Patent Description:
Polyolefins, in particular polyethylene and polypropylene, are increasingly consumed in large amounts in a wide range of applications, including packaging for food and other goods, fibres, automotive components, and a great variety of manufactured articles. Polypropylene flexible packaging articles, and therefore waste comprising these systems, are in general heavily printed, often metallized, small in size, and in contact to biological contaminations. These attributes result in a high contamination level, dark color, odor and emissions, which challenge mechanical recycling. In particular, film application requires high quality grades and challenges intrinsic material properties of recyclate materials.

Many attempts have been made for purifying recycling streams as originating from post-consumer trash/waste. Among those measures washing, sieving, aeration and the like may be mentioned. For example, <CIT> discloses a process for the production of polyolefin recyclates from mixed color polyolefin waste including packaging waste comprising cold washing the waste with water followed by washing with an alkali medium at <NUM>, followed by flake color sorting to receive color sorted (white, transparent, other colors) mono polyolefin rich fractions. Those fractions are then treated at <NUM> - <NUM>. <CIT> describes a process comprising contacting PCR polyolefin chips containing volatile impurities with a heated gas at a superficial velocity sufficient to substantially reduce the volatile impurities such as odor active substances. However, up to now the market is actively looking for the recycled materials with the features as close as possible to the virgin resins. Main applications of flexible polypropylene recyclates could be cast and BOPP film applications, decoration films for furniture, tapes, labels, or additive for injection molding applications to tailor properties, or base material for peroxide modified grades. Color is still a remaining problem not completely addressed. A specific demand exists for recyclates suitable for flexible articles such as films.

Thus, the problem of providing a more valuable polypropylene blend remains.

The present invention provides a mixed-plastic polypropylene blend having.

wherein the mixed-plastic polypropylene blend is a recycled material.

The present invention is also concerned with the mixed-plastic polypropylene blend in pellet form. The present invention further provides extruded articles made from the mixed-plastic polypropylene blend and a use for packaging.

It has been surprisingly found that the mixed-plastic polypropylene blend according to the present invention provides improved flexibly enabling numerous demanding end-use applications.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the invention pertains. Although, any methods and materials similar or equivalent to those described herein can be used in practice for testing of the present invention, the preferred materials and methods are described herein. In describing and claiming the present invention, the following terminology will be used in accordance with the definitions set out below.

Unless clearly indicated otherwise, use of the terms "a," "an," and the like refers to one or more.

As used herein, mixed plastics (also known as post-consumer waste) refers to objects having completed at least a first use cycle (or life cycle), i.e. having already served their first purpose; while "industrial waste" refers to manufacturing scrap, which does not normally reach a consumer. According to the present invention, the waste stream is a consumer waste stream, such a waste stream may originate from conventional collecting systems such as those implemented in the European Union. Post-consumer waste material may e.g. be characterized by a limonene content of from <NUM> to <NUM> ppm (as determined using solid phase microextraction (HS-SPME-GC-MS) by standard addition). Mixed plastic may e.g. be defined as the presence of low amounts of compounds usually not found in virgin polypropylene blends such as polystyrenes, polyamides, polyesters, wood, paper, limonene, aldehydes, ketones, fatty acids, metals, and/or long term decomposition products of stabilizers. Virgin polypropylene blends denote blends as directly originating from the production process without intermediate use. Thus, virgin materials and recycled materials easily can be differentiated based on absence or presence of contaminants such as limonene and/or fatty acids and/or paper and/or wood.

As a matter of definition, "mixed plastics" can be equated with detectable amounts of polystyrene and/or polyamide-<NUM> and/or limonene and/or fatty acids.

The mixed-plastic polypropylene blend further has a broadened molecular weight distribution because it is a mechanical blend of countless polypropylenes and some very minor amount of low density polyethylene as well as linear low density polyethylenes. It will be understood by those skilled in the art that polypropylenes from various manufactures end up in plastic trash streams particularly when presorted in polyolefin-rich plastic trash streams.

It further will be understood by those skilled in the art that a soluble fraction (SF) as obtained by CRYSTEX QC analysis having an intrinsic viscosity (iV(SF)) in the range from <NUM> to below <NUM> dl/g is typically found in material from recycling streams. In a preferred aspect of the invention the soluble fraction (SF) as obtained by CRYSTEX QC analysis has an intrinsic viscosity (iV(SF)) in the range from <NUM> to below <NUM> dl/g.

It should be understood that mixed plastics may vary broadly in composition, i.e. may include polyolefin homopolymers and polyolefin copolymers.

Conventionally the mixed plastics according to the present invention may have one or more of the following:.

TGA according to the following procedure:
Thermogravimetric Analysis (TGA) experiments may be performed with a Perkin Elmer TGA <NUM>.

Approximately <NUM>-<NUM> of material shall be placed in a platinum pan. The temperature is equilibrated at <NUM> for <NUM> minutes, and afterwards raised to <NUM> under nitrogen at a heating rate of <NUM>/min. The weight loss between about <NUM> and <NUM> (WCO<NUM>) is assigned to CO<NUM> evolving from CaCO<NUM>, and therefore the chalk content is evaluated as: <MAT>.

Afterwards the temperature is lowered to <NUM> at a cooling rate of <NUM>/min. Then the gas is switched to oxygen, and the temperature is raised again to <NUM>. The weight loss in this step is assigned to carbon black (Wcb). Knowing the content of carbon black and chalk, the ash content excluding chalk and carbon black is calculated as: <MAT>.

Where Ash residue is the weight% measured at <NUM> in the first step conducted under nitrogen. The ash content is estimated to be the same as the talc content for the investigated recyclates.

Paper and wood are determined by conventional laboratory methods including milling, flotation, microscopy and Thermogravimetric Analysis (TGA).

Limonene quantification can be carried out using solid phase microextraction (HS-SPME-GC-MS) by standard addition.

<NUM> ground samples are weighed into <NUM> headspace vials and after the addition of limonene in different concentrations and a glass-coated magnetic stir bar, the vial is closed with a magnetic cap lined with silicone/PTFE. Micro capillaries (<NUM> pL) are used to add diluted limonene standards of known concentrations to the sample. Addition of <NUM>, <NUM>, <NUM> and <NUM> ng equals <NUM>/kg, <NUM>/kg, <NUM>/kg and <NUM>/kg limonene, in addition standard amounts of <NUM>/kg, <NUM>/kg and <NUM>/kg limonene is used in combination with some of the samples tested in this application. For quantification, ion-<NUM> acquired in SIM mode is used. Enrichment of the volatile fraction is carried out by headspace solid phase microextraction with a <NUM> stable flex <NUM>/<NUM> pm DVB/Carboxen/PDMS fibre at <NUM> for <NUM> minutes. Desorption is carried out directly in the heated injection port of a GCMS system at <NUM>.

Fatty acid quantification is carried out using headspace solid phase micro-extraction (HS-SPME-GC-MS) by standard addition.

<NUM> ground samples are weighed in <NUM> headspace vial and after the addition of limonene in different concentrations and a glass coated magnetic stir bar the vial is closed with a magnetic cap lined with silicone/PTFE. <NUM>µL Micro-capillaries are used to add diluted free fatty acid mix (acetic acid, propionic acid, butyric acid, pentanoic acid, hexanoic acid and octanoic acid) standards of known concentrations to the sample at three different levels. Addition of <NUM>, <NUM>, <NUM> and <NUM> ng equals <NUM>/kg, <NUM>/kg, <NUM>/kg and <NUM>/kg of each individual acid. For quantification ion <NUM> acquired in SIM mode is used for all acids except propanoic acid, here ion <NUM> is used.

For the purpose of this invention the mixed-plastic polypropylene blend has preferably at least one of the following:.

A blend denotes a mixture of two or more components, wherein at least one of the components is polymeric. In general, the blend can be prepared by mixing the two or more components. Suitable mixing procedures are known in the art.

If not indicated otherwise "%" refers to weight-%.

When referred to compositions and the weight percent of the therein comprised ingredients it is to be understood that according to the present invention the overall amount of ingredients does not exceed <NUM>% (±<NUM>% due to rounding).

The mixed-plastic polypropylene blend according to the present invention has.

Preferably, the soluble fraction (SF) content determined according to CRYSTEX QC analysis is in the range from <NUM> to <NUM> wt. -%, more preferably from <NUM> to <NUM> wt. -%, even more preferably from <NUM> to <NUM> wt. -%, and in particular from <NUM> to <NUM> wt.

Preferably, the crystalline fraction (CF) content determined according to CRYSTEX QC analysis is in the range from <NUM> to <NUM>. -%, more preferably from <NUM> to <NUM> wt. -%, even more preferably from <NUM> to <NUM> wt. -%, still more preferably from <NUM> to <NUM> wt. -%, and in particular from <NUM> to <NUM> wt.

Preferably, the mixed-plastic polypropylene blend has ethylene units (C2) determined according to CRYSTEX QC analysis, in the range from <NUM> to <NUM> wt. -%, more preferably from <NUM> to <NUM> wt. -%, based on the total weight of the mixed-plastic polypropylene blend. Without being bound to any theory, it is assumed that when the C2 units of a polyolefin material are determined according to CRYSTEX QC the vast majority of the remaining polyolefin units may be attributed to propylene units (C3 units). Thus, the mixed-plastic polypropylene blend preferably has propylene units (C3) determined according to CRYSTEX QC analysis, in the range from <NUM> to <NUM> wt. -%, more preferably from <NUM> to <NUM> wt. -%, based on the total weight of the mixed-plastic polypropylene blend.

Preferably, the mixed-plastic polypropylene blend has an ethylene content of the crystalline fraction (measured by Infrared Spectroscopy (IR) during CRYSTEX analysis), in the range of <NUM> to <NUM> wt. -%, more preferably from <NUM> to <NUM> wt. -%, and even more preferably from <NUM> to <NUM> wt.

Preferably, the mixed-plastic polypropylene blend has an ethylene content of the soluble fraction (measured by Infrared Spectroscopy (IR) during CRYSTEX analysis), in the range of <NUM> to <NUM> wt. -%, more preferably from <NUM> to <NUM> wt. -%, and even more preferably from <NUM> to <NUM> wt.

Preferably, the soluble fraction (SF) has an ethylene-propylene rubber (EPR) content as expressed by equation (<NUM>) of <NUM> to less than <NUM> wt. -%, more preferably of <NUM> to <NUM> wt. -%, even more preferably of <NUM> to <NUM> wt. -%, and in particular of <NUM> to <NUM> wt. -%, where the EPR corresponds to the fraction with a molar mass higher than logM of <NUM> to <NUM> of the soluble fraction (SF) in TCB at <NUM> obtained by Cross Fractionation Chromatography (CFC) analysis <MAT> wherein Hj denotes the signal height at logM value j.

Preferably, the soluble fraction (SF) determined according to CRYSTEX QC analysis has an intrinsic viscosity (iV(SF)) in the range from <NUM> to <NUM> dl/g, more preferably from <NUM> to <NUM> dl /g, even more preferably from <NUM> to <NUM> dl/g, and in particular from <NUM> to <NUM> dl/g.

Preferably, the mixed-plastic polypropylene blend has a ratio of the molecular weight of the low crystalline polyethylene fraction (LCF-PE) as observed in CFC analysis in the range of <NUM> to <NUM> (Mw LCF(<NUM>-<NUM>)) to the molecular weight of the crystalline ethylene-propylene copolymer as observed in CFC analysis in the range of <NUM> to <NUM> (Mw EP Copo (<NUM>-<NUM>)) is of <NUM> to less than <NUM>, more preferably of <NUM> to <NUM>, even more preferably of <NUM> to <NUM>, and in particular of <NUM> to <NUM>.

Preferably, the mixed-plastic polypropylene blend has a molecular weight of the low crystalline polyethylene fraction (LCF-PE) as observed in CFC analysis in the range of <NUM> to <NUM> (Mw LCF(<NUM>-<NUM>)) is in the range of <NUM>,<NUM> to <NUM>,<NUM>/mol, more preferably of <NUM>,<NUM> to <NUM>,<NUM>/mol, and in particular of <NUM>,<NUM> to <NUM>,<NUM>/mol.

Preferably, the mixed-plastic polypropylene blend has a low crystalline polyethylene fraction (LCF-PE) content as expressed by equation (<NUM>) of less than <NUM> wt. -%, more preferably less than <NUM> wt. -%, and in particular less than <NUM> wt. -%, wherein said LCF-PE content is obtained by CFC analysis <MAT> wherein Hij denotes the signal height and i the elution temperature and j the logM value. Preferably, the mixed-plastic polypropylene blend has a low crystalline polyethylene fraction (LCF-PE) content as expressed by equation (<NUM>) of <NUM> to less than <NUM> wt. -%, more preferably <NUM> to <NUM> wt. -%, and in particular <NUM> to <NUM> wt. -%, wherein said LCF-PE content is obtained by CFC analysis <MAT> wherein Hij denotes the signal height and i the elution temperature and j the logM value.

Preferably, the mixed-plastic polypropylene blend has a Large Amplitude Oscillatory Shear - Non-Linear Factor [LAOS -NLF] (<NUM>, <NUM>%) higher than <NUM>, more preferably higher than <NUM> to <NUM>, even more preferably higher than <NUM> to <NUM>, and in particular higher than <NUM> to <NUM>, whereby <MAT> whereby.

Preferably, the mixed-plastic polypropylene blend has a CIELAB color space (L*a*b*) of.

Preferably, the mixed-plastic polypropylene blend has a melt flow rate (ISO1133, <NUM>; <NUM>) of <NUM> to <NUM>/<NUM>, preferably <NUM> to <NUM>/<NUM>, more preferably <NUM> to <NUM>/<NUM> and most preferably more than <NUM> to <NUM>/<NUM>. In another preferred embodiment, the mixed-plastic polypropylene blend has a melt flow rate (ISO1133, <NUM>; <NUM>) of <NUM> to <NUM>/<NUM>, preferably of <NUM> to <NUM>/<NUM>, more preferably of <NUM> to <NUM>/<NUM>, and in particular of <NUM> to <NUM>/<NUM>.

Preferably, the mixed-plastic polypropylene blend contains one or more of the following substances:.

Preferably, the mixed-plastic polypropylene blend comprises polyamide(s) determined by FTIR spectroscopy using the absorption of the band at <NUM>-<NUM> (PA6) in the range of up to <NUM> wt. -%, more preferably of <NUM> to <NUM> wt. -%, based on the total weight of the mixed-plastic polypropylene blend. Preferably, the mixed-plastic polypropylene blend comprises polystyrene (PS) determined by FTIR spectroscopy using the absorption of the band at <NUM>-<NUM> (PS) in the range of up to <NUM> wt. -%, more preferably up to <NUM> wt. -%, based on the total weight of the mixed-plastic polypropylene blend.

Preferably, the mixed-plastic polypropylene blend comprises chalk determined by TGA in the range of up to <NUM> wt. -%, more preferably of <NUM> to <NUM> wt. -%, based on the total weight of the mixed-plastic polypropylene blend. Preferably, the mixed-plastic polypropylene blend comprises talc determined by TGA in the range of up to <NUM> wt. -%, more preferably of <NUM> to <NUM> wt. -%, based on the total weight of the mixed-plastic polypropylene blend. Preferably, the mixed-plastic polypropylene blend comprises ash determined by TGA in the range of up to <NUM> wt. -%, more preferably of <NUM> to <NUM> wt. -%, based on the total weight of the mixed-plastic polypropylene blend.

Preferably, the mixed-plastic polypropylene blend comprises heavy metals selected from the group of cadmium, chromium, mercury, lead, and mixtures thereof determined by XRF in the range of up to <NUM> ppm, preferably up to <NUM> ppm, and in particular <NUM> ppm. In this connection, it is to be understood that <NUM> ppm denotes that the detection limit has been reached. Preferably, the mixed-plastic polypropylene blend comprises titanium determined by XRF in the range of up to <NUM> ppm, preferably of <NUM> to <NUM> ppm, and in particular <NUM> to <NUM> ppm.

Preferably, the density of the mixed-plastic polypropylene blend determined according to DIN EN ISO <NUM> is of <NUM> to <NUM>/m<NUM>, more preferably of <NUM> to <NUM>, even more preferably <NUM> to <NUM>/m<NUM>, and in particular of <NUM> to <NUM>/m<NUM>.

Preferably, the mixed-plastic polypropylene blend has an Eta(<NUM>. 05rad/s), <NUM> of <NUM> to <NUM> Pa. s, more preferably of <NUM> to <NUM> Pa. s, and in particular of <NUM> to <NUM> Pa.

Preferably, the mixed-plastic polypropylene blend has an Eta(300rad/s), <NUM> of <NUM> to <NUM> Pa. s, preferably of <NUM> to <NUM> Pa. s, and in particular of <NUM> to <NUM> Pa.

Preferably, the mixed-plastic polypropylene blend has a main peak of heat of fusion determined by DSC of <NUM> to <NUM> J/g, more preferably of <NUM> to <NUM> J/g.

Preferably, the mixed-plastic polypropylene blend has a tensile strain at break determined according to ISO527-<NUM>/A,><NUM> of <NUM> to <NUM>%, more preferably of <NUM> to <NUM>%, and in particular of <NUM> to <NUM>%. Preferably, the mixed-plastic polypropylene blend has a tensile strain at break determined according to ISO527-<NUM>/A,><NUM> of <NUM> to <NUM>%, more preferably of <NUM> to <NUM>%, and in particular of <NUM> to <NUM>%.

Preferably, the mixed-plastic polypropylene blend has a Shear Thinning Factor (STF), Eta(<NUM>)/Eta(<NUM>) of <NUM> to <NUM>, preferably of <NUM> to <NUM>.

Preferably, the mixed-plastic polypropylene blend is in form of pellets.

The process for providing the mixed-plastic polypropylene blend according to the present invention is pretty demanding. The process comprises the following steps:.

It is to be understood that the above process relates according to the present invention to the provision of a recycled polypropylene blend.

Preferably, the above mechanical polyolefin recycling process further comprises steps.

In a particular embodiment, the above mechanical polyolefin recycling process comprises steps l2)/m2) and l3/m3).

Preferable, the shredding of step d) of the above mechanical polyolefin recycling process is a wet shredding process, wherein the sorted polyolefin recycling stream (C) is first contacted with an alkaline aqueous solution (W0) having a pH in the range from <NUM> to <NUM> and the obtained suspension is subjected to shredding.

Preferably, the first aqueous washing solution (W1) comprises a detergent in an amount in the range from <NUM> wt. -% to <NUM> wt. -%, relative to the total weight of the first aqueous washing solution (W1).

The detergent(s) may be commercially available detergent mixtures or may be composed in any way known to the person skilled in the art. Suitable detergents include TUBIWASH SKP, TUBIWASH GFN, TUBIWASH EYE and TUBIWASH TOP, commercially available from CHT, KRONES colclean AD <NUM>, KRONES colclean AD <NUM> and KRONES colclean AD <NUM> from KIC KRONES, and P3-stabilon WT, P3 stabilon AL from ECOLAB Ltd.

Preferably, the second alkaline aqueous washing solution (W2) of the above mechanical polyolefin recycling process is an alkaline aqueous solution of a base selected from the group consisting of calcium hydroxide, potassium hydroxide, magnesium hydroxide, sodium bicarbonate, sodium hydroxide and mixtures thereof, preferably sodium hydroxide. In this connection, the amount of the base in the alkaline aqueous solution is preferably in the range from <NUM> to <NUM> wt. -%, more preferably in the range from <NUM> to <NUM> wt. -%, most preferably in the range from <NUM> to <NUM> wt. -%, relative to the total weight of the alkaline aqueous solution.

Preferably, the second aqueous washing solution (W2) comprises a detergent in an amount in the range from <NUM> wt. -% to <NUM> wt. -%, relative to the total weight of the second aqueous washing solution (W2).

The detergent(s) may be a commercially available detergent mixture or may be composed in any way known to the person skilled in the art. Suitable detergents include TUBIWASH SKP, TUBIWASH GFN, TUBIWASH EYE and TUBIWASH TOP, commercially available from CHT, KRONES colclean AD <NUM>, KRONES colclean AD <NUM> and KRONES colclean AD <NUM> from KIC KRONES, and P3-stabilon WT, P3 stabilon AL from ECOLAB Ltd.

Preferably, the alkaline aqueous washing solution removed in step h) of the above mechanical polyolefin recycling process is recycled for use as the first alkaline aqueous washing solution (W1) and the alkaline aqueous solution (W0), if present.

Preferably, the precursor mixed plastic recycling stream (A) of the above mechanical polyolefin recycling process originates from post-consumer waste, post-industrial waste, or a combination thereof, preferably from post-consumer waste.

Preferably, the precursor mixed plastic recycling stream (A) of the above mechanical polyolefin recycling process originates from post-consumer waste comprising more than <NUM> wt. -%, preferably more than <NUM> wt. -%, based on the total weight of the post-consumer waste of flexible polypropylene post-consumer waste. Flexible polypropylene post-consumer waste may origin from films, bags, pouches, and the like.

The person skilled in the art would be aware of multiple ways in which the sieving of step b) could be achieved and, as such, this sieving step is not particularly limited. That said, it is preferred that the sieving of step b) is achieved by using one sieve with a sieve diameter of <NUM> and another sieve with a sieve diameter of <NUM> to divide the precursor mixed recycling stream into three streams, an undersized stream of articles having a longest dimension of less than <NUM>, an oversized stream of articles having a longest dimension of greater than <NUM> and the sieved mixed plastic recycling stream (B). The undersized and oversized streams may either be discarded or redirected for use in other mechanical polyolefin recycling processes.

In the broadest sense, any optical sorter can be used to achieve the sorting of step c) (and step k)). In the context of the present invention, the term "optical sorter" refers to a sorting unit that uses any form of EM-radiation (visible or non-visible) to differentiate the pieces of the sieved mixed plastic recycling stream (B).

Suitable methods for sorting the recycling stream according to colour include camera systems (operating in the visible range of the EM-spectrum) and visible reflectance spectroscopy.

Suitable methods for sorting the recycling stream according to polyolefin type include near-IR spectroscopic analysis, mid-IR spectroscopic analysis, high-speed laser spectroscopic analysis, Raman spectroscopic analysis, Fourier-transform infrared (FT IR) spectroscopic analysis. Particularly preferred is near-IR spectroscopic analysis.

Suitable methods for sorting the recycling stream according to article type include camera systems (operating in the visible range of the EM-spectrum).

It is preferred that the sorting of step c) sorts according to colour and polyolefin type, meaning that the single-colour sorted polyolefin recycling stream (C) is of a single colour and all articles contain a single polyolefin.

In some embodiments, a single sensor type (e.g. near-IR sensor or camera system operating in the visible range of the EM spectrum) can be used to distinguish more than one property (e.g. colour and polyolefin type or colour and article form). Furthermore, many near-IR sensor units comprises visible reflectance units or may be configured to measure both the near-IR and visible areas of the EM spectrum, meaning that a single sensor unit may use multiple detection methods.

The term "article form", as used herein, refers to the shape and form of articles present in a polyolefin recycling stream. Such articles may be present, inter alia, in the form of films, bags, and pouches, which may be considered as flexible articles, and, inter alia, in the form of moulded articles such as food containers and trays, skin-care product containers, and plastic bottles, which may be considered as rigid articles. Commercial optical sorters, such as Tomra Autosort, RTT Steinert Unisort, Redwave, and Pellenc, are able to separate so-called rigid articles from so-called flexible articles via their aerodynamic properties (i.e. a stream of gas is typically applied to the stream and those articles being rigid articles will fall with a different arc than flexible articles), converting streams containing such articles into so-called rigid streams and flex streams.

Multiple detection methods and/or multiple sensors can be employed to achieve the sorting of step c).

It is further preferred that the sorting of step c) sorts according to colour, polyolefin type and article form, meaning that the single-colour sorted polyolefin recycling stream (C) is of a single colour, all articles contain a single polyolefin and that the stream contains only rigid or flexible articles.

Although the above processes are suitable for the isolation of any desired polyolefin from a polyolefin mixed recycling stream, the isolation of polyethylene or polypropylene is particularly desirable, since these will most likely be the major polyolefin components of any polyolefin mixed recycling stream, and isolated polyethylene or isolated polypropylene can be fed into pure recycled polyolefin streams or extruded and pelletized along to afford pellets of the desired polyolefin, i.e. of polyethylene or polypropylene.

Preferably, the single-colour sorted polyolefin recycling stream (C) of the above mechanical polyolefin recycling process is a single-colour sorted polypropylene recycling stream.

The sorting of step c) can be achieved through simple sorting algorithms, wherein the optical sensor(s) are programmed to assess which pieces should be selected or rejected based on simple binary considerations. Alternatively, more complex Al-based systems can be used to achieve a more precise sorting, in particular when sorting according to article form.

Step k) uses at least a first optical sorter to remove any flake that contains material other than the target polyolefin. The selection criteria in this optical sorter are that if any material other than the target polyolefin is present in a given flake, that this flake will be separated from the stream, affording a purified polyolefin recycling stream.

Multiple optical sorters having the same sorting criteria may be arranged in series to improve the purity of the intermediate (K). Alternatively or additionally, multiple optical sorters may be arranged in series to sort for different criteria, for example colour and/or article form; however, it is preferred that each of the one or more optical sorters of step k) are sorting by polyolefin type as described above.

Step h) involves removing the second alkaline aqueous washing solution (W2) and any material not floating on the surface of the first aqueous washing solution from the second suspended polyolefin recycling stream (G) to obtain a second washed polyolefin recycling stream (H).

In contrast to step f), wherein only minor amounts of foreign material suspended or dissolved in the alkaline aqueous washing solution are removed, step h) involves a so-called float/sink separation, whereby any and all material not floating on the surface of the alkaline aqueous washing solution is removed. This would be understood by the person skilled in the art to have the effect of removing any foreign material having a density of greater than <NUM>/cm<NUM>.

Step k) may be performed in a flake sorter, preferably in a belt-flake sorter.

The above-outlined mixed-plastic polypropylene blend can be used to produce any suitable article.

In a further aspect, the present invention relates to an extruded article made from the above-outlined mixed-plastic polypropylene blend.

The skilled person will be aware of how to obtain extruded articles under standard conditions.

Preferably, the extruded article is a film.

Preferably, the film is extruded at a melt temperature of <NUM> to <NUM>, preferably of <NUM> to <NUM>, and in particular of <NUM> to <NUM>.

Preferably, the film is extruded at a screw speed in the range of <NUM> to <NUM> rpm, preferably of <NUM> to <NUM> rpm, and in particular of <NUM> to <NUM> rpm.

Preferably, the film is extruded by using a chill roll, preferably wherein the chill roll temperature is in the range of <NUM> to <NUM>. The skilled person in the art is aware of the specific chill roll temperature that is to be chosen for a certain material.

Preferably, the film has a thickness of <NUM> to <NUM>, more preferably of <NUM> to <NUM>, even more preferably of <NUM> to <NUM>, and in particular of <NUM> to <NUM>.

Preferably, the film has an impact failure weight determined by the free falling dart test according to ASTM D1709 of <NUM> to <NUM>, more preferably of <NUM> to <NUM>, and in particular of <NUM> to <NUM>.

Preferably, the film has a normalised total penetration energy of film puncture determined according to ISO7765-<NUM>, <NUM>/s at <NUM> of more than <NUM> J/mm, more preferably of more than <NUM> to <NUM> J/mm, and in particular of <NUM> to <NUM> J/mm.

Preferably, the film has a MD relative tear resistance determined according to ISO6383-<NUM> of less than <NUM> N/mm, more preferably of <NUM> to <NUM> N/mm, and in particular of <NUM> to <NUM> J/mm. Preferably, the film has a TD relative tear resistance determined according to ISO6383-<NUM> of less than <NUM> J/mm, more preferably of <NUM> to less than <NUM> J/mm, and in particular of <NUM> to <NUM> J/mm.

Preferably, the film has a MD tensile modulus determined according to ISO527-<NUM>, <NUM> of more than <NUM> MPa, more preferably of <NUM> to <NUM> MPa, and in particular of <NUM> to <NUM> MPa. Preferably, the film has a TD tensile modulus determined according to ISO527-<NUM>, <NUM> of more than <NUM> MPa, more preferably of <NUM> to <NUM> MPa, and in particular of <NUM> to <NUM> MPa.

Preferably, the film has an MD (machine direction) gloss, film outside, determined according to ASTM D2457, <NUM>°, of more than <NUM>°, more preferably of <NUM> to <NUM>°, and in particular of <NUM> to <NUM>°. Preferably, the film has an TD (transverse direction) gloss, film outside, determined according to ASTM D2457, <NUM>°, of more than <NUM>°, more preferably of <NUM> to <NUM>°, and in particular of <NUM> to <NUM>°.

Preferably, the film has a clarity determined according to ASTM D1003 of more than <NUM>%, more preferably of <NUM> to <NUM>%, and in particular of <NUM> to <NUM>%. Preferably, the film has a haze determined according to ASTM D1003 of less than <NUM>%, more preferably of <NUM> to <NUM>%, and in particular of <NUM> to <NUM>%. Preferably, the film has a diffuse luminous transmittance determined according to ASTM D1003 of less than <NUM>%, more preferably of <NUM> to less than <NUM>%.

In a further aspect, the present invention relates to the use of the above-outlined mixed-plastic polypropylene blend for packaging.

All preferred aspects, definitions and embodiments as described above shall also hold for the extruded article and the use of the above-outlined mixed-plastic polypropylene blend for packaging.

The gist of the present invention will be further outlined in the following examples.

The following Examples are included to demonstrate certain aspects and embodiments of the invention as described in the claims. It should be appreciated by those of skill in the art, however, that the following description is illustrative only and should not be taken in any way as a restriction of the invention.

Melt flow rates were measured with a load of <NUM> (MFR<NUM>) at <NUM> as indicated. The melt flow rate is that quantity of polymer in grams which the test apparatus standardized to ISO <NUM> extrudes within <NUM> minutes at a temperature of <NUM> under a load of <NUM>.

MFR<NUM> (<NUM>) is measured according to ISO <NUM> (<NUM>, <NUM> load).

The Tensile Modulus was measured according to ISO <NUM>-<NUM> (cross head speed = <NUM>/min; <NUM>, unless identified differently) using injection molded specimens as described in EN ISO <NUM>-<NUM> (dog bone shape, <NUM> thickness). To determine stress at yield, a speed of <NUM>/min was used.

The Charpy notched impact strength was determined according to ISO <NUM>-<NUM>/1eA on notched <NUM> × <NUM> × <NUM> specimens (specimens were prepared according to ISO <NUM>-<NUM>/1eA). Testing temperatures were <NUM>±<NUM> and -<NUM>. Injection molding was carried out according to ISO <NUM>-<NUM>.

The flexural modulus was determined according to ISO <NUM> method A (<NUM>-point bending test) on <NUM> × <NUM> × <NUM> specimens. Following the standard, a test speed of <NUM>/min and a span length of <NUM> times the thickness was used. The testing temperature was <NUM>±<NUM>° C. Injection moulding was carried out according to ISO <NUM>-<NUM>.

The DSC was measured with a TA Instrument Q2000 differential scanning calorimetry (DSC) on <NUM> to <NUM> samples. DSC was run according to ISO <NUM> / part <NUM> /method C2 in a heat / cool / heat cycle with a scan rate of <NUM>/min in the temperature range of -<NUM> to +<NUM>. The crystallization temperature (Tc) was determined from the cooling step, while melting temperature (Tm) and melting enthalpy (ΔHm) can be determined from the second heating step. The crystallinity can be calculated from the melting enthalpy by assuming an ΔHm-value of <NUM> J/g for a fully crystalline polypropylene (see <NPL>).

The crystalline (CF) and soluble fractions (SF) of the polyolefin (PO) compositions, the final ethylene units content of the PO composition, the ethylene units content of the respective fractions, as well as the intrinsic viscosities of the respective fractions were analysed by the CRYSTEX QC Polymer Char (Valencia, Spain) on basis ISO <NUM> Annex B: <NUM> (E).

A schematic representation of the CRYSTEX QC instrument is presented in <NPL>. The crystalline and amorphous fractions are separated through temperature cycles of dissolution in <NUM>,<NUM>,<NUM>-trichlorobenzene (<NUM>,<NUM>,<NUM>-TCB) at <NUM>, crystallization at <NUM> and re-dissolution in <NUM>,<NUM>,<NUM>-TCB at <NUM>. Quantification of SF and CF and determination of ethylene content (C2) are achieved by means of an infrared detector (IR4) and an online <NUM>-capillary viscometer is used for the determination of the intrinsic viscosity (IV).

IR4 detector is a multiple wavelength detector detecting IR absorbance at two different bands (CH<NUM> stretching vibration (centred at approx. <NUM>-<NUM>) and CHx stretching vibration (<NUM>-<NUM>-<NUM>)) which can be used to determine of the concentration and the ethylene content in ethylene-propylene copolymers (EP copolymers). The IR4 detector is calibrated with series of <NUM> EP copolymers with known ethylene content in the range of <NUM> wt. -% to <NUM> wt. -% (determined by 13C-NMR) and each at various concentrations, in the range of <NUM> and <NUM>/ml. To account for both features, concentration and ethylene content at the same time for various polymer concentration expected during Crystex analyses the following calibration equations were applied: <MAT> <MAT>.

The constants a to e for equation <NUM> and a to f for equation <NUM> were determined by using least square regression analysis.

Equation <NUM>: The CH3/1000C is converted to the ethylene content in wt. -% using following relationship: <MAT>.

Amount of Soluble fraction (SF) and Crystalline Fraction (CF) are correlated through the XS calibration to the "Xylene Cold Soluble" (XCS) fraction and "Xylene Cold Insoluble" (XCI) fraction, respectively, determined according to standard gravimetric method as per ISO16152. XS calibration is achieved by testing various EP copolymers with xylene cold soluble (XCS) content in the range <NUM>-<NUM> Wt. The determined XS calibration is linear (Equation <NUM>): <MAT>.

Intrinsic viscosity (IV) of the parent EP copolymer and its soluble fraction (SF) and crystalline fraction (CF) are determined with a use of an online <NUM>-capillary viscometer and are correlated to corresponding IV's determined by standard method in decalin according to ISO <NUM>-<NUM>.

Calibration is achieved with several commercial EP PP copolymers with IV = <NUM>-<NUM> dL/g. The determined calibration curve between the Vsp, measured in CRYSTEX QC and normalized by the concentration (c), and the IV is linear (Equation <NUM>): <MAT> with a slope of a = <NUM>.

A sample of the PO composition to be analysed is weighed out in concentrations of <NUM>/ml to <NUM>/ml. After automated filling of the vial with <NUM>,<NUM>,<NUM>-TCB containing <NUM>/l <NUM>,<NUM>-tert-butyl-<NUM>-methylphenol (BHT) as antioxidant, the sample is dissolved at <NUM> until complete dissolution is achieved, usually for <NUM>, with constant stirring of <NUM> rpm to <NUM> rpm. To avoid sample degradation, polymer solution is blanketed with the N2 atmosphere during dissolution.

A defined volume of the sample solution is injected into the column filled with inert support where the crystallization of the sample and separation of the soluble fraction from the crystalline part is taking place. This process is repeated two times. During the first injection the whole sample is measured at high temperature, determining the IV[dl/g] and the C2[wt. -%] of the PO composition. During the second injection the soluble fraction (SF, at low temperature, <NUM>) and the crystalline fraction (CF, at high temperature, <NUM>) with the crystallization cycle are determined (Wt. -% C2, IV).

Quantitative <NUM>C{<NUM>H} NMR spectra were recorded in the solution-state using a Bruker Avance III <NUM> NMR spectrometer operating at <NUM> and <NUM> for <NUM>H and <NUM>C respectively. All spectra were recorded using a <NUM>C optimised <NUM> extended temperature probehead at <NUM> using nitrogen gas for all pneumatics. Approximately <NUM> of material was dissolved in <NUM> of <NUM>,<NUM>-tetrachloroethane-d<NUM> (TCE-d<NUM>) along with chromium (III) acetylacetonate (Cr(acac)<NUM>) resulting in a <NUM> solution of relaxation agent in solvent (<NPL>). To ensure a homogenous solution, after initial sample preparation in a heat block, the NMR tube was further heated in a rotatory oven for at least <NUM> hour. Upon insertion into the magnet the tube was spun at <NUM>. This setup was chosen primarily for the high resolution and quantitatively needed for accurate ethylene content quantification. Standard single-pulse excitation was employed without NOE, using an optimised tip angle, <NUM> recycle delay and a bi-level WALTZ16 decoupling scheme (<NPL>, <NPL>). A total of <NUM> (<NUM>) transients were acquired per spectra. Quantitative <NUM>C{<NUM>H} NMR spectra were processed, integrated and relevant quantitative properties determined from the integrals. All chemical shifts were indirectly referenced to the central methylene group of the ethylene block (EEE) at <NUM> ppm using the chemical shift of the solvent. This approach allowed comparable referencing even when this structural unit was not present. Characteristic signals corresponding to the incorporation of ethylene were observed (<NPL>) and the comonomer fraction calculated as the fraction of ethylene in the polymer with respect to all monomer in the polymer: <MAT>.

For systems with very low ethylene content where only isolated ethylene in PPEPP sequences were observed the method of Wang et. was modified reducing the influence of integration of sites that are no longer present. This approach reduced the overestimation of ethylene content for such systems and was achieved by reduction of the number of sites used to determine the absolute ethylene content to <MAT>.

Through the use of this set of sites the corresponding integral equation becomes <MAT> using the same notation used in the article of Wang et.

The density is measured according to ISO <NUM>-<NUM>. Sample preparation is done by compression moulding in accordance with ISO <NUM>-<NUM>:<NUM>.

The chemical composition distribution as well as the determination of the molecular weight distribution and the corresponded molecular weight averages (Mn, Mw and Mv) at a certain elution temperature (polymer crystallinity in solution) were determined by a full automated Cross Fractionation Chromatography (CFC) as described by <NPL>.

A CFC instrument (PolymerChar, Valencia, Spain) was used to perform the cross-fractionation chromatography (TREF x SEC). A four band IR5 infrared detector (PolymerChar, Valencia, Spain) was used to monitor the concentration. The polymer was dissolved at <NUM> for <NUM> minutes at a concentration of around <NUM>/ml.

To avoid injecting possible gels and polymers, which do not dissolve in TCB at <NUM>, like PET and PA, the weighed out sample was packed into stainless steel mesh MW <NUM>,<NUM>/D <NUM>,05mmm.

Once the sample was completely dissolved an aliquot of <NUM>,<NUM> was loaded into the TREF column and stabilized for a while at <NUM>. The polymer was crystallized and precipitate to a temperature of <NUM> by applying a constant cooling rate of <NUM>/min. A discontinuous elution process is performed using the following temperature steps: (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> and <NUM>).

In the second dimension, the GPC analysis, <NUM> PL Olexis columns and 1x Olexis Guard columns from Agilent (Church Stretton, UK) were used as stationary phase. As eluent <NUM>,<NUM>,<NUM>-trichlorobenzene (TCB, stabilized with <NUM>/L <NUM>,<NUM>-Di tert butyl-<NUM>-methyl-phenol) at <NUM> and a constant flow rate of <NUM>/min were applied. The column set was calibrated using universal calibration (according to ISO <NUM>-<NUM>:<NUM>) with at least <NUM> narrow MWD polystyrene (PS) standards in the range of <NUM>,<NUM>/mol to <NUM><NUM>/mol. Following Mark Houwink constants were used to convert PS molecular weights into the PP molecular weight equivalents. <MAT> <MAT>.

Data processing was performed using the software provided from PolymerChar with the CFC instrument.

Calculation of the relative fraction at certain molecular weight and elution temperature areas of iso-PP in wt.

To calculate the relative fraction at certain molecular weight and elution temperature areas of iso-PP in wt. -% in the first step the amount of iso-PP in wt. -% from the CFC contour plot needs to be calculated: <MAT>.

Where the EPR is the fraction with a molar mass higher than logM of <NUM> of the soluble fraction (SF) in TCB at <NUM> obtained by CFC analysis <MAT> wherein Hj denotes the signal height at logM value j.

Due to the slightly dependence of the TREF profile on the low MW part, the molecular weight limit of the low MW limit is elution temperature (Tel) dependent. The low MW limit was determined using the following formula:<MAT>.

Taking this into account the PE fraction is calculated using the following approach.

Where Hij is the 2D differential distribution at the corresponded elution temperature (Tel) i and the logM value j, obtained with the corresponded data processing software.

The High crystalline PE fraction (HCF-PE) is defined as the part of the PE fraction eluting from <NUM> to <NUM> of PE fraction. <MAT> wherein Hij denotes the signal height at logM value j, and i the elution temperature.

This fraction contains mainly homo PE and PE copolymers with very low amount of comonomer, below app. <NUM> SCB/1000TC (<NPL>).

Where the low crystalline PE Fraction (LCF-PE) is defined as the part of the PE fraction eluting between <NUM> and <NUM> of the PE fraction. <MAT> wherein Hij denotes the signal height at logM value j, and i the elution temperature.

This fraction contains mainly the copolymer fraction from HDPE and LLDPE obtained by ZN catalysts or the LLDPE from SS catalysts but also LDPE, as this kind of polymer are co-eluting due to their comparable amount of SCB/1000TC.

The calculation of Mw LCF(<NUM>-<NUM>) and Mw EP copo (<NUM>-<NUM>) is done using the following formula: <MAT> <MAT>.

Where wi is the weight fraction of TREF fraction at temperature i and Mwi is the corresponded weight average molecular weight of the fraction determined by CFC analysis.

In the case the LCF (<NUM>-<NUM>) region includes the CFC fraction at <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> and the EP copo fraction (<NUM>-<NUM>) the corresponded CFC fraction at <NUM>, <NUM> and <NUM>.

Fractions with less than <NUM> wt. -% are neglected in the calculation.

The investigation of the non-linear viscoelastic behavior under shear flow was done resorting to Large Amplitude Oscillatory Shear. The method requires the application of a sinusoidal strain amplitude, γ0, imposed at a given angular frequency, ω, for a given time, t. Provided that the applied sinusoidal strain is high enough, a non-linear response is generated. The stress, σ is in this case a function of the applied strain amplitude, time and the angular frequency. Under these conditions, the non-linear stress response is still a periodic function; however, it can no longer be expressed by a single harmonic sinusoid. The stress resulting from a non-linear viscoelastic response [<NUM>-<NUM>] can be expressed by a Fourier series, which includes the higher harmonics contributions: <MAT>.

The non-linear viscoelastic response was analysed applying Large Amplitude Oscillatory Shear (LAOS). Time sweep measurements were undertaken on an RPA <NUM> rheometer from Alpha Technologies coupled with a standard biconical die. During the course of the measurement the test chamber is sealed and a pressure of about <NUM> MPa is applied. The LAOS test is done applying a temperature of <NUM>, an angular frequency of <NUM> rad/s and a strain of <NUM> %. In order to ensure that steady state conditions are reached, the non-linear response is only determined after at least <NUM> cycles per measurement are completed. The Large Amplitude Oscillatory Shear Non-Linear Factor (LAOS_NLF) is defined by: <MAT>.

By FTIR spectroscopy using the absorption of the band at <NUM>-<NUM> (PS) and <NUM>-<NUM> (PA6).

VDA <NUM> is a determination of the odor characteristics of trim materials in motor vehicles. In this study, the odor is determined following VDA <NUM> (<NUM>) variant B3. The odor of the respective sample is evaluated by each assessor according to the VDA <NUM> scale after lifting the jar's lid as little as possible. The hexamerous scale consists of the following grades: Grade <NUM>: not perceptible, Grade <NUM>: perceptible, not disturbing, Grade <NUM>: clearly perceptible, but not disturbing, Grade <NUM>: disturbing, Grade <NUM>: strongly disturbing, Grade <NUM>: not acceptable. Assessors stay calm during the assessment and are not allowed to bias each other by discussing individual results during the test. They are not allowed to adjust their assessment after testing another sample, either. For statistical reasons (and as accepted by the VDA <NUM>) assessors are forced to use whole steps in their evaluation. Consequently, the odor grade is based on the average mean of all individual assessments, and rounded to whole numbers.

In the CIE L*a*b* uniform color space, measured according to DIN EN ISO <NUM>-<NUM>, the color coordinates are: L*-the lightness coordinate; a*-the red/green coordinate, with +a* indicating red, and -a* indicating green; and b*-the yellow/blue coordinate, with +b* indicating yellow, and -b* indicating blue. The L*, a*, and b*coordinate axis define the three dimensional CIE color space. Standard Konica/Minolta Colorimeter CM-3700A.

TGA according to DIN ISO <NUM>:<NUM> using a Perkin Elmer TGA <NUM>. Approximately <NUM>-<NUM> of material was placed in a platinum pan. The temperature was equilibrated at <NUM> for <NUM> minutes, and afterwards raised to <NUM> under nitrogen at a heating rate of <NUM>/min. The ash content was evaluated as the weight % at <NUM>.

The characterisation of polymer melts by dynamic shear measurements complies with ISO standards <NUM>-<NUM> and <NUM>-<NUM>. The measurements were performed on an Anton Paar MCR501 stress controlled rotational rheometer, equipped with a <NUM> parallel plate geometry. Measurements were undertaken on compression-moulded plates, using nitrogen atmosphere and setting a strain within the linear viscoelastic regime. The oscillatory shear tests were done at <NUM> applying a frequency range between <NUM> and <NUM>,<NUM> rad/s, with data evaluation of <NUM> datapoints per decade and a logarithmic ramped strain of <NUM>-<NUM>% that is used. The plate-plate geometry has a diameter of <NUM> and a gap size of <NUM>,<NUM> is used. The trimming is carried out at <NUM>,<NUM>.

In a dynamic shear experiment the probe is subjected to a homogeneous deformation at a sinusoidal varying shear strain or shear stress (strain and stress controlled mode, respectively). On a controlled strain experiment, the probe is subjected to a sinusoidal strain that can be expressed by <MAT>.

If the applied strain is within the linear viscoelastic regime, the resulting sinusoidal stress response can be given by <MAT> where.

Dynamic test results are typically expressed by means of several different rheological functions, namely the shear storage modulus G', the shear loss modulus, G", the complex shear modulus, G*, the complex shear viscosity, η*, the dynamic shear viscosity, η', the out-of-phase component of the complex shear viscosity η" and the loss tangent, tan δ which can be expressed as follows: <MAT> <MAT> <MAT> <MAT> <MAT> <MAT>.

ETA(x kPa) is determined according with equation <NUM>.

For example, the ETA(<NUM> kPa) is the defined by the value of the complex viscosity, determined for a value of complex modulus equal to <NUM> kPa.

Eta (x rad/s) is determined according with equation <NUM>.

For example, the ETA(<NUM> rad/s) is defined by the value of the complex viscosity, determined at a frequency sweep of <NUM> rad/s.

Equally, the ETA(<NUM> rad/s) is defined by the value of the complex viscosity, determined at a frequency sweep of <NUM> rad/s.

The values are determined by means of a single point interpolation procedure, as defined by Rheoplus software. In situations for which a given G* value is not experimentally reached, the value is determined by means of an extrapolation, using the same procedure as before. In both cases (interpolation or extrapolation), the option from Rheoplus "- Interpolate y-values to x-values from parameter" and the "logarithmic interpolation type" were applied.

The PI is determined by a so-called frequency sweep at <NUM> in nitrogen atmosphere using a plate-plate geometry of <NUM> diameter and a gap size of <NUM>,<NUM>. The trimming is carried out at <NUM>,<NUM>. An angular frequency range of <NUM> to <NUM>,<NUM> rad/s with data evaluation of <NUM> datapoints per decade and a logarithmic ramped strain of <NUM>-<NUM>% is used. By the dynamic shear measurement the loss modulus G"(w) and the storage modulus G'(w) are determined as a function of angular frequency. Cross-over modulus Gc at the cross-over frequency wc (also described as W(c)) is the intersection of the functions G'(w) and G"(w). The polydispersity index is defined as <MAT> and indicated in Pa^-<NUM>.

Eta0, the zero shear viscosity, is calculated via the RheoPlus Rheometer software (by Anton Paar GmbH) using the model of Carreau and Yasuda (method "Carreau Yasuda I model").

This method describes the semi-quantitative determination of organic compounds emitting from polyolefins. It is similar to the VDA <NUM> (October <NUM>) but includes specific adjustments.

Directly after the production the sample (injection moulded plaque, DIN-A5) is sealed in an aluminium-coated polyethylene bag and provided to the lab within <NUM> days. In the lab, it is stored openly for <NUM> days below <NUM>. After this period, an aliquot of <NUM> ± <NUM> is prepared from the stored sample. Trimming the aliquot should aim for a maximum coherent area. It is not the aim to create the largest possible surface area by cutting the aliquot into smaller pieces. The diameter of the sample injection tube should be used first. Length and thickness should be chosen accordingly, considering the specified aliquot weight. The aliquot is directly desorbed using heat and a flow of helium gas. Volatile and semi-volatile organic compounds are extracted into the gas stream and cryo-focused prior to the injection into a gas chromatographic (GC) system for analysis. The method comprises two extraction stages: In the analysis of low-boiling substances (LBS) the aliquot is desorbed at <NUM> for <NUM> to determine volatile organic compounds in the boiling / elution range up to n-C25 (n-pentacosane). The analysis of high-boiling substances (HBS) involves a further desorption step of the same aliquot at <NUM> for <NUM> to determine semi-volatile compounds in the boiling / elution range from n-C14 (n-tetradecane) to n-C32 (n-dotriacontane).

Similar to the VOC and FOG value in the VDA <NUM>, the LBS is calculated as toluene equivalent (TE) and the HBS is calculated as hexadecane equivalent (HE) applying a semi-quantitation and a respective calibration. The result is expressed in "µg/g".

Integration parameters for the LBS and HBS evaluation are chosen in such way that the "area reject" corresponds to the area of <NUM>µg/g (TE and HE, respectively). Thus, smaller peaks do not add to the semi-quantitative result. The GC oven program is kept the same, no matter if a calibration run, an LBS run or an HBS run was performed. It starts at <NUM> (<NUM> hold), followed by a ramp of <NUM>/min and an end temperature of <NUM> (<NUM> hold). For the GC column an Agilent DB5: <NUM> x <NUM> x <NUM> (or comparable) is used. The method requires a Thermal Desorption System TDS <NUM> (Gerstel) and a Cooled Injection System CIS <NUM> (Gerstel) as well as a GC system with a flame ionisation detector (FID) but does not involve a mass spectrometer. Instead of <NUM> the CIS end temperature is always set to <NUM>.

Determined according to <NUM> m/s, <NUM>, ISO7765-<NUM>.

Determined according to ISO <NUM>-<NUM>.

Determined according to ISO <NUM>-<NUM> at <NUM>.

Determined according to ASTM D2457 at <NUM> degree (film inside) on a cast film of <NUM> thickness produced on a monolayer cast film line with a melt temperature of <NUM> and a chill roll temperature of <NUM>-<NUM>.

Determined according to ASTM D1003 on cast films of <NUM> thickness produced on a monolayer cast film line with a melt temperature of <NUM> and a chill roll temperature of <NUM>-<NUM>.

IE1 and IE2 were pre-sorted by the above-outlined mechanical polyolefin recycling process comprising the quality control step l1)/m1). For IE1 a Swedish post-consumer plastic trash enriched in post-consumer flexible PP articles, was used as precursor mixed plastic recycling stream (A). For IE2, German post-consumer plastic trash fulfilling the specification DSD323-<NUM> was used as precursor mixed plastic recycling stream (A).

For CE1, the post-consumer plastic trash fulfilling the German specification DSD323-<NUM> was used as precursor mixed plastic recycling stream (A). However, the recycling process did not comprise the quality control step.

CE2, CE3, CE4 (visbroken using peroxides), CE5, and CE6 are commercially available post-consumer recyclates, which were not further pre-sorted by the above-outlined mechanical polyolefin recycling process comprising the quality control step l1)/m1).

As can be seen from Table <NUM>, commercially available recyclates, which were not pre-sorted by the above-outlined mechanical polyolefin recycling process comprising the quality control step l1)/m1), are not within the claimed EPR range (less than <NUM> wt. Without being bound to any theory, it is assumed that thus these feedstocks are not suitable starting material for the manufacturing of films, since they do not address challenges of conversion into films, such as polymer and melt homogeneity, and do not meet mechanical performance requirements of films.

The used PP material has further properties as outlined in Table <NUM>. Cast film (<NUM>) were manufactured with a melt temperature of <NUM> and a screw speed between <NUM> and 100rpm from the polypropylene material. Depending on the used polypropylene material chill roll temperatures in the range of <NUM> to <NUM> were used. A person skilled in the art is aware of the specific chill roll temperature that is to be chosen for a certain material. The film properties are also outlined in Table <NUM>.

Claim 1:
A mixed-plastic polypropylene blend having
(i) a density determined according to DIN EN ISO <NUM> of <NUM> to less than <NUM>/m<NUM>;
(ii) a soluble fraction (SF) content determined according to CRYSTEX QC analysis in the range from <NUM> to <NUM> wt.-%, wherein CRYSTEX QC analysis is carried out on basis of ISO <NUM> Annex B: <NUM> (E) as described in the experimental part of the specification, whereby
(iii) said soluble fraction (SF) has an ethylene-propylene rubber (EPR) content as expressed by equation (<NUM>) of less than <NUM> wt.-%, where the EPR corresponds to the fraction with a molar mass higher than logM of <NUM> to <NUM> of the soluble fraction (SF) in TCB at <NUM> obtained by Cross Fractionation Chromatography (CFC) analysis <MAT> wherein Hj denotes the signal height at logM value j, and wherein Cross Fractionation Chromatography (CFC) analysis is carried out as described in the experimental part of the specification; and
(iv) said soluble fraction (SF) has an intrinsic viscosity (iV(SF)) in the range from <NUM> to below <NUM> dl/g, preferably <NUM> to <NUM> dl/g, wherein the intrinsic viscosity is determined by CRYSTEX QC analysis on basis of ISO <NUM> Annex B: <NUM> (E) as described in the experimental part of the specification; and
whereby
(v) the mixed-plastic polypropylene blend has inorganic residues as measured by calcination analysis (TGA) according to DIN ISO <NUM>:<NUM> of <NUM> to <NUM> wt.-%, preferably <NUM> to <NUM> wt.-%, optionally <NUM> to <NUM> wt.-% with respect to the mixed-plastic polypropylene blend; and
wherein the mixed-plastic polypropylene blend is a recycled material.