Process for recycling containers

Abstract

A process to recycle cellulose fiber pulp-based containers comprising a cellulose fiber pulp-based shell or substrate layer, a first barrier layer, and a second barrier layer in the form of a parylene coating, wherein the process comprises the steps of separating the second barrier layer from the first barrier layer, soaking the container comprising the first barrier layer or particles of said container in water, and collecting the fibers.

Description

[0001] PROCESS FOR RECYCLING CONTAINERS

[0002] Background

[0003] Consumer products, in particular liquid or semi-liquid products require a packaging to hold shape, and to protect the product from influences from outside that potentially negatively affect the appearance or quality, such as for example moisture, light and oxygen. With increasing emphasis in the industry to use biodegradable packaging material instead of petroleum sourced materials, cellulose fiber pulp-based packaging is an interesting alternative. An additional complication with this type of packaging material, especially when liquid or semi-liquid products are used, is that the container itself needs to be protected against the influence of liquidcomprising, in particular water-comprising consumer product that is packaged. Absorption of liquid may damage the structure of the packaging, and consumer product may evaporate via the wall of the packaging product.

[0004] A coating of plastic, such as polyethylene, is suggested and used in the art, to protect the cellulose fiber pulp-based container against liquid, such as water, from the packaged product being absorbed by the container material. The problem with such plastics, such as polyethylene is that they are not biodegradable. Moreover, in particular when used in cellulose fiber pulpbased containers, which inherently have a relatively rough surface, the plastic coating needs to be relatively thick, to prevent pinholes in the coating, through which liquid can enter the fiberbased shell. Such a relatively thick coating renders the packaging product non-recyclable. This is because recyclability typically requires a minimum cellulose fiber content of 80 wt%, preferably higher, such as at least 85wt% or at least 90 wt%. In addition, the plastic layer is hard, if at all, to be separated from the pulp material in the recycling process.

[0005] In a recycling process for cellulose-fiber based products, such as paper, the cellulose fiberbased material typically is comminuted and soaked in water. The less plastic is deposited on the cellulose substrate, the easier the plastic separates.

[0006] A need therefore was recognized for cellulose fiber pulp-based packaging material that on the one hand is protected against liquid-comprising products at its inside, but on the other hand are easily recyclable, preferably are biodegradable. In particular a need was felt for a process to recycle such packaging products.

[0007] Summary of the invention

[0008] Surprisingly, this challenge was met by a process to recycle cellulose fiber pulp-based containers, the process comprising the steps of: a) Providing a container comprising: a. A cellulose fiber pulp-based shell (1) or substrate layer (1), b. A first barrier layer (2), c. A second barrier layer (3) in the form of a parylene coating b) Separating the second barrier layer from the first barrier layer c) Soaking the container comprising the first barrier layer resulting from step b) or fragments of said container, in water, and allowing the cellulose fiber pulp to separate from the first barrier layer, d) Collecting the cellulose fibers.

[0009] Detailed description of the invention

[0010] The process of the invention provides for a more efficient recycling of packaging material comprising a cellulose fiber pulp layer and a barrier laminate.

[0011] Step a

[0012] In step a) a container is provided.

[0013] Shell (1) or substrate layer (1)

[0014] The container is preferably a rigid container or a flexible container such as a sachet. Preferably the container is a rigid container. The rigid container comprises preferably a total of one, or a total of two, but preferably a total of one layer of cellulose pulp, preferably paper-pulp or cardboard pulp. Paper typically comprises cellulose fibers. The pulp layer forms the pulp-based shell (1) of the container.

[0015] A cellulose fiber pulp-based shell preferably has a grammage of between 200 and 1200 gram / m2, preferably of 300 and 800 gram / m2. This provides suitable rigidity to the final container product to comprise a consumer product (5), such as for example a bottle or jar, whereas the container can be suitably transported during manufacturing, filling and to points of sale.

[0016] The cellulose fibre pulp-based shell preferably has a thickness of between 0.5 and 5 mm, more preferably of from 0.5 to 3 mm, even more preferably from 0.6 to 2 mm and even more preferably from 0.7 to 1.7 mm.

[0017] A cellulose fiber pulp-based layer in a flexible paper-based barrier laminate, preferably comprising a paper layer, or more preferably being a paper layer, has preferably a grammage of between 40 and 100 gram / m2, preferably of 50 to 90 gram / m2and most preferably of 50 to 70 gram / m2.

[0018] In view of the aim of providing a container with less impact on the environment, cellulose fibre pulp, is preferably present in an amount of more than 50 wt%, more preferably more than 70 wt%, even more preferably more than 80 wt% and even more preferably more than 90 wt%, and most preferably more than 95 wt%, based on the weight of the container. Preferably, cellulose fibers constitute more than 50 wt%, more preferably more than 70 wt%, even more preferably more than 80 wt%, even more preferably more than 85 wt%, even more preferably more than 90 wt%, and most preferably more than 95 wt% of the weight of the container. The amount of total non-fibrous material, for example the amount of plastic, is preferably below 20 wt%, preferably below 10 wt%, and more preferably below 5 wt%, based on the weight of the container. It can be for example from 1 to 20 wt%, more preferred from 2 to 10 wt%, or more preferred from 3 to 5 wt%, based on the weight of the container. The total amount of petroleum derived material, for example the amount of petroleum-derived plastic, is preferably below 20 wt%, preferably below 10 wt%, and more preferably below 5 wt%, based on the weight of the container. It can be for example from 1 to 20 wt%, more preferred from 2 to 10 wt%, or more preferred from 3 to 5 wt%, based on the weight of the container.

[0019] Barrier laminate

[0020] At the inside wall of the container shell of the invention, a barrier laminate is provided. The barrier laminate comprises a first barrier layer (2) and a parylene barrier layer (3). It is preferred, that the first barrier layer (2) is positioned ‘upstream’ of the parylene layer (3), i.e. closer to the pulp-based shell, preferably between the shell (1) and the parylene layer (3), and most preferably the first barrier layer (2) is in contact with the shell (1). In this way, the first barrier layer (2) effectively may function as a pre-coat. The parylene layer (3) is preferably in contact with and deposited on the first barrier layer (2). As known to the skilled person, the object to be coated with parylene, e.g. the shell (1) or substrate layer (1), comprising a first barrier layer (2), typically is positioned into a deposition chamber, also called coating chamber. The process is essentially illustrated in Figure 1. The layer on which the parylene is deposited, typically the first barrier layer (2) is preferably not plasma-treated. This constellation, wherein the parylene layer (3) is not deposited on the shell (1) but preferably is deposited on an underlying layer, preferably the first barrier layer (2), provided the unexpected advantage that part of the barrier laminate, i.e. the part including and downstream of the parylene layer (3), could be removed relatively easily from the remaining part, e.g. including the first barrier layer (2), of the barrier layer and the shell (1). This is advantageous in recycling processes, wherein part of the barrier laminate is removed from the pulp-based shell, thereby reducing total amount of non-fibrous material in the recycling slurry and improving the recycling process and resulting recycled pulp material.

[0021] The thickness of the barrier laminate, including the first barrier layer (2) and the parylene layer (3), deposited at the inside of a shell, preferably is from 10gsm to 180gsm, more preferably from 30gsm to 120gsm, or 10pm to 150pm, more preferably 30pm to 100pm, or, 1wt% to 40wt%, more preferably, 5wt% to 25wt%

[0022] In the case of a flexible cellulose pulp fiber-based barrier laminate, the laminate comprises the cellulose pulp fiber layer, the first barrier layer and the second (parylene) barrier layer.

[0023] A first barrier layer (2) and a parylene barrier layer (3) are provided on the cellulose pulp-based flexible layer. It is preferred, that the first barrier layer (2) is positioned ‘upstream’ of the parylene layer (3), i.e. closer to the pulp-based layer, preferably between the pulp-based layer (1) and the parylene layer (3), and it may be preferred that the first barrier layer (2) is in contact with the pulp-based layer (1). In this way, the first barrier layer (2) effectively may function as a pre-coat. The parylene layer (3) is preferably in contact with and deposited on the first barrier layer (2). The layer on which the parylene is deposited, typically the first barrier layer (2) is preferably not plasma-treated. This constellation, wherein the parylene layer (3) is not deposited on the pulpbased layer (1) but preferably is deposited on an underlying layer, preferably the first barrier layer (2), provided the unexpected advantage that part of the barrier laminate, i.e. the part including and downstream of the parylene layer (3), could be removed relatively easily from the remaining part, e.g. including the first barrier layer (2), of the barrier layer and the pulp-based layer (1).

[0024] Parylene layer (3)

[0025] The container of the invention comprises a second barrier in the form of a layer of parylene (3), as part of the barrier laminate provided at the inside of the container.

[0026] Parylene is known in the art. Parylene is the common name of a class of polymers whose backbone consists of para-benzenediyl rings -CeH4- connected by 1 ,2-ethanediyl bridges - CH2-CH2-. Parylenes are obtain through polymerization of vaporized monomers, for instance parylene N can be obtained by polymerization of para-xylylene H2C=C6H4=CH2. Another name for parylene N is poly-(para-xylol).

[0027] Reaction scheme showing pyrolysis of dimer starting reagent to form the para-xylylene monomer which polymerises to form parylene N polymer.

[0028] Repeating unit of parylene N.

[0029] In traditional applications, parylene coatings are applied to electronic circuits and other equipment. They are used in medicine to prevent adverse reactions to implanted devices. Parylene coatings are typically applied by chemical vapor deposition in an atmosphere of the monomer such as para-xylylene.

[0030] Several varieties of parylene can be used in the context of the present invention. Derivatives of parylene can be obtained by replacing hydrogen atoms on the phenyl ring or the aliphatic bridge by other functional groups. Parylene N is the unsubstituted polymer that is obtained by polymerization of the para-xylylene intermediate. Parylene C has one hydrogen atom in the aryl ring replaced by chlorine. Parylene D has two chlorine substitutions on the ring with chorine at the meta position, as known in the art.

[0031] Repeating unit of parylene C Parylene AF-4 has the four hydrogen atoms on the aliphatic chain replaced by fluorine atoms. Parylene VT-4 (also called parylene F) has fluorine substituted for the four hydrogens on the aryl ring.

[0032] Specifically, replacement of one hydrogen on the phenyl ring by a methyl group or an ethyl group yields parylene M and parylene E, respectively.

[0033] Another common variant is parylene D, with two such substitutions on the ring.

[0034] Substitution may occur by alkyl groups on either the phenyl ring or the ethylene bridge, or both. Replacement of one hydrogen on the phenyl ring by a methyl group yields parylene M, substitution or an ethyl group yields and parylene E, respectively.

[0035] Suitably, the parylene used for a layer in the container of the invention is selected from the group consisting of parylene N (poly(p-xylene) or a derivative thereof. Accordingly, the layer is preferably selected from the group consisting of parylene N, parylene C (poly(2-chloro-p- xylene), parylene D, parylene F, parylene AF4, parylene E, parylene M, parylene A, parylene AM2 and mixtures thereof. More preferably, the parylene is selected from the group consisting of parylene N, parylene D or parylene C and mixtures thereof. Even more preferably, the parylene is selected from the group consisting of parylene N or parylene C and mixtures thereof. Most preferably, the parylene is parylene C. It was observed, that in the context of the present invention, parylene N and C showed a particular good resistance to moisture and impact of chemicals when used in cellulose fibre pulp-based rigid container for packaging consumer products. Parylene C is particularly preferred for example in a situation, but not necessarily limited to that situation, wherein no third barrier layer (4) is used in the cellulose pulp-based container.

[0036] Parylene layer in a shell

[0037] For a container comprising a shell, as described above, the parylene layer (3) has preferably a thickness of between 1 and 100 microns, preferably between 2 and 50 microns, preferably of between 2.5 and 30 micron, most preferably of between 3 and 25 micron, and can for example preferably be from 4 to 20 micron.

[0038] Preferably, the parylene layer (3) has a thickness of between 1 and 100 gsm (grams per square meter), more preferably of between 2 and 80 gsm, even more preferably between 3 and 60 gsm, even more preferably between 5 and 50 gsm, more preferably between 5 and 40 gsm. The thickness may preferably be from 5 to 25 gsm. The latter weight ranges (expressed as gsm) correspond typically with the respective thickness ranges indicated earlier (microns).

[0039] Accordingly, it can for example be preferred that when the parylene layer is parylene C and used in absence of a further barrier layer (4), such as a metal or metal oxide layer such as aluminum or aluminum oxide, the thickness of the parylene layer is of between 1 and 100 microns, preferably between 2 and 50 microns and even more preferably between 2.5 and 30 microns and most preferably between 3 and 25 microns. Also, it can be preferred that when the first parylene layer is parylene N and used in absence of a further barrier layer (4), such as preferably a metal or metal oxide layer such as aluminum or aluminum oxide, the thickness of the parylene layer is of between 1 and 100 microns, preferably between 2 and 50 microns and even more preferably between 2.5 and 30 microns and most preferably between 3 and 25 microns.

[0040] It is desired, that the grammage of the parylene layer (3) is less than 30wt%, preferably less than 20 wt%, even more preferably less than15wt%, even more preferably less than 10wt% of the total weight of the rigid container. In this manner optimal recyclability of the container is achieved. The grammage of the parylene layer (3) is preferably from 0.5 to 30wt%, more preferably from 1 to 15wt%, even more preferably from 2 to 20wt%, even more preferably from 3 to 15 wt% and even more preferably from 4 to 10wt%, based on the total weight of the container. The amount of polymer other than parylene may be from 1 to 20 wt%, preferably from 1.5 to 10 wt%, more preferably from 2 to 8 wt%, based on the weight of the container. It can be for example from 1 to 20 wt%, more preferred from 1.5 to 10 wt%, or more preferred from 2 to 8 wt%, based on the weight of the container.

[0041] The thickness of the barrier laminate, including the first barrier layer (2) and the parylene layer (3) preferably is from 10gsm to 180gsm, more preferably from 30gsm to 120gsm, or 10pm to 150pm, more preferably 30pm to 100pm, or, 1wt% to 40wt%, more preferably, 5wt% to 25wt%

[0042] Parylene in a cellulose fiber pulp-based barrier laminate

[0043] In the case the container is a flexible barrier laminate comprising a cellulose fiber pulp-based layer, the parylene layer (3) has preferably a thickness of between 0.5 and 30 microns, preferably between 1 and 20 microns, preferably of between 1.5 and 12 microns, more preferably of between 1.5 and 10 microns, even more preferably of between 1.5 and 8 microns, or most preferably of between 1.5 and 6 microns. A thickness may be preferred of between 3 and 12 microns or even 5 to 12 microns. Preferably, the parylene layer (3) has a thickness of between 0.45 and 23.5 gsm (grams per square meter), more preferably of between 0.45 and 20 gsm, even more preferably between 0.9 and 12.5 gsm, even more preferably between 1.35 and 6.25 gsm, and most preferably between 1.35 and 4.65 gsm. The latter weight ranges (expressed as gsm) correspond typically with the respective thickness ranges indicated earlier (microns).

[0044] Accordingly, it can for example be preferred that when the first parylene layer is parylene C and used in absence of a further barrier layer (4), such as a metal or metal oxide layer, such as aluminum or aluminum oxide, the thickness of the first parylene layer is of between 0.5 and 30 microns, preferably between 1 and 20 microns, preferably of between 1.5 and 10 microns, most preferably of between 1.5 and 6 microns. Also, it can be preferred that when the parylene layer is parylene N and used in absence of a further barrier layer (4), such as preferably a metal or metal oxide layer such as aluminum or aluminum oxide, the thickness of the parylene layer is of between 0.5 and 30 microns, preferably between 1 and 20 microns, preferably of between 1.5 and 10 microns, most preferably of between 1.5 and 6 microns.

[0045] It is desired, that the grammage of the parylene layer (3) is less than 15wt%, preferably less than 10wt%, more preferably less than 5wt% of the total weight of the cellulose fiber pulp-based barrier laminate. In this manner optimal recyclability of the barrier laminate is achieved. The grammage of the parylene layer (3) is preferably from 0.5 to 15wt%, more preferably from 1 to 15wt%, even more preferably from 1.5 to 10wt% of the total weight of the cellulose fiber pulpbased barrier laminate. The amount of polymer other than parylene may be from 1 to 20 wt%, preferably from 2 to 15 wt%, more preferably from 4 to 12 wt%, based on the weight of the cellulose fiber pulp-based barrier laminate.

[0046] First barrier layer (2)

[0047] The laminate deposited at the inner wall of the shell (1) comprises a first barrier layer (2). The first barrier layer (2) contributes to provide a consistent surface, which is beneficial in the context of cellulose pulp fiber-based shell. The first barrier layer (2) may, for example, be one or more layers, either with or without a mineral filler, selected from the group consisting of acrylic acid, ethylene-acrylic or methacrylic acid copolymers, butenediol vinyl alcohol copolymers (BVOH), cellulose nitrate, ethyl-vinyl acetates, ethylene vinyl alcohol (EVOH), microfibri Hated cellulose (MFC), nanocrystalline cellulose (NCC), native and chemically modified starches, polybutylene adipate terephthalate (PBAT), polybutylene succinate (PBS), polyisobutylene, poly(butylene succinate-co-adipate) (PBSA), polyesters, polyhydroxyalkanoates (PHA) and their copolymers, polylactic acid (PLA), polyolefins, polyurethanes (Pll), polyvinyl acetate (PVAc), polyvinyl alcohol (PVOH), polyvinyl dichloride, silanes, styrene acrylate, styrene- butadiene, waxes, or xylan and chemically modified xylan, preferably acrylic acid, ethylene-acrylic or methacrylic acid copolymers, butenediol vinyl alcohol copolymers (BVOH), ethyl-vinyl acetates, ethylene vinyl alcohol (EVOH), polyesters, styrene acrylate, styrene-butadiene, and combinations thereof.

[0048] The first barrier layer (2) has preferably a thickness of between 5 and 150 gsm, more preferably from 5 to 100 gsm, even more preferably from 10 to 50 gsm and even more preferably from 15 to 30 gsm. The first dispersion coating barrier layer can suitably be applied using flow coating or spray coating, as known to the skilled person.

[0049] It was observed in the present invention, that both a first barrier layer (2) and a parylene barrier layer (3) are relatively poor barrier barriers against water, and show insufficient barrier properties against water, when applied as a barrier layer in a cellulose fiber pulp-based rigid container, especially when used in relatively thin layers e.g. to allow recyclability. Surprisingly, a combination of these materials resulted in excellent barrier properties against water during long-term storage, while allowing recyclability in view of their thickness. It was furthermore observed, that typical barrier layers used in combination with rigid cellulose fibre pulp-based shells especially at a thickness that allows for recyclability of the container, showed very poor resistance to surfactant. It was surprisingly observed that the combination of a parylene layer (3) and a first barrier layer (2) resulted in a barrier laminate for a cellulose fibre pulp-based shell (1) that showed sufficiently resistant against surfactant. In this manner, a cellulose fiber pulp-based container can be provided that can comprise a surfactant-comprising consumer product, preferably a liquid surfactant-comprising consumer good, wherein the barrier laminate is as thin as possible and preferably wherein the container still meets requirements for recyclability.

[0050] In the case of a cellulose fiber pulp-based flexible barrier laminate, the first barrier layer (2) has preferably a thickness of between 1 and 5 gsm, preferable 1.5 to 4 gsm.

[0051] Third barrier layer (4)

[0052] The barrier laminate may further comprise an additional barrier layer (4), i.e. in addition to a first barrier layer (2) and a parylene layer (3). A third barrier layer (4) is preferably in contact with the parylene layer (3). The third barrier layer (4) is preferably located between the parylene layer (3) and the shell (1), more preferably between the first barrier layer (2) and the parylene layer (3), but it may be preferred that it is present not between the first barrier layer (2) and the parylene layer (3), for example forming the content-facing surface of the container. A third barrier layer (4) is preferably directly adjacent to the parylene layer (3).

[0053] The third barrier layer (4) may comprise a metal or metal oxide layer. The third barrier layer (4) preferably comprises one or more materials selected from the group consisting of aluminum metal, aluminum oxide, zinc oxide, titanium oxide, silicon oxide and combined layers of these. More preferably, the third barrier layer (4) comprises aluminum metal or aluminum oxide, and most preferably is an aluminum oxide layer. It may be preferred that the third barrier layer (4) is aluminum metal or aluminum oxide, preferably in combination with zinc oxide or titanium oxide. The third barrier layer (4), such as preferably the metal or metal oxide layer, may be deposited on the first barrier layer (2) that preferably directly coats the cellulose pulp fiber-based shell (1). The third barrier layer may be deposited using techniques used in the art, such as physical or chemical vapor deposition. In case the third barrier layer (4) comprises multiple materials, such as for example a combination of a metal and a metal oxide or two metal oxides, the layers are deposited on top of each other in layers. The parylene layer may be treated with plasma, preferably at least at the side facing the third barrier layer, if the third barrier layer, such as preferably the metal or metal oxide layer, is deposited adjacent to the parylene layer and not between the parylene layer (3) and the first barrier layer (2). If the third barrier layer (4) is deposited between the parylene layer (3) and the first barrier layer (2), plasma treatment is not required and it may be preferred that it is absent in that situation. If a metal layer or metal oxide layer is present as third barrier layer (4), it may be preferred, that a further pre-coat is present on which the metal or metal oxide is deposited. It is preferred that a total of one third barrier layer (4) is present. In such a case, a single third barrier layer may consist of layers of metal, metal oxide or both. Alternatively, it can be preferred that the single third barrier layer consists only of a single type of metal or a single type of metal oxide.

[0054] The additional barrier layer, i.e. the third barrier layer (4), preferably comprising a metal layer or metal oxide layer, and more preferably being an aluminum layer or an aluminum oxide layer, preferably has a thickness of between 0.01 and 1 micron.

[0055] In a preferred situation, the container of the invention comprises a first barrier layer (2), a metal or metal oxide layer (4), and a parylene layer (3), wherein the parylene layer is parylene N or parylene C. Especially if the parylene layer is parylene N, it may be preferred that a third barrier layer (4), preferably comprising metal or metal oxide, more preferably comprising aluminum or aluminum oxide, is present.

[0056] It can be preferred that no additional barrier layer, ie. third barrier layer (4) is present, preferably, that no metal or metal oxide layer is present in the barrier laminate provided in the container. It can be preferred that no additional, i.e. third barrier layer, (4) comprising polypropylene, polyethylene, polyethylene terephthalate, with or without metalisation is present. An advantage of the present invention, in the context of the use of a rigid cellulose fiber pulp-based container, is that no third barrier layer, such as a metal layer or metal oxide layer, is needed. The barrier laminate present at the inside of the shell may preferably consist of the first barrier layer (2) and the parylene layer (3).

[0057] It is preferred, however, that no plasma treated material is present in the container. It may be preferred that the shell (1) is not plasma treated. It may be preferred that the parylene layer is not plasma treated. In particularly it may be preferred that the layer on which the parylene is deposited is not plasma-treated. Preferably the second barrier layer (3) is not plasma-treated.

[0058] Ink layer

[0059] The packaging container of the invention is used to protect a consumer product (5). In this respect, it also provides a communication function to the consumers who will buy the consumer products, typically via information printed on the surface of the container facing the consumer, including information regarding ingredients, appealing artwork and advertisement etc. The container therefore preferably comprises a layer of ink (6). This layer of ink is preferably connected to the pulp-based shell (1) or to the cellulose fiber pulp-based layer in case of a flexible barrier lamiante. It may be preferred that there is a primer applied between the pulpbased shell or layer and the ink layer. Appropriate primers are known to the person skilled in the art, and may, for example, be a polyurethane primer. The layer of ink is preferably in direct connection with the cellulose-pulp-based shell (1) or layer (1) and typically faces the outside of the container, i.e. the site opposite to the site of the container that will be in contact with the consumer product to be packaged.

[0060] Protection layer

[0061] For example, to protect the ink layer (6), the container preferably comprises a protection layer (7) on top of the ink layer. The protection layer is typically facing the outside world. It is typically located opposite to the product-facing site of the container. The protection layer (7) may be an over-print varnish (OPV), OPVs are well-known to the person skilled in the art and the chosen varnish depends on the intended use of the container of the present invention. For example, the OPV may be selected from the group consisting of conventional offset letterpress varnishes, acrylic varnishes, UV varnishes, and gravure varnishes. OPVs can be water-based polymer formulations or solvent-based polymer formulations.

[0062] The protection layer may also be a layer comprising parylene, preferably being parylene C or parylene N. In the latter case, the container comprises more than one layer of parylene and preferably comprises a total of two layers of parylene. A second parylene layer (7) could be preferred, as it provides an additional protection layer to outside influences.

[0063] It might be preferred that a further barrier layer is applied at the outside of the container. This further barrier layer may function as a protection of an ink layer (6). This further barrier layer may preferably comprise a parylene or one or more from the list consisting of acrylic acid, ethylene-acrylic or methacrylic acid copolymers, butenediol vinyl alcohol copolymers (BVOH), cellulose nitrate, ethyl-vinyl acetates, ethylene vinyl alcohol (EVOH), microfibri Hated cellulose (MFC), nanocrystalline cellulose (NCC), native and chemically modified starches, polybutylene adipate terephthalate (PBAT), polybutylene succinate (PBS), polyisobutylene, poly(butylene succinate-co-adipate) (PBSA), polyesters, polyhydroxyalkanoates (PHA) and their copolymers, polylactic acid (PLA), polyolefins, polyurethanes (Pll), polyvinyl acetate (PVAc), polyvinyl alcohol (PVOH), polyvinyl dichloride, silanes, styrene acrylate, styrene-butadiene, waxes, or xylan and chemically modified xylan, preferably acrylic acid, ethylene-acrylic or methacrylic acid copolymers, butenediol vinyl alcohol copolymers (BVOH), ethyl-vinyl acetates, ethylene vinyl alcohol (EVOH), polyesters, styrene acrylate, styrene-butadiene, and combinations thereof.

[0064] The protection layer (7) typically is deposited directly on the ink layer (6), It is preferably in direct contact with the ink layer. The protection layer, e.g. a second parylene layer, faces an outside of the container, typically the site opposite to the site that is intended to face or faces the consumer product to be packaged.

[0065] The thickness of the protection layer (7), preferably of the second parylene layer, is preferably between 1 and 30 microns, preferably of between 5 and 15 microns.

[0066] Step a) of providing a container may comprise compression of the container. Compression can for example result from compressing paper-based material into bales, before the repulping step. Compression of the container is advantageous in the context of the invention, as it may contribute to the detachment of the second barrier layer comprising parylene from the first barrier layer, thereby helping delamination and enhancing efficiency.

[0067] Cutting

[0068] The process of the invention may comprise an optional step of cutting the container provided in step a). Although not necessary, this step may be considered suitable to carry out step b) more efficiently, e.g. by providing better access to the interior of the container. In particular, when the container is a rigid container, the presence of a cutting step may be preferred. The container may be cut for example in a total of 2 or more particles, for example from 2 to 100 particles, preferably 2 to 10 particles, more preferably 2 to 5 particles. The cutting may be executed for example along the longest dimension of the container, e.g. most efficient removal of the consecutive barrier layers from the first barrier layers (2) in the next steps of the process. It might be preferred that no cutting step is present before step b).

[0069] Step b)

[0070] In step b) of the process, the second barrier layer (3) is separated from the first barrier layer (2). This suitably is done, for example, by tearing the second barrier layer, comprising the parylene layer, from the first barrier layer. Step b) may be carried out by a consumer, for example, conveniently removing the second barrier layer comprising a parylene layer, before discarding the part of the container containing the pulp-based shell or layer and the first barrier layer. Step b) can advantageously occur concomitantly to step c), where separation of the second barrier layer (3) may occur during soaking in an aqueous solution, e.g. upon stirring thereof. An advantage of the present invention is that the parylene layer detaches easily from its underlying layer, typically the first barrier layer, during the soaking / repulping step b). In this manner, the barrier layer(s) comprising parylene separates relatively early in the recycling process and can be retrieved from the slurry relatively early and, later in the process, remaining parylene- containing parts can be conveniently removed by e.g. sieving, thereby minimizing the chance of parylene-comprising barrier layer being mixed or stuck to the fiber material, resulting in high quality of the recycled fiber material.

[0071] In the case that the barrier laminate comprises more layers than the first and the second barrier layer, in the step b) the further barrier layers, are removed together with the second barrier layer (the parylene layer). In this manner the thickness of the total of barrier layers is reduced to the thickness of the first barrier layer, improving the recyclability of the packaging material and rendering the recycling process more efficient.

[0072] Comminuting step

[0073] The packaging material of the container comprising the first barrier layer, may be comminuted, although not essential, to result in container particles. The comminution process is carried out as typically done in the art. Comminuting the container preferably is carried out before step c) and preferably before step c) and after step b) (i.e. when step b) is not carried out during step c) but before step c)). It might be preferred that the process of the invention has no comminuting step, preferably no comminuting step before step c), and more preferably no comminuting step between step b) and step c).

[0074] In step c), the parts of the container comprising the first barrier layer of the laminate are soaked in water. In this way an aqueous suspension is created. The cellulose fiber pulp-based shell or layer are repulped in this step. It may be that at least part of the containers or fragments thereof to be recycled and subjected to step c) do not comprise the second barrier layer (3), i.e. when this has been removed. Alternatively, typically at least part of the containers or fragments thereof to be recycled and subjected to step c) do comprise the second barrier layer (3), and separation thereof from the underlying layer (typically the first barrier layer) occur during the soaking / repulping step b), as mentioned above.

[0075] The aqueous solution allows the cellulose fiber to absorb water and the first barrier layer to separate from the cellulose fiber.

[0076] In step d), cellulose fiber is collected from the aqueous suspension. This is suitably done by steps known in the art. Fiber and non-fiber fraction may for example be separated based on density, by using sieving, filtration, or a combination of such techniques.

[0077] Step d) may be followed by a drying step to dry the recycled, cellulose fibers. Such a drying step may comprise compression of the wet fibers, heat-drying or both. The resulting fiber can be used to prepare paper. To this end, the process may further comprise the step of including additives to the fibers. The process may comprise a calendaring step to form a sheet. The process may further comprise a step of preparing reels of paper.

[0078] Example

[0079] The invention is now exemplified by the following non-limiting example.

[0080] Example 1

[0081] Wet-molded bottle shells manufactured from cellulose-pulp were used with a thickness of the all of 1000-micron. The shells were coated at the inside surface using flow coating technique. In some bottles a coating (first barrier layer) of 20 micron of REEF™1 from Cellucomp was applied (comparative example A), which is an acrylic polymer with curran (an MFC). In other shells, a parylene C coating (second barrier layer) was applied with a thickness of the coating of 50 micron (comparative example B). In other shells first a pre-coat (20 gsm) Cellucomp REEF™ 1 was applied followed by a 40 micron parylene C coating.

[0082] The pulp-based bottles coated with a pre-coat of a dispersion coating (REEF™ 1 ) and a parylene layer on top of it, were tested to remove part of the barrier laminate. The bottles were cut in half and the parylene was removed by pulling out the layer. The parylene layer (3) easily separated from the pre-coat (first barrier layer (2)). This exemplifies that a barrier laminate comprising a layer of parylene and possible any subsequent downstream layers is easily removed from the barrier layer on which the parylene is applied. This leaves a pulp-based shell with only one barrier layer behind that is easily recycled. Bottles with either a first barrier layer or parylene layer, didn’t allow removal of the barrier layer.

[0083] The shells comprising the first barrier layer are subjected to a recycling process by soaking them in an aqueous solution, and separating the fibrous phase from the non-fiber components via density separation. Large non-fibrous components are removed by a series of sieves. The cellulose fiber pulp is collected and dried.

[0084] Example 2 Example of different layers in a container with rigid cellulose fiber pulp-based shell

Claims

Claims1 . A process to recycle cellulose fiber pulp-based containers, the process comprising the steps of: a) Providing a container comprising:• A cellulose fiber pulp-based shell (1) or substrate layer (1),• A first barrier layer (2),• A second barrier layer (3) in the form of a parylene coating, wherein the first barrier layer (2) is positioned between the shell (1) or substrate layer (1) and the second barrier layer (3), b) Separating the second barrier layer from the first barrier layer c) Soaking the container comprising the first barrier layer or particles of said container, in water, and allowing the cellulose fiber pulp to separate from the first barrier layer, d) Collecting the cellulose fibers.

2. The process according to claim 1 , wherein step b) occurs during step c).

3. The process according to step 1 or 2, wherein the process further comprises the step of cutting the container, carried out before step b).

4. The process according to any one of the preceding claims, wherein the process comprises the step of comminuting the container, to result in particles, preferably carried out before step c) and preferably before step c) and after step b).

5. The process according to any one of the preceding claims, wherein the container comprises a shell (1) and the shell has a thickness of between 500 to 5000 micron, more preferably from 500 to 3000 microns, even more preferably from 600 to 2000 microns and even more preferably from 600 and 1700 micron.

6. The process according to any one of the preceding claims, wherein the parylene layer comprises parylene N, parylene C, or a mixture thereof.

7. The process according to any one of the preceding claims, wherein the parylene layer has a thickness of between 1 and 100 micron, preferably of between 2 and 50 micron.

8. The process according to anyone of the preceding claims, wherein the first barrier layer (2) comprises one or more from the list consisting of acrylic acid, ethylene-acrylic or methacrylic acid copolymers, butenediol vinyl alcohol copolymers (BVOH), cellulose nitrate, ethyl-vinyl acetates, ethylene vinyl alcohol (EVOH), microfibri Hated cellulose (MFC), nanocrystalline cellulose (NCC), native and chemically modified starches, polybutylene adipate terephthalate (PBAT), polybutylene succinate (PBS), polyisobutylene, poly(butylene succinate-co-adipate) (PBSA), polyesters, polyhydroxyalkanoates (PHA) and their copolymers, polylactic acid (PLA), polyolefins, polyurethanes (Pll), polyvinyl acetate (PVAc), polyvinyl alcohol (PVOH), polyvinyl dichloride, silanes, styrene acrylate, styrenebutadiene, waxes, or xylan and chemically modified xylan, preferably acrylic acid, ethyleneacrylic or methacrylic acid copolymers, butenediol vinyl alcohol copolymers (BVOH), ethyl- vinyl acetates, ethylene vinyl alcohol (EVOH), polyesters, styrene acrylate, styrenebutadiene, and combinations thereof.

9. The process according to anyone of the preceding claims, wherein the first barrier layer has a thickness of between 5 and 50 gsm, preferable 10 to 40 gsm, even more preferably from 15 to 30 gsm.

10. The process according to anyone of the preceding claims, wherein the thickness of the parylene layer (3) is less than 15%, preferably less than 10%, more preferably less than 3% of the total grammage of the container.

11. The process according to anyone of the preceding claims, wherein the container further comprises a further barrier layer applied at the outside of the container.

12. The process according to claim 11 , wherein the further barrier layer applied at the outside of the container is in the form of a parylene layer.

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