Patent Description:
The most commonly used material for a hinged component is polypropylene. Polypropylene has a superior hinge fatigue performance, good environmental stress crack resistance (ESCR) performance, low cost and ease of processing. However, bottles or tubes for cosmetic/personal care applications having a hinged cap are usually made of polyethylene. This means that the bottles and tubes and the unseparated polypropylene caps will end up after use in the mechanical recycled stream as contamination and deteriorate the mechanical performance of the polyethylene recyclates. Therefore, there is a need to develop polyethylene based hinged components to enable mono-material packaging solution in order to achieve better sustainability.

However, the hinged component still need to have a superior hinge fatigue performance and good mechanical performance. In particular, hinge fatigue performance, environmental stress crack resistance (ESCR), and processability of the material used for the hinged components are important. Likewise impact and cold temperature toughness are of importance. Consequently, new materials for a hinged component that meet those requirements need to be developed.

<CIT> (D1) relates to a hinged component comprising a polyethylene composition having a molecular weight distribution Mw/Mn, of from <NUM> to <NUM>; a density of at least <NUM>/cm<NUM>; a melt index, I<NUM> of from greater than <NUM>/<NUM> to <NUM>/<NUM>, a Z-average molecular weight Mz, of less than <NUM>,<NUM>; and a melt flow ratio I<NUM>/I<NUM>, of from <NUM> to <NUM>; where the hinged component has an average hinge life of more than <NUM> cycles.

<CIT> (D2) relates to a dual reactor solution polymerization process gives high density polyethylene compositions containing a first ethylene copolymer and a second ethylene copolymer and which have high dimensional stability, excellent processability as well as good organoleptic properties and reasonable stress cracking resistance. The polyethylene compositions are suitable for compression molding or injection molding applications and are useful, for example, in the manufacture of caps and closures for bottles, and for example, in bottles containing non-pressurized liquids.

It has now surprisingly been found that the use of a polyethylene composition comprising high density polyethylene (HDPE) and linear low density polyethylene (LLDPE) in the production of a hinged component results in an excellent combination of ESCR and hinge fatigue performance. At the same time the hinged component allows easy recycling.

The hinged component according to the invention comprises a polyethylene composition, the polyethylene composition comprising.

The hinged component according to the invention shows an excellent combination of ESCR and hinge fatigue performance. At the same time the hinged component allows easy recycling.

Preferably, the hinged component comprises HDPE in an amount which is in the range of <NUM>-<NUM> % by weight, preferably in the range of <NUM>-<NUM> % by weight of the total amount of HDPE and LLDPE, wherein the total amount of the HDPE and LLDPE is <NUM> % by weight.

Preferably, the hinged component comprises LLDPE in an amount which is in the range of <NUM>-<NUM> % by weight, preferably in the range of <NUM>-<NUM> % by weight of the total amount of HDPE and LLDPE, wherein the total amount of the HDPE and LLDPE is <NUM> % by weight.

More preferably, the hinged component comprises HDPE in an amount which is in the range of <NUM>-<NUM> % by weight of the total amount of HDPE and LLDPE.

More preferably, the hinged component comprises LLDPE in an amount which is in the range of <NUM>-<NUM> % by weight of the total amount of HDPE and LLDPE.

Most preferably, the hinged component comprises HDPE in an amount which is in the range of <NUM>-<NUM> % by weight of the total amount of HDPE and LLDPE;
and LLDPE in an amount which is in the range of <NUM>-<NUM> % by weight of the total amount of HDPE and LLDPE.

Most preferably, the hinged component comprises HDPE in an amount which is equal or higher than the amount of LLDPE by weight based on the total amount of HDPE and LLDPE.

The production processes of the HDPE and is summarised in "<NPL>. Suitable catalysts for the production of polyethylene include Ziegler Natta catalysts, chromium based catalysts and single site metallocene catalysts.

The unimodal polyethylene may be obtained for example by polymerizing ethylene and optionally at least one olefin comonomer in slurry in the presence of a silica-supported chromium-containing catalyst and/or an alkyl boron compound. Suitable comonomers include for example propylene, <NUM>-butene, <NUM>-pentene, <NUM>-methyl-<NUM>-pentene, <NUM>-hexene and/or <NUM>-octene.

The unimodal polyethylene may be obtained for example by polymerizing ethylene and optionally at least one olefin comonomer in a gas phase polymerisation or in slurry polymerisation process.

The production processes for bimodal high density polyethylene (HDPE) are summarised at <NPL>). The production of bimodal high density polyethylene (HDPE) via a low pressure slurry process is described by <NPL>). The characteristics of the polyethylene are determined amongst others by the catalyst system and by the concentrations of catalyst, comonomer and hydrogen. The production of bimodal high density polyethylene (HDPE) via a low pressure slurry process may also be performed via a three stage process. The concept of the two stage cascade process is elucidated at <NPL>).

The HDPE according to the invention may be unimodal HDPE or multimodal HDPE for example bimodal HDPE and trimodal HDPE. Preferably, the HDPE is unimodal HDPE. Unimodal HDPE needs to be understood as an HDPE that has been produced in one reactor under the same reaction conditions and one type of catalyst species.

Bimodal HDPE needs to be understood as an HDPE that is produced in two reactors in series under different polymerization conditions. Bimodal HDPE may for example be a reactor blend of HDPE produced in one reactor and LLDPE produced in another reactor and where the reactors are used in series.

Bimodal HDPE may also be a HDPE that is produced in one reactor in the presence of a catalyst system that comprises two or more different catalyst species, for example a catalyst system using two different active metal species, wherein those catalyst species lead to a reactor blend of polyethylene's having different properties, for example a different density and/or MFI.

Multimodal HDPE needs to be understood as an HDPE that is produced in two or more reactors in series under different polymerization conditions. Multimodal HDPE may for example be a reactor blend of HDPE produced in one or more reactors and LLDPE produced in one or more reactors.

The molecular weight distribution of the HDPE measured by SEC may show one or more distinct maxima or might show a distinctly broadened molecular weight distribution in comparison with the curves for the individual fractions of material with different composition.

Bimodal or multimodal HDPE may show one, two or several maxima/peaks in size exclusion chromatograms. It needs to be understood that the number of maxima/peaks or shoulders is not related to the terms unimodal, bimodal or multimodal HDPE according to the invention. A bimodal HDPE may for example show only one maxima/peak in a size exclusion chromatogram.

The hinged component may comprise HDPE having a density in the range of <NUM> to <NUM>/m<NUM>, as measured according to ISO <NUM>, method A.

The hinged component may comprise HDPE having a MFI in the range of <NUM> to <NUM>/<NUM>, preferably of <NUM> to <NUM>/<NUM>, more preferred of <NUM> to <NUM>/<NUM>, as measured according to ISO <NUM>-<NUM>:<NUM> at <NUM> and at a load of <NUM>.

The hinged component may comprise HDPE having a Mw in the range of <NUM>,<NUM> to <NUM>,<NUM>/mol, preferably in the range of <NUM>,<NUM> to <NUM>,<NUM>/mol, more preferably in the range of <NUM>,<NUM> to <NUM>,<NUM>/mol.

The hinged component may comprise HDPE having a Mw/Mn in the range of to <NUM> to <NUM>, preferably in the range from <NUM>-<NUM>, more preferably in the range from <NUM>-<NUM>.

The hinged component may comprise HDPE having a density in the range of <NUM> to <NUM>/m<NUM>, as measured according to ISO <NUM>, method A, and a MFI in the range of <NUM> to <NUM>/<NUM>, preferably of <NUM> to <NUM>/<NUM>, more preferred of <NUM> to <NUM>/<NUM>, as measured according to ISO <NUM>-<NUM>:<NUM> at <NUM> and at a load of <NUM>,.

The hinged component may comprise HDPE having a density in the range of <NUM> to <NUM>/m<NUM>, as measured according to ISO <NUM>, method A, and a MFI in the range of <NUM> to <NUM>/<NUM>, preferably of <NUM> to <NUM>/<NUM>, more preferred of <NUM> to <NUM>/<NUM>, as measured according to ISO <NUM>-<NUM>:<NUM> at <NUM> and at a load of <NUM>, and
a Mw in the range of <NUM>,<NUM> to <NUM>,<NUM>/mol, preferably in the range of <NUM>,<NUM> to <NUM>,<NUM>/mol, more preferably in the range of <NUM>,<NUM> to <NUM>,<NUM>/mol.

The hinged component may comprise HDPE having a density in the range of <NUM> to <NUM>/m<NUM>, as measured according to ISO <NUM>, method A, and a MFI in the range of <NUM> to <NUM>/<NUM>, preferably of <NUM> to <NUM>/<NUM>, as measured according to ISO <NUM>-<NUM>:<NUM> at <NUM> and at a load of <NUM>, and a Mw in the range of <NUM>,<NUM> to <NUM>,<NUM>/mol.

The hinged component may preferably comprise HDPE having a density in the range of <NUM> to <NUM>/m<NUM>, as measured according to ISO <NUM>, method A, and a MFI in the range of <NUM> to <NUM>/<NUM>, preferably of <NUM> to <NUM>/<NUM>, as measured according to ISO <NUM>-<NUM>:<NUM> at <NUM> and at a load of <NUM>, and
a Mw in the range of <NUM>,<NUM> to <NUM>,<NUM>/mol.

The hinged component may comprise HDPE having a density in the range of <NUM> to <NUM>/m<NUM>, as measured according to ISO <NUM>, method A, and.

Linear low-density polyethylene (LLDPE) may for example be obtained by polymerizing ethylene with at least one α-olefin, which may be selected from <NUM>-butene, <NUM>-pentene, <NUM>-methyl-<NUM>-pentene, <NUM>-hexene, <NUM>-heptene and/or <NUM>-octene, preferably <NUM>-butene.

Linear low-density polyethylene (LLDPE) may be produced for example using at least one or exactly one metallocene catalyst or at least one or exactly one Ziegler-Natta catalyst.

Preferably, the linear low-density polyethylene (LLDPE) used according to the invention may be produced for example using at least one Ziegler-Natta catalyst comprising Mg and at least one or one of Ti, Hf or Zr.

LLDPE may preferably be produced using a gas phase or slurry process. The production processes of polyethylenes are summarised in "<NPL>.

The hinged component may comprise LLDPE having a density in the range of <NUM> to <NUM>/m<NUM>, preferably in the range of <NUM> to <NUM>/m<NUM> as measured according to ISO <NUM>, method A.

The hinged component may comprise LLDPE having a MFI in the range of <NUM> to <NUM>/<NUM>, preferably of <NUM> to <NUM>/<NUM>, more preferred of <NUM> to <NUM>/<NUM>, as measured according to ISO <NUM>-<NUM>:<NUM> at <NUM> and at a load of <NUM>.

The hinged component may comprise LLDPE having a Mw in the range of to <NUM>,<NUM> to <NUM>,<NUM>/mol, preferably <NUM>,<NUM> to <NUM>,<NUM>/mol, more preferably <NUM>,<NUM> to <NUM>,<NUM>/mol.

The hinged component may comprise LLDPE having a Mw/Mn in the range of to <NUM> to <NUM>.

The hinged component may comprise LLDPE having a density in the range of <NUM> to <NUM>/m<NUM>, preferably in the range of <NUM> to <NUM>/m<NUM> as measured according to ISO <NUM>, method A, and a MFI in the range of <NUM> to <NUM>/<NUM>, preferably of <NUM> to <NUM>/<NUM>, more preferred of <NUM> to <NUM>/<NUM>, as measured according to ISO <NUM>-<NUM>:<NUM> at <NUM> and at a load of <NUM>.

The hinged component may comprise LLDPE having preferably a density in the range of of <NUM> to <NUM>/m<NUM> as measured according to ISO <NUM>, method A, and a MFI in the range of of <NUM> to <NUM>/<NUM>, as measured according to ISO <NUM>-<NUM>:<NUM> at <NUM> and at a load of <NUM>.

The hinged component may comprise LLDPE having a density in the range of <NUM> to <NUM>/m<NUM>, preferably in the range of <NUM> to <NUM>/m<NUM> as measured according to ISO <NUM>, method A, and.

The hinged component may comprise LLDPE preferably having a density in the range of of <NUM> to <NUM>/m<NUM> as measured according to ISO <NUM>, method A, and
a MFI in the range of of <NUM> to <NUM>/<NUM>, as measured according to ISO <NUM>-<NUM>:<NUM> at <NUM> and at a load of <NUM>, and a Mw in the range of <NUM>,<NUM> to <NUM>,<NUM>/mol.

The polyethylene composition of this disclosure can be made using any conventional blending method such as but not limited to physical blending and in-situ blending by polymerization in multi reactor systems, also called reactor blending.

The polyethylene composition may for example be prepared in at least two sequential polymerization stages, for example by a bimodal or trimodal process. Gas phase, slurry phase or solution phase reactor systems may be used. In such a case the polyethylene composition comprises bimodal or multimodal HDPE. The bimodal or multimodal HDPE is thus a reactor blend of HDPE and LLDPE.

The polyethylene composition may be a reactor blend of an HDPE and LLDPE made in two or more reactors in series under different polymerization conditions. Thus the polyethylene composition may be bimodal HDPE or may comprise bimodal HDPE.

The polyethylene composition may be a blend of bimodal HDPE and LLDPE or unimodal HDPE and LLDPE or may comprise a blend of bimodal HDPE and LLDPE or unimodal HDPE and LLDPE.

The polyethylene composition comprising HDPE and the LLDPE may be applied as dry blend. All components may be added directly on the injection molding machine using a gravimetric dosing system. All components may be added together as a dry blend. Mixing of the materials can be done by industrial mixing devices, such as Nauta mixer and Henschel mixers.

The polyethylene composition comprising HDPE and the LLDPE according to the invention may be obtained by physical blending by molten mixing or by solution blending.

All components of the polyethylene compositions may be added together as a compound by melt blending. The compounding is usually carried out in a mixer (also known as a compounder), a single screw extruder or a twin screw extruder, wherein the polymer and the additives are melt-blended. Compounding techniques are well-known in the art.

The polyethylene composition according to the invention as well as the HDPE and LDPE may contain additives, for instance nucleating agents and clarifiers, stabilizers, release agents, fillers, plasticizers, anti-oxidants, lubricants, antistatics, scratch resistance agents, high performance fillers, pigments and/or colorants, impact modifiers, blowing agents, acid scavengers, recycling additives, coupling agents, antimicrobial, anti-fogging additives, slip additives, anti-blocking additives and polymer processing aids. These additives are well known in the art. The skilled person will choose the type and amount of additives such that they do not detrimentally influence the aimed properties of the composition.

The hinged component may comprise a polyethylene composition which has a density in the range of <NUM> to <NUM>/m<NUM>, preferably of <NUM> to <NUM>/m<NUM> measured according to according to ISO <NUM>.

The hinged component may comprise a polyethylene composition which has a MFI in the range of <NUM> to <NUM>/<NUM>, preferably in the range of <NUM> to <NUM>/<NUM>, most preferably in the range of <NUM> to <NUM>/<NUM> measured according to ISO <NUM> at <NUM> and a load of <NUM>.

The hinged component may comprise a polyethylene composition which has a density in the range of <NUM> to <NUM>/m<NUM>, preferably of <NUM> to <NUM>/m<NUM> measured according to according to ISO <NUM> and a MFI in the range of <NUM> to <NUM>/<NUM>, preferably in the range of <NUM> to <NUM>/<NUM>, most preferably in the range of <NUM> to <NUM>/<NUM> measured according to ISO <NUM> at <NUM> and a load of <NUM>.

The hinged component may comprise a polyethylene composition which has a density in the range of <NUM> to <NUM>/m<NUM> measured according to according to ISO <NUM> and a MFI in the range of <NUM> to <NUM>/<NUM>, preferably in the range <NUM> to <NUM>/<NUM>, most preferably in the range of <NUM> to <NUM>/<NUM> measured according to ISO <NUM> at <NUM> and a load of <NUM>.

The hinged component may comprise a polyethylene composition which has a density in the range of <NUM> to <NUM>/m<NUM> measured according to according to ISO <NUM> and a MFI in the range of <NUM> to <NUM>/<NUM> measured according to ISO <NUM> at <NUM> and a load of <NUM>.

The hinged component may comprise a polyethylene composition which has an Mw in the range of <NUM>,<NUM> to <NUM>,<NUM>/mol, preferably in the range of <NUM>,<NUM> to <NUM>,<NUM>/mol, more preferably in the range of <NUM>,<NUM> to <NUM>,<NUM>/mol.

The hinged component may comprise a polyethylene composition which has a Mw/Mn in the range of <NUM> to <NUM>, preferably in the range of <NUM> to <NUM>, more preferably in the range of <NUM> to <NUM>, most preferably in the range of <NUM> to <NUM>.

The hinged component may comprise a polyethylene composition which has an Mw in the range of <NUM>,<NUM> to <NUM>,<NUM>/mol, preferably in the range of <NUM>,<NUM> to <NUM>,<NUM>/mol, more preferably in the range of <NUM>,<NUM> to <NUM>,<NUM>/mol and a Mw/Mn in the range of <NUM> to <NUM>, preferably in the range of <NUM> to <NUM>, more preferably in the range of <NUM> to <NUM>, most preferably in the range of <NUM> to <NUM>.

The hinged component may comprise a polyethylene composition which has an Mw in the range of <NUM>,<NUM> to <NUM>,<NUM>/mol, and a Mw/Mn in the range of <NUM> to <NUM>.

The hinged component may comprise a polyethylene composition which has a density in the range of <NUM> to <NUM>/m<NUM>, measured according to according to ISO <NUM> and a MFI in the range of <NUM> to <NUM>/<NUM>, preferably in the range of <NUM> to <NUM>/<NUM>, most preferably in the range of <NUM> to <NUM>/<NUM> measured according to ISO <NUM> at <NUM> and a load of <NUM> and a Mw in the range of <NUM>,<NUM> to <NUM>,<NUM>/mol, and a Mw/Mn in the range of <NUM> to <NUM>.

The hinged component may comprise a polyethylene composition which has a density in the range of <NUM> to <NUM>/m<NUM>, measured according to according to ISO <NUM> and a MFI in the range of <NUM> to <NUM>/<NUM> measured according to ISO <NUM> at <NUM> and a load of <NUM> and an Mw in the range of <NUM>,<NUM> to <NUM>,<NUM>/mol, and a Mw/Mn in the range of <NUM> to <NUM>.

The hinged component may comprise a polyethylene composition which has a flexural modulus in the range of <NUM> to <NUM> MPa, preferably in the range of <NUM> to <NUM> MPa measured according to ISO178.

The hinged component may comprise a polyethylene composition which has an ESCR F50 value in the range of <NUM> to <NUM> hours, preferably in the range of <NUM> to <NUM> hours, measured according to ASTM D1693B, condition B, <NUM>% Igepal CO-<NUM>, <NUM>.

The hinged component may comprise a polyethylene composition which has a strain hardening modulus in the range of <NUM> to <NUM> MPa, preferably in the range of <NUM> to <NUM> MPa measured according to ISO18488.

The hinged component may comprise a polyethylene composition which has an ESCR F50 value in the range of <NUM> to <NUM> hours, preferably in the range of <NUM> to <NUM> hours, measured according to ASTM D1693B, condition B, <NUM>% Igepal CO-<NUM>, <NUM> and a strain hardening modulus in the range of <NUM> to <NUM> MPa, preferably in the range of <NUM> to <NUM> MPa measured according to ISO18488.

The hinged component may comprise a polyethylene composition which has an ESCR F50 value in the range of <NUM> to <NUM> hours, preferably in the range of <NUM> to <NUM> hours, measured according to ASTM D1693B, condition B, <NUM>% Igepal CO-<NUM>, <NUM> and
a strain hardening modulus in the range of <NUM> to <NUM> MPa, preferably in the range of <NUM> to <NUM> MPa measured according to ISO18488 and flexural modulus in the range of <NUM> to <NUM> MPa, preferably in the range of <NUM> to <NUM> MPa measured according to ISO178.

The hinged component may comprise a polyethylene composition which has an ESCR F50 value in the range of <NUM> to <NUM> hours, measured according to ASTM D1693B, condition B, <NUM>% Igepal CO-<NUM>, <NUM> and
a strain hardening modulus in the range of <NUM> to <NUM> MPa, measured according to ISO18488 and flexural modulus in the range of <NUM> to <NUM> MPa, measured according to ISO178.

The hinged component may comprise a polyethylene composition which has an ESCR F50 value in the range of <NUM> to <NUM> hours, measured according to ASTM D1693B, condition B, <NUM>% Igepal CO-<NUM>, <NUM> and a strain hardening modulus in the range of <NUM> to <NUM> MPa, measured according to ISO18488 and flexural modulus in the range of <NUM> to <NUM> MPa, measured according to ISO178 and a density in the range of <NUM> to <NUM>/m<NUM>, preferably of <NUM> to <NUM>/m<NUM> measured according to according to ISO <NUM> and a MFI in the range of <NUM> to <NUM>/<NUM>, preferably in the range of <NUM> to <NUM>/<NUM>, most preferably in the range of <NUM> to <NUM>/<NUM> measured according to ISO <NUM> at <NUM> and a load of <NUM>.

The hinged component may comprise a polyethylene composition which has an ESCR F50 value in the range of <NUM> to <NUM> hours, measured according to ASTM D1693B, condition B, <NUM>% Igepal CO-<NUM>, <NUM> and a strain hardening modulus in the range of <NUM> to <NUM> MPa, measured according to ISO18488 and flexural modulus in the range of <NUM> to <NUM> MPa, measured according to ISO178 and a density in the range of <NUM> to <NUM>/m<NUM>, measured according to according to ISO <NUM> and a MFI in the range of <NUM> to <NUM>/<NUM>, measured according to ISO <NUM> at <NUM> and a load of <NUM>.

The amount of HDPE and LLDPE in the polyethylene composition may be <NUM>%, preferably <NUM> %, more preferably <NUM>%, most preferably <NUM>%.

Preferably HDPE and LLDPE are the only polymers in the polyethylene composition.

The amount of HDPE and LLDPE in the polyethylene composition may be <NUM>%, preferably <NUM> %, more preferably <NUM>%, most preferably <NUM>% and the amount of HDPE may be in the range of <NUM>-<NUM>% and the amount of LLDPE may be in the range of <NUM>-<NUM>% based on the total amount of HDPE and LLDPE, wherein the total amount of HDPE and LLDPE is <NUM>%.

The polyethylene compositions described herein are used in the formation of a hinged component. The hinged component can be a part of a cap or closure or it can be a cap or closure per se.

A hinged component is a component comprising of at least two bodies which are connected to one another through a flexible hinge. The flexible hinge may be a continuous, partial or segmented section, which is typically thinner than the two or more bodies, so as to act as a fulcrum or pivot point about which the two or more bodies may bend. For example the two or more bodies may bend about the flexible hinge from a molded position into a flexed position.

The hinged component may be a living hinge. A living hinge or integral hinge is a thin flexible hinge (flexure bearing) made from the same material as the two rigid pieces it connects. It is typically thinned or cut to allow the rigid pieces to bend along the line of the hinge.

The hinged component, can be made according to any known method, including for example injection molding and compression molding techniques that are well known to persons skilled in the art. Hence, the hinged component comprising the polyethylene composition defined herein can be prepared with a process comprising at least one compression molding step and/or at least one injection molding step.

The hinged component may be manufactured in an injection molding process that creates a thin flexible hinge (flexure bearing) made from the same material as the two rigid pieces at one time as a single piece, and if correctly designed and constructed, it can remain functional over the life of the part.

The hinged component may be made by thermoforming.

The hinged component may be a cap or a part of a cap, for example a screw cap or a snap-top cap. The hinged component is preferably a hinged cap or closure, or the like for bottles, containers, jars, pouches and the like.

Caps and closures may be formed by continuous compression molding or by injection molding. Such closures include, for example, hinged caps, hinged screw caps, hinged snap-top caps, and hinged closures for bottles, containers and the like.

Preferably, the closure or cap comprising the hinged component is made of the same material as the rest of the closure or cap.

Most preferably, the hinged component is a hinged closure or cap.

The hinged component may be a flip-top hinge closure, such as a flip-top hinge closure for use on a plastic bottle or similar containers.

The hinged component may be a one-piece hinged snap-on cap which has a bottom part and a top part linked to each other by a hinge.

When a closure is a hinged closure, it may comprise a hinged component and generally consists of at least two bodies which are connected by a thinner section that acts as a hinge allowing the at least two bodies to bend from an initially molded position. The thinner section may be continuous or web-like, wide or narrow.

A hinged component may be a hinged closure (for bottles, containers and the like) and may consist of two bodies joined to each other by at least one thinner bendable portion (e.g. the two bodies can be joined by a single bridging portion, or more than one bridging portion, or by a webbed portion, etc.). A first body may contain a dispensing hole and which may snap onto or screw onto a container to cover a container opening (e.g. a bottle opening) while a second body may serve as a snap on lid which may mate with the first body.

The hinged component may for example be a living hinged cap or a part of a living hinged cap, for example a living hinged screw cap or a living hinged snap-top cap.

Hinged caps and closures can be made according to any known method, including for example injection molding and compression molding techniques that are well known to persons skilled in the art. Hence, in a closure (or cap) comprising the polyethylene composition is prepared with a process comprising at least one continuous compression molding step and/or at least one injection molding step.

The hinged closures and caps of this disclosure may be used for sealing bottles, containers and the like, for example, bottles that may contain drinkable water, and other foodstuffs, including but not limited to liquids that are non-pressurized. The hinged closures and caps may also be used for sealing bottles and containers containing non-food, such as shampoo and for example cleaning solutions.

The terms cap and closure are used interchangeably in the current disclosure, and both connote any suitably shaped molded article for enclosing, sealing, closing or covering etc., a suitably shaped opening, a suitably molded aperture, an open necked structure or the like used in combination with a container, a bottle, a jar and the like.

A packaging article may comprise the hinged component. The packaging article may be a bottle, a pouch, a jar, a container or a tube, for example a cosmetic tube, a soft tube or a squeeze tube.

The hinged component may comprise a polyethylene composition, wherein the polyethylene composition comprises.

MFI was measured according to ISO <NUM> at <NUM> and a load of <NUM> for HDPE, LLDPE and inventive examples.

MFI was measured according to ISO <NUM> at <NUM> and a load of <NUM> for PP.

Density was measured according to ISO <NUM>. Specimens prepared according to ISO17855-<NUM>, compression molding temperature: <NUM>, compression molding cooling rate: <NUM>/min.

The F50 was measured according to ASTM D1693B, condition B, <NUM>% Igepal CO-<NUM>, <NUM>.

Strain hardening modulus was measured according to ISO18488.

For HDPE samples and inv. <NUM> the following conditions were applied.

For the PP (QR673K) sample the following conditions were applied.

The molecular structure parameters were calculated by SEC universal based on IR5. Method: IAV Molecular Characterisation, Code: SEC-HT-<NUM> (universal calculation) Chromatography: Polymer Laboratories PL-GPC220 (System ID: C7).

Detection: Polymer Laboratories PL BV-<NUM> viscometer; Refractive index detector. Column set: three Polymer Laboratories <NUM> PLgel Olexis, <NUM> x <NUM>.

PE molar mass calibration: performed with linear PE standards.

PP molar mass calibration: linear PE standard were used for calibration of the system. A PP molar mass calibration was obtained after conversion from PE to PP using the Mark-Houwink constants of PE and PP.

HDPE <NUM>-<NUM> are commercially available HDPE resins intended for use as screw caps. PP is a commercially available polypropylene random copolymer resin that is intended to be used for hinged caps.

<NUM> is a mixture of <NUM> wt% HDPE (HDPE resin CC3054 of SABIC) and <NUM> wt% LLDPE (HDPE resin R50035EE of SABIC). <NUM> was prepared by compounding in an extruder. This was done by using the KraussMaffei Berstorff GmbH ZE25Ax48D twin-screw extruder, with screw diameter of <NUM> and L/D ratio of <NUM>:<NUM>. Compounding was performed at <NUM> using a screw speed of <NUM> rpm.

Table <NUM> give an overview of the materials that were used and their MFI and density.

Table <NUM> gives an overview on SEC data.

Table <NUM> gives an overview on the mechanical properties.

Table <NUM> shows the process-ability of the materials for injection molding. First, injection molding with a spiral mould was performed, all the materials were injection molded with a melt temperature of <NUM>, injection speed of <NUM>/s and until an injection pressure of <NUM> bar was reached. The length of the flow at different thicknesses were measured and listed in Table <NUM>. The longer the flow length indicate the better processability of the material during injection molding. The process-ability of the <NUM>% CC3054 (HDPE) + <NUM>% R50035EE (LLDPE) is comparable to or slightly better than M1053.

A Husky injection machine H120-RS35/<NUM> with a <NUM>-cavity hinge cap mold was used. The machine has a clamping force of <NUM> tons and is equipped with a standard <NUM>-zone screw of Φ28mm & L/D <NUM>. The hinge cap tool has a typical butterfly hinge design and work with both PP and HDPE materials. There is also in-mold-closing unit integrated in the tool, which enables to close the caps in the tool before the caps been ejected.

The maximum injection pressure measured during cap injection molding also indicate the process-ability of the materials. The process-ability of the <NUM>% CC3054 (HDPE) + <NUM>% R50035EE (LLDPE) is comparable to or slightly better than M1053, which is in line with the results from the spiral mould results.

The fatigue performance of the hinged caps was evaluated by flexing the hinge using a bending tester. The base part and the flip-top part of the cap are clamped separately by the fixture, and the base part was bended along the hinge while the flip-top was fixed and not moved. The base part of the caps were bent from <NUM>° (open) to an angle of <NUM>° that is close to the closing position. Each cap was bended until hinge failure was observed or reached <NUM> times of bending. The results are listed in Table <NUM>.

<NUM> showed good hinge fatigue performance (> <NUM> bending cycles).

The ESCR performance of the hinged cap was evaluated in the following way ESCR of a hinged cap.

The ESCR performance of the hinged cap was evaluated in the following way.

Table <NUM> shows the ESCR test results, reported are the average number of bending cycles until hinge failure or up to <NUM> cycles.

<NUM> showed a good hinge performance (> <NUM> open/close cycles) after ESCR conditioning.

Claim 1:
Hinged component comprising a polyethylene composition, the polyethylene composition comprising
- a high density polyethylene (HDPE) having a density in the range of <NUM> to <NUM>/m<NUM> measured according to ISO <NUM>, a melt flow index in the range of <NUM> to <NUM>/<NUM> measured according to ISO <NUM> at a load <NUM> and a temperature of <NUM>, a weight average molecular weight Mw measured by size exclusion chromatography of in the range of <NUM>,<NUM> to <NUM>,<NUM>/mol, a molecular weight distribution Mw/Mn in the range of <NUM> to <NUM>, and
- a linear low density polyethylene (LLDPE) having a density in the range of <NUM> to <NUM>/m<NUM> measured according to ISO <NUM>, a melt flow index in the range of <NUM> to <NUM>/<NUM> measured according to ISO <NUM> at a load <NUM> and a temperature of <NUM>, a weight average molecular weight Mw measured by size exclusion chromatography in the range of <NUM>,<NUM> to <NUM>,<NUM>/mol and a molecular weight distribution Mw/Mn in the range of <NUM> to <NUM>;
wherein the polyethylene composition has an overall density in the range of <NUM> to <NUM>/m<NUM> measured according to ISO <NUM> and an overall melt flow index in the range of <NUM> to <NUM>/<NUM> measured according to ISO <NUM> at a load <NUM> and a temperature of <NUM>,
wherein the amount of the HDPE is in the range of <NUM>-<NUM>% by weight of the total amount of the HDPE and LLDPE
and wherein the amount of the LLDPE is in the range of <NUM>-<NUM>% by weight of the total amount HDPE and LLDPE and wherein the total amount of the HDPE and LLDPE is <NUM> % by weight.