WO2019069292A1

WO2019069292A1 - Improved recycling of polyester bottles

Info

Publication number: WO2019069292A1
Application number: PCT/IB2018/057766
Authority: WO
Inventors: Dirk De Cuyper; William Dierickx; Tom Anthierens
Original assignee: Resilux N.V.
Priority date: 2017-10-05
Filing date: 2018-10-05
Publication date: 2019-04-11
Also published as: BE1025626B1; BE1025626A1

Abstract

The invention relates to the use of a ring-shaped support collar (1) for a plastic bottle, wherein the ring-shaped support collar has flat regions and facets (3) at least partially around its circumference, as a sorting means for a difficult to recycle plastic bottle; in particular, as a recognition means for an opaque polyester bottle in a food or beverage packaging or as a recognition means for a transparent polyester bottle in a non-food packaging. The invention also relates to a method for recognizing difficult to recycle polyester bottles using the sorting means; as well as bottles and preforms of a polyester composition that is problematic for recycling provided with the sorting means.

Description

IMPROVED RECYCLING OF POLYESTER BOTTLES

TECHNICAL FIELD The invention is situated in the domain of packaging and recycling. The invention relates to the use of a sorting means for recognizing polyester bottles that are difficult to recycle. The invention also relates to a method for recognizing polyester bottles that are difficult to recycle by means of the tool. The invention also relates to plastic bottles and preforms provided with the sorting means.

BACKGROUND

The use of plastic in the production of packagings is well-known. Plastic is often used instead of glass because the latter material is heavy and breakable.

A popular synthetic material is polyester, in particular polyethylene terephthalate, abbreviated as PET. PET is a commonly recycled packaging material. PET recyclate can be used again for producing packagings. It is also used in fibre applications. In the market of beverage packaging, household products and toiletry products, there is a shift of high-density polyethylene (HDPE) towards PET. This shift in synthetic material is made because of cost price, marketing and durability reasons. However, the substitution of HDPE by PET is turning the recycling market upside down. France even thinks about banning problematic PET packagings.

Before, PET was almost exclusively used in food and beverage packaging. This allowed to sort the packagings into three production streams: uncoloured or transparent, transparent blue, particoloured and opaque. The introduction of PET in non-food applications results in a considerable increase of particoloured and/or opaque PET packagings. Today, there barely is a market for this material.

Bottles are a well-known form of packaging. This type of container is typically made of a bottle body, a bottle neck that is connected to the bottle body and a mouthpiece that is connected to the bottle neck. The mouthpiece is provided with an opening through which the bottle can be filled. For milk bottles, there is an additional problem. Milk bottles are often made opaque by means of titanium dioxide pigment, for guaranteeing the storage life of milk. An increase of titanium dioxide pigment in PET recyclate material however, causes processing problems. This leads to a reduced transparency (Haze effect) combined with virgin PET material. Another disadvantage are reduced mechanical characteristics. This has an impact on the downstream processing. In textile for example, PET yarns are often coloured with a very low concentration of Ti02, usually 0.01-0.1 w/w% and at most 1 w/w%. In higher concentrations, a reduction in pull- stretch strength occurs when spinning the fibres.

An oversupply of PET recyclate material from non-food applications also causes processing problems because its percentage in recyclate material for food applications is strongly regulated. It should remain low in order to avoid contamination problems. A polyester recyclate material is considered not to be problematic when the content of polyester from non-food applications is below 5%.

Different actors are looking for solutions to the problem of the increased presence of problematic PET packaging material in waste streams that are offered for recycling. Today, the use of chemical tracers, such as UV fluorescence markers, for PET packagings is studied. They can be applied to a packaging wrapping, as a coating or as an additive in PET compositions. Packaging wrappings are however separated from the packaging in a recycling installation. Coatings can be abraded in use. The addition of extra additives to PET raw materials goes against the trend to use fewer chemical additions in packaging, especially in packaging for beverages or food.

An alternative solution that is studied at present, is the use of a digital watermark. This can be applied in an invisible way in printings (ttps://www. recycling- magazine. com/2017/05/19/laying-markers-plastic-packaging-recycling/). Another approach is to break down packaging materials to its monomers and additives, with recovery and re-use of the monomers. This requires the construction of large new installations for the treatment of the new waste streams. The investment can be problematic because of the oversupply on the one hand, and the lack of sufficient markets on the other hand. EP 0 869 067 discloses a plastic bottle with a neck ring. The neck ring is used as a sorting means for plastic bottles.

US 2016/368649 discloses an opaque container from thermoplastic material comprising an opacifier.

JP H06 239350 describes a three-layered plastic container, wherein the middle layer is coloured and opaque. EP 2 641 837 describes a preform for a multi-layered PET container, wherein the opacifier comprises aluminium metal.

The above-mentioned disclosures do not describe the problems of polyester plastic bottles that are difficult to recycle (ODR). No solution is offered for the problem of the increased presence of problematic PET packaging material or problematic additives in plastic waste streams. No tool is provided that gives information about a combination of characteristics indicative of recycling problems.

Consequently, there is a need for further alternatives and improvements, in particular for packagings in the form of bottles, which constitute a large volume of the problematic waste stream.

The present invention aims to solve one or more of the above-mentioned problems. Specifically, the invention aims to offer a simple and durable solution.

SUMMARY OF THE INVENTION

The invention offers a solution for the problem of signaling polyester bottles of which the recyclate material makes recycling of transparent polyester bottles difficult. It relates to polyester bottles with a high content of opacifiers and non-food polyester bottles. In the recycling industry, these problematic bottles are indicated with the collective term "opaque and difficult to recycle" or shortly ODR. The invention relates to a means that can be used for signaling a combination of an unexpected use, a kind of synthetic material and information about the presence of additives. The term "opaque and difficult to recycle^" from the recycling industry means a combination of a synthetic composition+use that occurs unexpectedly in a waste stream and that is difficult to process to a recyclate material for which there is a market,

The present invention thereto provides the use of a ring-shaped support collar for a plastic bottle, wherein the ring-shaped support collar is provided at least partially around its circumference with flat regions and facets as a means of recognition, characterised in that, the ring-shaped support collar is used as a recognition and sorting means for one or more of the following plastic bottles that are difficult to recycle: a food or beverage packaging comprising a plastic bottle that is made of a polyester composition with opacifier, and a non-food packaging comprising a transparent plastic bottle that is made of a polyester composition that is substantially free of opacifier; and wherein a predetermined combination of flat regions and facets is used for signaling a field of application of the plastic bottle together with a polyester composition.

The use of said support collar has the advantage that this is a sorting means that is easy to recognize, both at manual and at automatic sorting. The collar is easily visibly recognizable by a person or a camera and image processing system. This is an important advantage compared to fluorescent marking substances or a digital watermark, that are not visible without the use of means such as a fluorescent lamp or a scanner. A support collar according to the invention can be used combined with other identification techniques. The support collar with flat regions and facets offers a means of recognition that is less subject to friction or damage than markings that are applied separately to a bottle.

In a further aspect, the invention provides an opaque plastic bottle that is made of a composition comprising polyester for the packaging of food, wherein the neck of the bottle is provided with a ring-shaped support collar having flat regions and facets at least partially around its circumference.

A bottle with a sorting means for opaque and difficult to recycle plastic material can be easily recognized. This contributes to the separation of such bottles and the separate treatment thereof. In another aspect, the invention provides a transparent plastic bottle for non-food packaging made of a composition comprising polyester, wherein the neck of the bottle is provided with a ring-shaped support collar having fiat regions and facets at least partially around its circumference.

For said bottles, a predetermined combination of flat regions and facets is used for signaling the field of application of the plastic bottle together with a polyester composition, The presence of the sorting means allows to distinguish for example PET bottles from PP/PP bottles. The bottles can already be sorted without the use of a chemical analysis method.

In an additional aspect, the invention provides a preform for a polyester plastic bottle of milk according to an embodiment of the invention, comprising a ring-shaped support collar that is provided at least partially around its circumference with fiat regions and facets.

A predetermined combination of flat regions and facets is used for signaling a field of application of the preform together with a polyester composition.

This has the advantage that the use of a chemical sorting means, such as a tracer, becomes superfluous. The sorting means can be introduced from the start of the production line. It remains visible during the different phases of a production up to the end product: preforms, bottle, packaging with bottle. The sorting means is not subject to wear because of temperature or friction during the production of the packaging. If desired, a combined use of visible and invisible sorting means can be used. This has the advantage that it increases the chance of detection. In a further aspect, the invention provides a method for improved recycling of plastic bottles, comprising the following step:

recognizing a sorting means provided on difficult to recycle plastic bottles according to an embodiment of the invention, characterized in that, the sorting means comprises a predetermined ring-shaped support collar having flat regions and facets at least partially around its circumference, and wherein a predetermined combination of fiat regions and facets is used for signaling a field of application of the plastic bottle together with a polyester composition,

sorting the recognized plastic bottles,

treating the sorted plastic bottles, hereby providing an improved recyciate material.

Said method has the advantage that difficult to recycle plastic bottles can be extracted from a waste stream offered. As the sorting means is predetermined, and can for example be linked to a composition, the type of waste stream is identified better. The treatment can take place with less disturbance of the general process. The recyciate material can be controlled better. The quality of the recyciate material that can be obtained from the treatment of the waste stream from which difficult to recycle plastic bottles have been taken, can be regulated better. In a last aspect, the invention provides a sorting device for difficult to recycle plastic bottles according to an embodiment of the invention, comprising :

a detection means for recognizing a sorting means that has been provided on difficult to recycle plastic bottles according to an embodiment of the invention, wherein the sorting means comprises a predetermined ring- shaped support collar having flat regions and facets at least partially around its circumference, and

a sorting means for separating the plastic bottles provided with the sorting means according to an embodiment of the invention;

wherein a predetermined combination of fiat regions and facets is used for signaling a field of application of the plastic bottle together with a polyester composition.

A sorting device can consist of a sorting machine. This device can be used for the collection of difficult to recycle plastic bottles in department stores. A sorting device can also consist of a large-scale industrial waste treatment installation.

Further preferred embodiments have been described in the dependent claims.

DESCRIPTION OF THE FIGURES Figures 1 and 2 show a schematic illustration of a side view of a plastic bottle with a ring-shaped support collar that has been applied under the bottle opening provided with a threaded part. Figure 3 shows a plan view of the devices according to figures 1 and 2.

Figures 4 and 5 show a partial plan view of possible other embodiments of the ring- shaped support collar. DETAILED DESCRIPTION OF THE INVENTION

Unless otherwise specified, all terms used in the description of the invention, including technical and scientific terms, shall have the meaning as they are generally understood by the worker in the technical field the present invention relates to. Furthermore, definitions of the terms have been included for a better understanding of the description of the present invention.

As used here, the following terms shall have the following meaning : "A", "an" and "the", as used here, refer to both the singular and the plural form unless clearly understood differently in the context. For example, "a compartment" refers to one or more than one compartment.

"Approximately" as used here, that refers to a measurable value such as quantity, parameter, a quantity, a period or moment, etc., is meant to include variations of +/-20% or less, preferably +/-10% or less, more preferably +/-5% or less, still more preferably +/-1% or less, and even still more preferably +/-0.1% or less of the cited value, as far as such variations are appropriate for realizing the invention that is described. It will however be clear that the value to with the term "approximately" relates, will also be described specifically. The terms "include", "including" and "included", as used here, are synonym with "comprise", "comprising" and "comprises" and are inclusive or open terms that indicate the presence of what follows e.g. a component, and that do not exclude the presence of additional, non- said components, characteristics, elements, members, steps, that are well-known from or described in the state of the art. The citation of numeric intervals by means of end points includes all integers and fractions included within that interval, including these end points.

The term "w/w%" as used here, refers to a weight percentage wherein the ratio of the weight of an ingredient to the total weight of a bottle with closing means, is expressed as a percentage.

The term "difficult to recycle" from the recycling industry means a combination of a plastic composition and rare use. When this combination occurs unexpectedly in a waste stream and this combination is not removed from the waste stream and is not treated separately, the treatment of the waste stream results in a recyciate material with undesired composition for which it is difficult to find a market. The rare and for the recycling industry often unknown combination results in what is called a "difficult to recycle synthetic material" in the field. This is a term that is specifically used in the recycling industry.

The indication "difficult to recycle plastic material" is not about the indication of the type of plastic material or the kind of plastic material or the application as such, but about a previously unknown combination. Specific examples are the use of polyester as a substitute for polyethylene/polypropylene in non-food applications and the combination of polyester with a problematic amount of opacifier, in particular titanium dioxide. Other problematic polyester bottles are grey, red, brown or black polyester bottles. They are problematic because of the presence of mineral additives in the composition. Colourless, blue and green transparent polyester containers are not problematic. Known recycling processes are adapted thereto.

The term "non-food" as used here, means products that do not fall under the category of food and beverages. The term "opacity" as used here, means the degree of transparency or non- translucency of a material. Opacity is measured under standard conditions, typically with a D65 lamp to simulate day light. Opacity is expressed in percent. A material with a transmission higher than 20% is considered opaque. The lower the number, the more transparent the material. The opacity of a container or bottle is influenced by its composition and production method. Amongst other things the used fillers, such as pigments and colorants in a composition determine to a large extent the transparency. The opacity of a plastic container can be measured by means of a spectrophotometer.

Opacity is determined by a residual transmission of light measured with a spectrophotometer according to a standard measuring procedure, such as ASTM D1003, using a D65 lamp simulating natural daylight. Less than 20% of transmission is considered as opaque, while more than 20% of transmission corresponds to a transparent or translucent material. Opaque bottles are especially used for milk bottles and detergent bottles.

With the term "opacifier is meant, an additive that increases the degree of non- transparency or non-translucency of a material. The operation is based on the characteristic to scatter light. The more light-scattering and the more opacifier in a composition, the more light is scattered outwardly and the more a container seems opaque. Opacifiers are for example calcium carbonate, lead white, zinc oxide, antimony oxide, iithopone, zinc sulphide, carbon black also known as black, and/or titanium dioxide. The rutiie form of titanium dioxide is more light-scattering than its anatase form. These additives give polyester plastic materials a white colour. As a synonym for these opacifiers, the term white pigment can be used.

A polyester composition with a transmission smaller than 25%, preferably smaller than 20%, more preferably smaller than 15%, most preferably smaller than 10% is considered as problematic for the recycling of transparent PET. In particular, the presence of titanium dioxide is problematic. This is already problematic in smaller amounts compared to most opacifiers.

A polyester composition with 1 w/w% of titanium dioxide or more; preferably at least 2 w/w%, more preferably at least 5 w/w%, most preferably at least 10 w/w% or more is considered as problematic for the recycling of transparent PET. As the compositions are used in blowing processes, the content is limited to at most 15 w/w%. Above the indicated limit, the blowing process can be influenced negatively by the large presence of additives. Transparency and the impact of an opacifier on a transparent plastic material (Haze effect) can be measured by means of a standard testing method, such as ASTM D1003 (method B) or BS EN ISO 13468 and ISO 14782. A pre-eminent packaging that is appropriate for the application of the invention is a bottle. The industrial production of plastic bottles starts from the production of a preform, by means of injection moulding. The preform is converted to a bottle shape in a stretch-blowing process. By stretching the synthetic material into two directions, a thinner, though stronger material is obtained.

More in particular, the invention provides the use of a ring-shaped support collar for a plastic bottle, more in particular a bottle made of a polyester composition. The ring- shaped support collar is at least partially around its circumference provided with fiat regions and facets. The thus configured support collar serves as a means of recognition for a difficult to recycle plastic bottle. More in particular, the support collar serves as a means of recognition for an opaque polyester bottle in a food or beverage packaging or as a means of recognition for a transparent polyester bottle in a nonfood packaging. In particular, the present invention provides the use of a ring-shaped support collar for a plastic bottle, wherein the ring-shaped support collar has flat regions and facets at least partially around its circumference as a means of recognition, characterised in that, the ring-shaped support collar is used as a recognition and sorting means for one or more of the following plastic bottles that are difficult to recycle: a food or beverage packaging comprising a plastic bottle that is made of a polyester composition with opacifier, or a non-food packaging comprising a transparent plastic bottle that is made of a polyester composition that is substantially free of opacifier; and wherein a predetermined combination of flat regions and facets is used for signaling a field of application of the plastic bottle together with a polyester composition.

The use of said support collar has the advantage that it is easy to recognize, both at manual and at automatic sorting. The collar is easily visibly recognizable by both a person and a camera and image processing system. The collar is easy to apply to a plastic bottle with techniques that are known to the skilled worker. Injection moulding of a preform in a mould configured for providing a support collar in the end product is an example.

The support collar is preferably executed as a polygon, at least over a part of its circumference. The polygon is preferably executed as a hexagon, or a polygon with 12 or 24 angles.

In a preferred embodiment of a use according to the invention, a fiat region at the edge of the support collar each time adjoins a facet at the upper ring-shaped surface of the support collar.

The polyester plastic material that is used in the invention, is preferably selected from polyethylene terephthaiate (PET), polyethylene furanoate (PEF), polyethylene naphthalate (PEN), polybutylene terephthaiate (PBT) or combinations thereof; most preferably PET.

The use according to a preferred embodiment of the invention is preferably as a means of recognition for a polyester bottle containing at least 1 w/w%, preferably at least 2 w/w%, more preferably at least 5 w/w%, most preferably at least 10 w/w% titanium dioxide.

The food application is preferably an opaque beverage bottle, preferably a milk bottle, more preferably a milk bottle comprising titanium dioxide. The content of titanium dioxide in the milk bottle composition is at least 1 w/w%, preferably at least 2 w/w%, more preferably at least 5 w/w%, most preferably at least 10 w/w%.

The support collar can be executed to reflect an increasing amount of titanium dioxide. The number of angles can be a measure for the amount of opacifier that is present in a polyester composition . A polygon with a small number (hexagon) can for example be used for a low content of titanium dioxide; while a large number (24- gon) can for example be used for a high content of titanium dioxide.

In a further aspect, the invention provides an opaque plastic bottle that is made of a composition comprising polyester and an opacifier for the packaging of food, wherein the neck of the bottle is provided with a ring-shaped support collar having flat regions and facets at least partially around its circumference. More in particular, the invention provides a plastic bottle made of a composition comprising polyester, wherein the neck of the bottle is provided with a ring-shaped support collar having flat regions and facets at least partially around its circumference, characterized in that the poiyester plastic bottle is opaque, is provided for the packaging of food, and said support collar is applied to said difficult to recycle plastic bottle; and wherein a predetermined combination of fiat regions and facets is used for signaling a field of application of the plastic bottle together with a poiyester composition, The invention preferably provides an opaque plastic bottle that is made of a composition comprising poiyester and opacifiers for the packaging of food, characterized in that, the neck of the bottle is provided with a ring-shaped support collar that is provided at least partially around its circumference with flat regions and facets; preferably a poiyester bottle containing at least 1 w/w%, more preferably 2 w/w%, most preferably 3 w/w% of titanium dioxide. The support collar can be applied as a neck ring.

A bottle from opaque and difficult to recycle poiyester plastic material (ODR) can now be recognized easily. This makes it easier to separate such bottles and keep poiyester recyciate material with a content of opacifiers lower than 1 w/w% separate.

Another preferred embodiment of the invention is the use of said collar as a means of recognition for a polyester composition that is substantially free from opacifier, or transparent, in a non-food application.

The term "substantially free" of opacifier or "transparent" means a material with a transmission higher than 20%. The amount of opacifier is preferably lower than 1 w/w% of opacifier. Preferably, the amount is lower than 0.5 w/w%, more preferably lower than 0.1 w/w%, most preferably free from opacifier.

In another further aspect, the inventions provides a transparent plastic bottle for the packaging of non-food made of a composition comprising polyester, characterised in that the neck of the bottle is provided with a ring-shaped support collar having fiat regions and facets at least partially around the circumference. In particular, the invention provides a plastic bottle made of a polyester composition, wherein the neck of the bottle is provided with a ring-shaped support collar having flat regions and facets at least partially around its circumference, characterized in that the polyester plastic bottle is transparent, is provided for the packaging of non- food, and said support collar is applied on said difficult to recycle plastic bottle; wherein a predetermined combination of flat regions and facets is used for signaling a field of application of the plastic bottle together with a polyester composition.

Furthermore, the invention provides a transparent plastic bottle for the packaging of non-food made of a polyester composition with an amount of opacifiers lower than 1 w/w%, preferably lower than 0.5 w/w%, more preferably lower than 0.1 w/w%, characterised in that the neck of the bottle is provided with a ring-shaped support collar having flat regions and facets at least partially around its circumference. A non-food application is a packaging application outside the category of food or beverages (food stuffs). This also comprises the application of foodstuffs for animals.

The use of said collar as a means of recognition for non-food polyester bottles contributes to keeping food and non-food polyester bottles separate. In this way, the stringent regulation for materials coming in contact with food and/or the regulation for the recycling industry can be respected ; such as for example in the European regulation 1935/2004 with respect to materials intended to come in contact with foodstuffs, the European regulation for synthetic materials 10/2011 and the European regulation 282/2008 with respect to materials and objects of recycled plastic materials intended to come in contact with foodstuffs. A polyester recyciate material is considered not to be problematic when the amount of polyester of non-food applications is below 5 w/w%.

Examples of the use of polyester compositions for non-food bottles are bottles for detergents, bubble bath, shampoo or motor oil. It is thus a preferred embodiment of the present invention to use said collar in these packagings.

The invention also provides a polyester bottle with a sorting means for difficult to recycle polyester. In a further aspect, the invention provides an opaque polyester bottle for the packaging of beverages or food, characterized in that the bottle is provided on the neck with a ring-shaped support collar having fiat regions and facets at least partially around its circumference.

In another aspect, the invention provides a transparent plastic bottie made of polyester for a non-food packaging, characterized in that the bottle is provided on the neck with a ring-shaped support collar having flat regions and facets at least partially around its circumference.

A predetermined combination of fiat regions and facets gives information about the field of application of the plastic bottle together with a polyester composition.

The term "polyester bottie" means a packaging in bottle shape made of a polyester composition. Next to polyester, the composition can also comprise other plastic materials. The compositions comprises at least 50 w/w% of polyester plastic material, preferably at least 75 w/w% of polyester plastic material, more preferably at least 95 w/w% of polyester plastic material. In said polyester bottles, the polyester is preferably selected from polyethylene terephthalate (PET), polyethylene furanoate (PEF), polyethylene naphthalate (PEN), polybutylene terephthalate (PBT) or combinations thereof. The polyester bottle is preferably a bottle made of a polyester composition with at least 50 w/w% of PET in the polyester composition, i.e. a PET bottle.

The PET content in the polyester composition is at least 75 w/w%, more preferably at least 85 w/w%, most preferably at least 95 w/w%. Preferably, the PET content in the bottle composition is at least 75 w/w%, more preferably at least 85 w/w%, most preferably at least 95 w/w% of PET.

The polyester, preferably PET, can comprise recycled polyester material. A bottle according to an embodiment of the invention preferably comprises at least 30 w/w% of recycled polyester or recycled PET (rPET); more preferably at least 50 w/w% of recycled polyester or recycled PET (rPET); most preferably at least 80 w/w%. The ring-shaped support collar used in the present invention is preferably executed as a polygon, Most preferably, the polygon is an octagon, a polygon with 12, 16 or 24 angles. The ring-shaped support collar used in the present invention is preferably configured with a fiat region area at the edge of the support collar each time adjoining a facet at the upper ring-shaped surface of the support collar,

At the lower ring-shaped surface, the ring-shaped support collar can additionally be provided with facets.

The provision of a bottie with sorting means has the advantage that difficult to recycle plastic is signalled. Sorting of waste streams can be adjusted thereto. Thus, the detection of the sorting means can contribute to the separation of the PET and PE/PP bottles in a supply of white milk bottles.

In a preferred embodiment of a polyester bottie according to the invention, the bottle comprises a bottie opening with screw thread, characterized in that a distance is provided of at least 2 mm, preferably at least 5 mm, between the lower side of the screw thread and the upper edge of the support collar, oriented towards the pouring opening.

The provision of a distance between the support collar and a screw thread that can accept a closing means, ensures a better visibility of the collar. The collar can be more easily be detected from above.

Said support collar is preferably executed as a gripping means. This can be realized by the collar for providing a bottle neck and having it protrude sufficiently for offering a gripping surface. This is advantageous for the lifting of the bottle. The bottle can be transported more easily. The gripping can serve as a reference point for the detection and reading of the collar in a recycling device.

In a further aspect, the invention provides a preform for an opaque polyester bottle according to an embodiment of the invention, comprising a ring-shaped support collar having flat regions and facets at least partially around its circumference. In particular, the invention provides a preform for a polyester bottle according to an embodiment of the invention, comprising a ring-shaped support collar having flat regions and facets at least partially around its circumference, characterized in that said support collar is provided on the preform of said difficult to recycle plastic bottle; wherein a predetermined combination of flat regions and facets is used for signaling a field of application of the preform together with a polyester composition.

The preform is preferably a preform for a plastic bottle of milk according to an embodiment of the invention, comprising a ring-shaped support collar having fiat regions and facets at least partially around its circumference.

Already applying the sorting means onto a preform, during the production of the preform, has the advantage that the use of a chemical sorting means, such as a tracer, becomes superfluous. The sorting means can be introduced from the start of the production line. This is cost-saving. It reduces the risk of errors. It remains visible during the different phases of a production up to the end product: preforms, bottle, packaging with bottle. The sorting means is not subject to wear because of temperature or friction during the production of the packaging. A preform according to an embodiment of the invention is preferably a multi-layered preform. The number of layers is preferably at least three. More preferably, the middle layer comprises or contains recycled PET (rPET). Most preferably, the presence of rPET is limited to the middle layer. The protection of rPET material with other layers, preferably virgin PET material, has the advantage that a possibly negative impact of rPET is limited. Hereby, one can think of the occurrence of a difference in colour between rPET and virgin PET. Possibly, the colour of the rPET materials is instable or in other words varying. By limiting the rPET material to one or more layers, preferably to the middle layer, virgin material can be used in other layers. This has the advantage that rPET can still be processed without the advantages, such as stability in characteristics, of virgin material being abandoned. rPET material can be introduced in the middle layer by means of co-injection techniques. In this way, virgin PET is on the outside, and it can thus be coloured in a stable way by means of opaque colorants. By introducing recycled polyester material, preferably rPET, a risk of chemical contaminants linked to the use of recyclate material, can be limited. Especially dosing large amounts of recyclate material can lead to undesired migration of contaminants. This is problematic for the use in food applications. By putting recyclate material, preferably rPET, in a middle layer, food comes in contact with virgin polyester material, preferably virgin PET.

The layer with recyclate material can still be provided with one or more barrier layers. The choice of the barrier is adjusted to the potential presence of contaminants. Preferably, the layer of recyclate material is provided between two barrier layers, of which the layer at both sides in the longitudinal direction is provided with a barrier layer.

The invention further also relates to bottles made of a multi-layered preform as described above.

In a further aspect, the invention provides a method for improved recycling of plastic bottles, comprising the following steps:

recognizing a sorting means provided on difficult to recycle plastic bottles, wherein the sorting means comprises a predetermined ring-shaped support collar having flat regions and facets at least partially around its circumference, and wherein a predetermined combination of flat regions and facets is used for signaling a field of application of the plastic bottle together with a polyester composition ;

- sorting the recognized plastic bottles;

treating the sorted plastic bottles, hereby providing an improved recyclate material.

A method according to an embodiment of the invention preferably comprises the following steps:

providing a waste stream of plastic bottles comprising PE, PP and polyester bottles;

sorting polyester bottles with an amount of opacifiers higher than 5 w/w% by means of information that is obtained from reading the support collar and comparing with a data file comprising the predetermined combinations of fiat regions and facets for signaling the field of application of polyester plastic bottles together with the polyester composition; treating the remaining plastic bottles thereby providing an improved recyclate material ; preferably with an amount of opacifiers lower than 5 w/w%.

The many configuration possibilities of the support collar allow for a large number of possibilities as to the use as a sorting means. The sorting means can be used for signaling different types of problematic material for recycling. The use can occur according to predetermined agreements between producers and the recycling sector. For recognizing the sorting means, different techniques can be used, such as visual recognition or recognition by means of image processing techniques. At recognition, the synthetic bottles can be separated from the other material stream. They can be kept separate from transparent foodstuff packaging. Consequently, a treatment can be carried out specifically for the treatment of the supplied material and the demand of the market for particular types of recyclate material. The recyclate material resulting from the method is better identified and can be processed in a better way.

Preferably, the improved recyclate material has a percentage of non-food PET recyclate material lower than 5 w/w%.

In a last aspect, the invention provides a sorting device for difficult to recycle synthetic plastic bottles, comprising :

a detection means for recognizing a sorting means provided on difficult to recycle plastic bottles, wherein the sorting means comprises a predetermined ring-shaped support collar having fiat regions and facets at least partially around its circumference, and wherein a predetermined combination of flat regions and facets is used for signaling a field of application of the plastic bottle together with a polyester composition; and a sorting means for separating the plastic bottles provided with the sorting means.

The use of the support collar according to an embodiment of the invention is advantageous for different types of waste processors. On small scale, a consumer can recognize the problematic bottles and separate them for recycling. Also, sorting devices can be provided for treating this type of waste. The sorting device can be both a device for collecting the problematic bottles of consumers, for example in a department store, and an industrial installation at a waste treatment facility. Before the waste can be sorted, detection of the problematic materials is required. To each problematic composition, a sorting means can be assigned. With a detection means provided for recognizing a predetermined configuration of the ring-shaped support collar, the problematic materials can be detected. Isolation of problematic materials can be carried out with a sorting means. This can for example be a hatch that is opened when the detection means detects a plastic bottle with problematic composition by means of the predetermined ring-shaped support collar configuration. One can also think of a gripping arm and separate conveyor belt.

Preferably, a sorting device according to an embodiment of the invention further comprises a collector for collecting and storing non-food polyester plastic bottles and a collector for collecting and storing food polyester plastic bottles; wherein the polyester plastic bottles are provided with a recognition and sorting means as described above.

In a preferred embodiment of a sorting device, the sorting device comprises a suspension means for suspending supplied bottles at the support collar. The suspended bottles can be transported along a predetermined path. Detection means, such as a camera, arranged along the path can take images of the support collars. The images can be compared to the stored information comprising support collars with a predetermined selection of flat regions and facets and information about the combination of the field of application of the plastic bottle together with a polyester composition.

The invention is further illustrated by means of examples and figures. These are non- limiting. Preferred embodiments of the invention are illustrated in Figures 1 to 5. EXAMPLES

Figure 1 shows a ring-shaped support collar 1 on the bottle neck of a difficult to recycle polyester plastic bottle, such as a milk bottle from PET and opacifier, applied under the bottle opening 4. In order to close off the bottle opening, the neck is provided with a screw thread 5 at the opening for receiving a screw cap (not shown). The ring-shaped support collar is preferably made of polyester, more preferably PET. Figure 2 shows an alternative embodiment. It differs from the image shown in Figure 1 as to the inclination of the support collar with respect to the edge of the bottle. Figure 3 shows a schematic plan view of a difficult to recycle plastic bottle with a ring-shaped support collar 1. Here, it is clearly shown that the support collar 1 surface at the upper ring surface is provided with facets 3 and at the edge of polygons 2. In Figure 3, a polygon with 24 angles is shown, wherein a region at the periphery of the support collar each time adjoins a facet on the collar.

Figures 4 and 5 show a partial plan view in different ways onto which the support collar can be realized. Each time, a polygon with 12 angles is formed. Figure 4 is an embodiment without facet. In Figure 5, additional facets 3 are applied. The facets can be applied at the top and/or at the bottom of the support collar surface. A practically unlimited number of possibilities of combinations offers access to a set of identification possibilities. The use of predetermined and agreed combinations in the recycling sector can avoid the problem of difficult to recycle polyester, in particular PET. The support collar can be realized in an opaque way by using an opaque preform, for example in the production of PET milk bottles. The use of a transparent support collar with predetermined configuration can serve as an indication that the bottle for a foodstuff is realized in difficult to recycle polyester, especially PET, as a result of the presence of opacifiers.

Claims

1. Use of a ring-shaped support collar (1) for a plastic bottle, wherein the ring- shaped support collar (1) has fiat regions (2) and facets (3) at least partially around its circumference as a means of recognition, characterized in that the ring-shaped support collar (1) is used as a recognition and sorting means for one or more of the following plastic bottles that are difficult to recycle: a food or beverage packaging comprising a plastic bottle that is made of a polyester composition with opacifier, and a non-food packaging comprising a transparent plastic bottle that is made of a polyester composition that is substantially free of opacifier; and wherein a predetermined combination of fiat regions and facets is used for signaling a field of application of the plastic bottle together with a polyester composition, 2, The use according to claim 1, characterized in that the support collar (1) is executed as a polygon, at least over a part of its circumference.

3. The use according to claim 2, characterized m that the support collar (1) is executed as a hexagon, a polygon with 12 angles or a polygon with 24 angles,

4, The use according to any of claims 1 to 3, characterized m that a flat region at the edge of the support collar (1) each time adjoins a facet (3) at the upper ring-shaped surface of the support collar (1). 5, The use according to any of claims 1 to 4, wherein the polyester composition comprises a polyester selected from polyethylene terephthalate (PET), polyethylene furanoate (PEF), polyethylene naphthalate (PEN), polybutylene terephthalate (PBT) or combinations thereof; most preferably PET, 6. The use according to any of claims 1 to 5, as a recognition means for a polyester bottle containing at least 1 w/w% titanium dioxide.

7, The use according to any of previous claims 1 to 6, characterized in that the beverage packaging is a milk bottle; preferably a milk bottle with a content of opacifiers of at least 5 w/w%. The use according to any of previous claims 1 to 7, characterized n that the use of polyester in a transparent non-food application, is the use of a transparent polyester plastic bottle as packaging for a detergent, bubble bath, shampoo or motor oil.

A plastic bottle made of a composition comprising polyester, wherein the neck of the bottle is provided with a ring-shaped support collar (1) having flat regions (2) and facets (3) at least partially around its circumference, characterized in that the polyester plastic bottle is opaque, is provided for the packaging of food, and said support collar (1) is applied on said difficult to recycle plastic bottle; and wherein a predetermined combination of fiat regions and facets is used for signaling a field of application of the plastic bottle together with a polyester composition,

A plastic bottle made of a polyester composition, wherein the neck of the bottle is provided with a ring-shaped support collar (1) having flat regions (2) and facets (3) at least partially around its circumference, characterized m that the polyester plastic bottle is transparent, is provided for the packaging of nonfood, and said support collar (1) is applied on said difficult to recycle plastic bottle; wherein a predetermined combination of flat regions and facets is used for signaling a field of application of the plastic bottle together with a polyester composition.

The polyester bottle according to claim 9 or 10, wherein the polyester is selected from polyethylene terephthalate (PET), polyethylene furanoate (PEF), polyethylene naphthalate (PEN), poiybutylene terephthalate (PBT) or combinations thereof; most preferably PET,

The polyester bottle according to any of claims 9 to 11, characterized in that said ring-shaped support collar (1) is executed as a polygon; preferably as an octagon, a polygon with 12 angles or a polygon with 24 angles.

The polyester bottle according to any of claims 9 to 12, characterized in that on said ring-shaped support collar (1), a flat region on the edge of the support collar (1) each time adjoins a facet (3) on the upper ring-shaped surface of the support collar (1).

14. The polyester bottle according to any of claims 9 to 13, comprising a bottle opening (4) with screw thread (5); characterized n that a distance of at least 0.5 cm is provided between the lower side of the screw thread (5) and the upper edge of the support collar (1) oriented towards the pouring opening.

15. A preform for a polyester bottle according to any of claims 9 to 14, comprising a ring-shaped support collar (1) having flat regions (2) and facets (3) at least partially around its circumference, characterized in that said support collar (1) is provided on the preform of said difficult to recycle plastic bottle; wherein a predetermined combination of flat regions and facets is used for signaling a field of application of the preform together with a polyester composition.

16. The preform according to claim 15 for a milk bottle, comprising a polyester composition with at least 1 w/w% of titanium dioxide.

17. The preform according to claim 15 or 16, wherein the preform is made of several layers; preferably is made of a multi-layered structure with a middle layer comprising recyclate polyester provided between layers made of virgin polyester.

18. A method for improved recycling of plastic bottles, comprising the following step:

recognizing a sorting means provided on difficult to recycle plastic bottles according to any of claims 9 to 14, characterized in that the sorting means comprises a predetermined ring-shaped support collar (1) having fiat regions (2) and facets (3) at least partially around its circumference, and wherein a predetermined combination of flat regions and facets is used for signaling a field of application of the polyester plastic bottle together with a polyester composition;

- sorting the recognized polyester plastic bottles;

treating the sorted polyester plastic bottles, hereby providing an improved recyclate material.

19, The method according to claim 18, comprising the following step

providing a waste stream of plastic bottles comprising

polyester bottles; sorting polyester bottles with an amount of opacifiers higher than 5 w/w% by means of information that is obtained from reading the support collar and comparing with a data file comprising the predetermined combinations of flat regions and facets for signaling the field of application of polyester plastic bottles together with the polyester composition; treating the remaining plastic bottles thereby providing an improved recyciate material; preferably with an amount of opacifiers lower than 5 w/w%.

A sorting device for difficult to recycle plastic bottles according to any of claims

9 to 14, comprising :

a detection means for recognizing a sorting means that has been provided on difficult to recycle plastic bottles according to any of claims 9 to 14, wherein the sorting means comprises a predetermined ring-shaped support collar (1) having flat regions (2) and facets (3) at least partially around its circumference, and

a sorting means for separating the plastic bottles provided with the sorting means of according to any of claims 9 to 14;

wherein a predetermined combination of fiat regions and facets is used for signaling a field of application of the plastic bottle together with a polyester composition,

The sorting device according to claim 20, further comprising a collector for collecting and storing non-food polyester plastic bottles and a collector for collecting and storing food polyester plastic bottles; wherein the polyester plastic bottles are provided with a recognition and sorting means as described in claim 1.