Method of manufacturing of a foam-formed cellulosic fibre material, sheet and laminated packaging material
AssigneeTetra Laval Holdings & Finance S.A.
InventorsCristian Neagu, Katarina Jonasson
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Abstract
The invention relates to a method of manufacturing a new low density foam-formed cellulose material comprising dialcohol-modified celllulose, and to bulk sheets, layers, laminates or moulded articles comprising such material. Furthermore, the invention relates to a laminated packaging material comprising a layer or sheet comprising the low density cellulose material as well as to packaging containers comprising the laminated packaging material. In particular, the invention relates to packaging containers intended for liquid or semi-liquid food packaging, comprising the laminated packaging material.
Claims20
Method for manufacturing a foam-formed low-density material of cellulose fibres to be used in packaging material for producing packaging containers suitable for liquid and semi-liquid food products, comprising
- a. forming an aqueous foam comprising water and a foaming agent,
- b. adding cellulose fibres to the aqueous foam, thus forming a fibrous foam composition, the cellulose fibres added to the aqueous foam comprising both modified cellulose fibres as a cellulose reinforcement fraction and coarse, unmodified cellulose fibres, the modified cellulose fibres containing dialcohol cellulose, the coarse, unmodified cellulose fibres being selected from the group consisting of mechanical, chemi-mechanical, thermomechanical, chemithermo-mechanical pulp (CTMP) fibres and Neutral Sulfite Semi Chemical (NSSC) pulp fibres;
- c. distributing the fibrous foam composition onto a substrate or into a mould,
- d. reducing the amount of water in the distributed fibrous foam composition to obtain the foam-formed low-density material of cellulose fibres in its final shape which is usable in the packaging material for producing the packaging containers suitable for liquid and semi-liquid food products, and
- e. optionally, drying the foam-formed low density material of cellulose fibres;
- wherein a final content of the dialcohol cellulose, based on the total number of C2-C3 bonds in a final fibrous foam composition, is 0.5 to 5%.
Method for manufacturing a foam-formed low-density material of cellulose fibres to be used in packaging material for producing packaging containers suitable for liquid and semi-liquid food products, the method comprising
- a. forming an aqueous foam comprising water and a foaming agent,
- b. adding cellulose fibres to the aqueous foam, thus forming a fibrous foam composition, the cellulose fibres added to the aqueous foam comprising both modified cellulose fibres as a cellulose reinforcement fraction and coarse, unmodified cellulose fibres, the modified cellulose fibres comprising bleached, chemical pulp fibres and containing dialcohol cellulose, the coarse, unmodified cellulose fibres being selected from the group consisting of mechanical, chemi-mechanical, thermomechanical, chemithermo-mechanical pulp (CTMP) fibres and Neutral Sulfite Semi Chemical (NSSC) pulp fibres;
- c. distributing the fibrous foam composition onto a substrate or into a mould,
- d. reducing the amount of water in the distributed fibrous foam composition to obtain the foam-formed low-density material of cellulose fibres in its final shape which is usable in the packaging material for producing the packaging containers suitable for liquid and semi-liquid food products, and
- e. optionally, drying the foam-formed low density material of cellulose fibres;
- wherein a final content of the dialcohol cellulose, based on the total number of C2-C3 bonds in a final fibrous foam composition, is 0.5 to 5%.
Dependencies are inferred from the claim text.