EP3256402B2

EP3256402B2 - Packaging unit of foamed moulded fiber material and method for manufacturing such packaging unit

Info

Publication number: EP3256402B2
Application number: EP16715914.4A
Authority: EP
Inventors: Harald John Kuiper
Original assignee: Huhtamaki Molded Fiber Technology BV
Current assignee: Huhtamaki Molded Fiber Technology BV
Priority date: 2015-02-11
Filing date: 2016-02-10
Publication date: 2025-12-17
Anticipated expiration: 2036-02-10
Also published as: EP3256402A1; EP3256402B1; NL2014276B1; RU2017131344A3; DK3256402T3; RU2714938C2; WO2016130006A1; RU2017131344A; DK3256402T4; ES2732470T3

Description

The present invention relates to a method for manufacturing a packaging unit made of moulded pulp for products like eggs, and similar products like kiwi's and tomatoes, for example.
Conventional packages, containers or cartons are generally manufactured from moulded pulp originating from (recycled) paper material. Such packaging units comprise a bottom part that is provided with compartments for individual products. Products can be transported in these units and can also be displayed on shelves in supermarkets, for example.
In the manufacturing process of such conventional packaging units the fibers of the raw material require a large amount of water to provide the mouldable pulp material from which the packaging units can be formed in the manufacturing process. After forming the packaging units, a relatively intensive drying process is needed requiring a large amount of energy. This results in high manufacturing costs for such conventional packaging unit.
WO 2014/080084 A1 discloses a moldable fibrous foam-formed product and method there for. WO 2013/160553 A1 discloses a fibrous web of paper or board and method of making the same. WO 2015/036659 A1 discloses a method of forming a fibrous product. Samadi, S. et al "Production of single cell protein from sugarcane bagasse by Saccaromyces cerevisiae in tray bioreactor", International Journal of Engineering vol. 29 No. 8 pp. 1029-1036, August 2016, discloses the production of protein from sugarcane bagasse. Lunsin, R. et al "Effect of urea- and molasses-treated sugarcane bagasse on nutrient composition and in vitro rumen fermentation in dairy cows", Agriculture and Natural Resources, 52 (2018) pp.622-627, discloses effects of sugarcane bagasse. El-Sayed, S. et al "Bioconversion of sugarcane bagasse into a protein-rich product by white rot fungus", Conservation and Recycling, 12 (1994) pp. 195-200, discloses bioconversion of sugarcane bagasse.
The present invention has for its object to obviate or at least reduce the above stated problems in conventional packaging units.
The present invention provides for this purpose a method for manufacturing a packaging unit made of moulded pulp for products like eggs according to claim 1.
According to the invention, mouldable pulp that is used for the forming of the packaging unit in a manufacturing process comprises a foamed mouldable fiber material having a fiber material and a foaming agent. The fiber material may relate to conventional mouldable pulp material originating from recycled paper, for example, and that is foamed with the aid of the foaming agent. This provides a foamed mouldable pulp that can be used for forming the packaging unit according to the invention in the manufacturing process. After forming, and before the post forming drying operation, the solid content of the fiber material in the packaging unit according to the invention is above 35% by weight. Therefore, the solid content of the fiber material in de final product after drying is even higher, and certainly above this 35% by weight. This solid content after forming achieves a considerable higher fiber material content after forming, and before drying, as compared to conventional manufacturing processes with a mouldable pulp material. Such conventional packaging units have a solid content of the fiber material of mostly less than 30% by weight. This increase of solid content significantly reduces the amount of water that needs to be removed in the drying operation, thereby reducing the energy usage in the drying operation resulting in a significant reduction of the energy costs in the manufacturing process of the packaging unit obtained by the method according to the present invention. Optionally, the moulded pulp may comprise additional components, such as wet strength agent, dry strength agent, dye/pigment, starch derivatives, releasing agents such as calcium stearate.
Furthermore, it was surprisingly shown that the quality of the resulting packaging unit has even improved as compared to conventional packaging units. For example, the weight of the product in relation to its strength is improved. Furthermore, the packaging unit is more homogeneous and a significant decrease in roughness is achieved as compared to conventional packaging units. This improves the haptic appearance of the packaging unit obtained by the method according to the present invention. Furthermore, the visual appearance of the packaging unit is further improved as will be appreciated by the consumers.
Furthermore, by providing a packaging unit made of moulded pulp a full fiber packaging unit is achieved. Such full fiber packaging unit can be recycled favourably. In addition, the packaging unit obtained by the method according to the present invention is preferably provided free of additional labels, additives and/or chemical substances. This achieves a significant effect on the sustainability. Furthermore, a packaging unit made from foamed moulded fiber material may decompose more effectively and also in that respect contributes to a more sustainable product as compared to conventional packaging units.
As a further effect of using foamed mouldable fiber pulp for forming the packaging unit, a similar strength of the packaging unit can be achieved with less weight, and, therefore, less raw material is required. This raw material involves recycled paper, for example. This means that from a given amount of raw material more packaging units can be produced and/or stronger packaging units can be manufactured from the same amount of raw material. This results in a more effective manufacturing process.
Due to the improved roughness and homogeneity of the packaging unit obtained by the method according to the invention it is possible to develop packaging units having a smaller stacking pitch such that a stack of packaging units may consist of a higher number of packaging units according to the invention as compared to a stack of packaging units having a conventional design. This improves the handling of packaging units.
Furthermore, the improved strength of the packaging unit from foamed moulded fiber material enables other shapes or designs for the packaging unit obtained by the method according to the present invention as for conventional packaging units would be possible. This improves the overall flexibility and freedom in the design of packaging units.
Furthermore, the reduction of the roughness of the packaging unit from foamed moulded fiber material may improve the printing possibilities for the packaging unit. This may obviate the need for providing separate labels. This simplifies the manufacturing process of the packaging units and/or reduces the amount of required material for a packaging unit.
As an even further effect the foamed mould fiber of the packaging unit can be produced with improved heat insulation as one of the characteristics, thereby improving protecting/insulating the products in the packaging unit against (varying) outside conditions. This improves keeping products in the packaging unit according to the present invention.
Preferably, the solid content of the fiber material after forming is above 36% by weight, preferably above 37% by weight, more preferably above 38% by weight, and most preferably above 39% by weight. It is shown that with the use of a foamed mouldable fiber pulp in the manufacturing process a higher solid content of the fiber material in the packaging unit after forming can be achieved, above 35% by weight and even higher. This significantly reduces the requirements for the drying operation as described above.
The foamed mould fiber material comprises a volume percentage of more than 50% air, preferably more than 60%, and is most preferably in the range of 60-75%. In the context of the invention air relates to the gas that is provided and/or used when foaming the moulded pulp material. This high volume of air improves the aforementioned effects in relation to the foamed moulded fiber material.
The foaming agent in the foamed mould fiber material comprises SLES, SDS and/or ALS. SLES (sodium lauryl ether sulphate), SDS (sodium lauryl sulphate and/or sodium dodecyl sulphate) and/or ALS (ammonium lauryl sulphate) is provided to be mouldable fiber pulp and achieves a foamed mouldable fiber pulp that is used for forming a packaging unit of a foamed moulded fiber material.
According to the present invention moulded pulp has before forming a consistency, relating to the fiber-water ratio, of above 1.0% by weight, preferably above 1.3% by weight, more preferably above 2.0% by weight, and most preferably above 2.5% by weight.
Conventional consistency ranges are below 1.0% by weight. Increasing this consistency weight ratio provides a stronger product after forming. This enables a reduction in the weight of the packaging unit having similar strength, for example.
Material for the packaging unit according to the invention may comprise recycled fiber material and/or so-called virgin fiber material.
Preferably, the material of the packaging unit comprises a recycled fiber material including raw material originating from (recycled) paper and/or carton and/or similar waste streams. This recycled fiber material can be used as alternative to so-called virgin fiber material and/or in combination therewith. The use of recycled fiber material may contribute to a more sustainable manufacturing process.
According to the present invention the material comprises natural fibers of non-wood lignocellulosic biomass.
By providing lignocellulosic biomass from other resources as the conventional paper recycling, an alternative source for the material for the packaging unit of moulded pulp is provided. This improves the availability of raw (starting) material when manufacturing packaging units according to the invention. In addition, the use of this biomass provides additional visual effects that may provide the packaging unit with a more natural feel, and, in addition, may improve the sustainability of the packaging unit according to the present invention.
In a presently preferred embodiment the moulded pulp may comprise at least 10% by weight non-wood lignocellulosic biomass, preferably at least 50% by weight, more preferably at least 80% by weight, even more preferably at least 85% by weight, and most preferably at least 92.5% by weight non-wood lignocellulosic biomass. Preferably, the lignocellulosic biomass comprises biomass originating from plants of the family of Poaceae Family including grass type of plants, including grass and barley, mais, rise, weed, oaths, rye, weed grass, bamboo, sugar cane, grape seeds, other cereals, etcetera. Especially the use of so-called nature grass provides good results on manufacturing packaging units such as packages. Such nature grass may originate from a natural landscape, for example. This material shows effective manufacturing possibilities in combination with providing the packaging unit with a sustainable appearance to the consumer. The use of this alternative raw material as a foamed moulded fiber material provides additional possibilities to improve the packaging units.
The protein content of the biomass is below 2% and most preferably below 1.75% of dry weight of the biomass. Removing protein from lignocellulosic biomass is known per se, like from the patent publication WO 2012/023848 A1 to Danvos B.V. The combination of using this biomass raw material in combination with, or as an alternative to, moulded pulp originating from paper and/or paperboard provides further possibilities for the use of different raw materials, and improves the "green" sustainable appearance of the resulting packaging units. Foaming such alternative (non-wood) fiber material provides similar effects and advantages as described for the (recycled) paper material.
In a further preferred embodiment according to the present invention the packaging unit further comprises a cover part having a length, a width and a depth.
By providing a cover part, the combination of the carrier part and cover part provides a packaging unit that protects substantially the whole product, such as eggs.
Preferably, the packaging unit comprises a hinge from foamed moulded fiber material hingedly connecting the carrier part and the cover part. This provides a packaging unit with a bottom part and a cover part, and enabling transport and display of products without damaging the products. This is especially relevant in case of vulnerable products like eggs. Preferably, the cover part is hingedly connected to the bottom part on the rear side thereof. It is shown that the hinge manufactured from foamed moulded fiber material is capable of performing the operation of opening and closing the cover part from the bottom part.
Preferably, on the front side of the packaging unit a lock is provided comprising a first locking element on a bottom part and an opening in a cover part that is configured for receiving the first locking element. By locking the cover part and a bottom part of the front surface the packaging unit can be closed. Preferably, the bottom part is provided with a protrusion shaped as an edge or a notch acting as first locking element. Such protrusion can be provided directly by the bottom part or a separate closing flap that is hingedly connected to the bottom part. It will be understood that other configurations according to the invention would also be conceivable.
Furthermore, the foamed moulded fiber material for the packaging unit obtained by the method according to the present invention showed good manufacturing possibilities such that a carrier and/or cover part can be provided that has a length, a width and a substantial depth of preferably 3 cm or more, preferably 4 cm or more, and even more preferably 5 cm or more.
According to a further preferred embodiment of the packaging unit obtained by the method according to the invention, the packaging unit is one or more of an egg package, cup carrier, fast food packaging unit, bottle dividers, food containers for ready meals, and protective packaging unit.
Such packaging units are preferably substantially made of foamed moulded fiber material and benefit from the associated effects that have been described earlier. Egg packaging may relate to packaging units, preferably a bottom part with a cover part that are hingedly connected, capable of transporting and displaying eggs. A cup carrier can be used to carry one or more cups, such as coffee cups. Fast food packaging units may relate to containers for holding hamburgers and french fries, for example. Bottle dividers protect bottles and the use of foamed moulded fiber material improves the protection of the bottles and especially the crown corks thereof. Food containers for ready meals from foamed moulded fiber improve storage, transport and presentation of food stuff to a consumer, wherein the container is preferably laminated with a barrier film, such as a biofilm or polyolefin film, and is further preferably made of so-called virgin fiber material to prevent migration of undesired components from the material towards the food. Protective packaging units may relate to packaging units carrying electronic components, for example.
In fact, the method can be used to manufacture different embodiments of packaging units according to the invention.
According to the invention, after forming, and before drying, the solid content of the fiber material is above 35% by weight, and in preferred embodiments preferably above 36% by weight, more preferably above 37% by weight, even more preferably above 38% by weight, and most preferably above 39% by weight.
According to the invention, the mouldable pulp before forming has a consistency relating to the fiber-water ratio of above 1.0% by weight, preferably above 1.3% by weight, more preferably above 2.0% by weight, and most preferably above 2.5% by weight.
Further advantages, features and details of the invention are illustrated on the basis of preferred embodiments thereof, wherein reference is made to the accompanying drawings, in which:

Figure 1 shows a hybrid pack embodiment of the packaging unit obtained by the method according to the invention in a closed position;
Figure 2 shows the packaging unit of figure 1 in an open position;
Figure 3 shows an alternative packaging unit obtained by the method according to the invention;

Hybrid pack 2 (figure 1) comprises first packaging unit 4 and second packaging unit 6 according to the invention of a foamed moulded fiber material. First and second packaging units 4, 6 are connected with bridging part 8. Bottom part 10 comprises front surface 12, two side surfaces 14, back side 15, and bottom side 16. Cover part 18 is hingedly connected to bottom part 10 and comprises front surface 20, two side surfaces 22, back side surface 24 and top surface 26. In the illustrated embodiment packaging units 4, 6 are provided with label 28 that is provided with top surface 30 on which text 32 is printed. In this illustrated embodiment label 28 is provided with front surface 34, and extended part 36 for front side 34. Extended part 36 and front surface 34 are connected with folding line 38. Edge 40 defines the transition between top surface 30 and front surface 34. Packaging units 4, 6 are provided with indent 42 having an egg-shape 44. In the illustrated embodiments label 28 is provided with corresponding cut-out 46.
Packaging unit 2 is manufactured from a foamed moulded fiber material comprising fiber material and a foaming agent including the hinge connecting bottom part 10 with cover part 18. It will be understood that different designs and dimensions of packaging unit 2 can be envisaged according to the invention.
In the illustrated embodiment, on the inside of bottom part 10 (figure 2) compartments 48 are provided having contours matching at least partially the outer contours of eggs P. Support cones 50 are provided to add stability and strength to packaging units 4, 6. Lip 52 is hingedly connected to front surface 12 of bottom part 10 and is provided with cut-out 54. Along the edge of cut-out 54 there is provided a support edge 56 for distributing loads. In addition, a support nock 58 is provided. Cover part 18 and bottom part 10 are hingedly connected via hinge 60 that is also provided of the foamed moulded fiber material. Cover part 18 is provided with a window opening 62 through which the back side 64 of label 28 is visible. In the illustrated embodiment back side 64 of label 28 is provided with text and/or images 66. Alternatively, label 28 is provided with transparent material for window opening 62.
Front 20 of bottom part 10 is provided with edge, protrusion, or projection 70 that fits in opening 68 that is provided in front surface 34 of label 28 together providing lock 72 that can be provided in the label and/or the moulded fiber material.
When manufacturing a packaging unit, such as hybrid pack 2, a moulded pulp from recycled paper, cardboard etc. is provided as a moulded pulp. A foaming agent is added to produce a foamed mouldable fiber material. With a (vacuum) moulding device, packaging unit 2 is formed from the foamed mouldable fiber material. After forming, packaging unit 2 is dried to produce the packaging unit, such as hybrid pack 2, made of foamed moulded fiber material.
Alternative packaging unit 102 (Figure 3) comprises bottom part 104 with front surface 106, two side surfaces 108, back side 110, and bottom side 112. In the illustrated embodiment, cover part 114 is hingedly connected with hinge 116 to bottom part 104 to allow cover part 114 to move relatively to bottom part 4 between an open and a closed position. Cover part 114 further comprises front surface 118, two side surfaces 120, back side surface 122 and top surface 124.
On the inside of bottom part 104 product receiving compartments 126 are provided having contours matching at least partially the outer contours of the products, like eggs, kiwis and tomatoes, for example. Support cones 128 are provided to add stability and strength to packaging unit 102. Lock 130 comprises opening 132 in cover part 114 and cam 134 of bottom part 104. Optionally, packaging unit 102 is provided with a label.
The package 102 is made from foamed moulded fiber material containing a substantial amount of grass fibers, for example 50%, or 80%, or 90% or 95%.
Reinforcing elements comprise groove 138 with starting position 140 at top 124 of cover part 114 and ending position 142 at front surface 118 of cover part 114. Alternative reinforcing elements that may be applied in combination with grooves 138 comprise strengthening rods, rims and/or protrusions.
Fibers 148, in the illustrated embodiment grass fibers, are provided in the foamed packaging material. After drying, some of the (grass) fibers 150 may protrude from a package surface, including the surface of compartment 126, that protrude to such an extent that separate (grass) fibers can be distinguished by sight and/or touch. In compartment 126 protruding fibers 150 provide a cushioning effect that may further contribute to the reduction of product damage.
These longer (grass) fibers 148, 150 have a length of about 25 mm. The longer (grass) fibers 148, 150 have a length such that the fibers are able to float on a foamed fiber pulp or pulp mix during manufacturing, which enables that during moulding these long fibers are positioned at the package surface. These protruding fibers 50 even more improve the appealing effect of the package 102. Fibers 150 protrude even more from a package inside surface also because that inside surface is determined by the suction side of a mould. This suction side of a mould is a well known concept in manufacturing a moulded fiber food packaging.
When manufacturing packaging unit 102, a fiber pulp for a moulding process from natural (grass) fibers is contained in a pulp container also referred to as storage tank and also known as thick stock tank. The process of moulding a moulded fiber package is not described here since this is known per se. Such a process of moulding a moulded fiber package is fed with the fiber pulp mix from the pulp container.
According to the invention, the foamed pulp comprises lignocellulosic biomass not originating from wood, wherein in the illustrated embodiment the lignocellulosic biomass contains between 0 to 2% protein in dry weight.
The method comprises pre-processing of the lignocellulosic biomass involving a number of steps. Depending on the product all steps are required or, alternatively only some steps need to be performed optionally with further steps. This pre-processing may be done on site or (partly) elsewhere. When the lignocellulosic biomass is pre-processed elsewhere, the lignocellulosic biomass fibers may be added directly to the pulp mix. Here, the pre-processing comprises soaking the lignocellulosic biomass in water for a soaking period of at least 1 day preferably at least 2 days. Here, the pre-processing comprises cutting the lignocellulosic biomass, preferably before the soaking, for obtaining visible lignocellulosic biomass fibers having a length such that the visible lignocellulosic biomass fibers may surface on the fiber pulp mix.
The pre-processing in the illustrated embodiment comprises refining the visible lignocellulosic biomass fibers for facilitating interaction between the fiber pulp and the visible lignocellulosic biomass fibers in the pulp mix.
The refining is performed in a refining device (not shown) comprising a number of refiner discs arranged at a mutual disc distance. The degree of refining the visible lignocellulosic biomass fibers is set by adjusting the disc distance between 0.5 and 1.5 mm. The refining of the visible lignocellulosic biomass fibers is done at a concentration of between 10 kg to 75 kg, preferably about 25 kg visible lignocellulosic biomass fibers in dry weight, per 1000 litre of water. An example of such a refiner is a Sprout Waldron disc refiner.
Before providing the lignocellulosic biomass, the lignocellulosic biomass may be processed for removing protein from the lignocellulosic biomass such that the lignocellulosic biomass contains between 0 to 2% protein in dry weight. This process is not shown here.
Optionally, in the manufacturing process colouring agents/pigments can be added. Also, additional components can be added, for example including dewatering polymers.
The fiber material is provided with foaming agent and a foamed mouldable fiber material is provided. Next, the forming process forms form this material a packaging unit. After forming, a drying operation is performed to produce the packaging unit from foamed moulded fiber material.
It will be understood that different designs for the packaging unit are possible according to the invention. Also, the use of different raw materials for different designs would be possible. For example, hybrid pack 2 can be manufactured from lignocellulosic biomass and packaging unit 102 from a moulded fiber origination from recycled paper and cardboard.
To illustrate the possibilities and characteristics of packaging units 2, 102 from foamed mouldable fiber material a number of experiments was performed.
A conventional water-forming manufacturing process was performed with 135 g recycled fibers and 16865 g water achieving a 0.8% consistency.
A foam manufacturing process was performed with 116 g of the same fiber material, 20 g foaming agent and 8364 g water achieved a pulp consistency of about 1.4%. After performing the foam forming process the resulting packaging unit of foamed moulded fiber material showed a 6.2-6.5% higher dryness after forming.
Experiments with higher consistencies also showed a significant increase in dryness after forming. Further experiments with consistencies ranging from 1-2.8% showed a solid fiber content after forming in the range of 35% and even higher. It will be understood that the actual content may depend on the type and amount of raw material that is used. Foaming agent dosage varied between about 1.5 and 3 g/l.
As a further effect of providing packaging units 2, 102 from foamed moulded material a higher bulk was achieved, with an increase between 5 and 15% in cm³/g.
The present invention is by no means limited to the above described, preferred embodiments thereof. The rights sought are defined by the following claims, within the scope of which many modifications are possible. For example, the packaging unit according can be applied to eggs and other vulnerable food and non-food products as well as to other products. Non-limiting examples of products include eggs, vegetables, fruit, electronic products such as DVD players, displays, mobile phones, tablets etc.

Claims

Method for manufacturing a packaging unit (2), comprising the steps of:
- providing a foamed moulded fiber material, comprising fiber material and a foaming agent, wherein the foaming agent comprises SLES, SDS and/or ALS; and

- moulding the packaging unit, wherein the packaging unit comprises:
- a carrier part (10) having a length, a width and a depth; and

- one or more product compartments (48) that are provided in the carrier and are configured for receiving a product,

wherein the moulded pulp comprises a foamed moulded fiber material, comprising a fiber material, wherein the material comprises natural fibers of a non-wood lignocellulosic biomass, and a foaming agent, characterized by the foaming agent comprising SLES, SDS and/or ALS, wherein the depth is above 2 cm, and the solid content of the fiber material after forming and before drying is above 35% by weight, wherein the foamed mouldable fiber material comprises a volume percentage of more than 50% air, wherein air relates to the gas that is provided and/or used when foaming the moulded pulp material, wherein the mouldable pulp before forming has a consistency relating to the fiber-water ratio of above 1.0% by weight, and wherein the protein content of the biomass is below 2% of dry weight of the biomass.
Method according to claim 1, wherein the solid content of the fiber material after forming and before drying is above 36% by weight, preferably above 37% by weight, more preferably above 38% by weight, and most preferably above 39% by weight.
Method according to claim 1 or 2, wherein the mouldable pulp before forming has a consistency relating to the fiber-water ratio of above 1.3% by weight, more preferably above 2.0% by weight, and most preferably above 2.5% by weight.