A container and a method of manufacturing the same

Abstract

This disclosure relates to a container comprising an internal chamber for receiving sensitive products. The internal chamber is delimited by a wall consisting of three or more layers. The three or more layers comprise an outer layer configured to be in contact with an external atmosphere surrounding the container and an active structure arranged inwards from the outer layer. The outer layer comprises a base polymer in an amount of at least 95 wt%. The active structure comprises a first active layer comprising a base polymer and active material (s), the first active layer comprising a first wt % amount C1 of said active material (s), and a second active layer comprising all the materials present in the other layers of the wall of the container, in an amount of at least 95 wt%, the second active layer comprising a second wt% amount C2 of said active material (s), wherein the second wt% amount C2 is smaller than the first wt% amount C1.

Description

[0001] A Container and a Method of Manufacturing the Same

[0002] Technical Field

[0003] The present disclosure relates to a container for receiving and protecting sensitive products , such as pharmaceutical or medical goods , drugs , pills , tablets , test strips , granulate , powder, or food products , etc .

[0004] This disclosure also relates to a method of manufacturing a container using a multilayer coextrusion blow device , and to a method for preparing an active compound suitable for extrusion blow molding .

[0005] Technical Background

[0006] Containers for protecting sensitive products , such as moisture sensitive products ( for example , pharmaceutical or medical goods ) , are important for being able to preserve such products and to secure their quality . Such containers may in particular comprise a desiccant layer and / or other active layer ( s ) . The container may need to be airtight , in order to avoid a deterioration of the stored products , even after the container has been opened and closed several times .

[0007] Containers for protecting sensitive products may be manufactured using multilayer extrusion blow molding of desiccant polymer compounded materials . Such material compounds comprise a desiccant embedded into a polymer resin matrix and form the desiccant layer of the container .

[0008] There is an ongoing need for improving the moisture protection properties of such containers as well as for facilitating the manufacturing of such containers . There is also a desire to avoid direct contact between the desiccant layer of the container and contents received in the container . In other words , it is desirable for such containers to comprise a contact layer that is suitable for being in contact with an internal space of the container that receives the goods . Moreover, there is a desire to promote environmental friendliness of the manufacturing methods employed to make the containers .

[0009] There is , hence , a need for improvements to containers and their manufacturing methods which address at least one of the above-mentioned shortcomings .

[0010] Summary

[0011] One aspect of the present disclosure relates to a container comprising an internal chamber for receiving sensitive products . The term sensitive products may in particular cover moisture sensitive products ( such as , for example , food, pharmaceutical , or medical goods )

[0012] The internal chamber is delimited by a wall consisting of three or more layers . The term "delimited" does not mean that the wall must fully encapsulate the internal chamber . The wall may comprise one or several openings that provide access to the internal chamber . Typically, the internal chamber may have a base surface and a side surface , as well as an opening at the top that may be closeable by a lid member . An example of a container is a bottle shaped container .

[0013] The three or more layers may comprise an outer layer configured to be in contact with an external atmosphere surrounding the container . When the container is placed in an external atmosphere (e . g . , when the container is standing in a spot where it is used to store goods ) , the outer layer is in contact with said external atmosphere .

[0014] The outer layer may comprise a base polymer in an amount of at least 95 wt% (weight percent ) . Throughout this text , a wt% amount of a component in a layer is the % of weight of the component over the total weight of the composition of the layer .

[0015] When reference is made to a base polymer in this text , the base polymer may comprise ( or consist of ) any one or several of the following base polymers : polyolefins , polyisoprene , thermoplastic cellulose , ethylene-vinyl acetate copolymers , ethylene-methacrylate copolymer, ethylene-butacrylate copolymer, acrylonitrile butadiene styrene , polystyrene , styrene-ethylene-butylene-styrene copolymers , styrene- butylene-styrene copolymers , styrene butadiene copolymers , polyesters , polyanhydrides , polysulfones , polyacrylic ester, thermoplastic polyurethane (TPU) , polyacetal ( POM) , polylactic acid ( PLA) , and mixtures thereof .

[0016] The base polymer may in particular include or consist of a polyolefin . Typical polyolefin base polymers include polyolefins , such as homo-polymers and copolymers of monoolefins and di-olefins , for example polypropylene ( PP) , polyethylene ( PE ) which optionally can be crosslinked such as high density polyethylene (HDPE ) , low density polyethylene (LDPE ) .

[0017] The three or more layers may comprise an active structure that is arranged inwards from the outer layer . Being located inwards from the outer layer means that the outer layer faces the outside (and, hence , the external atmosphere ) , while the inner side of the outer layer faces the active structure .

[0018] The inner side of the outer layer may directly face the active structure in the sense that said outer layer may be in contact with the active structure . The active structure in this case comprises a layer that is in contact with the inner side of the outer layer . Alternatively, the inner side of the outer layer may indirectly face the active structure . In this case , there may be one or several layers in-between the outer layer and the active structure. Put differently, when considering all of the three or more layers starting from the internal chamber towards the external atmosphere, the sequence is as follows: (optional further layer (s) ) , the active structure, (optional further layer (s) ) , and the outer layer.

[0019] The container may, hence, for example, consist of the following layers from inside to outside: the active structure and the outer layer.

[0020] The active structure may comprise a first active layer. Said first active layer may comprise a base polymer and active material (s) . The first active layer may comprise a first wt% amount Cl of said active material (s) .

[0021] Whenever active material is referred to in this text, the active material may belong to a group comprising humidity absorbers (or desiccants) ; oxygen absorbers (or oxygen scavengers) ; odor absorbers; emitters of humidity; emitters of volatile organic compounds such as a fragrance, an aroma, a nutrient; and mixtures thereof.

[0022] It is understood that, within the meaning of the present disclosure, the term "absorb", when referring to a given active material, is used to encompass all chemical and physical phenomena by which a gas may be retained by said active material. In particular, this includes bulk phenomena, generally referred to as "absorption", where gas molecules enter the active material; or surface phenomena, generally referred to as "adsorption", where gas molecules attach to the surface of the active material.

[0023] The active material may comprise or consist of an inorganic desiccant material, optionally selected from the group comprising molecular sieves, zeolites, silica gel, clay, hydrate salts, metal oxides, and mixtures thereof. The active structure may comprise a second active layer . The second active layer may comprise all the materials present in the other layers of the wall of the container, amongst the three or more layers , in an amount of at least 95 wt% . The second active layer may comprise a second wt% amount C2 of said active material ( s ) , wherein the second wt% amount C2 i s smaller than the first wt% amount Cl . The term "other layers of the wall of the container" refers to all of the layers except the second active layer itself .

[0024] The provision of the second active layer may allow reducing manufacturing waste and may thus promote environmental friendliness . In particular, material scrap from a blow molding process during manufacturing may be re-used .

[0025] The container may be manufactured using (amongst other things ) a multilayer extrusion blow molding (EBM) process .

[0026] The multilayer extrusion blow molding (EBM) process may involve the steps of coextruding different materials into a parison and closing two mold halves around the parison .

[0027] At the bottom of the parison, where the two mold halves meet , the parison may be compressed into a flat shape by a pinch-off portion of the blow molding mold . The parison may be then stretched with air to press it against the walls of the mold .

[0028] After the container has cooled and solidified in the mold cavity, the excess material at the neck and bottom portions of the container may be cut off . Thi s excess material discarded at the bottom is termed the ' pinch-off ' , because the bottom end of the material is pinched and sealed in the mold to form the container base . The material that may be discarded at the top is termed ' neck flash ' and may be removed by a cutting device , which corresponds to the cutting region on the mold . Instead of discarding the pinch-off, the pinch-off may be partially or fully reused. After regrinding, the material scrap may be coextruded to form the second active layer with a concentration of active material (s) lower than the concentration in the first active layer. The concentration is lower as there may be a 'dilution' with the material of the outer layer and / or other layers.

[0029] Thus, the container may be manufactured in a more efficient and environmentally friendly manner, with less scrap and high recyclability .

[0030] Similarly to the pinch-off, instead of discarding the neck flash, the neck flash may be partially or fully reused. After regrinding, the material scrap comprising either only the pinch-off, only the neck flash, or a combination of neck-flash and pinch-off, may be coextruded to form the second active layer with a concentration of active material (s) lower than the concentration in the first active layer. The concentration is lower as there may be a 'dilution' with the material (s) of the outer layer and / or other layers.

[0031] A ratio of the second wt% amount C2 of said active material (s) in the second active layer to the first wt% amount Cl of said active material (s) in the first active layer may be less than 0.75, preferably less than 0.6, preferably less than 0.5. Such a concentration gradient of active material (s) between the first active layer and the second active layer may correspond to a 'dilution' of the material of the first active layer with the material (s) of the outer layer and / or other layers. Such a 'dilution' may be obtained from regrinding the material scrap from the blow molding process to form the second active layer. This reduces manufacturing process scraps and promotes recyclability .

[0032] The second active layer with a lower fill rate of active material (s) and a higher amount of base polymer as compared to the first active layer may offer a higher resistance to the diffusion of gas than the first active layer . It may, hence , be easier for gas (e . g . , for moisture and / or oxygen) to travel across the first active layer than across the second active layer . Thus , a concentration gradient of active material ( s ) between the first active layer and the second active layer may allow gas traveling from the outside or the inside of the container to be blocked between the second active layer and another 'barrier' layer (e . g . , outer layer or inner layer) , so that it may remain and diffuse inside the more permeable first active layer, thereby increasing the possibilities of it being absorbed by the active material ( s ) .

[0033] The first wt% amount Cl of said active material ( s ) in the first active layer may be equal to or higher than 50 wt% . It may be equal to or higher than 60 wt% . These ranges of at least a minimum wt% value may ensure a sufficient function such as e . g . , absorption capacity of the container . In addition, these ranges of at least a minimum wt% value may provide an adapted desiccant fill rate that is suited for forming the second active layer by regrinding the material scrap from the blow molding process .

[0034] The second active layer may be arranged inwards from the first active layer . This means that from inside to outside of the container wall , the sequence of layers may be ( optional layer ( s ) ) -second active layer-optional layer ( s ) -first active layer- ( optional layer ( s ) ) -outer layer . This arrangement may promote that gas reaching the container from the outside first reaches the "more active" first active layer before it reaches layers further inside .

[0035] The second active layer may be adj acent to the first active layer . As mentioned above , the second active layer with a lower fill rate of active material ( s ) and a higher amount of base polymer as compared to the first active layer may offer a higher resistance to the diffusion of gas than the first active layer . It may, hence , be easier for gas (e . g . , for moisture and / or oxygen) to travel across the first active layer than across the second active layer . Then, gas traveling from the outside of the container and passing through the outer 'barrier' layer may tend to be blocked by the second active layer located on the inner side of the first active layer, so that it may diffuse within the more permeable first active layer, where it may get trapped by the active material ( s ) before reaching the internal chamber of the container .

[0036] The container may comprise an inner layer configured to be in contact with an internal atmosphere of the container . When being used, the inner layer may be in contact with the internal atmosphere of the container ( j ust like the inner surface of a bottle is in contact with the inside space inside of a bottle ) .

[0037] The inner layer may comprise a base polymer in an amount of at least 95 wt% .

[0038] The active structure may be arranged between the outer layer and the inner layer . This may offer the benefit of avoiding direct contact between the active material ( s ) and the content of the container . This may protect sensitive products . The container may, for example , be suitable to hold food and / or pharmaceutical and / or medical products .

[0039] Advantageously, when the active structure is arranged between an outer layer and an inner layer as described above , gas traveling from the outside of the container and passing through the outer 'barrier' layer may tend to be blocked by the inner layer, so that it may remain and diffuse within the active layers of the active structure , thereby increasing the possibilities of it being absorbed by the active material ( s ) .

[0040] The inner layer may have a thickness of less than or equal to 0 . 5 mm . The inner layer may have a thickness of less than or equal to 0 . 3 mm . The thickness of the inner layer may be sufficiently low to ensure effective absorption of gas from the internal chamber of the container.

[0041] The base polymer of the outer layer may be a polyethylene (PE) . The base polymer of the outer layer may be a high density polyethylene (HDPE) with a Melt Flow Index (MFI) lower than 1 g / lOmin when measured according to ASTM D1238 (190°C, 2.16 kg) . The outer layer may in this case have both high gas barrier properties and be well suitable for multilayer extrusion blow molding (e.g., HDPE grade designed for extrusion blow molding) .

[0042] Throughout this text, the Melt Flow Index (MFI) values are measured according to Procedure A of standard test method ASTM D1238, with a weight of 2.16 kg and at a temperature of 190°C.

[0043] The outer layer may have a thickness of equal to or higher than 0.3 mm. The outer layer may have a thickness of equal to or higher than 0.4 mm. The thickness of the outer layer may in this way be sufficiently high to block gas from the outside.

[0044] The first active layer may comprise the same base polymer as the outer layer. This may promote chemical compatibility. It may also promote cohesion during extrusion blow molding processes, as the materials may be less prone to rupture or separation when blow-stretching during the manufacturing process .

[0045] The first active layer may comprise active material (s) , optionally desiccant ( s ) .

[0046] The base polymer and the active material (s) together may constitute at least 95 wt% of the first active layer. This may promote chemical compatibility. It may also promote cohesion during extrusion blow molding processes, as the materials may be less prone to rupture or separation when blow-stretching. The first active layer may comprise a base polymer and molecular sieve. The base polymer and molecular sieve may together constitute at least 95 wt% of the first active layer. Molecular sieve may keep very low humidity levels and may therefore be very well suited for packaging of moisturesensitive products such as probiotics or diagnostic test strips .

[0047] The active structure may comprise an intermediate layer arranged between the first active layer and the second active layer. The intermediate layer may comprise a base polymer in an amount of at least 95 wt%.

[0048] The first and second active layers may be, hence, for example, separated by a 'barrier' intermediate layer. This may, e.g., result in a '5-layer' container wall structure, comprising in the direction from the inside of the container to the outside the following sequence of layers: inner layer (e.g., HDPE with white colorant) , second active layer (for example, a desiccant compound layer) , intermediate layer, first active layer (for example another desiccant compound layer) , the three latter layers being an active structure, outer layer (e.g., HDPE with white colorant) . Thanks to the presence of the intermediate layer with unimpaired gas barrier properties, gas traveling from the outside of the container is captured in the first active layer, while gas from the inside of the container is captured in the second active layer.

[0049] The active structure may comprise one or several further layers. For example, the active structure may comprise one or several EVOH layer (s) adding oxygen barrier properties.

[0050] The container wall may comprise polyethylene (PE) , optionally high density polyethylene (HDPE) , and active material (s) , optionally desiccant ( s ) . The polyethylene (PE) and active material (s) together may constitute at least 95 wt% of the container wall. This may simplify the structure and, hence, the manufacturing, as one nature of a base polymer is employed for the composition of the container . Moreover, this choice of materials may promote homogeneity of the composition of the material scrap from the blow molding process .

[0051] The container wall may comprise polyethylene ( PE ) , optionally high density polyethylene (HDPE ) , and molecular sieve . The polyethylene ( PE ) and molecular sieve together may constitute at least 95 wt% of the container wall . This may allow for a further simplification of the material recipe ( only one nature of desiccant ) for the composition of the container, and the material properties may reduce the variability in the properties of the material scrap from the blow molding process .

[0052] The container wall may comprise high density polyethylene (HDPE ) and molecular sieve , and the high density polyethylene (HDPE ) and molecular sieve together may constitute at least 95 wt% of any of the layers of the container wall . This may allow the material scrap from the blow molding process to also be composed of at least 95 wt% of high density polyethylene (HDPE ) and molecular sieve , which may increase the compatibility between a layer of reground material obtained from regrinding the material scrap from the blow molding process and its adj acent layer ( s ) .

[0053] The container wall may comprise between 60 wt% and 90 wt% of high density polyethylene (HDPE ) , between 10 wt% and 40 wt% of molecular sieve , and between 0 wt% and 10 wt% , optionally between 0 wt% and 5 wt% , of additives . This may provide an adapted desiccant fill rate that i s suited for ' recyclability' into a blow-moldable layer . Thus , the manufacturing process of the container may be sustained with high efficiency .

[0054] The additives may include colorant masterbatches and / or processing aids .

[0055] The container may be an extrusion blow molded container having a stretch ratio equal to or higher than 25% . The stretchability may be maintained despite the presence of active layers comprising active material ( s ) , for which the melt is prone to separate at the interface between the base polymer and the active material ( s ) .

[0056] The stretch ratio is to be understood to be a ratio between the greatest and smallest outer dimensions of the container . Dimensions are measured in a plane perpendicular to a main axis corresponding to the direction of extrusion . In case of containers with a circular cross section ( circular shape in a section plane perpendicular to the main axis ) , the stretch ratio is the ratio of the outer diameter of the container measured on its sidewall and the outer diameter of the neck of the container (not including the thread) .

[0057] The container may be an extrusion blow molded container having a stretch ratio equal to or higher than 30 % . The stretchability may be maintained with particularly high reliability despite the presence of active layers comprising active material ( s ) , for which the melt is prone to separate at the interface between the base polymer and the active material ( s ) .

[0058] The wall of the container may be regrindable such that it results in a reground material compound comprising at least one base polymer and at least one active material , with a Melt Flow Index (MFI ) of between 0 . 1 and 2 . 0 g / l Omin, optionally between 0 . 1 and 1 . 0 g / l Omin, when measured according to ASTM D1238 ( 190 ° C, 2 . 16 kg) . The MFI of the reground material compound, which is obtained from regrinding the pinch-off and / or neck flash and which forms the second active layer, may thus remain within a processable MFI window . Input parameters to arrive at this desired MFI range may be a selection of the raw materials and processing parameters at compounding ( screw design, operating parameters ) . For a polymeric resin to be processable in a multilayer extrusion blow molding machine , the MFI of the material may need to be carefully adj usted . A too high MFI ( lower viscosity) may lead to parison sag, i . e . the extruded parison may be subj ected to drawdown ( sag) under its own weight . In contrast , too low MFI (higher viscosity) may impact productivity or render the resin impossible to extrude . The MFI of the reground material compound may thus need to be in a window where it can be processed by extrusion blow molding . The claimed range may be suitable .

[0059] The present disclosure also relates to a container comprising an internal chamber for receiving sensitive products , the internal chamber being delimited by a wall . The term "delimited" does not mean that the wall must fully encapsulate the internal chamber . The wall may comprise one or several openings that provide access to the internal chamber . Typically, the internal chamber may have a base surface and a side surface , as well as an opening at the top that is closeable by a lid member .

[0060] The wall may comprise an outer layer configured to be in contact with an external atmosphere surrounding the container . When the container is placed in an external atmosphere (e . g . , when the container is standing in a room) , the outer layer is in contact with said external atmosphere ( j ust like the outer surface of a bottle is in contact with an external atmosphere ) .

[0061] The outer layer may comprise a base polymer in an amount of at least 95 wt% .

[0062] The wall may comprise an active structure that is arranged inwards from the outer layer . Being located inwards from the outer layer means that the outer layer faces the outside (and, hence , the external atmosphere ) , while the inner side of the outer layer faces the active structure . The inner side of the outer layer may directly face the active structure in the sense that said outer layer may be in contact with the active structure . The active structure then comprises a layer that is in contact with the inner side of the outer layer . Alternatively, there may be one or several layers in-between the outer layer and the active structure.

[0063] Put differently, when considering all layers starting from the internal chamber towards the external atmosphere, the sequence may be as follows: (optional further layer (s) ) , the active structure, (optional further layer (s) ) , and the outer layer. The container may, hence, for example, consist of the following layers from inside to outside: the active structure and the outer layer.

[0064] The active structure may comprise a base polymer and at least one active material.

[0065] The wall of the container may be regrindable such that it results in a reground material compound comprising at least one base polymer and at least one active material, with a Melt Flow Index (MFI) of between 0.1 and 2.0 g / lOmin, optionally between 0.1 and 1.0 g / lOmin, when measured according to ASTM D1238 (190°C, 2.16 kg) .

[0066] The present disclosure also relates to a method of manufacturing a container comprising an internal chamber for receiving sensitive products. The term sensitive products may in particular cover moisture sensitive products (such as, for example, food, pharmaceutical, or medical goods) .

[0067] The method may comprise coextruding different materials into a parison with a multilayer extrusion blow molding machine comprising a plurality of hoppers. The parison may be tubular shaped .

[0068] The method may comprise closing two mold halves of a blow molding mold around the parison to enclose the parison in a mold cavity of the blow molding mold.

[0069] At a bottom portion of the parison, where the two mold halves meet , the parison may be compressed, e . g . , into a flat shape , by a pinching-off portion of the blow molding mold .

[0070] The method may comprise inflating the parison with air and pressing it against the walls of the mold .

[0071] The method may comprise letting the parison cool and solidify in the mold cavity .

[0072] Excess material at the bottom portion of the parison may be cut off , and the bottom portion of the parison may, after the cutting off , be pinched to form a pinch-off portion, to thereby form the container with the internal chamber being delimited by a wall having the pinch-off portion at a bottom .

[0073] At least a part of the excess material may be reground . The regrinding results in reground material . The reground material may be comprised exclusively of pinch-off , exclusively of neck flash, or of a combination of both . The reground material may be fed to at least one of the hoppers of the multilayer extrusion blow machine .

[0074] In other words , instead of discarding all of the excess material , at least a part ( optionally : all ) of the exces s material may be reused . After regrinding, the material scrap may be coextruded to form an additional ( the second) active layer with a concentration of active material lower than the concentration in a first active layer . The concentration is lower as there may be a 'dilution ' with the material of the outer layer and / or other layers .

[0075] Thus , the container may be manufactured in a more efficient and environment friendly manner .

[0076] Neck flash excess material at a top portion of the parison may be cut off . An opening may be formed at the top of the parison . This disclosure also relates to a container manufactured by the described method .

[0077] This disclosure also relates to a method for preparing an active compound suitable for extrusion blow molding (EBM) . The method may comprise steps of :

[0078] (a) mixing a base polymer and at least one active material so that the at least one active material is distributed within the base polymer to obtain a resulting active compound;

[0079] (b) forming a container comprising an internal chamber by extrusion blow molding (EBM) , by coextruding : an outer layer configured to be in contact with an external atmosphere surrounding the container, wherein the outer layer comprises a base polymer in an amount of at least 95 wt% , and an active structure arranged inwards from the outer layer, wherein the active structure comprises said resulting active compound in such a way that a wt% amount of said resulting active compound in the container is at least 20 wt% ;

[0080] ( c) optionally, adj usting a Melt Flow Index (MFI ) of the base polymer used to obtain the resulting active compound and repeating steps (a) and (b) , until a Melt Flow Index (MFI ) of a reground material compound, obtained by regrinding the wall of the container, is between 0 . 1 and 2 . 0 g / l Omin, optionally between 0 . 1 and 1 . 0 g / l Omin, when measured according to ASTM D1238 ( 190 °C, 2 . 16 kg) .

[0081] The resulting active compound may be a homogenous active compound, for which the wt% amount of the at least one active material in the active compound remains constant , within a tolerance of ±5% .

[0082] The compounding device to carry out the mixing step (a) may be a co-rotating twin-screw extruder .

[0083] A wt% amount of the at least one active material in the active compound may be equal to or higher than 50 wt% , optionally equal to or higher than 60 wt% .

[0084] The at least one active material may be at least one desiccant , optionally molecular sieve . A molecular sieve desiccant (e . g . , a 4A molecular sieve in powder form with an average particle si ze of 8pm) may be added to the melted base polymer and blended in the twin compounding device . A wt% amount of the molecular sieve desiccant in the active compound may be 65 wt% ± 5 wt% .

[0085] Additional advantages and features of the present disclosure , that can be reali zed on their own or in combination with one or two or more features discussed above , insofar as the features do not contradict each other, will become apparent from the following description of particular embodiments .

[0086] Brief Description of the Drawings

[0087] For a better understanding of the present disclosure and to show how the same may be carried into effect , reference will now be made , by way of example only, to the accompanying drawings .

[0088] The description is given with reference to the accompanying drawings , in which :

[0089] Figure 1 is an elevational view of an embodiment of a container for atmosphere control in accordance with this disclosure ;

[0090] Figure 2 is a cross-sectional view of an embodiment of a container for atmosphere control in accordance with this disclosure as well as an enlarged view of a part of a four-layer wall of the container ; Figure 3 is a cross-sectional view of an extrusion head with four hoppers that is used during manufacture of an embodiment of a container for atmosphere control in accordance with this disclosure ;

[0091] Figure 4 is a schematic drawing of different stages of an embodiment of a manufacturing method in accordance with the present disclosure involving extrusion blow molding;

[0092] Figure 5 is a graph illustrating experimental results regarding short-term absorption of an exemplary container for atmosphere control in accordance with this disclosure ;

[0093] Figure 6 is a graph illustrating experimental results regarding long-term absorption of an exemplary container for atmosphere control in accordance with this disclosure ;

[0094] Figure 7 is a cross-sectional view of an embodiment of a container for atmosphere control in accordance with this disclosure as well as an enlarged view of a part of a three-layer wall of the container ; and

[0095] Figure 8 is a cross-sectional view of an embodiment of a container for atmosphere control in accordance with this disclosure as well as an enlarged view of a part of a five-layer wall of the container .

[0096] Fig . 1 is an elevational view of an embodiment of a container 1 for atmosphere control in accordance with this disclosure .

[0097] The container 1 comprises an internal chamber for receiving sensitive products . The internal chamber 2 is delimited by a wall 3 . The container 1 is provided with an opening 4 and with a neck 5 that is provided with a thread 6 onto which a lid (not shown) can be screwed to close the container 1.

[0098] Fig. 2 depicts a cross-sectional view of the container 1 of Fig. 1 along the line II-II depicted in Fig. 1. As shown on the right-hand side of Fig. 2, this embodiment of a container 1 is comprises a wall 3 that in turn consists of four layers.

[0099] The four layers of the wall 3 comprise an outer layer 30 that is in contact with an external atmosphere surrounding the container 1.

[0100] The outer layer 30 comprises a base polymer in an amount of at least 95 wt%. The base polymer of the outer layer 30 is, in the case of this embodiment, a high density polyethylene (HDPE) with a Melt Flow Index (MFI) lower than 1 g / lOmin when measured according to ASTM D1238 (190°C, 2.16 kg) . However, other embodiments may comprise other base polymers, e.g., another polyethylene (PE) . The outer layer of this embodiment has a thickness that is higher than 0.4 mm. However, the thickness may be lower for other embodiments.

[0101] The four layers of the wall 3 also comprise a multilayer active structure 40 that is arranged inwards from the outer layer 30.

[0102] The embodiment of Fig. 1 also comprises an inner layer 35 that is located inwards with respect to the multilayer active structure 40. In other words, the multilayer active structure 40 is arranged between the outer layer 30 and the inner layer 35.

[0103] The inner layer 35 is in contact with an internal atmosphere of the container that is present in the inside space 2. The inner layer 35 comprises a base polymer in an amount of at least 95 wt%. The base polymer of the inner layer 35 is, in the case of this embodiment, a high density polyethylene (HDPE) . However, other embodiments may comprise other base polymers, e.g., another polyethylene (PE) . The inner layer of this embodiment has a thickness of less than 0.3 mm. However, the inner layer of other embodiments may be thicker.

[0104] The multilayer active structure 40 comprises a first active layer 41 comprising a base polymer and an active material. The first active layer 41 comprises a first wt% amount Cl of said active material.

[0105] The first wt% amount Cl of said active material in the first active layer 41 is, in the case of this embodiment, higher than 60 wt%. However, other embodiments may have lower wt% amounts .

[0106] The first active layer comprises at least 95 wt% of the same base polymer as the outer layer and desiccants. Other embodiments may additionally or alternatively comprise other active material (s) .

[0107] The base polymer and active material (s) together constitute at least 95 wt% of the first active layer 41.

[0108] The first active layer 41 comprises a base polymer and molecular sieve. The base polymer and molecular sieve together constitute at least 95 wt% of the first active layer 41.

[0109] The multilayer active structure 40 also comprises a second active layer 42. The second active layer 42 comprises all of the materials present in any of the other layers, that is, in the first active layer 41, the outer layer 30, and the inner layer 35.

[0110] In fact, the second active layer 42 to at least 95 weight% consists of the materials present in the first active layer 41, the outer layer 30, and the inner layer 35. The second active layer 40 comprises a second wt% amount C2 of said active material, wherein the second wt% amount C2 is smaller than the first wt% amount Cl.

[0111] The second active layer 42 is adjacent to the first active layer 41 and is located inwards with respect to the first active layer 41.

[0112] The container wall, as a whole, comprises between 60 wt% and 90 wt% of high density polyethylene (HDPE) , between 10 wt% and 40 wt% of molecular sieve, and between 0 wt% and 10 wt% of additives. The additives may include known colorant masterbatches and / or known processing aids.

[0113] The container 1 of Figs. 1 and 2 is an extrusion blow molded container having a stretch ratio higher than 30%. However, other containers may have lower stretch ratios.

[0114] The wall of the container 1 is regrindable such that it results in a reground material compound comprising at least one base polymer and at least one active material, with a Melt Flow Index (MFI) of between 0.1 and 2.0 g / lOmin, optionally between 0.1 and 1.0 g / lOmin, when measured according to ASTM D1238 (190°C, 2.16 kg) .

[0115] Fig. 3 depicts a multilayer extrusion blow molding machine 50 comprising a plurality of hoppers 51, 52, 53, 54 that is used for carrying out an embodiment of a method of manufacturing a container comprising an internal chamber for receiving sensitive products.

[0116] Fig. 4 illustrates a method of manufacturing a container comprising an internal chamber for receiving sensitive products .

[0117] Step SI is illustrated on the left-hand side of Fig. 4. It relates to the coextruding of different materials into a parison 55 using the multilayer extrusion blow molding machine 50 of Fig. 3. In the case of the illustrated embodiment of the method, the parison is tubularly shaped.

[0118] Two mold halves 60, 61 of a blow molding mold are closed around the parison 55 to enclose the parison 55 in a mold cavity of the blow molding mold.

[0119] At a bottom portion 56 of the parison 55 (see the second figure from the left in Fig. 4 illustrating step S2) , where the two mold halves 60, 61, meet, the parison 55 is, in step S2, crushed into a flat shape by a pinching-off portion of the blow molding mold.

[0120] In step S3, the parison 55 is inflated with air and pressed against the walls of the two mold halves 60, 61.

[0121] The parison 55 is then let cool and solidify in the mold cavity .

[0122] In step S4 (illustrated on the right-hand side in Fig. 4) , the two mold halves 60, 61 are opened. An excess material portion 57 is still attached to the bottom portion 56 of the parison 55. This excess material portion 57 would, in accordance with known methods, be cut off and then discarded.

[0123] In accordance with the embodiment, the excess material portion 57 is cut off, to form a pinch-off portion at the bottom of the container (as shown, e.g., in Figs. 1 and 2) , to thereby form the container 1 with the internal chamber being delimited by a wall having the pinch-off portion at the bottom.

[0124] The excess material portion 57 is reground into reground material and fed to at least one of the hoppers 51, 52, 53, 54 of the multilayer extrusion blow machine 50 shown in Fig. 3. The illustrated embodiment of the method further comprises a step of cutting off neck flash excess material 58 at a top portion of the parison 55 and thereby forming an opening at the top of the parison 55 .

[0125] Prior to the use of the extrusion blow molding machine 50 illustrated in Fig . 3 and to the carrying out of the method steps illustrated by Fig . 4 , an active compound suitable for extrusion blow molding (EBM) is prepared . To this end, a base polymer and an active material are mixed to obtain a homogenous active compound .

[0126] Bottles , as examples of containers in accordance with the present disclosure , were manufactured . The moisture protection efficiency of the manufactured bottles was then experimentally assessed .

[0127] In particular, 60 cm3bottles were manufactured ( this is described in more detail in the section on "examples" ) .

[0128] A data logger was placed inside manufactured bottles , and the bottles were sealed with an induction foil seal . The bottles containing the data logger were kept in a climate chamber set at 40 ° C and 75%RH .

[0129] The humidity inside the bottle was recorded by the data logger every 30 minutes .

[0130] After 26 days , the bottle was removed from the climate chamber and opened to remove the data logger and collect the %RH recorded over time by the data logger .

[0131] Fig . 5 depicts the obtained measurement results . As can be seen from Fig . 5 , showing the evolution of the %relative humidity in the 60 cm3bottle over time , the moisture inside the bottle dropped to 0 %RH within the 10 first days and from thereon remained at 0 %RH until the end of the test on the 26th day . The humidity inside the bottle dropped from initially 50 %RH to below 10 %RH within less than 24 hours .

[0132] The manufactured multilayer bottle acting as an active moisture barrier is efficient in both removing the moisture contained inside the bottle and blocking the ingress of moisture coming from the outer environment .

[0133] Measurements were also carried out over longer time periods .

[0134] Fig . 6 illustrates experimentally obtained results .

[0135] Again, a data logger was placed inside manufactured bottles , and the bottles were sealed with an induction foil seal . The bottles containing the data logger were kept in a climate chamber set at 40 ° C and 75%RH .

[0136] The humidity inside the bottle was recorded by the data logger every 30 minutes .

[0137] After 130 days , the bottle was removed from the climate chamber and opened to remove the data logger and collect the %RH recorded over time by the data logger .

[0138] As can be seen in the graph of Fig . 6 , showing the evolution of the %relative humidity in the 60 cm3bottle over time , the moisture inside the bottle was kept at 0 %RH over at least 100 days .

[0139] The multilayer bottle acting as an active moisture barrier is efficient in both removing the moisture contained inside the bottle and blocking the ingress of moisture coming from the outer environment .

[0140] Fig . 7 is a cross-sectional view of an embodiment of a container 1 for atmosphere control in accordance with thi s disclosure as well as an enlarged view of a part of a three- layer wall of the container 1 . Parts of the description would be analogous to the description provided for the embodiment of Figs. 1 and 2. A repetition will be omitted, but like reference signs are used to denote analogous components.

[0141] A difference between the embodiment of Fig. 7 and the embodiment of Figs. 1 and 2 is that the wall 3 of the embodiment of Fig. 7 comprises three (instead of four) layers.

[0142] The three layers of the wall 3 of the container 1 of Fig. 7 comprise an outer layer 30 that is in contact with an external atmosphere surrounding the container 1.

[0143] The outer layer 30 comprises a base polymer in an amount of at least 95 wt%. The base polymer of the outer layer 30 is, in the case of this embodiment, a high density polyethylene (HDPE) with a Melt Flow Index (MFI) lower than 1 g / lOmin when measured according to ASTM D1238 (190°C, 2.16 kg) . However, other embodiments may comprise other base polymers, e.g., another polyethylene (PE) . The outer layer of this embodiment has a thickness that is higher than 0.4 mm. However, the thickness may be lower for other embodiments.

[0144] The three layers of the wall 3 also comprise a multilayer active structure 40 that is arranged inwards from the outer layer 30.

[0145] The multilayer active structure 40 comprises a first active layer 41 comprising a base polymer and an active material. The first active layer 41 comprises a first wt% amount Cl of said active material.

[0146] The first wt% amount Cl of said active material in the first active layer 41 is, in the case of this embodiment, higher than 60 wt%. However, other embodiments may have lower wt% amounts . The first active layer comprises at least 95 wt% of the same base polymer as the outer layer and desiccants . Other embodiments may additionally or alternatively comprise other active material ( s ) .

[0147] The base polymer and active material ( s ) together constitute at least 95 wt% of the first active layer 41 .

[0148] The first active layer 41 comprises a base polymer and molecular sieve . The base polymer and molecular sieve together constitute at least 95 wt% of the first active layer 41 .

[0149] The multilayer active structure 40 also comprises a second active layer 42 . The second active layer 42 comprises all of the materials present in any of the other layers , that is , in the first active layer 41 and the outer layer 30 , respectively .

[0150] In fact , the second active layer 42 to at least 95 weight! consists of the materials present in the first active layer 41 and the outer layer 30 .

[0151] The second active layer 40 comprises a second wt% amount C2 of said active material , wherein the second wt% amount C2 i s smaller than the first wt% amount Cl .

[0152] The second active layer 42 is adj acent to the first active layer 41 and is located inwards with respect to the first active layer 41 .

[0153] The container 1 of Fig . 7 is an extrusion blow molded container having a stretch ratio higher than 30 % . However, other containers may have lower stretch ratios .

[0154] The wall of the container 1 is regrindable such that it results in a reground material compound comprising at least one base polymer and at least one active material , with a Melt Flow Index (MFI) of between 0.1 and 2.0 g / lOmin, optionally between 0.1 and 1.0 g / lOmin, when measured according to ASTM D1238 (190°C, 2.16 kg) .

[0155] Fig. 8 is a cross-sectional view of an embodiment of a container 1 for atmosphere control in accordance with this disclosure as well as an enlarged view of a part of a five- layer wall of the container 1.

[0156] Parts of the description would be analogous to the description provided for the embodiment of Figs. 1 and 2 and for the embodiment of Fig. 7. A repetition will be omitted, but like reference signs are used to denote analogous components.

[0157] A difference between the embodiment of Fig. 7 and the embodiment of Fig. 8 is that the wall 3 of the embodiment of Fig. 8 comprises five (instead of three) layers.

[0158] The five layers of the wall 3 comprise an outer layer 30 that is in contact with an external atmosphere surrounding the container 1.

[0159] The outer layer 30 comprises a base polymer in an amount of at least 95 wt%. The base polymer of the outer layer 30 is, in the case of this embodiment, a high density polyethylene (HDPE) with a Melt Flow Index (MFI) lower than 1 g / lOmin when measured according to ASTM D1238 (190°C, 2.16 kg) . However, other embodiments may comprise other base polymers, e.g., another polyethylene (PE) . The outer layer of this embodiment has a thickness that is higher than 0.4 mm. However, the thickness may be lower for other embodiments.

[0160] The five layers of the wall 3 also comprise a multilayer active structure 40 that is arranged inwards from the outer layer 30.

[0161] The embodiment of Fig. 8 also comprises an inner layer 35 that is located inwards with respect to the multilayer active structure 40. In other words, the multilayer active structure

[0162] 40 is arranged between the outer layer 30 and the inner layer

[0163] 35.

[0164] The inner layer 35 is in contact with an internal atmosphere of the container that is present in the inside space 2. The inner layer 35 comprises a base polymer in an amount of at least 95 wt%. The base polymer of the inner layer 35 is, in the case of this embodiment, a high density polyethylene (HDPE) . However, other embodiments may comprise other base polymers, e.g., another polyethylene (PE) . The inner layer of this embodiment has a thickness of less than 0.3 mm. However, the inner layer of other embodiments may be thicker.

[0165] The multilayer active structure 40 comprises a first active layer 41 comprising a base polymer and an active material. The first active layer 41 comprises a first wt% amount Cl of said active material.

[0166] The first wt% amount Cl of said active material in the first active layer 41 is, in the case of this embodiment, higher than 60 wt%. However, other embodiments may have lower wt% amounts .

[0167] The first active layer comprises at least 95 wt% of the same base polymer as the outer layer and desiccants. Other embodiments may additionally or alternatively comprise other active material (s) .

[0168] The base polymer and active material (s) together constitute at least 95 wt% of the first active layer 41.

[0169] The first active layer 41 comprises a base polymer and molecular sieve. The base polymer and molecular sieve together constitute at least 95 wt% of the first active layer 41. The multilayer active structure 40 also comprises a second active layer 42. The second active layer 42 comprises all of the materials present in any of the other layers, that is, in the first active layer 41, the outer layer 30, and the inner layer 35.

[0170] In fact, the second active layer 42 to at least 95 weight! consists of the materials present in the first active layer 41, the outer layer 30, and the inner layer 35.

[0171] The second active layer 40 comprises a second wt% amount C2 of said active material, wherein the second wt% amount C2 is smaller than the first wt% amount Cl.

[0172] The multilayer active structure 40 comprises an intermediate layer 43 that is located between the first active layer 41 and the second active layer 42. In other words, the multilayer active structure 40 of this embodiment is a three layer active structure. The intermediate layer 43 comprises a base polymer in an amount of at least 95 wt%. The base polymer of the intermediate layer 43 is, in the case of this embodiment, a high density polyethylene (HDPE) . However, other embodiments may comprise other base polymers, e.g., another polyethylene (PE) .

[0173] The container 1 of Fig. 8 is an extrusion blow molded container having a stretch ratio higher than 30%. However, other containers may have lower stretch ratios.

[0174] The wall of the container 1 is regrindable such that it results in a reground material compound comprising at least one base polymer and at least one active material, with a Melt Flow Index (MFI) of between 0.1 and 2.0 g / lOmin, optionally between 0.1 and 1.0 g / lOmin, when measured according to ASTM D1238 (190°C, 2.16 kg) .

[0175] Examples Examples of containers 1 in accordance with the present disclosure carrying out examples of methods in accordance with the present disclosure have been manufactured, and measurements have been performed on these containers 1 , to explore a number of their properties .

[0176] In particular, four-layer bottles with an inner capacity of 60 cm3, 100 cm3and 150 cm3were produced, as examples of containers , using multilayer extrusion blow molding .

[0177] The manufactured four-layer bottles comprise four layers : an inner layer, an active structure comprising a second active layer (adj acent to the inner layer) , and a first active layer (adj acent to the outer layer) , and an outer layer facing the outside .

[0178] The material composition of the manufactured bottles is summari zed in Table 1 : Table 1

[0179] The Melt Flow Index (MFI) of the constitutive material of each of the outer and inner layer was 0.22 g / lOmin when measured according to ASTM D1238 (190°C, 2.16 kg) .

[0180] The Melt Flow Index (MFI) of the reground material resulting from regrinding the material scrap from the blow molding process of the container may be determined by cutting a portion of the side wall of the container and regrinding it before measuring the MFI of the reground thus obtained according to ASTM D1238 (190°C, 2.16 kg) . Using this procedure, the Melt Flow Index (MFI) of the reground material resulting from regrinding the material scrap from the blow molding process of the container, used for the second active layer, was 0.18 g / lOmin when measured according to ASTM D1238 (190°C, 2.16 kg) .

[0181] The stretch ratio for each of the three bottle sizes is given in Table 2 below:

[0182] Table 2

[0183] The manufacturing of the bottles was carried out in accordance with an example of the disclosed method.

[0184] The compounding of the active compound of the first active layer (layer 2 in Table 1) comprised the following steps:

[0185] - 35 wt% of the melt HDPE base polymer and 65 wt% of the molecular sieve desiccant were mixed in a twin-screw extruder heated at about 200°C; - The blended mix of HDPE base polymer and molecular sieve desiccant was extruded into a strand;

[0186] - The strand was cooled and pelleti zed;

[0187] - Samples of the resulting active compound pellets were taken at the beginning, middle and end of a 7 -hour production trial at an output of 15 kg / hour, and the wt% amount Cl of the molecular sieve desiccant in the active compound was measured . The resulting data of the wt% amount Cl in the active compound are listed in Table 3 below :

[0188] Table 3

[0189] The compounding process was considered completed when the resulting active compound was homogenous with a wt% amount Cl of active material in the active compound constant within a tolerance of ±5% .

[0190] The selection of the HDPE base polymer used to obtain the active compound comprised the following steps :

[0191] - the active compound was used to form layer 2 of a multilayer extrusion blow molded test container having an internal chamber and the layer structure described in Table 1 above ;

[0192] - the Melt Flow Index (MFI ) of the reground material compound obtained by regrinding the wall of the test container was measured, and the Melt Flow Index (MFI ) of the HDPE base polymer used to obtain the active compound was adj usted until the Melt Flow Index (MFI ) of the reground material compound was between 0 . 1 and 1 . 0 g / l Omin when measured according to ASTM D1238 ( 190 ° C, 2 . 16 kg) . During each molding cycle, excess material was produced as scrap at the neck and bottom portions of the bottle. The extrusion blow molding (EBM) process scraps were reground to form the second active layer (layer 3 in Table 1) , instead of discarding the scrap material ('pinch-off' and 'neck flash' ) for each bottle. The scrap material from both the top and bottom was kept clean, and was reground and returned to the production process. 100% of the reground material can be reused if required.

[0193] A four-layer extrusion blow molding (EBM) machine as shown in Fig. 3, fitted with a bottle mold, was used to produce the exemplary four-layer bottles.

[0194] The hoppers of the extrusion blow molding (EBM) machine were filled as follows: hopper (1) , corresponding to the outer layer, and hopper (4) , corresponding to the inner layer, were filled with 97 wt% of HDPE and 3 wt% of white colorant masterbatch, hopper (2) , corresponding to the first active layer, was filled with the moisture absorbent compound prepared from the HDPE base polymer and the desiccant molecular sieve, and hopper (3) , corresponding to the second active layer, was filled with the moisture absorbent compound obtained from regrinding the extrusion blow molding (EBM) process scraps.

[0195] The extrusion of the parison was started and the consistency and straightness were checked. If the parison was not extruded correctly, the machine temperatures and pressures were adjusted until they were consistent.

[0196] Once the consistency and straightness of the parison were confirmed, the extrusion blow molding (EBM) machine was operated according to normal operating standards , and bottle samples were collected .

[0197] The bottle samples were cut and the layers were inspected using a microscope or another optical measurement device . Then, based on the measurements , the extruders were adj usted to achieve the desired thickness for each layer .

[0198] Once the thickness of each layer was confirmed, extrusion blow molding (EBM) operation resumed and the finished bottles were collected into an aluminum bag and the bag was sealed to preserve the absorbent properties of the bottles .

[0199] As a next step, layer thickness measurements were carried out . To this end, the bottles were cut in half vertically next to the seam line .

[0200] Then, a section of the bottle was cut out from the straight portion of the side wall . The cutout should be as close to the center of the bottle (vertically) as feasibly possible .

[0201] The section was then placed in a microtome and several slivers ( typically 2 -3 ) were cut and discarded until the cutting surface was fresh and free of nicks or distortions .

[0202] Then, a sliver to be measured was cut . It had to be less than 0 . 75 mm in thickness .

[0203] The sliver to be measured was placed in a fixture in such a way that the sliver laid flat , parallel to the surface .

[0204] The fixture was moved to an optical measurement device such as a SmartScope from OGP for measurement of the layer thicknesses . Thicknesses were measured perpendicular to the side wall of the bottle , at the middle of the sliver length . The measured layer thickness for each size of bottles are given in Table 4 below.

[0205] Table 4

[0206] An advantage of sandwiching at least one active layer (e.g., desiccant layer) between two 'virgin layers' of polymer resin may lie in the ability to incorporate thin active layer (s) (e.g., desiccant layer (s) ) . Within the meaning of the invention, it is understood that a 'virgin layer' of polymer resin is a layer of polymer resin not comprising an active material. In the above examples, this is the case of the outer layer and the inner layer, possibly also the intermediate layer .

[0207] In case of material compounds comprising a base polymer and a mineral fill such as a desiccant, the melt is prone to rupture at the interface between the polymer and the mineral fill (desiccant) .

[0208] In the molten form of the active polymer compound, e.g., desiccant polymer compound, the particles of active material, e.g., desiccant particles, form zones of increased fragility and the parison is prone to tear up with a breaking point starting from a particle of active material, e.g., desiccant particle .

[0209] By sandwiching the active polymer layer (s) , e.g., desiccant polymer layer (s) , between two adjacent layers comprising a 'virgin polymer' resin of the same chemical family as the one used in the active polymer compound, e.g., desiccant polymer compound, the thinness of the active polymer layer (s) is not limited by the need to produce an unsupported parison and the ability of stretching the active polymer layer (s) , e.g., desiccant polymer layer (s) , without causing tears during the subsequent blow molding sequence may be greatly improved.

[0210] This may be considered particularly important because: the active polymer, e.g., desiccant polymer, is more expensive than the barrier polymer typically used to produce moisture barrier containers; the amount of active polymer, e.g., desiccant polymer, used simply needs to be sufficient to provide the desired performance, and in a layer formed from an active polymer, e.g., desiccant polymer, it takes longer for a pollutant, e.g., a water molecule, to reach the particles located far from the surface; to keep appropriate reactivity of the active material, e.g., desiccant, it may be preferable to reduce the thickness of the active layer, e.g., desiccant layer. This may be all the more important as the preferred polymer for forming the active polymer compound, e.g., desiccant compound, is HDPE, known to be a moisture barrier material .

[0211] As a next step, the moisture protection efficiency of the manufactured bottles was assessed. The results of the measurements were described above in connection with Figs . 5 and 6 .

[0212] It will be apparent to those skilled in the art that various modifications and variations can be made in the disclosed devices and systems without departing from the scope of the disclosure . Other aspects of the disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the features disclosed herein . It is intended that the specification and examples be considered as exemplary only . Many additional variations and modifications are possible and are understood to fall within the framework of the disclosure .

Claims

Claims1. A container comprising an internal chamber for receiving sensitive products, the internal chamber being delimited by a wall consisting of three or more layers, the three or more layers comprising: an outer layer configured to be in contact with an external atmosphere surrounding the container, wherein the outer layer comprises a base polymer in an amount of at least 95 wt%; an active structure arranged inwards from the outer layer, wherein the active structure comprises: a first active layer comprising a base polymer and active material (s) , the first active layer comprising a first wt% amount Cl of said active material (s) , a second active layer comprising all the materials present in the other layers of the wall of the container, in an amount of at least 95 wt%, the second active layer comprising a second wt% amount C2 of said active material (s) , wherein the second wt% amount C2 is smaller than the first wt% amount Cl.

2. The container of claim 1, wherein a ratio of the second wt% amount C2 of said active material (s) in the second active layer to the first wt% amount Cl of said active material (s) in the first active layer is less than 0.75, preferably less than 0.6, preferably less than 0.5.

3. The container of claim 1 or 2, wherein the first wt% amount Cl of said active material (s) in the first active layer is equal to or higher than 50 wt%, optionally equal to or higher than 60 wt%.

4. The container of any one of the preceding claims, wherein the second active layer is arranged inwards from the first active layer.

5. The container of any one of the preceding claims, wherein the second active layer is adjacent to the first active layer .

6. The container of any one of the preceding claims, comprising an inner layer configured to be in contact with an internal atmosphere of the container, wherein the inner layer comprises a base polymer in an amount of at least 95 wt%, the active structure being arranged between the outer layer and the inner layer.

7. The container of claim 6, wherein the inner layer has a thickness of less than or equal to 0.5 mm, optionally less than or equal to 0.3 mm.

8. The container of any one of the preceding claims, wherein the base polymer of the outer layer is a polyethylene (PE) , optionally a high density polyethylene (HDPE) with a Melt Flow Index (MFI) lower than 1 g / lOmin when measured according to ASTM D1238 (190°C, 2.16 kg) .

9. The container of any one of the preceding claims, wherein the outer layer has a thickness of equal to or higher than 0.3 mm, optionally equal to or higher than 0.4 mm.

10. The container of any one of the preceding claims, wherein the first active layer comprises the same base polymer as the outer layer and active material (s) , optionally desiccant ( s ) , the base polymer and active material (s) together constituting at least 95 wt% of the first active layer .

11. The container of any one of the preceding claims, wherein the first active layer comprises a base polymer and molecular sieve, the base polymer and molecular sieve together constituting at least 95 wt% of the first activelayer .

12. The container of any one of the preceding claims, wherein the active structure comprises an intermediate layer arranged between the first active layer and the second active layer, the intermediate layer comprising a base polymer in an amount of at least 95 wt%.

13. The container of any one of the preceding claims, wherein the container wall comprises polyethylene (PE) , optionally high density polyethylene (HDPE) , and active material (s) , optionally desiccant ( s ) , the polyethylene (PE) and active material (s) together constituting at least 95 wt% of the container wall.

14. The container of any one of the preceding claims, wherein the container wall comprises polyethylene (PE) , optionally high density polyethylene (HDPE) , and molecular sieve, the polyethylene (PE) and molecular sieve together constituting at least 95 wt% of the container wall.

15. The container of any one of the preceding claims, wherein the container wall comprises: between 60 wt% and 90 wt% of high density polyethylene (HDPE) ,- between 10 wt% and 40 wt% of molecular sieve,- between 0 wt% and 10 wt%, optionally between 0 wt% and 5 wt%, of additives.

16. The container of any one of the preceding claims, wherein the container is an extrusion blow molded container having a stretch ratio equal to or higher than 25%, optionally equal to or higher than 30%.

17. The container of any one of the preceding claims, wherein the wall of the container is regrindable such that itresults in a reground material compound comprising at least one base polymer and at least one active material, with a Melt Flow Index (MFI) of between 0.1 and 2.0 g / lOmin, optionally between 0.1 and 1.0 g / lOmin, when measured according to ASTM D1238 (190°C, 2.16 kg) .

18. A container comprising an internal chamber for receiving sensitive products, the internal chamber being delimited by a wall comprising: an outer layer configured to be in contact with an external atmosphere surrounding the container, wherein the outer layer comprises a base polymer in an amount of at least 95 wt%; an active structure arranged inwards from the outer layer, wherein the active structure comprises a base polymer and at least one active material, wherein the wall of the container is regrindable such that it results in a reground material compound comprising at least one base polymer and at least one active material, with a Melt Flow Index (MFI) of between 0.1 and 2.0 g / lOmin, optionally between 0.1 and 1.0 g / lOmin, when measured according to ASTM D1238 (190°C, 2.16 kg) .

19. A method of manufacturing a container comprising an internal chamber for receiving sensitive products, the method comprising steps of: coextruding different materials into a parison with a multilayer extrusion blow molding machine comprising a plurality of hoppers; closing two mold halves of a blow molding mold around the parison to enclose the parison in a mold cavity of the blow molding mold, wherein at a bottom portion of the parison, where the two mold halves meet, the parison is compressed by a pinching-off portion of the blow molding mo 1 d ; inflating the parison and pressing it against thewalls of the mold; letting the parison cool and sol idify in the mold cavity; wherein excess material at the bottom portion of the parison is cut off , and the bottom portion of the parison is , after the cutting off , pinched to form a pinch-off portion, to thereby form the container with the internal chamber being delimited by a wall having the pinch-off portion at a bottom, wherein at least a part of the excess material is reground into reground material , and wherein the reground material is fed to at least one of the hoppers of the multilayer extrusion blow machine .20 . A container manufactured by the method of claim 19 .21 . A method for preparing an active compound suitable for extrusion blow molding (EBM) , comprising steps of :(a) mixing a base polymer and at least one active material so that the at least one active material is distributed within the base polymer to obtain a resulting active compound;(b) forming a container comprising an internal chamber by extrusion blow molding (EBM) , by coextruding : an outer layer configured to be in contact with an external atmosphere surrounding the container, wherein the outer layer comprises a base polymer in an amount of at least 95 wt% , and an active structure arranged inwards from the outer layer, wherein the active structure comprises said resulting active compound in such a way that a wt% amount of said resulting active compound in the container is at least 20 wt% ;( c) optionally, adj usting a Melt Flow Index (MFI ) of the base polymer used to obtain the resulting active compound and repeating steps (a) and (b) , until a Melt Flow Index (MFI ) of a reground material compound, obtained byregrinding the wall of the container, is between 0.1 and 2.0 g / lOmin, optionally between 0.1 and 1.0 g / lOmin, when measured according to ASTM D1238 (190°C, 2.16 kg) .

22. An active compound obtainable by the method of claim 21, wherein a wt% amount of the at least one active material in the active compound is equal to or higher than 50 wt%, optionally equal to or higher than 60 wt%.

23. The active compound of claim 22, wherein the at least one active material is at least one desiccant, optionally molecular sieve.

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