The packaging demonstrators made in VTT’s Industrial Biomaterial program proved that making completely bio-based and biodegradable packaging from renewable sources is possible. Now we challenge industry to implement such products in their production. One of the packaging demonstrators is a candy bag having a circle translucent window prepared using translucent paper technique. Another bio-based packaging demonstrator is a sandwich package with a transparent window made from hemicellulose-based film.
Hemicelluloses such as xylans or glucomannans existing in high amounts in woods and agricultural plants are potential raw materials for different kind of novel materials and applications. The highly transparent and flexible films prepared from modified hemicelluloses without any additives (softeners etc.) have had mechanical properties, for example, tensile strengths up to 44 MPa, elongation at break 5-22 %, Young’s modulus 500-1000 MPa, and reasonable barrier properties: water vapour permeability (5-10 g,mm/kPa,m2,d) and oxygen permeability (12-30 cm3, m/kPa,m2d). The properties are mainly dependent on modifications (type of substituent(s), degree of substitution etc.) but also on the amounts and type of additives used.
Tags: hemicellulose-based film, xylans, glucomannans
Source: ForestTech, 2012-04-30.