Dry methylcellulose foams: Investigation of simple foaming and drying methods for applications in the field of conservation and restoration

This paper explores the foaming of methylcellulose (MC) using straightforward foaming and drying methods for different applications in the field of conservation and restoration. The aim was to elaborate a low-tech, inexpensive and reproducible foaming method to achieve dimensionally stable, homogeneous, dried foams. Crucial influencing parameters of the foaming process such as viscosity grade, concentration, water temperature, mixing device, whipping time and drying method were investigated. Dried foams were produced with MC A4C 5–7 wt% and A4M 4–6 wt% and then characterized by comparing them with industrial polyethylene foams, as reference material, with respect to their cell size and compressive strength. The tested samples consisted of heterogenous cells between 0.3 and 2.3 mm in diameter, and the hardness was 1.2–15.1 N/cm2. Possible areas of application of dried MC foam in the field of conservation-restoration, e.g. as a filling material, are explored within a case study.