Active moisture control material for packaging

Abstract

An active moisture control material comprising a fiber based material and at least one active additive, wherein said active additive is adapted to control moisture transfer in the active moisture control material, and wherein said moisture control material is produced in a paper or board making process, wherein the active additive is incorporated into said active moisture control material.

Claims

1. An active moisture control material comprising a fiber based material and at least one active additive, wherein said active additive controls moisture transfer in the active moisture control material, and wherein the active moisture control material is produced in a paper or board making process wherein the active additive is incorporated into the active moisture control material, and wherein the active additive is any one of sodium chloride, calcium chloride and potassium chloride, a sodium silicate, phosphates, silica gel, bentonite clay, molecular sieve, calcium oxide, calcium sulfate, microfibrillated cellulose, a synthetic super absorbent polymer, a polysaccharide based super absorbent polymer, or a polyaminoacid based super absorbent polymer; a passive barrier material laminated or coated onto the active moisture control material, wherein the passive barrier material comprises a synthetic polymer or a renewable polymer; and a paper or board layer on the passive barrier material.

2. The active moisture control material as claimed in claim 1 wherein the active additive is incorporated during the production of the active moisture control material in said paper or board making process.

3. The active moisture control material as claimed in claim 1, wherein said fiber based material is any one of a paper, paper board, or microfibrillated cellulose.

4. The active moisture control material as claimed in claim 1, wherein the active moisture control material has a thickness in the range of 20 μm to 3 mm.

5. The active moisture control material as claimed in claim 1, wherein the active additive is provided at well-defined areas of the fiber based material, such that a moisture control pattern is provided.

6. The active moisture control material as claimed in claim 1 wherein the active additive is incorporated during the production of the active moisture control material in a foam forming process.

7. The active moisture control material as claimed in claim 1, wherein the active moisture control material has a thickness in the range of 40 μm-1000 μm.

8. The active moisture control material as claimed in claim 1, wherein the active moisture control material has a thickness in the range of 40 μm to 500 μm.

9. The active moisture control material as claimed in claim 1, wherein the active additive is microfibrillated cellulose.

10. The active moisture control material as claimed in claim 1, wherein the active additive is a polyaminoacid based super absorbent polymer.

11. The active moisture control material as claimed in claim 1, wherein the active additive is added to the fiber based material by mixing the active additive with fibers.

12. The active moisture control material as claimed in claim 1, wherein the active additive is added to the fiber based material by surface sizing or coating the active additive on the fiber based material.

13. The active moisture control material as claimed in claim 1, wherein the fiber based material comprises at least 50 wt% cellulose fibers.

14. The active moisture control material as claimed in claim 1, wherein the passive barrier material comprises any one of low density polyethylene (LDPE), high density polyethylene (HDPE), polypropylene (PP), polyethylene terephthalate (PET), polylactic acid, and polybutylene succinate (PBS).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The present solution will now be described, by way of example, with reference to the accompanying schematic drawing.

(2) FIG. 1 illustrates a schematic perspective view of a packaging.

DETAILED DESCRIPTION

(3) The invention relates to a fiber material into which an active component is added during the manufacturing process of the fiber material. The fiber material may be used for applications such as packaging.

(4) The fiber material is, due to the addition of the active component or additive, able to pick up, and release, moisture. It is therefore an active moisture control material. By adding the active component or additive to or into the fiber material there is thus formed an active moisture control material.

(5) The moisture absorption and/or desorption may be based mainly on fibers and the active additives may boosting the effect. The fiber material may thus create a high enough capacity for moisture control.

(6) The fiber material may be any one of a paper, paper board, microfibrillated cellulose. The fiber material may essentially be any type of web type material, where fiber material is produced from non-fossile based raw materials, and which is used in conventional paper or board making processes. The fiber material may be any type of a cellulose based material. Preferably, the fiber material comprises cellulose fibers e.g. to an amount of at least 50 wt % calculated on the total solid content of the material, but it may comprise as much as at least 75 wt % or at least 80 wt % of cellulose fibers.

(7) The active component or additive is thus adapted to control moisture transfer in the active moisture control material.

(8) The active additive is preferably any one of sodium chloride, calcium chloride and potassium chloride. It may further be a sodium silicate, phosphates or a superabsorbent polymer or a mixture thereof. The sodium silicate may be for instance be Na.sub.2O.sub.3Si, known as liquid glass or water glass. The salt may have any suitable grade or form. The active additive may also be an additive essentially only capable absorbing moisture such as silica gel, bentonite clay, molecular sieve, calcium oxide or calcium sulfate.

(9) The superabsorbent polymer (SAP) may be any one of a synthetic super absorbent polymer, a polysaccharide bases super absorbent polymer and a polyaminoacid based super absorbent polymer.

(10) Examples of synthetic SAP may be those produced from acrylic monomers, such as acrylic acid (AA) or acryl amide (AM). One example of a synthetic SAP which can be added as an active additive is sodium polyacrylate.

(11) Examples of polysaccaride based SAP are carboxymethylcellulose (CMC) and hydroxyethylcellulose (HEC). One example is sodium carboxymethylcellulose.

(12) The active additive may also be a microfibrillated cellulose, which may have been modified.

(13) The active component or additive may be added to or into the fiber material in paper/board machine directly, i.e. in an online process, or in an offline operation.

(14) In the alternative the active additive may be incorporated in a separate process step after board making process

(15) Examples of an online operation may be for instance adding the active additive into the pulp mixture, either in a conventional way or through a so called in-line production process. The pulp mixture may, in addition to cellulose fibers from e.g. hardwood and/or softwood, further comprise fillers, retention agents, wet and/or dry strength additives, OBAs, and conventional wet-end chemicals well known to the skilled paper or paperboard maker. Online operation may further comprise any one of a size press or coating unit. The online operation may also comprise foam forming technologies. The foam forming may give a very thick structure of the material, which may enable a high capacity for moisture absorbance, especially compared to full plastic materials.

(16) Examples of offline operation may be printing machine technology, coating technology, such as blade, rod, curtain, spray technologies, or impregnation, for instance through a size press.

(17) The active control material may be used as a blank or base packaging material to for different types of packages.

(18) In one examples, as shown by FIG. 1 the active control material may be used for a cigarette package 1. The package 1 has an inside 2, where the cigarettes (not shown) are placed and an outside 3.

(19) The inside 2 may thus comprise the active control material 4. In one example the outside 3 comprises the active control material or alternatively an outside passive barrier material 5.

(20) The passive barrier material 5 may be any one of a synthetic or renewable polymer. Examples of synthetic polymers may be any one of low density polyethylene (LDPE), high density polyethylene (HDPE), polypropylene (PP) and polyethylene terephthalate (PET). Examples of renewable polymeras may be so called green polyethylene (PE), green polyethylene terephthalate (PET), polylactic acid and polybutylene succinate (PBS). The passive barrier material may be applied onto the active control material during the manufacturing, for instance as a coating or film layer, or afterwards as a detachable film.

(21) Examples of film application are film lamination, glue lamination, pressure sensitive lamination. The barrier layer may alternatively be applied through dispersion, water or solvent based coating systems. It may also be extrusion coated or extrusion laminated onto the active moisture control material.

(22) The active moisture control material may have a thickness in the range of 20 μm to 3 mm, or in the range of 40 μm-1000μ, or in the range of 40 μm to 500 μm. The moisture absorption capacity will depend in the thickness and be higher with thicker material.

(23) The packaging formed from the active moisture control material may be pre-conditioned prior to the closing of the package.

(24) This pre-conditioning may take place during converting the blank into the packaging material or during filling of the packaging.

(25) The packaging comprising the active control material may be used for all types of moisture sensitive products, such as cigarettes, medicaments, cosmetics, electronics, metal products, apparel, shoes and food.

(26) The material or packaging may alternatively also be provided with a pattern, or a so called moisture absorption pattern. In some applications there might be a need to have moisture absorption properties only at certain areas of the packaging or packaging material. The pattern may be achieved by offline operations e.g. printing process or slot die coating etc. such that the active additive is provided at well-defined areas, or in a pattern of the fiber material. One of the advantages may be that there is less stiffness reduction due to absorbed moisture in the package.

(27) In addition to providing the active moisture control material with a passive barrier, it may also be provide with a paper or board layer in a laminate structure, i.e. board/passive barrier/moisture control material. The active moisture control material would be inside the package. This would provide the advantage that stiffness to the package is generated mainly from outer board/paper layer which would not be absorbing moisture to any greater extent.

(28) In view of the above detailed description of the present invention, other modifications and variations will become apparent to those skilled in the art. However, it should be apparent that such other modifications and variations may be effected without departing from the spirit and scope of the invention.