US-12618196-B2 - Method for producing a cellulose product and a cellulose product

US12618196B2US 12618196 B2US12618196 B2US 12618196B2US-12618196-B2

Abstract

A method for producing a cellulose product from an air-formed cellulose blank structure includes the steps of providing a cellulose-based material to a mill, milling the cellulose-based material, and providing an air-formed cellulose blank structure, wherein the cellulose blank structure is air-formed from cellulose fibres.

Inventors

Ove Larsson
Martin Ljungberg
Edward Guidotti
Björn Arlerot
Olle Högblom
Patrik Larsson

Assignees

Pulpac AB

Dates

Publication Date: 20260505
Application Date: 20221215
Priority Date: 20211223

Claims (11)

1 . A method for forming an air-formed cellulose blank structure for producing a cellulose product, wherein the method comprises: providing a flow of cellulose-based material to a mill, defibrating the cellulose-based material in the mill into cellulose fibres, providing an air-formed cellulose blank structure, wherein the cellulose blank structure is air-formed from the cellulose fibres, wherein the step of air-forming comprises the step of feeding the cellulose fibres to a first opening in a forming hood, wherein the cellulose fibres are directed onto a first side of a conveyer belt by the forming hood via a second opening in the forming hood, wherein a suction box is arranged in connection to a second side of the conveyer belt opposite the second opening of the forming hood, wherein the suction box comprises a fan that is connected to the suction box that creates an under-pressure generating a negative pressure gradient between the first side and the second side of the conveyer belt via through openings in the conveyer belt for forming the cellulose blank structure from the cellulose fibres directed onto the first side of the conveyer belt, providing the cellulose blank structure to a forming mould for forming the cellulose blank structure into a three dimensional cellulose product, intermittently operating the forming mould to apply a forming pressure onto the cellulose blank structure, and synchronizing the conveyer belt to intermittently form the cellulose blank structure simultaneously to the intermittent operation of the forming mould or between two intermittent operations of the forming mould, wherein the step of air-forming comprises the step of feeding the conveyer belt vertically such that the fibres are fed to the conveyer belt horizontally.
2 . The method according to claim 1 , wherein the step of providing the cellulose blank structure to a forming mould comprises the step of feeding the cellulose blank structure essentially vertically.
3 . The method according to claim 2 , wherein the step of intermittently operating the forming mould to apply a forming pressure onto the cellulose blank structure, comprises the step of operating the forming mould in a horizontal pressing stroke.
4 . The method according to claim 1 , wherein the method comprises a step of cutting out the cellulose product from the cellulose blank structure in and/or after the forming mould, thereby forming a residual cellulose fibre structure of the remaining cellulose blank structure, and feeding the material of the residual cellulose fibre structure to the mill as a complement to the flow of cellulose-based material.
5 . The method according to claim 1 , wherein the method comprises the step of providing a first tissue layer onto one side of the cellulose blank structure, wherein the first tissue layer comprises a barrier chemistry composition.
6 . The method according to claim 5 , wherein the method comprises the step of providing a second tissue layer to one side of the cellulose blank structure, wherein the second tissue layer comprises a barrier chemistry composition.
7 . The method according to claim 6 , wherein the barrier chemistry composition is provided to the first and/or second tissue layer during production and/or the step of providing the barrier chemistry composition to the first and/or second tissue layer by providing the barrier chemistry composition before production.
8 . The method according to claim 1 , wherein the method comprises the step of step of providing a barrier chemistry composition to the cellulose-based material before production and/or in production.
9 . A cellulose product machine configured to form an air-formed cellulose blank structure for producing a cellulose product, wherein the machine comprises a first transport unit, a mill, a forming hood, a conveyer belt, a suction box, a second transport unit and a forming mould, wherein the first transport unit is configured to: provide a flow of cellulose-based material to the mill, wherein the mill is configured to defibrate the cellulose-based material into cellulose fibres, wherein the forming hood comprises a first opening in fluid communication with the mill and a second opening in fluid communication with a first side of the conveyer belt, wherein the suction box is arranged in connection to a second side of the conveyer belt opposite the second opening of the forming hood, wherein the suction box comprises a fan that is connected to the suction box that creates an under-pressure generating a negative pressure gradient between the first side and the second side of the conveyer belt via through openings in the conveyer belt, wherein the forming hood is configured to provide an air-formed cellulose blank structure onto the conveyer belt, wherein the cellulose blank structure is air-formed from the cellulose fibres by the mill being configured to feed the cellulose fibres to the first opening in the forming hood, wherein the forming hood is configured to direct the cellulose fibres onto the first side of the conveyer belt via the second opening in the forming hood, wherein the second transport unit is configured to provide the cellulose blank structure to the forming mould for forming the cellulose blank structure into a three dimensional cellulose product, wherein the forming mould is configured to intermittently operating the forming mould to apply a forming pressure onto the cellulose blank structure, wherein the conveyer belt is synchronized with the forming mould to intermittently form the cellulose blank structure simultaneously to the intermittent forming pressure of the forming mould or between two intermittent operations of the forming mould, and wherein the conveyer belt is configured to run vertically such that the fibres are fed to the conveyer belt horizontally.
10 . The cellulose product machine according to claim 9 , wherein the second transport unit is configured to provide the cellulose blank structure to the forming mould vertically.
11 . The cellulose product machine according to claim 9 , wherein the forming mould is configured to operate in a horizontal pressing stroke.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application is a 35 U.S.C. § 371 national stage application for International Application No. PCT/EP2022/086132, entitled “A METHOD FOR PRODUCING A CELLULOSE PRODUCT AND A CELLULOSE PRODUCT”, filed on Dec. 15, 2022, which claims priority to Swedish Patent Application No. 2151618-2, filed on Dec. 23, 2021, the disclosures and contents of which are hereby incorporated by reference in their entireties. TECHNICAL FIELD The present disclosure relates to a method and an apparatus for forming an air-formed cellulose blank structure for producing a cellulose product, wherein the method comprises the steps of providing a flow of cellulose-based material to a mill, defibrating the cellulose-based material in the mill into cellulose fibres, providing an air-formed cellulose blank structure, wherein the cellulose blank structure is air-formed from the cellulose fibres. BACKGROUND Cellulose fibres are often used as raw material for producing or manufacturing products. Products formed of cellulose fibres can be used in many different situations where there is a need for having sustainable products. A wide range of products can be produced from cellulose fibres and a few examples are disposable plates and cups, blank structures and packaging materials. Forming moulds are commonly used when manufacturing cellulose products from raw materials including cellulose fibres, and traditionally the cellulose products have been produced with wet-forming technologies. A material commonly used for cellulose fibre products is wet moulded pulp. Wet moulded pulp has the advantage of being considered as a sustainable packaging material, since it is produced from biomaterials and can be recycled after use. Consequently, wet moulded pulp has been quickly increasing in popularity for different applications. Wet moulded pulp articles are generally formed by immersing a suction forming mould into a liquid or semi liquid pulp suspension or slurry comprising cellulose fibres, and when suction is applied, a body of pulp is formed with the shape of the desired product by fibre deposition onto the forming mould. With all wet-forming technologies, there is a need for drying of the wet moulded product, where the drying is a time and energy consuming part of the production. The demands on aesthetical, chemical and mechanical properties of cellulose products are increasing, and due to the properties of wet-formed cellulose products, the mechanical strength, flexibility, and chemical properties are limited. It is also difficult in wet-forming processes to control the mechanical properties of the cellulose products with high precision. One development in the field of producing cellulose products is the forming of cellulose fibres without using wet-forming technologies, and instead the cellulose products are produced in a dry-forming process. In the dry-forming process, an air-formed cellulose blank structure is used. The air-formed cellulose blank structure is inserted into a forming mould and during the forming of the cellulose products the cellulose blank structure is subjected to a high forming pressure and a high forming temperature. When using cellulose products made according to the dry-forming process, the cellulose products may be exposed to liquids, food or other substances that may affect the stiffness and rigidity of the cellulose products due to the tendency of the formed cellulose products to absorb for example water, moisture, or other substances. Plastic films that are laminated to the cellulose products may be used for preventing liquid from affecting the cellulose products. However, with the demand for more environmentally friendly products there is a desire to produce the cellulose products without plastic materials. There is thus a need for an improved method for producing cellulose products from an air-formed cellulose blank structure, where the cellulose products can be produced to resist contact with liquids, food and other substances for longer time periods without affecting the mechanical properties of the cellulose products. There is further a demand for certain types of products to hold liquids or food, where no harmful substances are added to the cellulose products. SUMMARY An object of the present disclosure is to provide an improved method and apparatus for producing a cellulose blank structure and a method for producing a cellulose product where the previously mentioned problems are avoided. This object is at least partly achieved by the features of the independent claims. The dependent claims contain further developments of the method for producing a cellulose product and the cellulose product. The description below will refer to Scala as a collective name for a machine for producing a cellulose product according to the invention, where the machine will comprise a variety of parts that will be explained below and in connection to the drawings. The invention relates to a method f