Method of manufacturing a receptacle for cosmetic compositions, receptacle obtainable by the method, and use of the receptacle for a cosmetic composition

Abstract

The present invention relates to a method of manufacturing a receptacle (1) for a cosmetic composition, in particular round plastic bottle, wherein the receptacle (1) is made from a plastic preform (P) by means of blow moulding, in particular stretch blow moulding, wherein the method comprises the steps of: - providing, in a first step (a), a plastic preform (P) having an axial direction (Ax) for manufacturing a receptacle (1) extending along the axial direction (Ax), wherein the plastic preform (P) comprises a circumferential preform wall (BWP) that has a uniform thickness (dP); - heating, in a second step (c), the plastic preform (P) by means of a heat source (HS) to obtain a heated plastic preform (P), wherein heating the plastic preform (P) includes non-uniformly heating an outer periphery (OP) of the circumferential preform wall (BWP) in a fixed rotational arrangement with respect to the heat source (HS), wherein, by heating the outer periphery (OP) of the circumferential preform wall (BWP), the temperature in at least one first angular section (SC1) of the circumferential preform wall (BWP) is raised to higher level than the temperature in at least one second angular section (SC2) of the circumferential preform wall (BWP), wherein each first angular section (SC1) and each second angular section (SC2) extends over an limited angular range (AnR) of less than 180°, in particular less than 90° about the axial direction (Ax); - blow moulding, in particular stretch blow moulding, in a third step (e), the heated plastic preform (P) to obtain the receptacle (1) extending along the axial direction (Ax) and including a circumferential wall (BW), wherein a first wall segment (A) of the circumferential wall (BW) is obtained by blow moulding the at least one first angular section (SC1) of the circumferential preform wall (BWP) and a second wall segment (B) of the circumferential wall (BW) is obtained by blow moulding the at least one second angular section (SC2) of the circumferential preform wall (BWP), wherein a thickness of the second wall segment (B) is larger than a thickness of the first wall segment (A).

Description

[0001] Method of manufacturing a receptacle for cosmetic compositions, receptacle obtainable by the method, and use of the receptacle for a cosmetic composition

[0002] Description

[0003] FIELD OF THE INVENTION

[0004] The present invention relates to methods of manufacturing receptacles from polymers and receptacles obtained by such processes. More specifically, the invention relates to the manufacturing of receptacles for cosmetic compositions, like, for example round plastic bottles comprising a bottle neck, a bottle bottom and a circumferential wall. The present invention further relates to the use of such receptacles for dispensing, transporting and / or storing cosmetic compositions, in particular hair care products, like, for example, shampoos or hair conditioners. The present invention also relates to a container comprising the receptacle, in particular round plastic bottle, and a cap.

[0005] BACKGROUND OF THE INVENTION

[0006] In the cosmetics industry, clever packaging utilizing sustainable packaging materials has become increasingly important over the past years. For example, it is favourable to avoid non-recyclable polymers as constituents in packages for cosmetic products in order to facilitate the end-of-life management of such packages. For this and other reasons, recycled or recyclable polymers such as polyethylene (PE) or polyethylene terephthalate (PET) are increasingly being preferred as constituents for containers intended to contain cosmetic compositions. Round bottles made from recycled polyethylene (PE) or polyethylene terephthalate (PET) are frequently used for containing liquid cosmetic compositions such as shampoos or hair conditioners. Typically, a cap is screwed or snapped on the container. The liquid composition contained in the container may be dispensed therefrom by squeezing an outer periphery of the container. However, it might be difficult for the consumer to squeeze out a satisfiable amount of the liquid composition contained in a rather stiff receptacle, in particular when the receptacle has already partially been emptied. Dispensing the remaining content and / or fully emptying the known receptacles, may require additional effort from the consumer. In some cases, the receptacle has to be shaken several times or cut open to reach the remaining content, which has generally a negative impact on the user experience.

[0007] JPH 0449023 A discloses a method for producing a bottle from a bottomed cylindrical parison consisting of a resin such as polyethylene terephthalate by stretch blow moulding. JPH 0449023 A teaches to regulate the local temperature of the parison before stretch blow moulding to obtain wall sections with different thickness. The temperature of the parison is regulated by inserting a temperature regulating bar and locally cooling the parison from the inside. The temperature regulating bar includes projections to facilitate local cooling of the inner surface of the parison in proximity of the projections. The obtained bottle may have longitudinal, stripe-shaped sections of increased thickness which correspond to the low temperature areas of the parison before blow moulding.

[0008] JPH 06255643 A relates to the manufacture of a bottle container from a preform by means of blow moulding. The preform is heated substantially at the same temperature in a circumferential direction and a high temperature heating portion and a low temperature heating portion are alternately generated in an axial direction. In particular, the preform is rotated around its axis to facilitate heating thereof to substantially the same temperature in the circumferential direction.

[0009] It is an object of the present invention to provide a method of manufacturing a receptacle, in particular plastic bottle, for a cosmetic composition and / or, respectively, which is capable to at least partially overcome the aforementioned disadvantages of the prior art. In particular, it is an object of the present invention to provide a receptacle that is adapted to convey an improved user experience. Even more particularly, it is an object to provide a method of manufacturing that can readily be implemented in existing assembly lines, preferably at relatively low costs.

[0010] SUMMARY OF THE INVENTION

[0011] The aforementioned object is obtained by a method for manufacturing a receptacle, in particular round plastic bottle, for a cosmetic composition including the features of the appended claim 1 and, respectively, a receptacle including the features of the appended claim 11. Possible embodiments of the invention are given in the dependent claims.

[0012] In an aspect of the invention, a method of manufacturing a receptacle for a cosmetic composition, in particular round plastic bottle is provided. The receptacle is made from a plastic preform by means of blow moulding or stretch blow moulding. The method at least comprises the steps of:

[0013] - providing, in a first step, a plastic preform that has an axial direction for manufacturing a receptacle extending along the axial direction, wherein the plastic preform comprises a circumferential preform wall that has a uniform thickness; - heating, in a second step, the plastic preform by means of a heat source to obtain a heated plastic preform, wherein heating the plastic preform includes non-uniform ly heating an outer periphery of the circumferential preform wall in a fixed rotational arrangement with respect to the heat source, wherein, by heating the outer periphery of the circumferential preform wall, the temperature in at least one first angular section of the circumferential preform wall is raised to a higher level than the temperature in at least one second angular section of the circumferential preform wall, wherein each first angular section and second angular section extends over an angular range of less than 180° about the axial direction, in particular wherein each of the at least one first angular section and second angular section of the circumferential preform wall extends over an angular range of 90° or less about the axial direction;

[0014] -blow moulding, in particular stretch blow moulding, in a third step, the heated plastic preform to obtain the receptacle extending in the axial direction and including a circumferential wall, wherein a first wall segment of the circumferential wall is obtained by blow moulding the at least one first angular section of the circumferential preform wall and a second wall segment of the circumferential wall is obtained by blow moulding the at least one second angular section of the circumferential preform wall, wherein a thickness of the second wall segment is larger than a thickness of the first wall segment.

[0015] The receptacle made from the preform by the proposed method has a hollow body with a section that extends in the axial direction. The circumferential wall of the receptacle may circumferentially be arranged around the axial direction. Likewise, the circumferential preform wall of the preform may circumferentially be arranged around the axial direction. In some embodiments, the circumferential wall of the receptacle may have the shape of a cylinder. According to various embodiments of the invention, the preform and the receptacle may have approximate axial symmetry with respect to the axial direction. Terms relating to an approximate axial symmetry of an element should generally be understood in the sense that the element comprises a body which has essentially a rotational symmetry, in particular continuous or discrete rotational symmetry, around the axial direction. In case of the receptacles, it is in particular to be understood that this property relates to the body part of the receptacle holding the compositions, which is bounded by the circumferential wall in a radial direction perpendicular to the axial direction. Deviations from a strict rotational symmetry, like, for example, projections provided by decor elements or functional elements adapted to provide or mount closure means of the receptacle and / or receptacles having oval, square or rectangular cross-sections are understood to be encompassed by this definition. During non-uniform heating of the preform, heat is disposed unevenly in the circumferential preform wall. The heat is disposed by heating the outer periphery of the preform, which was found to be particularly beneficial to produce receptacles having wall strengths that vary smoothly along the circumference of the body portion. In particular, exposing the preform to heat from the outside allows for manufacturing receptacles having wall strengths that gradually vary along the circumference of the receptacle. The body portion of the receptacle may in particular be more flexible in the areas of the first wall segments. These areas may in particular be designed to be easily squeezed by the consumer. Even more particularly, the first wall segments may provide well-defined areas of the body portion of the receptacle that are configured to be elastically deformed to facilitate dispensing the content, in particular cosmetic composition, contained in the receptacle. On the other hand, the second wall segments may provide improved mechanical stability. Preferably, the first and second wall segments are dimensioned and configured to provide a receptacle, like for example a bottle, that is stable in shape.

[0016] Terms relating to a “thickness of a wall” or a “wall strength” may be used interchangeably through this disclosure. Terms relating to an angle or an angular range “about” or “around” a direction or axis may be used interchangeably through this disclosure.

[0017] According to various possible embodiments of the present invention, each first angular section and second angular section of the circumferential preform wall may extend over an angular range of at least 5° about the axial direction, in particular over an angular range of 45° or more about the axial direction.

[0018] According to various possible embodiments of the present invention, at least one first angular section of the circumferential preform wall may be arranged with respect to the at least one second angular section of the circumferential preform wall at an angle of 70° to 110° about the axial direction, preferably at an angle of 80° to 100° about the axial direction, most preferably at an angle of approximately 90°about the axial direction.

[0019] In the second step, the step of non-uniform ly heating the outer periphery of the circumferential preform wall may, according to some embodiments of the invention, include the step of heating the first angular section of the circumferential preform wall to a first temperature Tcin the range from 80°C to 120°C.

[0020] Optionally, the second step of heating the plastic preform may include at least approximately uniformly pre-heating the outer periphery of the circumferential preform wall in an angular range of 360° about the axial direction by rotating, in particular continuously rotating the plastic preform during pre-heating around the axial direction. In principle pre-heating may occur before or after non-uniform heating of the preform. Preferably, uniform pre-heating occurs before non-uniform heating of the preform.

[0021] Optionally, the step of at least approximately uniformly pre-heating the outer periphery of the circumferential preform wall may include heating a circumferential section of the circumferential preform wall in an angular range of 360° about the axial direction to a pre-heat temperature TBin the range from 80°C to 120°C.

[0022] According to preferred embodiments of the invention, the plastic preform is provided by an injection moulding process, in particular made from polyethylene terephthalate (PET).

[0023] According to various embodiments of the invention, non-uniformly heating the outer periphery of the circumferential preform wall in the fixed rotational arrangement includes maintaining an angular orientation of the preform about the axial direction relative to the heating source during non-uniform heating.

[0024] In some embodiments of the invention, the non-uniformly heating of the preform includes maintaining the angular orientation of the preform about the axial direction relative to the heating source while moving the preform in a direction perpendicular to the axis of rotation.

[0025] According to various embodiments of the invention, non-uniformly heating the outer periphery of the circumferential preform wall in the fixed rotational arrangement includes introducing the plastic preform into a heating device and / or maintaining an angular orientation of the preform about the axial direction relative to the heating device during non-uniform heating.

[0026] According to various embodiments of the invention, non-uniformly heating the outer periphery of the circumferential preform wall includes heating the outer periphery of the circumferential preform wall in two first angular sections, in particular to the first temperature Tc, that are arranged diametrically opposite each other. In other words, the two first angular sections are arranged at an angle of 180° this respect to the axial direction.

[0027] The outer periphery of the circumferential preform wall may be uniformly or non- uniformly heated in the axial direction, in particular during uniform or non-uniform heating of the outer periphery of the circumferential preform wall. The first wall segment may be provided to extend over a substantial part of the body portion of the receptacle in the axial direction. The receptacle provided by the disclosed method may in particular include a touch area extending of a substantially axial section of the receptacle that may easily be deformed.

[0028] In another aspect of the invention, a receptacle is provided. The receptacle may in particular be obtained from the method of manufacturing disclosed herein.

[0029] The receptacle has a body that gradually varies along the circumference around the axial direction. The body includes the circumferential wall at least one first segment of reduced thickness. The thickness of the first wall segment or segments of the circumferential wall may in particular be smaller than an average wall strength of the circumferential wall. The circumferential wall of the receptacle also includes at least one second segment of increased thickness. The thickness of the second wall segment or segments of the circumferential wall may in particular be larger than an average wall strength of the circumferential wall.

[0030] According to various embodiments of the invention, each of the at least one first wall segment and each of the at least one second wall segment of the circumferential wall extends over an angular range of less than 180°, in particular over an angular range of 90° or less, about the axial direction.

[0031] According to various embodiments of the invention, each first wall segment and each of the at least one second wall segment of the circumferential wall extends over an angular range of at least 5°, in particular over an angular range of 45° or more, about the axial direction.

[0032] According to various embodiments of the invention, the at least one first wall segment of the circumferential wall is arranged with respect to the at least one second wall segment of the circumferential wall at an angle of 70° to 110° about the axial direction, preferably at an angle of 80° to 100° about the axial direction, most preferably at an angle of approximately 90° about the axial direction.

[0033] According to various embodiments of the invention, the circumferential wall includes two first wall segments that are arranged diametrically opposite to each other with respect to the axial direction, in particular to provide a receptacle with touch areas that are disposed on the body portion diametrically opposite to each other. Another aspect of the invention relates to the use of the receptacle disclosed herein for transporting, storing and / or dispensing a cosmetic composition, in particular haircare product, such as shampoo or hair conditioner.

[0034] The receptacle may relate to a bottle. In another aspect of the invention, a round plastic bottle is provided. The round plastic bottle comprises a bottle neck, a bottle bottom, and the circumferential wall. The circumferential wall comprises at least one first wall segment and at least one second wall segment, wherein a thickness of the second wall segment is larger than a thickness of the first wall segment.

[0035] Rather surprisingly, it was found that the round plastic bottle can easily be squeezed. The consumer has a more comfortable squeeze experience when squeezing the cosmetic composition out of the round plastic bottle of the present disclosure as compared to the squeeze experience provided by the available plastic bottles of the prior art. The round plastic bottle further facilitates dispensing its content even when the content of the bottle decreases. The bottle provides a receptacle that may easily be squeezed, in order facilitate complete dispense of the liquid composition contained therein.

[0036] Moreover, the round plastic bottle may be produced from recycled polyethylene terephthalate (PET), which may provide improved environmental sustainability and may also result in lower production costs.

[0037] The round plastic bottle of the present disclosure has a round shape but is adapted to facilitate squeezing similar to bottles having oval shapes or cross-sections. The round shape helps to reduce the amount of plastic material used during production, in particular when considering the capacity provided by the round plastic bottle in comparison to bottles exhibiting non-circular cross-sections.

[0038] According to various possible embodiments of the present invention, the first wall segment of the round plastic bottle for cosmetic compositions may have a thickness in the range from 0,2 mm to 1 ,0 mm, preferably in the range from 0,2 mm to 0,8 mm, more preferably in the range from 0,2 mm to 0,5 mm.

[0039] According to various possible embodiments of the present invention, the second wall segment of the round plastic bottle for cosmetic compositions may have a thickness in the range from 0,4 to 2,0 mm, preferably in the range from 0,4 to 1 ,8 mm, more preferably in the range from 0,4 to 1 ,4 mm. According to various possible embodiments of the present invention, a ratio between the thickness of the first wall segment and the thickness of the wall of the second wall segment may take a value in the range from 10% to 60%, preferably in the range from 20% to 40%.

[0040] According to various possible embodiments of the present invention, a ratio between the thickness of the first wall segment and the thickness of the second wall segment may take a value in the range from 1 :10 to 1 :1.7, more preferably in the range from 1 :5 to 1 :2.5.

[0041] In at least one embodiment, the round plastic bottle is produced from polyethylene terephthalate (PET), preferably from recycled polyethylene terephthalate (PET) or comprises polyethylene terephthalate (PET), preferably recycled polyethylene terephthalate (PET), as a constituent.

[0042] According to various possible embodiments of the present invention, a translucency of the round plastic bottle may range from transparent to opaque.

[0043] According to various possible embodiments of the present invention, the round plastic bottle may have a capacity in the range between 50 ml and 500 ml, more preferably in the range between 200 ml and 400 ml.

[0044] Terms relating to the “capacity” of a receptacle and the “volume” of a receptacle, in particular the round plastic bottle, may be used interchangeably throughout this disclosure.

[0045] In at least one embodiment, the circumferential wall comprises two first wall segments and two second wall segments, wherein

[0046] - the two first wall segments are arranged opposite to each other, in particular diametrically opposite to each other; and

[0047] - the two second wall segments are arranged opposite to each other, in particular diametrically opposite to each other.

[0048] According to various possible embodiments of the present invention, the first wall segment is positioned with respect to the second wall segment at an angle about the axial direction that lies in the range from 70° to 110°, more preferably in the range from 80° to 100°, most preferably at an angle of 90°. In at least one embodiment, the round plastic bottle for cosmetic compositions is produced by stretch blow moulding (SBM).

[0049] According to various embodiments of the method of manufacturing the round plastic bottle, the round plastic preform may be provided by an injection moulding process.

[0050] The round plastic preform may, for example, be produced from polyethylene terephthalate (PET).

[0051] Another aspect of the invention relates to the use of the receptacle, in particular round plastic bottle, for transporting, dispensing or storing cosmetic compositions, like haircare products, for example shampoos or hair conditioners.

[0052] Another aspect of the invention relates to a container comprising the receptacle, in particular round plastic bottle, and a cap that provides a closure for the receptacle.

[0053] DETAILED DESCRIPTION OF THE INVENTION

[0054] In the following, exemplary embodiments of the present invention will be described in more detail with respect to the accompanying drawings, in which

[0055] Fig. 1 depicts a schematic illustration of a receptacle, in particular bottle, according to an embodiment of the invention;

[0056] Fig. 2 shows a cross section of the receptacle in a plane perpendicular to an axial direction;

[0057] Fig. 3 shows a second embodiment of the receptacle, in particular bottle;

[0058] Fig. 4 shows a third embodiment of the receptacle, in particular bottle;

[0059] Fig. 5 depicts a schematic illustration of a plastic preform used to manufacture receptacles according to various embodiments;

[0060] Fig. 6 illustrates schematically heating of the plastic preform in fixed rotational arrangement with respect to a heat source;

[0061] Identical or corresponding elements are indicated in all figures by corresponding reference symbols. The receptacle 1 of various embodiments may in particular be embodied by a round plastic bottle. In the following, embodiments of the receptacle 1 extending substantially in an axial direction may in particular be described with reference to a round plastic bottle as a possible embodiment.

[0062] As indicated in particular in Fig. 1 , the receptacle 1 , in particular round plastic bottle, for cosmetic compositions comprises a bottle neck BN, a bottle bottom BB and a circumferential wall BW, wherein the circumferential wall BW comprises at least one first wall segment A and at least one second wall segment B, wherein the wall of the second wall segment B is thicker than the wall of the first wall segment A. The circumferential wall BW may also be referred to as bottle wall BW. The round plastic bottle for cosmetic compositions comprises a bottle neck BN, a bottle bottom BB and a circumferential wall BW (also: bottle wall BW).

[0063] Preferably, the bottle neck BN surmounts the circumferential wall BW and defines an opening of the round plastic bottle. The circumferential wall B preferably has a round cylindrical shape, wherein the bottle bottom BB is the lower base area of the round cylindrical shape. Thus, the bottle bottom BB has preferably a round shape.

[0064] Preferably, the round cylindrical shape is open at the top and the circumferential wall BW builds a shoulder there with a shoulder angle in the range from 5 to 50°. Preferably, the transition from the bottle bottom BB to the circumferential wall BW and, preferably, the transition to the shoulder is smoothed.

[0065] In case the bottle bottom BB has a round shape, the bottle bottom BB preferably has a diameter dBBin the range from 30 to 80 mm. In case the circumferential wall BW has a round cylindrical shape, the circumferential wall BW preferably has a diameter dBWin the range from 50 to 80 mm. The diameter dBWof the circumferential wall BW is determined at half the height hBWof the circumferential wall BW as shown in Figures 1 , 3 and 4, The height hBWof the circumferential wall BW is the distance between the bottle bottom BB and the bottle neck BN. The height hBWof the circumferential wall BW is preferably in the range from 90 to 130 mm. In a preferred embodiment, the round plastic bottle has a total height h in the range from 120 to 160 mm. The total height h of the round plastic bottle is defined as the distance between the bottle bottom BB and the opening of the bottle neck BN as shown in Figures 3 and 4.

[0066] In a preferred embodiment, a cap is mounted onto the round plastic bottle, preferably onto the bottle neck of the round plastic bottle. The embodiment comprising a round plastic bottle and a cap is also called “a container”.

[0067] A container may comprise the round plastic bottle and a cap. In a preferred embodiment, the cap is configured to cooperate with the bottle neck, in particular by screwing or snapping on, in order to seal the inventive round plastic bottle. In one embodiment, the cap has the shape of a mushroom. However, also other shapes of the cap are possible. For example, the cap has a flip-top closure. In a preferred embodiment, the cap is produced from polypropylene (PP).

[0068] In figure 1 , a receptacle 1 , in particular round plastic bottle, and, respectively, a container 100 is shown. The round plastic bottle comprises a bottle neck BN, a bottle bottom BB and a circumferential wall BW. The bottle neck BN surmounts the circumferential wall BW and defines an opening of the round plastic bottle 1 . The circumferential wall BW has a round cylindrical shape, wherein the round-shaped bottle bottom BB provides the lower base area of the round cylindrical shape. The round cylindrical shape is open at the top and the circumferential wall BW builds a shoulder with a shoulder angle of 45°. The transition from the bottle bottom BB to the circumferential wall BW and the transition to the shoulder is round. A cap C is mounted onto the bottle neck BN of the round plastic bottle 1. The embodiment comprising the inventive round plastic bottle 1 and the cap C may also be referred to as container. The cap C has the shape of a mushroom. The circumferential wall BW has a diameter dBWin the range from 55 to 60 mm. The diameter dBWof the circumferential wall BW may be determined at half the height hBWof the circumferential wall BW. The height hBWof the circumferential wall BW is the distance between the bottle bottom BB and the bottle neck BN.

[0069] In figure 3, another embodiment of the receptacle 1 , in particular round plastic bottle 1 is shown. The round plastic bottle comprises a bottle neck BN, a bottle bottom BB and a circumferential wall BW. The bottle neck BN surmounts the circumferential wall BW and defines an opening of the round plastic bottle. The circumferential wall BW has a round cylindrical shape, wherein the round-shaped bottle bottom BB is the lower base area of the round cylindrical shape. The round cylindrical shape is open at the top. The transition from the bottle bottom BB to the circumferential wall BW and the transition to the bottle neck BN is round. The circumferential wall BW has a diameter dBWof 70 mm. The diameter dBWof the circumferential wall BW may be determined at half the height hBWof the circumferential wall BW. The height hBWof the circumferential wall BW may be taken the distance between the bottle bottom BB and the bottle neck BN. The round plastic bottle has a total height h in the range from 130 to 135 mm. The total height h of the round plastic bottle is defined as the distance between the bottle bottom BB and the opening of the bottle neck BN.

[0070] In figure 4, another embodiment of the receptacle, in particular round plastic bottle 1 is shown. The round plastic bottle 1 comprises a bottle neck BN, a bottle bottom BB and a circumferential wall BW. The bottle neck BN surmounts the circumferential wall BW and defines an opening of the round plastic bottle 1 . The circumferential wall BW has a round cylindrical shape, wherein the round-shaped bottle bottom BB is the lower base area of the round cylindrical shape. The round cylindrical shape is open at the top and the circumferential wall BW builds a shoulder there. The transition from the bottle bottom BB to the circumferential wall BW and the transition to the shoulder is round. The circumferential wall BW has a diameter dBWin the range from 60 to 70 mm. The diameter dBWof the circumferential wall BW is determined at half the height hBWof the circumferential wall BW. The height hBWof the circumferential wall BW may be determined by the distance between the bottle bottom BB and the bottle neck BN. The round plastic bottle has a total height h in the range from 140 to 145 mm. The total height h of the round plastic bottle may be determined by the distance between the bottle bottom BB and the opening of the bottle neck BN.

[0071] The circumferential wall BW comprises at least one first wall segment A and at least one second wall segment B, wherein the wall of the second wall segment B is thicker than the wall of the first wall segment A.

[0072] The receptacle 1 can comprise any number of first wall segments A and any number of second wall segments B desired by a skilled person.

[0073] However, in a preferred embodiment, the circumferential wall BW comprises two first wall segments A and two second wall segments B, wherein the two first wall segments A are arranged diametrically opposite each other, and the two second wall segments B are arranged diametrically opposite each other.

[0074] Throughout this disclose, a diametrically opposite arrangement of wall segments or angular sections is in particular to be understood as an arrangement of the respective elements at an angle An of approximately 180° about the axial direction Ax. As indicated in figure 2, the circumferential wall BW may comprise two first wall segments A and two second wall segments B, wherein the two first wall segments A are arranged diametrically opposite to each other, and the two second wall segments B are arranged diametrically opposite to each other. The receptacle 1 of this embodiment may in particular comprise relative flexible areas provided by the two first wall segments A of reduced wall strength that are disposed on opposite sides of a body part of the receptacle 1 .

[0075] Preferably, the first wall segments A are arranged with respect to the second wall segments B at an angle An in the range from 70° to 110°, more preferably at an angle An in the range from 80° to 100°, most preferably, as indicated in figure 2, at an angle An of approximately 90°, about the axial direction Ax.

[0076] As illustrated in particular in figure 2, the receptacle 1 for a cosmetic composition may include a circumferential wall BW which comprises two first wall segments A and two second wall segments B, wherein the two first wall segments A are arranged diametrically opposite each other, and the two second wall segments B are arranged diametrically opposite each other.

[0077] The at least one first wall segment A may have any thickness desired by a skilled person, provided that the wall of the at least one first wall segment A is thinner than the wall of the at least one second wall segment B. More particularly, the at least one first wall segment A may have a thickness that is smaller than an average thickness of the circumferential wall BW. Respectively, the wall of the at least one second wall segment B may be larger than an average thickness of the circumferential wall BW.

[0078] In a preferred embodiment, the first wall segment A has a thickness in the range from 0,2 mm to 1 ,0 mm, preferably in the range from 0,2 mm to 0,8 mm, more preferably in the range from 0,2 mm to 0,5 mm. The thickness of the first wall segment A may in particular be determined by the thinnest part of the circumferential wall BW. The circumferential wall BW may in particular have an average thickness in the range between 0,3 mm to 0,6 mm.

[0079] Another aspect of the present invention also relates to a receptacle 1 for cosmetic compositions, wherein the first wall segment A has a thickness in the range from 0,2 mm to 1 ,0 mm. The at least one second wall segment B can also have any thickness desired by a skilled person, provided that the thickness of the at least one second wall segment B is larger than the thickness of the at least one first wall segment A.

[0080] In another preferred embodiment, the second wall segment B may have a thickness in the range from 0,4 mm to 2,0 mm, preferably in the range from 0,4 to 1 ,8 mm, more preferably in the range from 0,4 mm to 1 ,4 mm. The thickness of the second wall segment B may in particular be determined by the thickness of the thickest part of the circumferential wall BW.

[0081] According to various embodiments, the thickness of the second wall segment B may take any value in the range from 0,4 mm to 2,0 mm.

[0082] The wall thickness of the circumferential wall BW may gradually vary along its circumference around the axial direction. In preferred embodiments, the segments A and B merge seamlessly.

[0083] In various embodiments, it may be preferred that the thickness of the first wall segment A is in the range from 10 to 60%, preferably in the range from 20 to 40%, of the thickness of the wall of the second wall segment B.

[0084] It may also be preferred that the ratio of the thickness of the wall of the first wall segment A to the thickness of the wall of the second wall segment B is in the range from 1 :10 to 1 :1 .7, more preferably in the range from 1 :5 to 1 :2.5.

[0085] In Figure 2, a cross section of the circumferential wall BW is shown. The circumferential wall BW comprises two first wall segments A and two second wall segments B, wherein the wall of the second wall segment B is thicker than the wall of the first wall segment A. The two first wall segments A are arranged diametrically opposite each other, and the two second wall segments B are arranged diametrically opposite each other. The first wall segments A are positioned relative to the second wall segments B at an angle An of 90 degree about the axial direction An. The segments A and B merge seamlessly.

[0086] The receptacle 1 , in particular round plastic bottle, is preferably produced from polyethylene terephthalate (PET), more preferably from recycled polyethylene terephthalate (PET). A translucency of the receptacle 1 , in particular round plastic bottle can range from transparent to opaque. The receptacle 1 , in particular round plastic bottle can be dimensioned to contain any desired volume of the cosmetic composition. Preferably, the capacity of the round plastic bottle 1 may be in the range from 50 ml to 500 ml, more preferably from 200 ml to 400 ml. Preferably, the receptacle 1 , in particular round plastic bottle is produced by stretch blow moulding (SBM).

[0087] In the following, various embodiments relating to methods of manufacturing the receptacle 1 , in particular round plastic bottle are described in more detail.

[0088] A method of manufacturing the receptacle 1 for a cosmetic composition, comprises the steps of:

[0089] - providing, in a first step a) (see in particular fig. 5), a plastic preform P for manufacturing a receptacle 1 extending in the axial direction Ax. The plastic preform P comprises a circumferential preform wall BWP, that has a uniform thickness dP;

[0090] - heating, in a second step c) (see in particular fig. 6), the plastic preform P by means of a heat source HS to obtain a heated plastic preform P. Heating of the plastic preform P includes non-uniform ly heating an outer periphery OP of the circumferential preform wall BWPin a fixed rotational arrangement with respect to the heat source HS.

[0091] In particular, non-uniform ly heating the outer periphery OP of the circumferential preform wall BWP in the fixed rotational arrangement may include introducing the plastic preform P into a heating device 80 and maintaining an angular orientation of the preform P about the axial direction Ax relative to the heating device 80 during non-uniform heating, as indicated in Fig. 6.

[0092] By non-uniformly heating the outer periphery OP of the circumferential preform wall BWP, the temperature in at least one first angular section SC1 of the circumferential preform wall BWPis raised to higher level than the temperature in at least one second angular section SC2 of the circumferential preform wall BWP(see in particular in particular Figs. 2 and 6).

[0093] In the fixed rotational arrangement, a rotation of the preform P around the axial direction Ax is suppressed to establish non-uniform heating of the circumferential preform wall BWP. However, the preform P may be linearly moved in a direction 5, as indicated in Fig. 6, perpendicular to the axial direction Ax, which may help to smoothen the heat deposited along the axial direction Ax.

[0094] Each first angular section SC1 and each second angular section SC2 may extend over a limited angular range AnR of less than 180°, preferably less than 90° about the axial direction Ax, as in particular illustrated in Fig. 2, and extend along an axial length parallel to the axial direction Ax;

[0095] The non-uniform ly heated preform P is blow moulded, in particular stretch blow moulded, in a third step e) to obtain the receptacle 1 extending in the axial direction Ax and including the circumferential wall BW. The first wall segment A of the circumferential wall BW is obtained by blow moulding the at least one first angular section SC1 of the circumferential preform wall BWP. A second wall segment B of the circumferential wall BW is obtained by blow moulding the at least one second angular section SC2 of the circumferential preform wall BWP. A thickness of the second wall segment B is, as in particular indicated in Fig. 2, larger than a thickness of the first wall segment A.

[0096] As indicated in Fig. 2 each first angular section SC1 and each second angular section SC2 of the circumferential preform wall BWPmay extend over an angular range AnR of at least 5° about the axial direction Ax, in particular over an angular range AnR of 15° or more about the axial direction Ax.

[0097] The at least one first angular section SC1 of the circumferential preform wall BWPmay be arranged with respect to the at least one second angular section SC2 of the circumferential preform wall BWPat an angle An of 70° to 110° about the axial direction Ax, preferably at an angle An of 80° to 100° about the axial direction Ax. Most preferably, as indicated in Fig. 2, the at least one first angular section SC1 of the circumferential preform wall BWPis arranged with respect to the at least one second angular section SC2 of the circumferential preform wall BWPat an angle An of approximately 90° about the axial direction Ax.

[0098] In the second step c, the step of non-uniformly heating the outer periphery OP of the circumferential preform wall BWPmay optionally include heating the first angular section SC1 of the circumferential preform wall BWPto a first temperature Tcin the range from 80°C to 120°C.

[0099] In the second step c, heating the plastic preform P may optionally include at least approximately uniformly pre-heating the outer periphery OP of the circumferential preform wall BWPin an angular range of 360° about the axial direction Ax by rotating the plastic preform P during pre-heating around the axial direction Ax with respect to the heat source HS.

[0100] In the second step c, the step of at least approximately uniformly pre-heating the outer periphery OP of the circumferential preform wall BWPmay optionally include heating a circumferential section of the circumferential preform wall BWPin an angular range of 360° about the axial direction Ax to a pre-heat temperature TBin the range from 80°C to 120°C.

[0101] In the second step c, non-uniform ly heating the outer periphery OP of the circumferential preform wall BWPin the fixed rotational arrangement may in particular include introducing the plastic preform P into a heating device 80 and maintaining an angular orientation of the preform P about the axial direction Ax relative to the heating device 80 during non-uniform heating.

[0102] A linear movement of the preform P relative to the heat source HS in a direction 5 perpendicular to the axial direction Ax is possible and may in particular be useful to compensate the temperature distribution.

[0103] As indicated in figure 6, the heating device 80 may in particular include heat sources HS arranged diametrically opposite to each other with respect to the axial direction Ax.

[0104] In the second step c, non-uniform ly heating the outer periphery OP of the circumferential preform wall (BWP) may in particular include heating the outer periphery OP of the circumferential preform wall BWPin two first angular sections SC1 , in particular to the first temperature Tc, that are arranged diametrically opposite each other. Non-uniformly heating of the two first angular sections SC1 may in particular occur simultaneously by for example employing the heating device 80 schematically illustrated in figure 6.

[0105] In the second step c, the outer periphery OP of the circumferential preform wall BWPmay be uniformly heated in the axial direction Ax or non-uniformly heated in the axial direction. In particular, the heat source HS may be configured to emit heat in accordance with a heat distribution that does not vary or exhibits only minor variations in the axial direction Ax.

[0106] The receptacle 1 obtained or obtainable by the method as disclosed herein may comprise first wall segments A of reduced thickness and second wall segments B of increased thickness. Each first wall segment A and each second wall segment B of the circumferential wall BW may extend over an angular range AnR of less than 180°, in particular over an angular range AnR of 90° or less, about the axial direction Ax. According to various embodiments, each first wall segment A and each second wall segment B of the circumferential wall BW respectively extend over an angular range AnR of at least 5°, in particular over an angular range AnR of 15° or more, about the axial direction Ax. According to various embodiments, the at least one first wall segment A of the circumferential wall BW my be arranged with respect to the at least one second wall segment B of the circumferential wall BW at an angle An of 70° to 110° about the axial direction Ax, preferably at an angle An of 80° to 100° about the axial direction Ax, most preferably at an angle An of approximately 90°about the axial direction (Ax). According to various embodiments, the circumferential wall BW includes two first wall segments A that are arranged diametrically opposite to each other.

[0107] The round plastic bottle 1 may preferably be prepared by a method, wherein, according to a possible embodiment, the method comprises the steps of: a providing a round plastic preform P of the round plastic bottle, wherein the round plastic preform P comprises a preform bottle neck BNP, a preform bottle bottom BBPand a circumferential preform wall BWP, wherein circumferential preform wall BWPhas a uniform thickness, b introducing the round plastic preform P provided in step a) into a heating device, wherein, in the heating device, the wall of the circumferential preform wall BWPis uniformly heated by a vertical rotation of the round plastic preform P at a temperature Tb, c orientating the uniformly heated round plastic preform P obtained in step b) in the heating device 80 so that at least one first position of the circumferential preform wall BWPis heated at a temperature Tc, wherein a round plastic preform P with a circumferential preform wall BWPis obtained, wherein the circumferential preform wall BWPcomprises at least one first angular section SC1 and at least one second angular section SC2, the first angular section SC1 having a higher temperature than the second angular section SC2, d removing the round plastic preform P obtained in step c) from the heating device 80, and e stretch blow moulding the round plastic preform P to obtain a round plastic bottle comprising a bottle neck BN, a bottle bottom BB and a bottle wall BW, wherein the bottle wall BW comprises at least one first wall segment A and at least one second wall segment B, wherein the thickness of the second wall segment B is larger than the thickness of the first wall segment A.

[0108] Step a In the first step a, a round plastic preform (P) for the round plastic bottle is provided.

[0109] In the context of the present invention the term “preform (P)” means an intermediate product from which the round plastic bottle is made by means of blow moulding or stretch blow moulding.

[0110] The preform P can be provided by any method known to the skilled person. In a preferred embodiment, the round plastic preform P is provided by an injection moulding process.

[0111] The round plastic preform P is preferably produced from polyethylene terephthalate (PET), more preferably from recycled polyethylene terephthalate (PET).

[0112] The round plastic preform P comprises a bottle neck BNP, a bottle bottom BBPand a bottle wall BWP. Preferably, the bottle neck BNPsurmounts the bottle wall BWPand defines an opening of the round plastic preform P. The bottle wall BWPpreferably has a round cylindrical shape, wherein the bottle bottom BBPis the lower base area of the round cylindrical shape. The bottle bottom BBPhas preferably a round shape and is preferably convex. Preferably, the round cylindrical shape is open at the top and the circumferential wall (BWP) builds a shoulder there with a shoulder angle in the range from 5 to 50°.

[0113] The circumferential preform wall BWPhas a uniform thickness. Therefore, the preform P does preferably not comprise any segments.

[0114] Step b

[0115] In step b, the round plastic preform P provided in step a is introduced into a heating device, wherein, in the heating device, the circumferential preform wall BWPis uniformly pre-heated to a pre-heat temperature Tb. During pre-heating, an axial rotation of the round plastic preform P around the axial direction Ax is maintained. The pre-heat temperature Tbis preferably in the range from 80°C to 120 °C.

[0116] Step c

[0117] In the second step c, the pre-heated round plastic preform P obtained in step b is disposed within the heating device 80 in a fixed rotational arrangement. Heat is non- uniformly disposed along the circumference of the circumferential preform wall BWP. At least one first angular section SC1 of the circumferential preform wall BWPis heated at a first temperature Tc, wherein a non-uniformly heated round plastic preform P is obtained, wherein the non-uniformly heated circumferential preform wall BW comprises at least one first angular section SC1 and at least one second angular section SC2, the first angular section SC1 having a higher temperature than the second angular section SC2.

[0118] Preferably, the first temperature Tcis in the range from 80°C to 120°C. In a preferred embodiment, the first temperature Tcis identical to the pre-heat temperature Tb.

[0119] In a preferred embodiment, in the second step c, the uniformly pre-heated round plastic preform P obtained in step b is positioned in the heating device 80 in a rotational fixed arrangement such that two first angular sections SC1 of the circumferential preform wall BWPare heated at a temperature Tc, wherein the two first angular sections SC1 are arranged diametrically opposite to each other, and wherein a non-uniformly heated plastic preform P with a circumferential preform wall BW is obtained, wherein the circumferential preform wall BW comprises two first angular sections SC1 and two second angular sections SC2, wherein the first angular sections SC1 are arranged opposite each other, and the two second angular sections SC2 are arranged diametrically opposite each other.

[0120] Step d

[0121] In step d, the heated round plastic preform (P) obtained in the second step c is removed from the heating device 80.

[0122] Step e

[0123] In the third step e, the round plastic preform P is stretch blow moulded to obtain a round plastic bottle comprising a bottle neck BN, a bottle bottom BB and a circumferential wall BW, wherein the circumferential wall BW comprises at least one first wall segment A and at least one second wall segment B, wherein the thickness of the second wall segment B is larger than the thickness of the first wall segment A.

[0124] In a preferred embodiment, the stretch blow moulding in third step e comprises the following steps e1 ) to e6) e1 ) introducing the heated round plastic preform P into a mould, e2) closing the mould, e3) stretching and pre-blowing of the heated plastic preform P in the mould, e4) blowing the heated preform P in the mould to obtain a round plastic bottle comprising a bottle neck BN, a bottle bottom BB and a circumferential wall BW, wherein the circumferential wall BW comprises at least one first wall segment A and at least one second wall segment B, wherein the thickness of the second wall segment B is larger than the thickness of the first wall segment A, e5) opening the mould, and e6) discharging the round plastic bottle. Another object of the present invention is a round plastic bottle obtained by the method described above. The inventive round plastic bottle can be used for carrying or storing cosmetic compositions, preferably for carrying or storing cosmetic hair compositions, especially for carrying or storing shampoo or hair conditioner. Therefore, another object of the present invention is the use of the inventive round plastic bottle for carrying or storing cosmetic compositions, especially for carrying or storing shampoo or hair conditioner.

[0125] Reference signs

[0126] BN bottle neck

[0127] BW circumferential wall (bottle wall)

[0128] BB bottle bottom

[0129] C cap

[0130] A first wall segment

[0131] B second wall segment hBWheight of the circumferential wall dBWdiameter of the circumferential wall h total height of the round plastic bottle

[0132] 1 receptacle

[0133] P preform

[0134] BWPcircumferential preform wall

[0135] OP outer periphery

[0136] SC1 first angular section

[0137] SC2 second angular section

[0138] AnR angular range

[0139] Ax axial direction

[0140] An angle

[0141] HS heat source

[0142] 80 heating device

Claims

Claims1. A method of manufacturing a receptacle (1 ) for a cosmetic composition, in particular round plastic bottle, wherein the receptacle (1 ) is made from a plastic preform (P) by means of blow moulding, in particular stretch blow moulding, wherein the method comprises the steps of:- providing, in a first step (a), a plastic preform (P) having an axial direction (Ax) for manufacturing a receptacle (1 ) extending along the axial direction (Ax), wherein the plastic preform (P) comprises a circumferential preform wall (BWP) that has a uniform thickness (dP);- heating, in a second step (c), the plastic preform (P) by means of a heat source (HS) to obtain a heated plastic preform (P), wherein heating the plastic preform (P) includes non-uniform ly heating an outer periphery (OP) of the circumferential preform wall (BWP) in a fixed rotational arrangement with respect to the heat source (HS), wherein, by heating the outer periphery (OP) of the circumferential preform wall (BWP), the temperature in at least one first angular section (SC1 ) of the circumferential preform wall (BWP) is raised to higher level than the temperature in at least one second angular section (SC2) of the circumferential preform wall (BWP), wherein each first angular section (SC1 ) and each second angular section (SC2) extends over an limited angular range (AnR) of less than 180°, in particular less than 90° about the axial direction (Ax);- blow moulding, in particular stretch blow moulding, in a third step (e), the heated plastic preform (P) to obtain the receptacle (1 ) extending along the axial direction (Ax) and including a circumferential wall (BW), wherein a first wall segment (A) of the circumferential wall (BW) is obtained by blow moulding the at least one first angular section (SC1 ) of the circumferential preform wall (BWP) and a second wall segment (B) of the circumferential wall (BW) is obtained by blow moulding the at least one second angular section (SC2) of the circumferential preform wall (BWP), wherein a thickness of the second wall segment (B) is larger than a thickness of the first wall segment (A).

2. The method according to claim 1 , wherein each first angular section (SC1 ) and each second angular section (SC2) of the circumferential preform wall (BWP) extends over an angular range (AnR) of at least 5° about the axial direction (Ax), in particular over an angular range (AnR) of 15° or more about the axial direction (Ax).

3. The method according to any of the previous claims, wherein the at least one first angular section (SC1 ) of the circumferential preform wall (BWP) isarranged with respect to the at least one second angular section (SC2) of the circumferential preform wall (BWP) at an angle (An) of 70° to 110° about the axial direction (Ax), preferably at an angle (An) of 80° to 100° about the axial direction (Ax), most preferably at an angle (An) of approximately 90° about the axial direction (Ax).

4. The method according to any of the previous claims, wherein, in the second step (c), the step of non-uniform ly heating the outer periphery (OP) of the circumferential preform wall (BWP) includes heating the first angular section (SC1 ) of the circumferential preform wall (BWP) to a first temperature (Tc) in the range from 80°C to 120°C.

5. The method according to any of the previous claims, wherein the second step (c) of heating the plastic preform (P) includes at least approximately uniformly pre-heating the outer periphery (OP) of the circumferential preform wall (BWP) in an angular range of 360° about the axial direction (Ax) by rotating the plastic preform (P) during pre-heating around the axial direction (Ax).

6. The method according to claim 5, wherein, in the second step (c), the step of at least approximately uniformly pre-heating the outer periphery (OP) of the circumferential preform wall (BWP) includes heating a circumferential section of the circumferential preform wall (BWP) in an angular range of 360° about the axial direction (Ax) to a pre-heat temperature (TB) in the range from 80°C to 120°C.7 The method according to any of the previous claims, wherein the plastic preform (P) is provided by an injection moulding process, in particular made from polyethylene terephthalate (PET).

8. The method according to any of the previous claims, wherein, in the second step (c), non-uniformly heating the outer periphery (OP) of the circumferential preform wall (BWP) in the fixed rotational arrangement includes introducing the plastic preform (P) into a heating device (80) and maintaining an angular orientation of the preform (P) about the axial direction (Ax) relative to the heating device (80) during non-uniform heating.

9. The method according to any of the previous claims, wherein, in the second step (c), non-uniformly heating the outer periphery (OP) of the circumferential preform wall (BWP) includes heating the outer periphery (OP) of the circumferential preform wall (BWP) in two first angular sections (SC1 ), inparticular to the first temperature (Tc), that are arranged diametrically opposite each other.

10. The method according to any of the previous claims, wherein, in the second step (c), the outer periphery (OP) of the circumferential preform wall (BWP) is uniformly heated in the axial direction (Ax).

11. A receptacle (1 ) obtained by a method according to any previous claims, wherein each of the at least one first wall segment (A) and each of the at least one second wall segment (B) of the circumferential wall (BW) extends over an angular range (AnR) of less than 180°, in particular over an angular range (AnR) of 90° or less, about the axial direction (Ax).

12. The receptacle (1) according to claim 11 , wherein each first wall segment (A) and each of the at least one second wall segment (B) of the circumferential wall (BW) extends over an angular range (AnR) of at least 5°, in particular over an angular range (AnR) of 15° or more, about the axial direction (Ax).

13. The receptacle (1 ) according to any of the previous claims 11 or 12, wherein the at least one first wall segment (A) of the circumferential wall (BW) is arranged with respect to the at least one second wall segment (B) of the circumferential wall (BW) at an angle (An) of 70° to 110° about the axial direction (Ax), preferably at an angle (An) of 80° to 100° about the axial direction (Ax), most preferably at an angle (An) of approximately 90°about the axial direction (Ax).

14. The receptacle (1 ) according to any of the previous claims 10 to 13, wherein the circumferential wall (BW) includes two first wall segments (A) that are arranged diametrically opposite to each other.

15. Use of the receptacle (1 ) according to any of the previous claims 10 to 14 for transporting, storing and / or dispensing a cosmetic composition, in particular haircare product, such as shampoo or hair conditioner.

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