EP4251338A1 - Facility and method for recycling containers made of plastic material - Google Patents

Abstract

Facility (10) for recycling plastic "refillable" containers, comprising a cleaning line (11) provided with a sorting station (12) followed by a station (13) for washing the containers, the facility being supplied, at the inlet, with used containers (1) and returning, at the outlet, compliant containers (3) and non-compliant containers (30); a line (14) for producing final containers (4), in particular bottled final containers, which line is at least supplied with compliant containers (3) by the cleaning line (11); the facility is characterised in that it comprises a conversion line (15) for converting non-compliant containers (30), which line is supplied by the cleaning line (11); the conversion line (15) comprising a unit (150) for grinding non-compliant containers (30) into flakes (8) and a unit (151) for processing the flakes (8) into granules (9). A corresponding recycling method is also claimed.

Description

DESCRIPTION

Installation and process for recycling containers made of plastic material The invention relates to the recycling of containers made of plastic material. In particular, the invention relates to the recycling of containers, such as bottles, made of plastic material of the “refillable” type and intended to receive an agrifood liquid.

In the rest of the description, the term "container" encompasses an individual object. Such a container is in the form of a bottle or a flask.

A container is intended to contain, in a non-exhaustive manner, a fluid or a liquid, in particular of the food-processing or cosmetic type, preferably food-processing, such as drinks, such as juices, sodas or mineral waters.

A container is made of plastic material, in particular PET (for “polyethylene terephthalate”) or PEN (for “polyethylene naphthalate”) or even PEF (for “polyethylene furanoate”).

At the present time, in a context of sustainable development and environmental protection, the recycling of containers made of plastic material can comprise a recovery circuit with a view to reusing the containers. Such a reusable container made of plastic material is often referred to as “refillable” (for “can be refilled”).

It will be noted that the refillable containers have a specific manufacture, in particular due to a specific plastic material, to which additives are incorporated, conferring characteristics adapted to the manufacturing process for a greater thickness to the preforms and to the walls of the containers, increasing their resistance and longevity, which allows them to follow several successive rotations, from initial manufacture to filling, followed by use by a consumer and their return to be bottled again after having been previously cleaned, and so on .

The invention relates specifically to the recycling of containers made of plastic material of the refillable type, hereinafter “refillable container” or “container”.

This being the case, a consumer brings the empty and used containers to a place dedicated to their collection, such as a store intended for marketing, where said containers are placed in boxes or on trays commonly called “trays”. The filled crates are then transported to a site dedicated to their rehabilitation.

Referring to Figure 1, showing an example of architecture of the state of the art for the recycling of containers, a rehabilitation site 100 includes a cleaning line 101, at the entrance of which arrive the boxes filled with used containers 1 previously collected and recycled. A first step consists in sorting the used containers 1, through a sorting station 102 of the cleaning line 101, in particular to check their compliance with a view to reuse. In addition, this sorting makes it possible to disburse the used containers 1 in order to remove those which are not of the refillable type or which do not correspond to the cleaning line 101, to remove the plugs and organs possibly present on the necks, or else to check the integrity of their body, or even the internal presence of a substance unsuitable for consumption, resulting for example from misuse by a consumer or from contamination linked to the storage environment.

Indeed, the plastic material of the containers has a certain porosity. It is therefore likely to imprison certain molecules, in particular odorous molecules such as aromas. In addition, plastic deteriorates at temperatures exceeding 60 degrees Celsius (°C), as well as in contact with certain products, such as hydrocarbons, for example. Therefore, such refillable containers are provided for a finite number of reuse rotations, for example of the order of 12 to 20 rotations, before a container is too damaged to consider a new rotation, in particular undergoes the constraints a new bottling cycle, which depends in particular on the specificities of the bottling.

Thus, the sorting makes it possible to remove from the rehabilitation cycle and to send to scrap 103 the used containers 1 considered as defective containers 2. The other used containers 1 are considered as compliant containers 3 and are then transported to a washing station 104, where they will be stripped of their labels and washed internally, in particular by adding suitable cleaning substances. On leaving the washing station 104, the compliant containers 3 are clean and can be sent to a production line 105 to be filled and capped again, through several stages, including in particular bottling and labeling, possibly followed a packaging step, such as packing or grouping several containers into a batch. On leaving the production line 105, the final containers 4 are said to be “finished” and can be transported to the sites where they are marketed.

It will be noted that the production line 105 can also receive new containers 5 obtained from a production line 106 located upstream. This manufacture of a new container 5 is specific to the refillable type and is carried out by blow molding or stretch-blow molding in a mold from a preform 6.

In addition, a preform 6 is obtained by a plastic injection operation, from granules and/or a plastic resin having specific characteristics. This injection is performed by an injection line 107 generally located on a dedicated and distinct injection site 108 . The preforms 6 obtained are then transported to the rehabilitation site 100 when it includes a line 106 for manufacturing new containers 5. If the rehabilitation site 100 does not include a manufacturing line 106, then the new containers obtained on a separate site are transported empty to the rehabilitation site 100 towards the entrance of the production line 105.

Furthermore, the manufacture of new containers 5 is extremely complex, especially in the case of refillable containers, resulting in the loss of non-compliant containers, which are also sent to scrap 103. Relatedly, the conformity of the preforms 6 at the input of the manufacturing line 106 can be checked and the preforms 6 found to be faulty can also be sent to scrap 103.

As such, the content of the scrap 103 is then transported to a separate reconversion site 109, where all the plastic material coming from several sites will undergo a reconversion with a view to making other objects 7, for example clothes, or even injection of plastic and composite parts.

Further on, a reconversion site 109 comprises a grinding unit 110 to create flakes 8 of plastic, also called “flakes”. This grinding can be carried out in several stages, dry after a step of drying the containers, or else in a so-called “wet” manner with a step of drying the flakes 8 occurring subsequently. An intermediate stage of filtration by centrifugation also makes it possible to separate the materials resulting from the grinding, in order finally to recover at the outlet only flakes 8 of plastic, in particular of a given plastic material.

Then, the flakes 8 must undergo treatments to obtain a plastic material in the form of granules 9 compatible with a subsequent injection operation. These treatments are carried out through a dedicated treatment unit 111 and may comprise several steps, including in particular extrusion, crystallization and finally polymerization. On output, the granules 9 can be sent to a manufacturing unit 112, with dedicated steps depending on the object 7 to be manufactured. Such a manufacturing unit 112 is generally located on a separate site, inducing an additional transport step.

As it stands, there are significant transport stages between the different sites, resulting in a substantial and detrimental carbon footprint.

In addition, each separate site involves reprocessing of waste, such as effluents, from certain stations, such as station 104 washing, through dedicated 113,114 reprocessing stations specific to each site.

In addition, during such recycling, the plastic material specific to the manufacture of containers of the refillable type finds itself reconverted into other objects 7, leaving the field of the food industry, inducing a consequent loss due to the specificity of this material and the constraints of its transformation into refillable containers. From this observation, the invention envisages optimizing the recycling of plastic dedicated to containers of the refillable type and, as far as possible, to maintain the specific plastic material in the sector of containers of the refillable type for the field of agri-food. The invention proposes to set up a dedicated reconversion installation on the site of the refillable-type receptacle rehabilitation line, or even directly supplying a production line with preforms or receptacles. In particular, the conversion of non-compliant containers makes it possible to obtain plastic granules which, instead of being converted into other products, are used on site for the manufacture of preforms, or even for the blow molding of containers.

To do this, the invention provides for pooling part of the stations and stages of a conversion line and a refillable-type receptacle cleaning line, in order to optimize many aspects, such as the installation on the ground , the cost, the treatment of waste, in particular effluents.

To do this, the invention firstly relates to an installation for recycling containers made of plastic material of the "refillable" type, comprising

- a cleaning line provided with a sorting station followed by a station for washing said containers, supplied at the input with used containers and returning at the output compliant containers and non-compliant containers;

- a final container production line provided with at least one bottling station, at least supplied with conforming containers by said cleaning line.

Such a recycling installation is characterized in that it comprises at least:

- a line for converting non-compliant containers, supplied by said cleaning line;

- said conversion line comprising at least one unit for grinding non-compliant containers into flakes and a unit for processing said flakes into granules. According to additional, non-limiting characteristics, such a recycling installation may comprise, downstream of the washing station, a station for transferring at least non-compliant containers washed to said conversion line. Said recycling installation may comprise, downstream of said conversion line, a station for injecting preforms from said granules.

Said recycling installation may comprise, downstream from said injection line and upstream from said production line, a line for manufacturing new containers from said preforms.

Said recycling installation may comprise a station for checking the conformity of new containers into conforming containers supplying said production line and non-conforming containers supplying said conversion line.

Said recycling installation may comprise an effluent reprocessing station at least common to said cleaning line and to said conversion line. The invention also relates to a process for recycling containers made of plastic material of the “refillable” type, in which at least:

- used containers are supplied to a cleaning line, said used containers are sorted into compliant containers and non-compliant containers;

- Said compliant containers are washed;

- the compliant containers are sent to a production line for final containers, with a view to bottling them.

Such a recycling process is characterized in that it comprises at least the following steps:

- during washing, non-compliant containers are washed;

- non-compliant containers are sent to a pellet conversion line. According to additional, non-limiting features, during such a recycling process, said granules can be sent to a preform injection line; then said preforms are sent to a production line for new containers by blow molding from said preforms; then said production line is supplied with said new containers.

Within the conversion line, said non-compliant containers can be ground into plastic flakes; then said flakes are processed into plastic granules; said grinding being devoid of a new washing step.

Other characteristics and advantages of the invention will emerge from the detailed description which will follow of the non-limiting embodiments of the invention, with reference to the appended figures, in which:

Figure 1 schematically represents a view of an example of an architecture of the state of the art relating to the recycling of containers, as previously described, showing in particular the various treatment sites and the stages of transport between the sites;

FIG. 2 schematically represents a view of a first embodiment of a recycling architecture according to the invention, showing in particular the pooling of a washing station; and

FIG. 3 schematically represents a view of a second embodiment of a recycling architecture according to the invention within the same site, showing in particular the incorporation of the injection of preforms and the manufacture of containers with from such preforms.

The present invention relates to the recycling of containers made of plastic material. In particular, the invention relates to the recycling of containers, such as bottles, made of plastic material of the “refillable” type and intended to receive an agrifood liquid. In the rest of the description, the term "container" encompasses an individual object. Such a container is in the form of a bottle or a flask.

A container is intended to contain, in a non-exhaustive manner, a fluid or a liquid, in particular of the food-processing or cosmetic type, preferably food-processing, such as drinks, such as juices, sodas or mineral waters.

A container is made of plastic material, in particular PET (for “polyethylene terephthalate”) or PEN (for “polyethylene naphthalate”) or even PEF (for “polyethylene furanoate”).

In addition, the container is of the "refillable" type (for "can be refilled"). The plastic material used for the manufacture of such a refillable container has specific characteristics. In particular, the material comprises a specific co-monomer content, ensuring that the rate of crystallization of PET (commonly called "slow crystallization") is limited, which makes it possible to inject preforms suitable for the manufacture of thick-walled containers. In addition, the specific intrinsic viscosity gives good mechanical and chemical resistance to washing agents.

In addition, the process for manufacturing a refillable container has specific features and dedicated constraints.

In this context, the invention relates to an installation 10 for recycling containers made of plastic material of the “refillable” type.

Such a recycling installation firstly comprises a cleaning line 11, supplied at the input with used containers 1 and returning at the output from the containers 3 compliant and non-compliant containers. Once cleaned, a compliant container 3 can be used again, while a non-compliant container 30 must be reconverted, for example when it is damaged.

In addition, the cleaning line 11 can also send to waste 20 defective containers 2, namely whose plastic material or a substance present prohibits any use in the food industry. The content of the scrap 20 is then sent to a separate site, where a dedicated actor takes charge of the conversion of the plastic material.

Further, the cleaning line 11 is provided with a sorting station 12 followed by a station 13 for washing said containers 3.30.

First of all, sorting can include several successive stages, through dedicated units. For example, a first sorting can be carried out, during which a possible stopper closing a container can be removed during an uncorking step, followed by unpacking of the used containers 1. In addition, checks of several characteristics of the used products 1 can be carried out, such as the detection of the presence of unsuitable or dangerous substances, or the verification of the integrity of each used container 1 or even of its dimensions.

In short, the sorting station 12 makes it possible, on the one hand, to exclude the defective containers 2 to send them to waste 20 and, on the other hand, to separate the compliant containers 3 and the non-compliant containers 30 .

Then, the washing station 13 then washes the containers 3.30, namely the outside but especially the inside, as well as getting rid of any labels affixed to the outer wall of the products.

Such a washing station 13 may comprise a washing unit, in particular in the form of a tunnel traversed by at least one conveyor transporting the containers 3.30. Such washing is carried out by sprinkling and immersing a heated liquid, such as water, to which a cleaning adjuvant is added, optionally followed by rinsing and then drying steps.

Already, the invention advantageously provides for washing the compliant containers 3 and also the non-compliant containers 30 . In short, the non-compliant containers 30 are not sent to waste 20 during sorting, but are washed with the compliant containers 3; it is only after washing that the containers 3.30 are sent to separate treatments.

In addition, on leaving the wash, non-compliant containers 30 are "bare", devoid of labels and caps, as well as any residual or undesirable substance, which makes it possible in particular to facilitate subsequent steps and to obtain a better plastic material once recycled.

In addition, an additional check can be carried out at the wash outlet, to check that the cleaning is proceeding correctly, possibly returning non-compliant containers to a new washing step. This control can also consist of reading information affixed to the container 3.30, in particular information relating to the number of cycles that the container 3.30 has already undergone. In the event of an additional check which proves negative, the container is considered to be a non-compliant container.

Further on, the recycling installation 10 comprises a line 14 for producing final containers 4 . This production line 14 is provided with at least one bottling station. Such a bottling station can comprise several units, making it possible to carry out various successive treatments, such as filling, capping and labeling, until said final containers 4 are obtained at the outlet.

In addition, the production line 14 is located downstream of the cleaning line 11 and is at least supplied with conforming containers 3 by said cleaning line 11. According to one embodiment, visible in FIG. 2, the production line 14 can be supplied with new containers 5 by a production line 16 located on a separate site 160 .

According to another embodiment, visible in FIG. 3, the recycling installation 10 comprises the line 16 for manufacturing new containers 5 . The production line 14 can then also be supplied with new containers 5 via the production line 16.

In addition, in one mode as in the other, the compliant containers 3 and the new containers 5 can be mixed together with a view to their processing by the production line 14 .

Further on, the manufacturing line 16 may comprise at least one station 161 for blow molding new containers 5 from preforms 6, through a blow molding or stretch-blow molding step.

Advantageously, the invention provides for keeping non-compliant containers 30 in the agri-food circuit.

To do this, the recycling installation 10 comprises a line 15 for converting non-compliant containers 30 . This conversion line 15 is supplied by said cleaning line 11, then located upstream.

In addition, as mentioned above, the non-compliant containers 30 have already undergone a washing step, before reaching the conversion line 15, which makes it possible to to dispense with a subsequent washing or else to carry out a lighter subsequent washing, using less fluid or with fewer additives, or else with less intense pressure and temperature conditions.

Further on, the conversion line 15 comprises at least one unit 150 for grinding non-compliant containers 30 into flakes 8 and a unit 151 for processing said flakes 8 into granules 9.

Concerning the grinding unit 150, it makes it possible to reduce the non-compliant containers 30 into flakes 8, but also to filter the materials, by removing any undesirable element, such as a component of a more or less high density, compared to the density of the plastic material which wishes to be recovered at the output in flakes 8.

Such grinding can be carried out dry or wet. In either case, due to the prior washing of the non-compliant receptacles 30, the grinding can dispense with a step of washing the flakes 8, limiting the constraints relating to such washing. In addition, this grinding can be carried out on only the containers to be converted, without having to process the materials resulting from the grinding of other components, such as in particular the labels, the caps and the tamper evident rings. Concerning the processing unit 151, it makes it possible to transform the flakes 8 into granules 9, through several successive stages, including in particular drying, crystallization, followed by extrusion into granules 9, with polymerization. These granules 9 are then ready for the manufacture of new containers 5.

The invention provides for sending said granules 9 thus obtained to a preform injection line 6. Such an injection line is in particular provided with at least one station 162 for injecting preforms 6. This injection takes place from at least said granules 9 thus recovered.

According to one embodiment, the injection line is located on a separate site. According to the embodiment shown in Figure 2, the injection station 162 is integrated upstream of the production line 16, directly supplying preforms 6 to the station 161 for blowing new containers 5.

According to another embodiment, visible in FIG. 3, the injection line is integrated into the conversion line 15 on the same site. Injection station 162 is then incorporated downstream of stations 150, 151 of said conversion line 15, said preform injection station 162 then being supplied directly from at least said granules 9.

In addition, additional granules can come from other sources of supply, in order to supply a sufficient quantity to the injection station 162, depending on the rate required and the injection process. Such additional granules come from an ancillary source and are free from any prior use.

By adjusting the ratios between the granules 9 and the additional granules, it is then possible to maintain a suitable grade of resin so as to maintain the characteristics linked to the manufacturing process, namely by blowing or stretch-blow molding.

According to yet another embodiment, the injection line is integrated into the manufacturing line 16 on the same site. The injection station 162 is then incorporated upstream of the blowing station 161.

In addition, the installation can plan to check at each stage of production the quality of the elements produced, namely the flakes 8 or the granules 9, but especially the preforms 8 or the new containers 5. If these elements are compliant, then they can be sent to the next station, otherwise the invention provides for returning these elements to the input of the conversion line 15, in order to limit the loss of plastic material, which should be keep in this specific “refillable” sector.

According to one embodiment, visible in FIG. 3, the recycling installation 10 comprises a verification of the conformity of the new containers 5 into conforming containers 3 supplying said production line 14 and non-conforming containers 30 supplying said production line 15. conversion.

According to a variant embodiment, visible in FIG. 3, the recycling installation 10 comprises a verification of the conformity of the preforms 6 supplying the blow molding station 161, the non-compliant preforms being sent to supply said conversion line 15 .

According to one embodiment, the recycling installation 10 comprises an effluent reprocessing station 17 at least common to said cleaning line 11 and to said conversion line 15 . In particular, the reprocessing station 17 makes it possible to receive the effluents from the various stations and units, with a view to channeling and reprocessing them jointly, in particular the effluents coming from the washing station 13, from the 150 crushing unit and/or of the processing unit 151. Such pooling of effluent reprocessing is visible in Figures 1 and 2.

The invention also relates to a process for recycling containers made of plastic material of the “refillable” type.

Such a recycling method is preferably adapted to the implementation of the recycling installation 10 according to the invention. he

During such a recycling process, used containers 1 are supplied to a cleaning line 11 . Such a supply can be carried out directly by conveying said used containers 1 in crates or “trays”, or else after a station located upstream which carries out a preliminary unpacking, or even a pre-sorting.

Then, said used containers 1 are sorted into conforming containers 3 and non-conforming containers 30 . In addition, such sorting also makes it possible to extract containers 2 checked as defective.

Once sorted, said compliant containers 3 are washed, then these washed compliant containers 3 are sent to a line 14 for producing final containers 4, for bottling.

Advantageously, the invention provides that during such a recycling process, at the time of said washing, the non-compliant containers are washed. Then, the washed non-compliant containers 30 are sent to a line 15 for conversion into granules 9. According to one embodiment, within the conversion line 15, said non-compliant containers 30 are ground into flakes 8 of plastic, then said flakes 8 are treated into plastic granules 9.

Advantageously, due to the prior washing of the non-compliant containers, said grinding is devoid of a new washing step. Such grinding is therefore carried out entirely dry or by humidification.

According to one embodiment, after the conversion, said granules 9 are sent to a preform injection line 6. As mentioned above, such an injection line can be integrated into the line 14 for producing new containers 5 from preforms 6, or located on a separate site 160.

Then, said preforms 6 are sent to a line 16 for manufacturing new containers 5 by blow molding from said preforms 6. These new containers 5 then supply said production line 14 .

It will be noted that the supplies are made via suitable conveyors, transporting the containers 3.30 along, to and from the various lines 11, 14, 15, 16.

According to one embodiment, the recycling installation 10 comprises, downstream of the washing station 13, a station for transferring washed non-compliant containers 30 to said conversion line 15 . This transfer station can also ensure the transfer of washed compliant containers 3 to said production line 14 .

Thus, the recycling according to the invention, through its installation 10 and its process, makes it possible to pool at least the washing of used containers 1, whether they are compliant or not, to avoid or limit additional washing when converting non-compliant containers. In addition, the invention provides for integrating this conversion on site, in order to considerably reduce intermediaries and unnecessary transport between separate sites. For example, the invention makes it possible to target different sorting steps prior to washing, with a view to recycling only viable containers 1, avoiding losses of material, unnecessary transport and non-negligible risks of contamination.

Claims

1 . Installation (10) for recycling containers made of plastic material of the “refillable” type, comprising - a cleaning line (11) provided with a sorting station (12) followed by a station (13) for washing said containers, supplied at the input with used containers (1) and returning at the output compliant containers (3) and non-compliant containers (30); - a line (14) for producing final containers (4) provided with at least one bottling station, at least supplied with conforming containers (3) by said cleaning line (11); characterized in that it comprises at least: - A line (15) for converting non-compliant containers (30), supplied by said cleaning line (11); - said conversion line (15) comprising at least one unit (150) for grinding non-compliant containers (30) into flakes (8) and a unit (151) for processing said flakes (8) into granules (9). 2. Installation (10) for recycling according to the preceding claim, characterized in that it comprises - Downstream of the washing station (13), a station for transferring at least non-compliant containers washed to said conversion line (15). 3. Installation (10) for recycling according to the preceding claim, characterized in that it comprises - Downstream of said conversion line (15), a station (162) for injecting preforms (6) from said granules (9). 4. Installation (10) for recycling according to the preceding claim, characterized in that it comprises - downstream of said injection line (162) and upstream of said production line (14), a line (16) for manufacturing new containers (5) from said preforms (6). 5. Installation (10) for recycling according to the preceding claim, characterized in that it comprises - A station for checking the conformity of new containers (5) into conforming containers (3) supplying said production line (14) and non-conforming containers (30) supplying said conversion line (15). 6. Installation (10) for recycling according to any one of the preceding claims, characterized in that it comprises - an effluent reprocessing station (17) at least common to said cleaning line (11) and to said conversion line (15). 7. Process for recycling containers made of plastic material of the “refillable” type, in which at least: - used containers (1) are supplied to a cleaning line (11) - Said used containers (1) are sorted into compliant containers (2) and non-compliant containers (30); - Said containers (3) comply are washed; - the conforming containers (3) are sent to a line (14) for producing final containers (4), with a view to their bottling; characterized in that it comprises at least the following steps: - During washing, the non-compliant containers (30) are washed; - The non-compliant containers (30) are sent to a line (15) for converting into granules (9). 8. Recycling process according to the preceding claim, characterized in that - Said granules (9) are sent to a preform injection line (6); - Said preforms (6) are sent to a line (16) for manufacturing new containers (5) by blow molding from said preforms (6); - Said production line (14) is supplied with said new containers (5). 9. Recycling process according to any one of claims 7 or 8, characterized in that, within the line (15) of conversion, - Said non-compliant containers (30) are ground into plastic flakes (8); - Said flakes (8) are treated into plastic granules (9); and in that - Said grinding is devoid of a new washing step.