Process to produce food-contact multilayered hollow articles from recycled polyethylene resin and articles thereof

Abstract

The disclosure provides a process to produce a multilayered hollow article comprising two or three layers wherein the article comprises at least 30 wt.% of recycled polyethylene resin wherein the process comprises a preliminary step of preparing one or more recycled- containing polyethylene compositions to be used as the first, second and optional third layer.

Description

[0001] PROCESS TO PRODUCE FOOD-CONTACT MULTILAYERED HOLLOW ARTICLES FROM RECYCLED POLYETHYLENE RESIN AND ARTICLES THEREOF

[0002] TECHNICAL FIELD

[0003] The disclosure relates to multilayered hollow articles comprising a recycled polyethylene resin, and to processes to produce such articles.

[0004] TECHNICAL BACKGROUND

[0005] The circular economy concept aims to recycle more polymers from recycled polyethylene resins such as post-consumer resins (PCR) and post-industrial resins (PIR). The postconsumer resins of polyethylene type are mainly coming from domestic or household waste. The volume of recycled polyethylene is increasing and brand-owners and converters are fostering to use of more and more recycled polyethylene resins in their marketed articles to answer final customers’ demands to lower carbon footprint impact and energy consumption. Polyethylene (PE) recycling is challenging because of several problems encountered, such as contamination and polymer degradation during the recycling process. As a consequence, recycled polyethylene shows inferior mechanical properties such as rigidity and processability by comparison to virgin products.

[0006] The food industry is demanding opportunities to use recycled polyethylene resins but at the same time is facing rigorous specifications both in terms of performance of the articles (such as top load properties and drop impact resistance) and food-contact requirements

[0007] WO2022216239 (A1) discloses a laminated tube comprising of post-industrial and / or postconsumer recycled resin and the amount of the blends to provide acceptable tube performances and recyclability. The use of recycled resin is to reduce the carbon footprint of packaging tube and closed-loop recycling. A layer of multilayer flexible sheet to produce recyclable packaging by the selection of virgin plastics is used. The tube is interesting but fails to provide the desired balance of mechanical properties.

[0008] US2023192973 (A1) discloses a shrink film comprising a monolayer or multi-layer film having at least one layer comprising a formulated resin; wherein the formulated resin comprises: a post-consumer recycled resin sourced from recycled high density polyethylene (HDPE) resin; wherein the post-consumer recycled resin has a density of from 0.94 g / cc to 0.97 g / cc, and a melt index, 12, of from 0.2 g / 10 min to 1 g / 10 min, and (i) a low density polyethylene (LDPE) wherein the LDPE has a density of from 0.915 g / cc to 0.925 g / cc and a melt index, 12, of from 0.1 g / 10 min to 1 g / 10 min, or (ii) a linear low density polyethylene (LLDPE) wherein the LLDPE has a density of from 0.915 g / cc to 0.945 g / cc and a melt index, 12, from 0.1 g / 10 min to 1 g / 10 min, or (iii) a combination of (i) and (ii).

[0009] US2022396689 (A1) describes compounded virgin and post-consumer recyclate HDPE compositions with improved processability and mechanical properties, including processes of making, products and application in food packaging are described herein.

[0010] WO2022227014 discloses a lamination film structure including a combination of: (a) at least one first layer of an oriented polyethylene film and (b) at least one second layer of a blown or cast polyethylene film, wherein the first oriented polyethylene film layer is laminated with the second blown or cast polyethylene film layer; and wherein the blown or cast polyethylene film of component (b) is a blown polyethylene film or a cast polyethylene film comprising a formulated resin including a combination or mixture of: (bi) a predetermined amount of a postconsumer recycled resin sourced from a recycled high density polyethylene resin; and (bii) a predetermined amount of a polyethylene resin; a process for making the above lamination film structure; and a film or article made from a recyclate of the above lamination film structure.

[0011] The present disclosure aims to provide polyethylene compositions and articles comprising at least 30 wt.% of recycled polyethylene resin that show the same or improved mechanical properties as the ones made from virgin material only, and at the same time comply with the food contact requirements. The present disclosure also aims to provide a process to produce such compositions and / or articles.

[0012] SUMMARY

[0013] It has now been found that it was possible to reconcile the use of recycled material with demanding applications such as food-contact applications such as hollow articles for dairy packaging; toys, or bottles for milk, beverage, or oil.

[0014] According to a first aspect, the disclosure provides a process to produce an article being a multilayered hollow article comprising; a) Providing a first, a second and an optional third polyethylene compositions, wherein each of the first polyethylene composition, the second polyethylene composition, and the third polyethylene composition, when present, has a melt index ranging from 0.4 to 2.0 g / 10 min as determined according to ISO 1133-2011 at 190 °C under a load of 2.16 kg; b) Forming a multilayered hollow article comprising a first layer made from a first polyethylene composition being the inner layer; a second layer made from a second polyethylene composition; optionally a third layer made from a third polyethylene composition being an outer layer; wherein the process is remarkable in that the article comprises at least 30 wt.% of recycled polyethylene resin based on the total weight of the article; wherein the recycled polyethylene resin is selected to have a melt index MI2 ranging from 0.2 to 2.2 g / 10 min as determined according to ISO 1133-2011 at 190 °C under a load of 2.16 kg; in that the process comprises a preliminary step of preparing one or more recycled-containing polyethylene compositions to be used as the first polyethylene composition, the second polyethylene composition, and / or the third polyethylene composition, when present; and in that said step of preparation of the or at least one recycled-containing polyethylene composition comprises:

[0015] - a thermal treatment of the recycled polyethylene resin to increase its melt index and obtain a thermally treated recycled polyethylene resin; and / or

[0016] - blending the recycled polyethylene resin or the thermally treated recycled polyethylene resin with one or more boosters.

[0017] The article is not a film.

[0018] For example, step b) of forming the multilayered hollow article is a step of molding, blow molding, rotomolding, injection molding, injection blow molding, or extrusion blow molding.

[0019] In a preferred embodiment, the second layer has a thickness equal to or greater than the thickness of the first layer; with preference, the thickness of the second layer is from 1.1 to 4.0 times the thickness of the first layer.

[0020] In an embodiment, the step of preparation of the or at least one recycled-containing polyethylene composition comprises a thermal treatment of the recycled polyethylene resin to increase its melt index wherein the thermal treatment comprises extruding the recycled polyethylene resin in an extruder at a temperature of at least 300°C in one or more hot zones of the extruder to obtain a thermally treated recycled polyethylene resin; with preference, the extrusion is performed with a residence time ranging from 10 to 180 seconds; and / or the temperature of the thermal treatment is ranging from 320 to 460°C.

[0021] With preference, the step of preparation of the or at least one recycled-containing polyethylene composition comprises blending the thermally treated recycled polyethylene resin with one or more boosters selected from: a first booster being a polyethylene having a melt index greater than the melt index of the thermally treated recycled polyethylene resin; and / or a second booster being a polyethylene having a melt index lower than the melt index of the thermally treated recycled polyethylene resin.

[0022] For example, the first booster is a polyethylene resin having a melt index of at least 1.0 g / 10 min as determined according to ISO 1133-2011 at 190 °C under a load of 2.16 kg; preferably at least 1.2 g / 10 min; more preferably, at least 1.5 g / 10 min; even more preferably, at least 1.8 g / 10 min; and most preferably, at least 2.0 g / 10 min.

[0023] With preference, the first booster has: a melt index ranging from 2.0 to 10.0 g / 10 min; and / or a density of at least 0.958 g / cm3as determined according to ISO 1183-1 :2012 at 23°C; and / or a bimodal molecular weight distribution; and / or is Ziegler Natta catalyzed.

[0024] For example, the second booster is a polyethylene resin having a melt index of at most 2.0 g / 10 min as determined according to ISO 1133-2011 at 190 °C under a load of 2.16 kg; ; preferably at most 1.8 g / 10 min; more preferably, at most 1.5 g / 10 min; even more preferably, at most 1 .0 g / 10 min; and most preferably, at most 0.8 g / 10 minor at most 0.6 g / 10 min.

[0025] With preference, the second booster has: a melt index of at most 0.4 g / 10 min; and / or a density of at most 0.960 g / cm3as determined according to ISO 1183-1 :2012 at 23°C; and / or is metallocene catalyzed or Ziegler Natta catalyzed or chromium catalyzed.

[0026] With preference, the content of the one or more boosters in a recycled-containing polyethylene composition ranges from 5 to 50 wt.% based on the total weight of the recycled-containing polyethylene composition.

[0027] With preference, the recycled polyethylene resin is selected to have a melt index MI2 ranging from 0.4 to 1.8 g / 10 min, preferably from 0.8 to 1.5 g / 10 min.

[0028] With preference, the multilayered hollow article is selected from a bottle, a container, a can, a jerrycan, and a toy.

[0029] With preference, the article has a thickness of at least 150 pm; preferably ranging from 150 to 700 pm. With preference, at least the second polyethylene composition is a recycled-containing polyethylene composition.

[0030] For example, the article comprises two layers; the second polyethylene composition is a recycled-containing polyethylene composition selected to comprise from 0.5 to 10.0 wt.% of a white pigment or colored pigment based on the total weight of the recycled-containing polyethylene composition and the first polyethylene composition is a virgin polyethylene composition comprising from 1.0 to 10.0 wt.% of carbon black based on the total weight of the first polyethylene composition; with preference the recycled-containing polyethylene composition further comprises from 1.0 to 30.0 wt.% of reinforcement material based on the total weight of the recycled-containing polyethylene composition.

[0031] For example, the article comprises three layers, and the second polyethylene composition is a recycled-containing polyethylene composition is selected to comprise carbon black at a content ranging from 0.1 to 10.0 wt.% based on the total weight of the recycled-containing polyethylene composition; with preference the first polyethylene composition is a virgin polyethylene composition and / or the first and the third polyethylene composition are the same.

[0032] For example, the article comprises three layers, the second polyethylene composition is a recycled-containing polyethylene composition is selected to comprise carbon black at a content ranging from 0.1 to 10.0 wt.% based on the total weight of the recycled-containing polyethylene composition, and the third polyethylene composition is a recycled-containing polyethylene composition; with preference, the third polyethylene composition is a recycled- containing polyethylene composition is selected to comprise from 0.5 to 10.0 wt.% of a white pigment based on the total weight of the recycled-containing polyethylene composition.

[0033] According to a second aspect, the disclosure provides a multilayered hollow article remarkable in that it is produced according to the process of the first aspect; with preference, the article is selected from a molded article, a blow molded article, a rotomolded article, an injection molded article, an injection blow molded article; or an extrusion blow molded article.

[0034] With preference, the multilayered hollow article is selected from a bottle, a container, a can, a jerrycan, and a toy; preferably the multilayered hollow article is a milk bottle.

[0035] The article is not a film.

[0036] DETAILED DESCRIPTION

[0037] For the purpose of the disclosure, the following definitions are given. The terms "comprising", "comprises" and "comprised of' as used herein are synonymous with "including", "includes" or "containing", "contains", and are inclusive or open-ended and do not exclude additional, non-recited members, elements or method steps. The terms "comprising", "comprises" and "comprised of" also include the term “consisting of”.

[0038] The recitation of numerical ranges by endpoints includes all integer numbers and, where appropriate, fractions subsumed within that range (e.g., 1 to 5 includes 1 , 2, 3, 4 when referring to, for example, a number of elements, and can also include 1.5, 2, 2.75 and 3.80, when referring to, for example, measurements). The recitation of endpoints also includes the recited endpoint values themselves (e.g., from 1.0 to 5.0 includes both 1.0 and 5.0). Any numerical range recited herein is intended to include all sub-ranges subsumed therein.

[0039] The reference throughout this specification to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present disclosure. The particular features, structures, characteristics, or embodiments may be combined in any suitable manner, as would be apparent to a person skilled in the art from this disclosure, in one or more embodiments. Furthermore, while some embodiments described herein include some but not other features included in other embodiments, combinations of features of different embodiments are meant to be within the scope of the disclosure and form different embodiments, as would be understood by those in the art.

[0040] Unless otherwise defined, all terms used in disclosing the disclosure, including technical and scientific terms, have the meaning as commonly understood by one skilled in the art to which this disclosure belongs. By means of further guidance, definitions for the terms used in the description are included to better appreciate the teaching of the present disclosure.

[0041] As used herein, the terms “melt blending” involves the use of shear force, extensional force, compressive force, ultrasonic energy, electromagnetic energy, thermal energy or combinations comprising at least one of the foregoing forces or forms of energy and is conducted in a processing equipment wherein the aforementioned forces are exerted by a single screw, multiple screws, intermeshing co-rotating or counter-rotating screws, non-intermeshing corotating or counter-rotating screws, reciprocating screws, screws with pins, barrels with pins, rolls, rams, helical rotors, or combinations comprising at least one of the foregoing. Melt blending may be conducted in machines such as single or multiple screw extruders, Buss kneaders, Eirich mixers, Henschel, helicones, Ross mixers, Banbury, roll mills, moulding machines such as injection moulding machines, vacuum forming machines, blow moulding machines, or the like, or combinations comprising at least one of the foregoing machines. It is generally desirable during melt or solution blending of the composition to impart a specific energy of about 0.01 to about 10 kilowatt-hours / kilogram (kW h / kg) of the composition. In a preferred embodiment, melt blending is performed in a twin-screw extruder, such as a Brabender co-rotating twin-screw extruder.

[0042] The terms “polyethylene” (PE) and “ethylene polymer” may be used synonymously. The term “polyethylene” encompasses homopolymer of ethylene as well as copolymer of ethylene which can be derived from ethylene and one or more comonomers selected from the group consisting of C3-C20 alpha-olefins, such as propylene, 1 -butene, 1 -pentene, 4-methyl-1 -pentene, 1- hexene, 1 -octene, 1 -decene, 1 -dodecene, 1 -tetradecene, 1 -hexadecene, 1 -octadecene and 1- eicosene.

[0043] The terms “polyethylene resin”, as used herein, refer to polyethylene fluff or powder that is extruded, and / or melted and / or pelletized and can be produced through compounding and homogenizing of the polyethylene resin as taught herein, for instance, with mixing and / or extruder equipment. As used herein, the term “polyethylene” that can be used as a shorthand for “polyethylene resin”. The terms “fluff” or “powder” as used herein refer to polyethylene material with the hard catalyst particle at the core of each grain and is defined as the polymer material after it exits the polymerization reactor (or the final polymerization reactor in the case of multiple reactors connected in series).

[0044] Under normal production conditions in a production plant, it is expected that the melt index (MI2, HLMI, Mis) will be different for the fluff than for the polyethylene resin. Under normal production conditions in a production plant, it is expected that the density will be slightly different for the fluff, than for the polyethylene resin. Unless otherwise indicated, density and melt index for the polyethylene resin refer to the density and melt index as measured on the polyethylene resin as defined above.

[0045] The terms “virgin polyethylene” is used to denote a polyethylene directly obtained from an ethylene polymerization plant. The terms “directly obtained” is meant to include that the polyethylene may optionally be passed through a pelletization step or an additivation step or both.

[0046] The terms “Post Consumer Resin”, which may be abbreviated as “PCR”, is used to denote the component of domestic waste, household waste or end of life vehicle waste. The terms “Post Industrial Resin”, which may be abbreviated as “PIR”, is used to denote the component of industrial waste. The terms “polyethylene post-consumer resin” (PCR-PE) is a recycled material that is a compound made of high-density polyethylene, low-density polyethylene, linear low-density polyethylene and may contain one or more other polymer such as polypropylene.

[0047] Ziegler-Natta catalyst systems are generally formed from the combination of a metal component (i.e., a catalyst precursor) with one or more additional components, such as a catalyst support, a co-catalyst and / or one or more electron donors.

[0048] Metallocene catalysts are compounds of Group IV transition metals of the Periodic Table such as titanium, zirconium, hafnium, etc., and have a coordinated structure with a metal compound and a ligand composed of one or two groups of cyclopentadienyl, indenyl, fluorenyl or their derivatives.

[0049] Chromium catalysts are known to the person skilled in the art. For example, chromium catalyst can be prepared by impregnating high surface area silica gel with chromium trioxide or related chromium compounds. The solid precatalyst is then calcined in air to give the active catalyst. EP2004704B1 provides a more detailed process of production of a suitable chromium catalyst.

[0050] As used herein, "blend", "polymer blend" and like terms refer to a composition of two or more compounds, for example, two or more polymers or one polymer with at least one other compound.

[0051] The particular features, structures, characteristics, or embodiments may be combined in any suitable manner, as would be apparent to a person skilled in the art from this disclosure, in one or more embodiments.

[0052] The disclosure provides a process to produce an article being a multilayered hollow article, and such an article. The disclosure also provides one or more recycled-containing polyethylene compositions to be used in such a process to produce such an article and the method to produce said one or more recycled-containing polyethylene compositions. The process, the article, the one or more recycled-containing polyethylene compositions, and the method will be jointly described.

[0053] The multilayered holl ow article and the process to produce the multilayered holl ow article

[0054] The disclosure provides a process to produce an article being a multilayered hollow article comprising; a) Providing a first, a second, and an optional third polyethylene compositions, wherein each of the first polyethylene composition, the second polyethylene composition, and the third polyethylene composition, when present, has a melt index ranging from 0.4 to 2.0 g / 10 min as determined according to ISO 1133-2011 at 190 °C under a load of 2.16 kg; b) Forming a multilayered hollow article comprising a first layer made from a first polyethylene composition being the inner layer; a second layer made from a second polyethylene composition; optionally a third layer made from a third polyethylene composition being an outer layer; the process being remarkable in that the article comprises at least 30 wt.% of recycled polyethylene resin based on the total weight of the article; wherein the recycled polyethylene resin is selected to have a melt index MI2 ranging from 0.2 to 2.2 g / 10 min, and preferably from 0.4 to 1.8 g / 10 min as determined according to ISO 1133-2011 at 190 °C under a load of 2.16 kg; in that the process comprises a preliminary step of preparing one or more recycled-containing polyethylene compositions to be used as the first polyethylene composition, the second polyethylene composition, and / or the third polyethylene composition, when present and in that said step of preparation of the or at least one recycled-containing polyethylene composition comprises:

[0055] - a thermal treatment of the recycled polyethylene resin to increase its melt index and obtain a thermally treated recycled polyethylene resin; and / or

[0056] - blending the recycled polyethylene resin or the thermally treated recycled polyethylene resin with one or more boosters.

[0057] For example, step b) of forming the multilayered hollow article is a step of molding, blow molding, rotomolding, injection molding, injection blow molding, or extrusion blow molding; with preference, a step of rotomolding, injection molding, or injection blow molding.

[0058] The multilayered hollow article preferably is selected from a molded article, a blow-molded article, a rotomolded article, an injection-molded article, an injection blow-molded article; or an extrusion blow-molded article; with preference a rotomolded article, an injection molded article, or an injection blow molded article.

[0059] The multilayered hollow article is preferably selected from a bottle, a container, a can, and a toy. Preferably the multilayered hollow article is a bottle such as a milk bottle with a light barrier layer suitable for ultra-high temperature (UHT) requirements. It is understood that the article is not a film.

[0060] The multilayered hollow article may have a thickness of at least 150 pm; preferably at least 200 pm; more preferably at least 250 pm. The multilayered hollow article may have a thickness ranging from 150 to 700 pm; preferably a thickness ranging from 200 to 500 pm; more preferably from 250 to 450 pm.

[0061] Each of the first polyethylene composition, the second polyethylene composition, and the third polyethylene composition, when present, has a melt index ranging from 0.4 to 2.0 g / 10 min as determined according to ISO 1133-2011 at 190 °C under a load of 2.16 kg; preferably, ranging from 0.8 to 2.0 g / 10 min; more preferably, ranging from 1.0 to 1.8 g / 10 min.

[0062] The one or more recycled-containing polyethylene compositions (i.e., the polyethylene composition comprising the recycled polyethylene resin) have a density of at least 0.940 g / cm3as determined according to ISO 1183-1 :2012 at 23 °C; preferably, at least 0.942 g / cm3; more preferably, at least 0.945 g / cm3; even more preferably, at least 0.950 g / cm3; most preferably, at least 0.955 g / cm3; and even most preferably, at least 0.958 g / cm3; or at least 0.960 g / cm3.

[0063] For example, the first polyethylene composition, the second polyethylene composition, and the third polyethylene composition, when present, are selected to have a melt index MI2 of at least 0.8 g / 10 min as determined according to ISO 1133-2011 at 190 °C under a load of 2.16 kg; preferably at least 0.9 g / 10 min; more preferably at least 1.0 g / 10 min; even more preferably at least 1.1 g / 10 min; most preferably at least 1.2 g / 10 min and even most preferably at least 1.5 g / 10 min.

[0064] For example, the first polyethylene composition, the second polyethylene composition, and the third polyethylene composition, when present, are selected to have a melt index MI2 of at most 2.0 g / 10 min as determined according to ISO 1133-2011 at 190 °C under a load of 2.16 kg; preferably at most 1.9 g / 10 min; more preferably at most 1.8 g / 10 min; even more preferably at most 1.7 g / 10 min; most preferably at most 1.6 g / 10 min.

[0065] The melt index of the first polyethylene composition, the second polyethylene composition, and the third polyethylene composition, when present, can be the same or different.

[0066] In a preferred embodiment, at least the second polyethylene composition is a recycled- containing polyethylene composition.

[0067] Multilayered hollow articles with two layers

[0068] Wherein the article is devoid of a third layer, the second layer becomes the outer layer.

[0069] It is preferred that at least the second polyethylene composition is a recycled-containing polyethylene composition. The first polyethylene composition can be a virgin polyethylene composition or a recycled-containing polyethylene composition; preferably, a virgin polyethylene composition. With preference, the first polyethylene composition comprises from 1 .0 to 30.0 wt.% of reinforcement material based on the total weight of the first polyethylene.

[0070] The second polyethylene composition can comprise a pigment being a colored pigment, a white pigment or carbon black. For example, wherein the article comprises two layers and the second polyethylene composition is a recycled-containing polyethylene composition; said recycled-containing polyethylene composition is selected to comprise: from 1.0 to 10.0 wt.% of a carbon black based on the total weight of the recycled- containing polyethylene composition; or from 0.5 to 10.0 wt.% of a white pigment based on the total weight of the recycled- containing polyethylene composition; or from 0.5 to 10.0 wt.% of a colored pigment based on the total weight of the recycled- containing polyethylene composition, the colored pigment being different from black and white.

[0071] For example, wherein the article comprises two layers and the second polyethylene composition is a recycled-containing polyethylene composition; said recycled-containing polyethylene composition is selected to comprise from 1.0 to 30.0 wt.% of reinforcement material based on the total weight of the recycled-containing polyethylene composition.

[0072] In an embodiment, wherein the article comprises two layers, the first polyethylene composition comprises from 1.0 to 10.0 wt.% of carbon black based on the total weight of the first polyethylene composition; wherein the carbon black is provided with a masterbatch compliant with the food contact requirements. In such a case, the light barrier properties are provided by the first layer and the second layer may be devoid of carbon black.

[0073] In a preferred embodiment, wherein the article comprises two layers and the second polyethylene composition is a recycled-containing polyethylene composition; the second layer has a thickness equal to or greater than the thickness of the first layer. For example, the thickness of the second layer from 1 .1 to 4.0 times the thickness of the first layer; preferably, from 1.2 to 3.0 times; more preferably from 1.3 to 2.5 times; even more preferably from 1.5 to 2.0 times.

[0074] Multilayered hollow articles with three layers

[0075] Wherein the article comprises a third layer, the second layer is an intermediate layer.

[0076] It is preferred that at least the second polyethylene composition is a recycled-containing polyethylene composition. With preference, the recycled-containing polyethylene composition used as the second polyethylene composition is selected to comprise carbon black at a content ranging from 0.1 to 10.0 wt.% based on the total weight of the recycled-containing polyethylene composition. In such a case, the light barrier properties are provided by the second layer and both the first and third layers may be devoid of carbon black.

[0077] In a preferred embodiment, wherein the article comprises three layers and the second polyethylene composition is a recycled-containing polyethylene composition; the second layer has a thickness equal to or greater than the thickness of the first layer. For example, the thickness of the second layer from 1 .1 to 4.0 times the thickness of the first layer; preferably, from 1.2 to 3.0 times; more preferably from 1.3 to 2.5 times; even more preferably from 1.5 to 2.0 times.

[0078] In an embodiment, the first and the third layer have the same thickness and / or the second and the third layer have the same thickness.

[0079] The first polyethylene composition can be a virgin polyethylene composition or a recycled- containing polyethylene composition; preferably, a virgin polyethylene composition. With preference, the first polyethylene composition comprises from 1.0 to 30.0 wt.% of reinforcement material based on the total weight of the first polyethylene composition.

[0080] The third polyethylene composition can be a virgin polyethylene composition or a recycled- containing polyethylene composition; preferably, a recycled-containing polyethylene composition.

[0081] The third polyethylene composition can comprise a pigment being a colored pigment or a white pigment. For example, the third polyethylene composition is a recycled-containing polyethylene composition; said recycled-containing polyethylene composition is selected to comprise: from 0.5 to 10.0 wt.% of a white pigment based on the total weight of the recycled- containing polyethylene composition; or from 0.5 to 10.0 wt.% of a colored pigment based on the total weight of the recycled- containing polyethylene composition, the colored pigment being different from black and white.

[0082] With preference, the third polyethylene composition comprises from 1.0 to 30.0 wt.% of reinforcement material based on the total weight of the third polyethylene composition.

[0083] In an embodiment, the first and the third polyethylene composition are the same.

[0084] The content of the recycled polyethylene resin in the article The multilayered hollow article according to the disclosure comprises at least 30 wt.% of recycled polyethylene resin based on the total weight of the polyethylene in the article; preferably, at least 32 wt.% of recycled polyethylene resin; more preferably, at least 35 wt.% of recycled polyethylene resin; even more preferably, at least 38 wt.% of recycled polyethylene resin; most preferably, at least 40 wt.% of recycled polyethylene resin; even most preferably, at least 42 wt.% of recycled polyethylene resin or at least 45 wt.% or at least 50 wt.%.

[0085] In a preferred embodiment, the multilayered hollow article comprises 100 wt.% of recycled polyethylene resin based on the total weight of the polyethylene in the article; preferably, at most 95 wt.% of recycled polyethylene resin; more preferably, at most 90 wt.% of recycled polyethylene resin; even more preferably, at most 85 wt.% of recycled polyethylene resin; most preferably, at most 80 wt.% of recycled polyethylene resin; even most preferably, at most 75 wt.% of recycled polyethylene resin or at most 70 wt.% or at most 65 wt.%.

[0086] The content of the recycled polyethylene resin within the article can be adapted by the person skilled in the art by selecting the number of layers comprising recycled polyethylene resin. When the article comprises three layers, the use of recycled polyethylene resin in at least two layers allows to increase the overall content of recycled polyethylene resin. Whether the article comprises two or three layers, the thickness of the one or more layers comprising a recycled- containing polyethylene composition can be increased by comparison to the one of a layer made from a virgin polyethylene composition, as a result, the overall content of recycled polyethylene resin will be increased. Also, as it will be seen below the content of booster in the recycled-containing polyethylene composition can be reduced by the use of a thermal treatment of the recycled polyethylene resin.

[0087] The one or more recycled-containing polyethylene compositions and the step to produce said one or more recycled-containing polyethylene compositions

[0088] The disclosure provides one or more polyethylene compositions made of or comprising a recycled polyethylene resin (hereafter named recycled-containing polyethylene compositions) and the step or method to prepare said one or more recycled-containing polyethylene compositions.

[0089] The recycled polyethylene resin is selected from one or more post-consumer polyethylene resins (PCR-PE); one or more post-industrial resins; and any blend thereof.

[0090] The recycled polyethylene resin is selected to have a density of at least 0.940 g / cm3as determined according to ISO 1183-1 :2012 at 23 °C; preferably, at least 0.942 g / cm3; more preferably, at least 0.945 g / cm3; even more preferably, at least 0.950 g / cm3; most preferably, at least 0.955 g / cm3; and even most preferably, at least 0.958 g / cm3; or at least 0.960 g / cm3.

[0091] In a preferred embodiment, the recycled polyethylene resin has an ESCR (100%) of at most 20 hours determined in accordance with condition B of ASTM D 1693 (2013); preferably of at most 15 hours. For example, the recycled polyethylene resin has a melt index below 1.5 g / 10 min as determined according to ISO 1133-2011 at 190 °C under a load of 2.16 kg; an ESCR (100%) ranging from 4 to 12 hours, preferably ranging from 5 to 10 hours. In another example, the recycled polyethylene resin has a melt index of at least 1.5 g / 10 min as determined according to ISO 1133-2011 at 190 °C under a load of 2.16 kg; an ESCR (100%) of at least 6 hours; preferably of at least 8 hours.

[0092] The recycled polyethylene resin is selected to have a melt index MI2 ranging from 0.2 to 2.2 g / 10 min as determined according to ISO 1133-2011 at 190 °C under a load of 2.16 kg; preferably ranging from 0.3 to 2.0 g / 10 min; more preferably ranging from 0.4 to 1.8 g / 10 min and even more preferably ranging from 0.8 to 1.5 g / 10 min.

[0093] For example, the recycled polyethylene resin is selected to have a melt index MI2 of at least 0.2 g / 10 min or at least 0.3 g / 10 min as determined according to ISO 1133-2011 at 190 °C under a load of 2.16 kg; preferably at least 0.4 g / 10 min or at least 0.5 g / 10 min; more preferably at least 0.6 g / 10 min; even more preferably at least 0.7 g / 10 min; most preferably at least 0.8 g / 10 min and even most preferably at least 0.9 g / 10 min, or at least 1 .0 g / 10 min.

[0094] For example, the recycled polyethylene resin is selected to have a melt index MI2 of at most 2.2 g / 10 min or at most 2.0 g / 10 min as determined according to ISO 1133-2011 at 190 °C under a load of 2.16 kg; preferably at most 1.8 g / 10 min or at most 1.7 g / 10 min; more preferably at most 1.6 g / 10 min; even more preferably at most 1.5 g / 10 min; most preferably at most 1.4 g / 10 min.

[0095] The one or more recycled-containing polyethylene compositions (i.e., the polyethylene composition comprising the recycled polyethylene resin) have a density of at least 0.940 g / cm3as determined according to ISO 1183-1 :2012 at 23 °C; preferably, at least 0.942 g / cm3; more preferably, at least 0.945 g / cm3; even more preferably, at least 0.950 g / cm3; most preferably, at least 0.955 g / cm3; and even most preferably, at least 0.958 g / cm3. For example, the one or more recycled-containing polyethylene compositions (i.e., the polyethylene composition comprising the recycled polyethylene resin) have a density of at most 0.980 g / cm3as determined according to ISO 1183-1 :2012 at 23 °C; preferably at most 0.975 g / cm3; and more preferably at most 0.972 g / cm3. The one or more recycled-containing polyethylene compositions (i.e., the polyethylene composition comprising the recycled polyethylene resin) have a melt index MI2 ranging from 0.8 to 2.0 g / 10 min as determined according to ISO 1133-2011 at 190 °C under a load of 2.16 kg; preferably ranging from 1.0 to 1.8 g / 10 min.

[0096] For example, the one or more recycled-containing polyethylene compositions are selected to have a melt index MI2 of at least 0.8 g / 10 min as determined according to ISO 1133-2011 at 190 °C under a load of 2.16 kg; preferably at least 0.9 g / 10 min; more preferably at least 1.0 g / 10 min; even more preferably at least 1.1 g / 10 min; most preferably at least 1.2 g / 10 min and even most preferably at least 1.5 g / 10 min.

[0097] For example, the one or more recycled-containing polyethylene compositions are selected to have a melt index MI2 of at most 2.0 g / 10 min as determined according to ISO 1133-2011 at 190 °C under a load of 2.16 kg; preferably at most 1.9 g / 10 min; more preferably at most 1.8 g / 10 min; even more preferably at most 1.7 g / 10 min; most preferably at most 1.6 g / 10 min.

[0098] In some embodiments, it may be desirable to perform a sub-step of rheologic control of the recycled polyethylene resin including a thermal treatment to increase its melt index. Such thermal treatment may also be used to further clean the recycled polyethylene resin by removing some volatile organic compounds (VOC). Thus, in some embodiments, the thermally treated recycled polyethylene resin has a VOC content lower than the VOC content of the initial recycled polyethylene resin (i.e., the recycled polyethylene resin prior to the thermal treatment).

[0099] The rheologic control is a thermal treatment of the recycled polyethylene resin performed to increase its melt index. Such a thermal treatment preferably comprises heating the recycled polyethylene resin by extruding it in an extruder at a temperature of at least 300°C in one or more hot zones of the extruder. Such heating can be done either: by using the thermal regulation devices of the extruder to have a maximum barrel temperature ranging from 300 to 460°C in at least one hot zone of the extruder; and / or by self-heating of the recycled polyethylene resin using a specific screw design so that the extrusion is performed with mechanical specific energy greater than or equal to 0.4 kWh / kg.

[0100] The thermal treatment of the recycled polyethylene resin is preferably done in a twin-screw extruder with thermal regulation devices.

[0101] With preference; the thermal treatment by self-heating of the recycled polyethylene resin is performed twin-screw extruder wherein the one or more hot zones have a total length equal to or greater than 6 D with D being the screw diameter, wherein the extrusion is performed with mechanical specific energy greater than or equal to 0.4 kWh / kg, wherein the screw profile comprises at least one hot zone with successive kneading blocks elements over a length of at least 4 D followed by a left-handed element with D being the screw diameter, wherein the thermal regulation devices, are set to initial imposed barrel temperatures ranging between 240 and 320 °C, and are switched off when the barrel temperature in the zone spontaneously exceeds the imposed barrel temperature by at least 3 °C without the need of external heat application.

[0102] With preference, the thermal treatment is performed by self-heating of the recycled polyethylene resin and the screw profile comprises two or more hot zones wherein a first hot zone comprises successive kneading blocks elements over a length of at least 4 D followed by a left-handed element with D being the screw diameter, and one or more additional hot zones placed downstream the first hot zone are filled mixing zones, each comprising kneading blocks elements over a length of at least 4 D followed by a kneading left-handed element or by a left-handed element with D being the screw diameter.

[0103] With preference, the thermal treatment is performed by self-heating of the recycled polyethylene resin and the successive kneading blocks elements of at least one hot zone of the extruder comprise disks with disks offset by 90 degrees and a disk width of at least 0.3 D wherein D being the screw diameter and / or in that one hot zone of the extruder is or comprises the melting zone of the extruder.

[0104] For example, the extrusion is performed at a screw speed ranging from 100 to 1200 rpm.

[0105] For example, the extrusion is performed with a residence time ranging from 10 seconds to 10 minutes; preferably with a residence time ranging from 20 seconds to 5 minutes; more preferably with a residence time ranging from 10 to 180 seconds; even more preferably, from 10 to 120 seconds; most preferably, from 20 to 100 seconds; and even most preferably, from 30 to 80 seconds.

[0106] For example, the thermal treatment self-heating of the recycled polyethylene resin or by heating of the recycled polyethylene resin wherein the extrusion is performed at a maximum barrel temperature ranging from 300 to 460°C in at least one hot zone; preferably at a maximum barrel temperature ranging from 310 to 450°C; more preferably at a maximum barrel temperature ranging from 320 to 430°C; even more preferably at a maximum barrel temperature ranging from 330 to 410°C and most preferably at a maximum barrel temperature ranging from 340 to 390 °C. With preference, the thermal treatment is performed to have the melt index of the recycled polyethylene resin that is increased by a factor k ranging from 1.1 to 5.0; preferably, from 1.2 to 4.8; more preferably from 1.5 to 4.5.

[0107] The thermal treatment can be performed alternatively or in complement to the addition of one or more boosters selected from a first booster and / or a second booster in at least recycled- containing polyethylene composition. The use of a thermal treatment on the recycled polyethylene resin in addition to the addition of one or more boosters allows to adjust the content of the one or more boosters to achieve the desired mechanical properties together with the desired melt index of the one or more of recycled-containing polyethylene compositions.

[0108] In some embodiments, it may be desirable that the or at least one recycled-containing polyethylene composition has a melt index greater than the melt index of the recycled polyethylene resin (or of the thermally treated recycled polyethylene resin if a thermal treatment was performed). In such a case, the step of preparation of the or at least one recycled-containing polyethylene composition comprises a sub-step of melt index adjustment performed by blending the recycled polyethylene resin, or of the thermally treated recycled polyethylene resin, with a first booster being a polyethylene resin having a greater melt index.

[0109] The first booster is preferably selected to be a polyethylene resin having a melt index of at least 2.0 g / 10 min as determined according to ISO 1133-2011 at 190 °C under a load of 2.16 kg.

[0110] With preference the first booster has a melt index MI2 ranging from 2.0 to 10.0 g / 10 min or from 2.0 to 8.0 g / 10 min as determined according to ISO 1133-2011 at 190 °C under a load of 2.16 kg; more preferably ranging from 3.0 to 7.0 g / 10 min.

[0111] For example, the first booster is selected to have a melt index MI2 of at least 2.0 g / 10 min as determined according to ISO 1133-2011 at 190 °C under a load of 2.16 kg; preferably at least 2.5 g / 10 min; more preferably at least 2.8 g / 10 min; even more preferably at least 3.0 g / 10 min; most preferably at least 3.2 g / 10 min and even most preferably at least 3.5 g / 10 min.

[0112] For example, the first booster is selected to have a melt index MI2 of at most 10.0 g / 10 min at most 9.0 g / 10 min as determined according to ISO 1133-2011 at 190 °C under a load of 2.16 kg; preferably at most 8.0 g / 10 min or at most 7.0 g / 10 min; more preferably at most 6.5 g / 10 min; even more preferably at most 6.0 g / 10 min; most preferably at most 5.5 g / 10 min. The first booster is preferably selected to be a polyethylene resin having a density of at least 0.955 g / cm3as determined according to ISO 1183-1 :2012 at 23°C; preferably, at least 0.956 g / cm3; and more preferably, at least 0.958 g / cm3.

[0113] The first booster is preferably selected to be a polyethylene resin having a density of at most 0.985 g / cm3as determined according to ISO 1183-1 :2012 at 23°C; preferably, at most 0.980 g / cm3; more preferably, at most 0.975 g / cm3; and even more preferably, at most 0.970 g / cm3; or at most 0.967 g / cm3.

[0114] In a preferred embodiment, the first booster has a monomodal or a bimodal molecular weight distribution; preferably the first booster has bimodal molecular weight distribution.

[0115] For example, the first booster is metallocene catalyzed or Ziegler Natta catalyzed; preferably the first booster is Ziegler Natta catalyzed.

[0116] Examples of commercially available polyethylene resins marketed by TotalEnergies® that are suitable as first boosters are:

[0117] - HDPE 20HD07 having a melt index MI2 of 4.0 g / 10 min (2.16 kg; 190°C) and a density of 0.960 g / cm3;

[0118] - HDPE HD 6081 having a melt index MI2 of 8.0 g / 10 min (2.16 kg; 190°C) and a density of 0.960 g / cm3;

[0119] - HDPE HD 6082 having a melt index MI2 of 8.0 g / 10 min (2.16 kg; 190°C) and a density of 0.960 g / cm3.

[0120] It was found that the use of a first booster in the one or more recycled-containing polyethylene compositions is also favorable to improve the mechanical properties of the final article such as the rigidity and the top load properties.

[0121] In some embodiments, it may be desirable that the or at least one recycled-containing polyethylene composition has a melt index lower than the melt index of the recycled polyethylene resin (or the thermally treated recycled polyethylene resin if a thermal treatment was performed). In such a case, the step of preparation of the recycled-containing polyethylene composition comprises a sub-step of melt index adjustment performed by blending the recycled polyethylene resin, or of the thermally treated recycled polyethylene resin, with a second booster being a polyethylene resin having a lower melt index.

[0122] The second booster is preferably selected to be a polyethylene resin having a melt index of at most 0.8 g / 10 min as determined according to ISO 1133-2011 at 190 °C under a load of 2.16 kg. With preference the second booster has a melt index MI2 ranging from 0.01 to 0.8 g / 10 min as determined according to ISO 1133-2011 at 190 °C under a load of 2.16 kg; more preferably ranging from 0.10 to 0.5 g / 10 min.

[0123] For example, the second booster is selected to have a melt index MI2 of at least 0.01 g / 10 min as determined according to ISO 1133-2011 at 190 °C under a load of 2.16 kg; preferably at least 0.05 g / 10 min; more preferably at least 0.08 g / 10 min; even more preferably at least 0.10 g / 10 min; most preferably at least 0.12 g / 10 min and even most preferably at least 0.15 g / 10 min.

[0124] For example, the second booster is selected to have a melt index MI2 of at most 0.80 g / 10 min as determined according to ISO 1133-2011 at 190 °C under a load of 2.16 kg; preferably at most 0.70 g / 10 min; more preferably at most 0.60 g / 10 min; even more preferably at most 0.50 g / 10 min; most preferably at most 0.40 g / 10 min; and even more preferably at most 0.38 g / 10 min or at most 0.35 g / 10 min.

[0125] The second booster is preferably selected to be a polyethylene resin having a density of at most 0.960 g / cm3as determined according to ISO 1183-1 :2012 at 23°C; preferably, at most 0.955 g / cm3; and more preferably, at most 0.950 g / cm3.

[0126] The second booster is preferably selected to be a polyethylene resin having a density of at least 0.935 g / cm3as determined according to ISO 1183-1 :2012 at 23°C; preferably, at least 0.938 g / cm3; more preferably, at least 0.940 g / cm3; and even more preferably, at least 0.945 g / cm3.

[0127] In a preferred embodiment, the second booster has monomodal or a bimodal molecular weight distribution; preferably the second booster has bimodal molecular weight distribution.

[0128] For example, the second booster is metallocene catalyzed or Ziegler-Natta catalyzed or chromium catalyzed; the second booster is metallocene catalyzed or chromium catalyzed.

[0129] In an embodiment, the second booster has a monomodal molecular weight distribution and is chromium catalyzed. In an embodiment, the second booster has a binomodal molecular weight distribution and is metallocene catalyzed or Ziegler-Natta catalyzed. Examples of commercially available polyethylene resins marketed by TotalEnergies® that are suitable as second boosters are:

[0130] - XRT70 having a melt index MI5 of 0.70 g / 10 min (5 kg; 190°C) and a density of 0.947 g / cm3;

[0131] - 5502 having a melt index MI2 of 0.25 g / 10 min (2.16 kg; 190°C) and a density of 0.954 g / cm3; - 5502 R3 having a melt index MI2 of 0.25 g / 10 min (2.16 kg; 190°C) and a density of 0.954 g / cm3.

[0132] It was found that the use of a second booster in the one or more recycled-containing polyethylene compositions is also favorable to improve the mechanical properties of the final article such as the melt strength and the weldability.

[0133] In an embodiment, the step of preparation of the or at least one recycled-containing polyethylene composition comprises blending the recycled polyethylene resin or the thermally treated recycled polyethylene resin with both a first booster and a second booster to improve the mechanical properties of the recycled-containing polyethylene composition by comparison to the recycled polyethylene resin or the thermally treated recycled polyethylene resin.

[0134] When blending the recycled polyethylene resin or the thermally treated recycled polyethylene resin with one or more boosters selected from a first booster and / or a second booster, the content of the one or more boosters is selected to be ranging from 5 to 50 wt.% based on the total weight of recycled-containing polyethylene composition.

[0135] In a preferred embodiment, the content of the one or more boosters in a recycled-containing polyethylene composition is ranging from 5 to 50 wt.% based on the total weight of recycled- containing polyethylene composition; preferably ranging from 7 to 40 wt.%; more preferably, ranging from 10 to 30 wt.%.

[0136] For example, the content of the one or more boosters in a recycled-containing polyethylene composition is at least 5 wt.% based on the total weight of recycled-containing polyethylene composition; preferably at least 7 wt.%; preferably at least 10 wt.%.

[0137] For example, the content of the one or more boosters in a recycled-containing polyethylene composition is at most 50 wt.% based on the total weight of recycled-containing polyethylene composition; preferably at most 40 wt.%; preferably at most 30 wt.%.

[0138] In some embodiments, at least one recycled-containing polyethylene composition further comprises from 1.0 to 10.0 wt.% of carbon black based on the total weight of the recycled- containing polyethylene composition; preferably from 1.0 to 5.0 wt.%; more preferably, from 2.0 to 4.0 wt.%. With preference, the carbon black is provided in the form of a masterbatch comprising carbon black and polyethylene as carrier resin. With preference the masterbatch comprises from 10 to 60 wt.% of carbon black based on the total weight of the masterbatch: preferably from 20 to 50 wt.%. Carbon black masterbatches are known to the person skilled in the art and are commercially available. Examples of suitable PE-CB masterbatches are marketed by the RTP Company under the commercial name PE 50HD65 BK MB (carrier resin: HDPE; pigment loaded 50%) and RTP PE 35Z19 BK MB (carrier resin: LLDPE; pigment loaded 35%; FDA compliant ingredients).

[0139] The use of carbon black in a polyethylene composition allows to comply with the light barrier requirements for ultra-high temperature (UHT) milk bottles. Carbon black also acts as a reinforcement material to enhance the mechanical properties of the polyethylene composition.

[0140] In some embodiments, at least one recycled-containing polyethylene composition further comprises from 0.5 to 10.0 wt.% of a white pigment based on the total weight of the recycled- containing polyethylene composition; preferably from 1.0 to 5.0 wt.%; more preferably, from 1.0 to 3.0 wt.%. The white pigment is preferably selected from titanium dioxide (TiCh), zinc oxide, zinc sulfide, and any mixture thereof. More preferably, the white pigment is or comprises titanium dioxide (TiCh).

[0141] With preference, the white pigment is provided in the form of a masterbatch comprising said white pigment and polyethylene as carrier resin. With preference the masterbatch comprises from 30 to 80 wt.% of the white pigment based on the total weight of the masterbatch: preferably from 50 to 70 wt.%.

[0142] White pigment masterbatches are known to the person skilled in the art and are commercially available. An example of a suitable PE-TiCh masterbatch is marketed by the RTP Company under the commercial name PE 70ZT WT MB (carrier resin: LLDPE; pigment loaded 35%; FDA-compliant ingredients).

[0143] In some embodiments, at least one recycled-containing polyethylene composition further comprises a reinforcement material different from carbon black. The reinforcement material is preferably selected from talc mineral filler, wollastonite, calcium carbonate, silica, and any mixture thereof. More preferably, the reinforcement material is calcium carbonate and / or silica.

[0144] The reinforcement material is preferably present at a content ranging from 1.0 to 30.0 wt.% based on the total weight of the recycled-containing polyethylene composition, preferably from 2.0 to 20.0 wt.% or from 3.0 to 10.0 wt.%.

[0145] Test methods

[0146] The melt flow index MI2 of the polyethylene is determined according to ISO 1133-1 :2022 at 190°C under a load of 2.16 kg. The density was measured according to the method of standard ISO 1183-1 :2012 (immersion method) at a temperature of 23 °C.

[0147] Examples

[0148] The following non-limiting examples illustrate the disclosure Example 1 : production of a recycled-containing polyethylene composition

[0149] An HDPE-PCR of an MI2 of 1.3 g / 10 min was blended with different boosters wherein Boost 1 is 5502, Boost 2 is 5802, Boost 3 is XRT70, and Boost 4 is 20HD07, all marketed by TotalEnergies ®. From the results, it can be seen that the addition of a booster allows adjusting the melt index of the recycled-containing polyethylene composition either by lowering it or by increasing it.

Claims

CLAIMS1 . A process to produce an article being a multilayered hollow article comprising; a) providing a first, a second; and an optional third polyethylene compositions, wherein each of the first polyethylene composition, the second polyethylene composition, and the third polyethylene composition, when present, has a melt index ranging from 0.4 to 2.0 g / 10 min as determined according to ISO 1133-2011 at 190 °C under a load of 2.16 kg; b) forming a multilayered hollow article comprising a first layer made from a first polyethylene composition being the inner layer; a second layer made from a second polyethylene composition; optionally a third layer made from a third polyethylene composition being an outer layer; wherein the process is characterized in that the article comprises at least 30 wt.% of recycled polyethylene resin based on the total weight of the article; wherein the recycled polyethylene resin is selected to have a melt index MI2 ranging from 0.2 to 2.2 g / 10 min as determined according to ISO 1133-2011 at 190 °C under a load of 2.16 kg; in that, the process comprises a preliminary step of preparing one or more recycled- containing polyethylene compositions to be used as the first polyethylene composition, the second polyethylene composition, and / or the third polyethylene composition, when present; and in that said step of preparation of the or at least one recycled-containing polyethylene composition comprises:- a thermal treatment of the recycled polyethylene resin to increase its melt index and obtain a thermally treated recycled polyethylene resin; and / or- blending the recycled polyethylene resin or the thermally treated recycled polyethylene resin with one or more boosters.

2. The process according to claim 1 is characterized in that the second layer has a thickness equal to or greater than the thickness of the first layer; with preference, the thickness of the second layer from 1 .1 to 4.0 times the thickness of the first layer.

3. The process according to claim 1 or 2 is characterized in that the step of preparation of the or at least one recycled-containing polyethylene composition comprises a thermal treatment of the recycled polyethylene resin to increase its melt index wherein the thermal treatment comprises extruding the recycled polyethylene resin in an extruder at atemperature of at least 300°C in one or more hot zones of the extruder to obtain a thermally treated recycled polyethylene resin.

4. The process of claim 3 is characterized in that the extrusion is performed with a residence time ranging from 10 to 180 seconds; and / or the temperature of the thermal treatment ranges from 320 to 460°C.

5. The process according to any one of claims 1 to 4 is characterized in that the step of preparation of the or at least one recycled-containing polyethylene composition comprises blending the recycled polyethylene resin or the thermally treated recycled polyethylene resin with one or more boosters selected from: a first booster being a polyethylene having a melt index greater than the melt index of the recycled polyethylene resin or the thermally treated recycled polyethylene resin; and / or a second booster being a polyethylene having a melt index lower than the melt index of the recycled polyethylene resin or the thermally treated recycled polyethylene resin.

6. The process according to claim 5 is characterized in that the first booster is a polyethylene resin having a melt index of at least 2.0 g / 10 min as determined according to ISO 1133- 2011 at 190 °C under a load of 2.16 kg; with preference, a melt index ranging from 2.0 to 10.0 g / 10 min.

7. The process according to claim 5 or 6 is characterized in that the first booster has: a density of at least 0.958 g / cm3as determined according to ISO 1183-1 :2012 at 23°C; and / or a bimodal molecular weight distribution; and / or is Ziegler Natta catalyzed.

8. The process according to any one of claims 5 to 7 is characterized in that the second booster is a polyethylene resin having a melt index of at most 0.8 g / 10 min as determined according to ISO 1133-2011 at 190 °C under a load of 2.16 kg; with preference, a melt index of at most 0.4 g / 10 min.

9. The process according to any one of claims 5 to 8 is characterized in that the second booster has a density of at most 0.960 g / cm3as determined according to ISO 1183-1 :2012 at 23°C; and / or is metallocene catalyzed or Ziegler Natta catalyzed or chromium catalyzed.

10. The process according to any one of claims 1 to 9 is characterized in that the content of the one or more boosters in a recycled-containing polyethylene composition is ranging from 5 to 50 wt.% based on the total weight of recycled-containing polyethylene composition.

11. The process according to any one of claims 1 to 10 is characterized in that the recycled polyethylene resin is selected to have a melt index MI2 ranging from 0.4 to 1.8 g / 10 min12. The process according to any one of claims 1 to 11 is characterized in that the multilayered hollow article is selected from a bottle, a container, a can, a jerrycan, and a toy.

13. The process according to any one of claims 1 to 12 is characterized in that the article has a thickness of at least 150 pm; preferably ranging from 150 to 700 pm.

14. The process according to any one of claims 1 to 13 is characterized in that at least the second polyethylene composition is a recycled-containing polyethylene composition.

15. The process according to claim 14 is characterized in that the article comprises two layers, in that the second polyethylene composition is a recycled-containing polyethylene composition selected to comprise from 0.5 to 10.0 wt.% of a white pigment or colored pigment based on the total weight of the recycled-containing polyethylene composition and in that the first polyethylene composition is a virgin polyethylene composition comprising from 1.0 to 10.0 wt.% of carbon black based on the total weight of the first polyethylene composition.

16. The process according to claim 15 is characterized in that the recycled-containing polyethylene composition further comprises from 1.0 to 30.0 wt.% of reinforcement material based on the total weight of the recycled-containing polyethylene composition.

17. The process according to claim 14 is characterized in that the article comprises three layers and in that the second polyethylene composition is a recycled-containing polyethylene composition is selected to comprise carbon black at a content ranging from 0.1 to 10.0 wt.% based on the total weight of the recycled-containing polyethylene composition.

18. The process according to claim 17 is characterized in that the first polyethylene composition is a virgin polyethylene composition and / or the first and the third polyethylene composition are the same.

19. The process according to claim 14 is characterized in that the article comprises three layers, in that the second polyethylene composition is a recycled-containing polyethylene composition is selected to comprise carbon black at a content ranging from 0.1 to 10.0 wt.% based on the total weight of the recycled-containing polyethylene composition and in that the third polyethylene composition is a recycled-containing polyethylene composition.

20. The process according to claim 19 is characterized in that the third polyethylene composition is a recycled-containing polyethylene composition is selected to comprise from 0.5 to 10.0 wt.% of a white pigment based on the total weight of the recycled- containing polyethylene composition.

21. The process according to any one of claims 1 to 20 is characterized in that step b) of forming the multilayered hollow article is a step of molding, blow molding, rotomolding, injection molding, injection blow molding, or extrusion blow molding; with preference a step of rotomolding, injection molding, or injection blow molding.

22. A multilayered hollow article is characterized in that it is produced according to the process of any one of claims 1 to 21 .

23. The multilayered hollow article according to claim 22 is characterized in that the article is selected from a molded article, a blow molded article, a rotomolded article, an injection molded article, an injection blow molded article; or an extrusion blow molded article; with preference a rotomolded article, an injection molded article, or an injection blow molded article.

24. The multilayered hollow article according to claim 22 or 23 is characterized in that the multilayered hollow article is selected from a bottle, a container, a can, a jerrycan and a toy; preferably the multilayered hollow article is a milk bottle.

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