Carnot PolyNat projects (2014–2018), a fully instrumented foaming pilot plant was designed, developed, and implemented at the Laboratory of Rheology and Processing (LRP). As an alternative to current industrial processes, its main advantage lies in the ability to precisely control the amount of air incorporated into the starting matrix while enabling continuous production adaptable to industrial scale. Promising results have already allowed the production of materials based on 100% cellulose blends. One of the current objectives is to carry out the most thorough and rigorous characterization of the manufactured liquid and solid materials, particularly regarding their structural properties—that is, determining the type and size distribution of the formed cells. Once characterized, we will study the relationships between formulation, structure, and functional properties, while maintaining precise control of the structural features through the process—a level of control not achievable with current industrial methods.

Through funding from PolyNat Carnot, GlycoAlps, and IRGA, we aim to develop bio-based foams with characteristics comparable to petroleum-based foams traditionally used in packaging, capable of resisting impacts, compression, or serving as thermal insulation (e.g., expanded polystyrene or polyurethane foams).

Results 

The foam generation aspect is now well advanced, with the formulation of suspensions based on microfibrillated cellulose (MFC) and the identification of the most suitable foaming technique. The projects have enabled the design and control of pilot-scale foam generators, allowing the continuous production of stable foams with a controlled air content. The teams are also investigating appropriate drying technologies to achieve a reproducible, bio-based foam production process that can be scaled up to industrial levels.

Partner Laboratories and Institutions

LGP2, CTP, LIG, Institut Carnot PolyNat, CDP Glyco@Alps

Industrial Partners 

Aerpanel