Neck finish, mold, and method for making the neck finish

Abstract

The invention relates to: a neck finish (10, 10', 10") for a bottle (60), for a container for liquids (50) or for a bottle or container preform (40); an assembly and a bottle that comprise the neck finish; a mold shaped to provide the neck finish; and a method for providing the neck finish by using the mold. The neck finish comprises an annular wall (12) extending around a vertical axis from an inlet section (TOF, 14). The annular wall comprises: a horizontal parting line (22); a flash-free annular sealing portion (24), comprised between the inlet section and the horizontal parting line; and an external threaded portion (16), composed of a number of threads )18) greater than or equal to one. Each thread wraps around the annular wall in a helical manner, starting from a thread starting section (20) arranged below the horizontal parting line. The horizontal parting line is spaced by more than 0.3 mm from the inlet section. The external threaded portion has a thread pitch of less than 2.4 mm. The product of the helical extension of each thread and the number of threads of the external threaded portion is strictly less than 600°.

Description

[0001] NECK FINISH, MOLD, AND METHOD FOR MAKING THE NECK FINISH

[0002] The present invention relates to a neck finish for a bottle, for a container for liquids, for a bottle preform or for a container preform, as well as to a mold shaped to make said neck finish. Moreover, the invention relates to a method for making said neck finish by injection molding and by using said mold.

[0003] Moreover, the present invention relates to an assembly that, in addition to said neck finish, comprises a capsule or closure that is couplable to said neck finish.

[0004] In addition, the present invention relates to a bottle comprising said neck finish.

[0005] In the context of the present invention, the expression “neck” refers to a part that forms (or is designed to form) the access to the inside of a bottle. Moreover, the term “neck finish” means a part that forms (or is designed to form) the head of the neck. For example, when a bottle is placed vertically on a table and the bottom of the bottle rests on said table, the neck forms the upper portion of the bottle, while the neck finish corresponds to the portion of the neck adapted to engage with a capsule or closure.

[0006] According to the present invention, the term “preform” means a preform of a bottle or a preform of a container.

[0007] According to the present invention, the term “parting line” means a marking - in the form of a step (or line) made of plastic - left on the outer surface of the neck finish by a discontinuity present within a mold that is shaped to make said neck finish. Typically, a so-called “parting line” has a radial thickness (i.e., a thickness measured transversely with respect to an axial direction of the neck finish) of a few hundredths of a millimeter (for example, 0.02 or 0.03 mm or less). As will be explained in greater detail hereinafter, a so-called “parting line” can be horizontal or vertical.

[0008] Moreover, in accordance with the so-called “TFRSC nomenclature” that the International Society of Beverage Technologists (in short: ISBT) uses in its Threadspecs™ guidelines for neck finishes in a 13-33 mm size range, reference will be made, in the present description, to the terminology summarized in Table 1 below (see “ISBT Threadspecs ©Nomenclature Card,” updated September 2022, referenced as “[TFRSC Nomenclature]” at https: / / www.isbt.com / threadspecs-downloads.asp).

[0009] Table 1 In practice, as known, when a neck finish is described by using the terminology of Table 1:

[0010] - “TOF” refers to an inlet section of the neck finish, at which the rim of the neck finish is located;

[0011] - “C” refers to an inner diameter of the neck finish at the TOF; - “S” refers to the distance of a thread start section with respect to the

[0012] TOF; - “T” refers to the diameter of the neck finish at the thread crests;

[0013] - “E” refers to the diameter of the neck finish at the thread start section;

[0014] - “P” refers to the thread pitch (i.e., the distance between two consecutive thread crests that are placed along a same vertical axis, i.e., spaced along the axial direction of the neck finish);

[0015] - “B” refers to the value of an outside diameter of the neck finish at a groove designed to accommodate a tamper evident band (or ring) (typically, the tamper evident band is connected to the capsule by means of bridges that are designed to break during unscrewing of the capsule);

[0016] - “D” refers to the distance of the above-mentioned groove with respect to the TOF;

[0017] - “X” refers to the distance of the bottom of a neck ring with respect to the TOF; and

[0018] - “PL” refers to the position of a parting line with respect to the TOF (more precisely, “PL” refers to both the distance of a horizontal parting line with respect to the TOF and the starting height of a vertical parting line).

[0019] As known, the injection molding of a preform causes the presence of two or three parting lines on the neck finish of the preform: a horizontal parting line, spaced by an extent “PL” from the TOF, and one or two vertical parting lines, which start from the horizontal parting line and move away from the TOF. Typically, a so-called “horizontal parting line” is formed due to the interface between, on one side, at least one female mold part that forms laterally the neck finish and, on the other side, the base that surrounds the plug of a male mold part that forms the rim and the inner surface of the neck finish. In contrast, the presence of one or two so-called “vertical parting lines” is usually due to the interface between the two neck rings with which the at least one female mold part is typically provided. In practice, a horizontal parting line extends substantially in parallel with respect to the rim of the neck finish (and, therefore, with respect to the TOF). In contrast, a vertical parting line extends substantially at right angles with respect to the rim of the neck finish (and therefore with respect to the TOF), and moves away from the TOF starting from the horizontal parting line.

[0020] According to the present invention, the term “lead” means the axial advancement of a point accompanying a single full 360° turn of a helix. Moreover, “full thread per lead” means, as known, the product between the helical extension (or angular extension) of each thread around the central axis of the neck finish and the number of threads that make up the external threaded portion of the neck finish.

[0021] In addition, the expression “29 / 25 neck finish” (i.e., a neck finish of the so-called “29 / 25 type”) means, as known, a neck finish where:

[0022] - the value of said diameter T (i.e., the value of the thread crest diameter) is about 29 mm, and

[0023] - the value of said diameter C (i.e., the value of the control diameter at TOF) is about 25 mm.

[0024] Similarly, the term “26 / 22 neck finish” means, as known, a neck finish that has a diameter T of about 26 mm and a diameter C of about 22 mm.

[0025] Moreover, the expressions “preform 29 / 25” and “preform 26 / 22” refer to preforms that have, respectively, a 29 / 25 neck finish and a 26 / 22 neck finish defined as above. Similarly, “29 / 25 neck” and “26 / 22 neck” mean necks that have, respectively, a 29 / 25 neck finish and a 26 / 22 neck finish defined as above.

[0026] As known, neck finishes for bottles, containers, and preforms are designed to pursue objectives such as the following: to ensure high hermetic sealing performance; to ensure high anti-tamper performance; to ensure high mechanical performance, in particular by resisting high axial loads without plastic deformation or breakage; to optimize the performance and / or dimensions of the molds that are designed to make the neck finishes; and to optimize the geometries of the neck finishes so as to reduce the materials, time, and / or cost required to mold bottle neck preforms.

[0027] However, objectives such as those discussed above often compete with each other and therefore must be conveniently balanced.

[0028] While useful and practical, neck finishes of the known type are not without their drawbacks, including those described below.

[0029] A first drawback resides in that in a condition of use in which one of these known neck finishes is sealed by application of a closure provided with a tamper-evident band, a stress exerted by the neck finish on the closure is such that, during a closure unscrewing operation, said closure tends to tilt. However, if this tendency is not conveniently counteracted by the person who is carrying out the closure unscrewing operation, the tilting of the closure can cause an early loss of seal, i.e., a leakage that occurs before breakage of the bridges which, by connecting the tamper evident ring to the rest of the closure, prevent the closure from being removed from the neck finish and give an indication of lack of tampering.

[0030] A second drawback of neck finishes of the known type resides in that they have non- optimized geometries.

[0031] In the context of this second drawback, some neck finishes of the known type have a rather high full thread per lead.

[0032] For example, in neck finishes of the known type that have an external threaded portion composed of three threads, each thread may have a rather large angular extension, typically 180°. As another example, in neck finishes of the known type that have an external threaded portion composed of a single thread, the angular extension of the single thread exceeds 650°.

[0033] According to the second drawback mentioned above, in the “valleys” (i.e. the regions at the bottom of which the thread's root is arranged) comprised between two consecutive crests of the external threaded portion of neck finishes of the known type there is a lot of potentially unnecessary space. Typically, in these known neck finishes, the width of a valley separating two mutually consecutive thread crests is more than 1 mm.

[0034] Also within the scope of the second drawback mentioned above, an outside diameter at the unthreaded portions of the annular wall may not be constant. Typically, in neck finishes of the known type the dimensions of this specific outside diameter vary as one moves vertically along the annular wall. In particular, in these known neck finishes the diameter E and the diameter B have mutually different values.

[0035] According to the second drawback mentioned above, these known neck finishes have the disadvantage of being rather massive. Typically, these specific neck finishes are in fact made of polyethylene terephthalate (in short: PET) by means of an injection molding process at the end of which a preform (or rather, a preform neck) with a total weight of not less than 2.4 g is obtained.

[0036] The aim of the present invention is to overcome the drawbacks of the background art described above by devising a neck finish that can more adequately achieve and / or balance one or more of the previously mentioned objectives and / or requirements.

[0037] Within the scope of this aim, a first object of the present invention is to optimize the geometries of a neck finish, maximizing the performance required of said neck finish.

[0038] In the context of this first object, the present invention aims at providing a neck finish that can ensure high hermetic sealing performance, in particular by cooperating with a respective closure. Accordingly, the present invention aims at improving the anti-tamper properties of a bottle.

[0039] A second object of the present invention is to obtain a neck finish that can provide superior mechanical performance with respect to neck finishes of the known type.

[0040] Within the scope of this second object, the present invention aims at obtaining a neck finish that can provide a higher grip force for a threaded closure that is or can be applied to said neck finish. Also within the scope of this second object, the present invention further aims at reducing the risk that, during unscrewing of the closure, the neck finish may cause said closure to tilt.

[0041] Remaining within the scope of this second object, the present invention further aims at reducing the risk of loss of parallelism between the closure and the neck finish during a closure screwing operation, in particular during the first steps of this operation.

[0042] Also within the scope of this second object, the present invention also aims at devising a neck finish provided with high resistance to axial compression.

[0043] A third object of the present invention is to optimize the geometries of the neck finish without affecting the possibility to produce by injection molding the preform comprising said neck finish.

[0044] Within the scope of this third object, the present invention aims at reducing the materials, time and / or cost required to mold the preform of a bottle.

[0045] A further object of the present invention is to devise a versatile neck finish designed to effectively seal bottles containing still beverages (i.e.: non-carbonated beverages), both bottles pressurized with nitrogen or other gases and non-pressurized bottles.

[0046] Not least object of the present invention is to provide a neck finish, a bottle, an assembly and a mold that are highly reliable, relatively easy to make, as well as economically competitive when compared to the background art.

[0047] The aim(s) above, as well as these and other objects that will become better apparent hereinafter, are achieved by a neck finish according to claim 1. The dependent claims define preferred embodiments.

[0048] The aim(s) and objects above are also achieved by an assembly according to claim 17, by a bottle according to claim 18, by a preform according to claim 19, by a mold according to claim 20, and by a method according to claim 21.

[0049] Further characteristics and advantages of the present invention will become better apparent from the description of some preferred but not exclusive embodiments of the neck finish according to the invention, illustrated by way of non-limiting example with the aid of the accompanying drawings, wherein:

[0050] Figures 1A and IB are two longitudinal sectional views, respectively a general view and a detail view, of a mold shaped to make a neck finish according to the invention;

[0051] Figures 2 A and 2B are two top views of a first version of a neck finish according to the invention;

[0052] Figures 3 A and 3B are two longitudinal sectional views obtained by sectioning the neck finish of Figure 2B along the sectional plane III-III;

[0053] Figure 3C is a detail view of Figure 3B;

[0054] Figure 4 is a side view of a preform of a neck comprising the first version of the neck finish according to the invention;

[0055] Figure 5 is a longitudinal sectional view, obtained by sectioning the preform of Figure 4 along the sectional plane V-V;

[0056] Figure 6 is a flattened view of an external threaded portion of the first version of the neck finish according to the invention;

[0057] Figure 7 is a longitudinal sectional view, showing an optimal sizing of the first version of the neck finish according to the invention;

[0058] Figure 8 is a top view of a second version of the neck finish according to the invention;

[0059] Figure 9 is a longitudinal sectional view, obtained by sectioning the neck finish of Figure 8 along the sectional plane IX-IX;

[0060] Figure 10 is a side view of a preform of a neck which comprises the second version of the neck finish according to the invention;

[0061] Figure 11 is a longitudinal sectional view, obtained by sectioning the preform of Figure 10 along the sectional plane XI-XI;

[0062] Figure 12 is a flattened view of the external threaded portion of the second version of the neck finish according to the invention;

[0063] Figure 13 is a longitudinal sectional view, showing an optimal sizing of the second version of the neck finish according to the invention;

[0064] Figure 14 is a bottom view of a closure that can be screwed onto any one of the neck finishes according to the invention;

[0065] Figure 15 is a longitudinal sectional view, obtained by sectioning the closure of Figure 14 along the sectional plane XV-XV;

[0066] Figure 16 is a longitudinal sectional view, showing an assembly procedure for an assembly comprising a neck finish according to the invention and the closure of Figures 14-15; and

[0067] Figures 17, 17A and 17B are three longitudinal sectional views, the first being a general view and the other two being detail views, in which the assembly of Figure 16 is in a condition of use in which the closure seals the neck finish.

[0068] With respect to the description of the preferred and illustrated embodiments, identical, similar or equivalent elements are designated by a same reference numeral. In the case of reference numerals consisting of a numeric part and an alphabetic part, elements belonging to a same structure or functional group are designated by reference numerals having the same numeric part.

[0069] With reference to the figures, each neck finish according to the present invention, generally designated by the reference numeral 10, comprises an annular wall 12 extending around a vertical axis (or direction) Z.

[0070] In particular, the vertical axis Z constitutes a central axis of the neck finish 10.

[0071] In each embodiment, the annular wall 13 extends from an inlet section 14 that corresponds to the TOF discussed above. In other words, the rim of the neck finish 10 is located at the inlet section 14.

[0072] Although the neck finish 10 according to the invention may constitute a stand-alone entity, in the preferred and illustrated embodiments the neck finish 10 is part of either a preform 40, or a container for liquids 50, or a bottle 60, which are provided with a neck.

[0073] Advantageously, the container for liquids 50 and / or the bottle 60 can be obtained from the preform 40 by means of known techniques such as blow molding.

[0074] The assembly formed by the neck finish 10 (possibly integrated into the preform 40, bottle 60 or container for liquids 50) and a corresponding capsule or closure 30 defines an assembly 70 according to the invention.

[0075] Advantageously, each neck finish 10 according to the invention can be made / produced by injection molding, by using a mold 100 such as the one shown in Figure 1A.

[0076] In practice, a method for making the neck finish 10 by injection molding comprises the steps described below.

[0077] In a first step, a male mold part 104 and a female mold part 106 (or, in the case of a molding system formed by multiple molds, at least one male mold and at least one female mold) are mated together to collectively form a molding interspace designed to reproduce the neck finish 10.

[0078] In a second step, the mold 100 (or said molding system) is closed, and the molding interspace is filled with a polymer (typically PET) in the liquid state , which is injected at high pressure into the mold 100.

[0079] Once the polymer has solidified, a neck finish having the desired shape is obtained, the male and female mold parts (or, in said molding system, molds) 104, 106 are moved mutually apart and the preform 40 can be released from the mold.

[0080] In each embodiment, the annular wall 12 (and, in particular, an outer surface of said annular wall 12) comprises: a horizontal parting line 22, an annular sealing portion 24, and an external threaded portion 16. The horizontal parting line 22 is a result of the molding of the preform 40. With reference to Figures 1A-1B, the horizontal parting line 22 is formed when plastic penetrates within a discontinuity that exists at a mating interface (or horizontal flash plane) 102 between two female molds (or mold parts) 106 and one male mold (or mold part) 104 which are mutually movable substantially parallel to the axis Z.

[0081] In the preferred and illustrated embodiments, the horizontal parting line 22 is an annular step.

[0082] In Figure 3B, where the letter “h” designates the extent (measured in a radial direction) of a step 23 due to unavoidable geometric inconsistencies between the parts 106 and 104 of the mold 100, the horizontal parting line 22 is at the outer edge of the step 23. Typically, the value of h is comprised between 0.005 mm and 0.06 mm.

[0083] In the preferred and illustrated embodiments, the horizontal parting line 22 is located at a vertical distance PL from the inlet section 14 or TOF. Hereinafter, this vertical distance PL is also referenced as “first vertical distance”.

[0084] In the mold 100 of Figures 1A-1B, the first vertical distance PL is determined by the depth of an annular groove 110.

[0085] In particular, the annular groove 110 is provided in the male mold (or mold part) 104 to form the rim of the neck finish 10. Moreover, the annular groove 110 is located around (i.e., at the base of) a mold core 112 designed to form the inside of the neck finish 10.

[0086] The annular sealing portion 24 is free of flash lines.

[0087] In practice, the annular sealing portion 24 is a smooth surface, free of any surface discontinuity that might prevent the neck finish 10 from cooperating effectively with the closure 30 (or, more generally, with an appropriate closure) in order to provide a gas-tight (i.e., hermetic) lateral seal.

[0088] Moreover, the annular sealing portion 24 is comprised between the inlet section 14 (i.e., the TOF) and the horizontal parting line 22.

[0089] In particular, the annular sealing portion 24 extends away from the inlet section 14 (i.e., in some embodiments, toward the bottom of the preform 40, container for liquids 50, or bottle 60), to the horizontal parting line 22.

[0090] In practice, the first vertical distance PL identifies, with respect to the inlet section 14, the maximum vertical distance at which the annular wall 12 can be used to perform the hermetic lateral seal with the closure 30.

[0091] In the preferred and illustrated embodiments, the annular sealing portion 24 is coaxial to the axis Z.

[0092] The external threaded portion 16 is composed of a number of threads 18 greater than or equal to one.

[0093] In some variants, the external threaded portion 16 comprises a plurality of threads 18, as for example shown by Figures 2A through 7. In alternative variants, the external threaded portion 16 is single-threaded (i.e., consists of just one single thread), as shown for example by Figures 8 to 13.

[0094] Regardless of the number of threads 18, each thread 18 wraps around the annular wall 12 according to a helical extension, starting from a thread starting section 20 arranged below the horizontal parting line 22. In other words, the crest of the external threaded portion 16 is arranged at a lower height with respect to the horizontal parting line 22.

[0095] In particular, each thread 18 extends from the thread starting section 20 to a thread ending section 23, for example in the manner shown in Figures 4, 6 and 13.

[0096] In practice, the thread starting section 20 corresponds to the plane that is at a distance S from the plane TOF, where S is the so-called “Height from TOF to start of full depth of thread” discussed above. In other words, the thread starting section 20 is located at a vertical distance S from the inlet section 14, and each thread 18 extends away from the inlet section 14 from this same vertical distance. Hereinafter, the distance S is also termed “second vertical distance.”

[0097] In the preferred and illustrated embodiments, each thread 18 extends away from the inlet section 14 in a helical manner, in particular toward the bottom of the preform 40, of the container for liquids 50 or of the bottle 60. In other words, the external threaded portion 16 is designed so that as one moves away from the thread starting section 20 along any thread 18, one moves further and further away from the inlet section 14.

[0098] Advantageously, the horizontal parting line 22 is more than 0.3 mm away from the inlet section 14.

[0099] More preferably, the first vertical distance PL is at least 0.4 mm. Even more preferably:

[0100] - in some variants, the first vertical distance PL is 0.6 mm;

[0101] - in alternative variants, the first vertical distance PL is 0.8 mm.

[0102] In practice, the values of PL according to the invention result in an extremely versatile neck finish 10, whose annular sealing portion 24 is capable of providing an effective lateral seal both in the case of application to bottles for non-pressurized still beverages and in the case of application to bottles for pressurized beverages.

[0103] Advantageously, the external threaded portion 16 has a thread pitch P of less than 2.4 mm. In other words, the thread pitch is strictly less than 2.4 mm.

[0104] Preferably, the width U (in the axial direction) of each valley that exists between two consecutive thread crests of the external threaded portion 16 is less than 0.95 mm.

[0105] Moreover, the product between the helical extension of each thread 18 and the number of threads 18 of the external threaded portion 16 is strictly less than 600°. In other words, the “full thread per lead” is less than 600°.

[0106] Thus, appropriate selection of the thread pitch, of the “full thread per lead”, and of the placement of the horizontal parting line 22 (i.e., of the first vertical distance PL) leads to a particularly practical and versatile neck finish 10 that is capable of balancing the previously mentioned aims and / or requirements in a more appropriate manner .

[0107] In some preferred embodiments, the neck finish 10 further comprises a groove 26 intended to accommodate a tamper-evident ring 32.

[0108] In embodiments that are particularly advanced from the standpoint of geometry and mass optimization, an outside diameter of the neck finish 10 at the groove 26 has a same size as an outside diameter of the neck finish 10 at the thread starting section 20.

[0109] In particular, a size of the diameter B (i.e., of the so-called “tamper evident band recess diameter”) may correspond to that of the diameter E (i.e., to a size of the so-called “thread root diameter”).

[0110] Further details regarding the beneficial effects obtainable from each neck finish according to the invention will become better apparent from the detailed description of the first and second versions of the neck finish according to the invention.

[0111] First version of the neck finish according to the invention

[0112] The first version of the neck finish 10 according to the invention (in short: “first version”) is described with reference to Figures 1A through 7.

[0113] The first version is particularly, but not exclusively, useful and practical for a 29 / 25 preform defined as above, i.e., for neck finishes with a diameter T of about 29 mm and a diameter C of about 25 mm.

[0114] In some preferred embodiments of the first version, the diameter T (i.e., the “thread crest diameter” according to the TFRSC nomenclature) is comprised between 27.25 mm and 29.60 mm.

[0115] More preferably, a size of the diameter T is comprised in the range 29.41±0.30 mm. Even more preferably, the diameter T is 29.40 mm (regardless of any machining tolerances in the order of magnitude of 0.1 mm).

[0116] In the first version, the external threaded portion 16 consists of four threads 18A-D.

[0117] In particular, the external threaded portion 16 is composed of a first thread 18A, a second thread 18B, a third thread 18C, and a fourth thread 18D.

[0118] In Figures 2 A through 7, the four threads 18A-D are continuous threads and are mutually separate. In a configuration that is not shown, the threads may have breaks which are adapted to lighten the weight of the neck and effectively evacuate any gas formed by the unintentional microbial degradation of the beverage contained within the bottle / container.

[0119] Moreover, in the figures related to the first version the four threads 18A-D are angularly mutually offset around the axis Z.

[0120] In some embodiments of the first version, the thread pitch P is comprised between 1.5 mm and 1.8 mm or, more preferably, between 1.6 mm and 1.65 mm.

[0121] In particularly preferred embodiments of the first version, the pitch P may be comprised between 1.62 and 1.63 mm. In other words, the thread pitch may be about 1.62 mm, even more preferably 1.624 mm.

[0122] For example, in Figures 3 A through 6, where the fourth thread 18D is adjacent to the first thread 18A for a portion, a crest 18A2 of the first thread 18A may be spaced about 1.6 mm from a crest 18D2 of the fourth thread 18D. Similarly, the third thread 18C is adjacent to the second thread 18B for a portion, and a crest 18C2 of the third thread 18C may be spaced about 1.6 mm from a crest 18B2 of the second thread 18B.

[0123] In practice, in the first version, the pitch P can be significantly lower than in known triple-threaded neck finishes, which typically have value of the pitch P greater than 2 mm (for example: 2.17 mm).

[0124] In particular, relatively low values of the pitch P can be achieved by an appropriate reduction of the width of the valleys of the external threaded portion 16. For example, in Figures 3A to 7 a pitch P of about 1.6 mm can be obtained by reducing the width U to a value of about 0.8 mm. As a result, with respect to known triple-threaded neck finishes, the neck finish 10 according to the first version has both a larger quantity of threads and a reduced thread pitch. In this way, the risk of a loss of horizontality between the closure 30 and the neck finish 10 during an operation for screwing or unscrewing the closure 30 can be significantly reduced, and a superior hermetic sealing performance can be ensured.

[0125] A reduction in the risk of loss of horizontality between the closure 30 and the neck finish 10 can also be achieved by alternative versions such as, for example, the second version of the neck finish 10 described hereinafter.

[0126] In the first version, the second vertical distance S is preferably at least 1.24 mm.

[0127] In some variants of the first version, the second vertical distance S is comprised within the range 1.34±0.10 mm. In alternative variants, the second vertical distance S assumes larger values, for example 1.65±0.10 mm.

[0128] In particular, in the first version, when the first vertical distance PL is (substantially) equal to 0.6 mm, the second vertical distance S is greater than or equal to 1.30 mm.

[0129] More preferably, the first vertical distance S is comprised between 1.34 mm and 1.44 mm. Even more preferably, the first vertical distance S is equal to 1.34 mm.

[0130] In practice, in the preferred embodiments that have the values of first vertical distance PL and second vertical distance S discussed above, the horizontal parting line 22 and the thread starting section 20 are located farther from the inlet section 14 than it occurs in known triple-threaded neck finishes discussed above. Typically, in these known triple-threaded neck finishes, PL does not exceed 0.3 mm, while S is about 1 mm.

[0131] Moreover, in the first version, the values of the second vertical distance S discussed above allow to make the neck finish 10 in a simple manner, using the mold 100, wherein the protruding portion 108 (which is designed to make the portion of the annular wall 12 comprised between the horizontal parting line 22 and the thread starting section 20) is inherently strong. In particular, the values of the second vertical distance S discussed above avoid the need to thicken the protruding portion 108 with respect to existing solutions, for example, for molding the known triple-threaded neck finishes discussed above.

[0132] In some particularly preferred embodiments, the threads 18 are equally spaced 90° apart along a circumferential direction.

[0133] For example, in the preferred and illustrated embodiments of the first version, the four threads 18A-D are arranged along the annular wall 12 so that the respective starts 18A1, 18B1, 18C1 and 18D1 are staggered by a center angle of 90° along a circumferential direction, as shown in Figure 2 A. In other words, in Figure 2 A the starts of the four threads 18A-D are arranged at 90° to each other (in terms of center angle).

[0134] In contrast, in the known triple-threaded neck finishes discussed above, the thread starts are mutually spaced 120° apart along the circumferential direction.

[0135] Preferably, the four threads 18A-D are substantially identical to each other.

[0136] In Figures 2A-7, the four threads 18A-D begin at a same height S along the axis Z and end at a same height also along the axis Z.

[0137] Advantageously, in the particularly preferred embodiments of the first version, each of the four threads 18A-D winds helically around the annular wall 12 for about 135°, in particular maintaining the same helical pitch as the thread of known triple-threaded neck finishes discussed above (in particular, maintaining a helical pitch of 6.49-6.50 mm). In contrast, in these known triple-threaded neck finishes the threads extend about 180° around a central axis of the neck finish.

[0138] In practice, with respect to the background art (in particular, of a known 29 / 25 neck finish) that has only three threads starting 120° apart from each other with respect to the axis Z and each extending about 180° around said axis, in the particularly preferred embodiments of the first version one thread has been added and all the threads have been shortened.

[0139] In particular, on the basis of the flattened extension of Figure 6, the length Lf of each thread (i.e., the “full thread per lead”) extends 135° about the axis Z.

[0140] In practice, in these particularly preferred embodiments of the first version, the external threaded portion 16 is designed so that the closure 30 can be fully screwed or unscrewed after a respective rotation of (about) 135° around the axis Z. As a result, the thread grip angle, expressed as the product of the number of threads composing the external threaded portion 16 and the length Lf, is (about) 540°.

[0141] However, alternative embodiments of the first version are also conceivable in which the neck finish 10 is designed to require more or fewer turns of the closure 30 in order to be fully opened or closed. For example, in these alternative embodiments, the neck finish 10 can be designed so that one full turn (i.e., a 120° rotation about the axis Z) is sufficient to completely unscrew / screw the closure 30.

[0142] In some preferred embodiments of the first version, the diameter E of the neck finish 10 (i.e., the “thread root diameter” according to the TFRSC nomenclature) has a value comprised between 26.25 mm and 27.75 mm, more particularly between 26.90 and 27.60 mm.

[0143] More preferably, a size of the diameter E lies in the range 27.40±0.30 mm. In other words, minus tolerances, the diameter E can measure 27.40 mm.

[0144] In addition or alternatively, in some preferred embodiments of the first version the B diameter (i.e., the “tamper evident band recess diameter” according to the TFRSC nomenclature) has a value comprised between 26.90 mm and 27.90 mm.

[0145] More preferably, a size of the diameter B lies in the range 27.40±0.30 mm. In other words, minus tolerances, the diameter B can measure 27.40 mm.

[0146] In practice, in the first version of the neck finish 10 according to the invention the geometries can be optimized by suitably changing one, some or all of the following parameters: mutual placement of the threads, length of the threads, diameter E, diameter B. In this way, the weight of the neck finish 10 can be significantly reduced.

[0147] For example, in Figure 4, assuming that:

[0148] - the preform 40 is made of PET with a maximum intrinsic viscosity of 0.76-0.82, and that

[0149] - the same preform 40 differs from a known 29 / 25 preform having S=1.04 mm, P=2.17 mm, E=27.60 mm, B=27.70 mm (wherein these values can be understood either as exact sizes or, alternatively, as nominal sizes subject to processing tolerances such as those discussed above) in that the preform 40 has:

[0150] ■ four threads that are 135° long and staggered by 90° (as described above),

[0151] ■ P=1.624 mm, PL=0.6 mm and S=1.34±0.10 mm, the same preform 40 can weigh 2.30 g. Moreover, by appropriately reducing the value of the dimensions (or diameters) E and B, the weight of the preform 40 can approach 2.1 g.

[0152] A reduction in weight can also be achieved by reducing a thickness of the annular wall 12, for example proximate to the thread starting section 20.

[0153] In particular, the half-difference between the diameter E and the diameter C (i.e.: (E-C) / 2) can be less than or equal to 1.15 mm.

[0154] For example, in Figure 7 the thickness of the annular wall 12 proximate to the thread starting section 20 (calculated as (E-C) / 2) is 1.15 mm. In contrast, in the known 29 / 25 neck finishes discussed above, the halfdifference between the dimensions E and C is 1.25 mm.

[0155] In some preferred embodiments of the first version, the half- difference between the diameter T and the diameter E is comprised between 0.7 and 1.5 mm. In other words, a parameter expressing the half-difference between the diameter T and the diameter E (i.e.: (T-E) / 2) can measure between 0.7 and 1.5 mm.

[0156] In practice, in some embodiments the neck finish 10 may have different dimensions T and E with respect to the known 29 / 25 neck finishes discussed above. However, the four threads of the neck finish 10 according to the first version may still have a radial thickness that is either substantially the same or slightly larger (for example, larger by about 0.1 mm) or smaller than the three threads of said known neck finishes. In addition or alternatively, in these specific embodiments the dimensions C and D may have the same values with respect to those of the aforementioned known neck finishes (in particular: C=25.10±0.13 mm; D=8.20±0.1 mm).

[0157] In some preferred embodiments, a space 11 comprised between the thread ending section 23 and a so-called “tear-off ring” 21 can be minimized, for example by reducing the vertical dimension of said space 11 to a value of about 1.0 mm. The reduction of the space 11 can be achieved, for example, by reducing the distance D (i.e., the so-called “tamper evident bead height” according to the TFRSC nomenclature) to a value comprised between 6.0 mm and 7.5 mm. In this way, both the weight of the neck preform 40 and the weight of the closure 30 can be further reduced. For example, the weight of the preform 40 can reach a value comprised between 1.5 g and 2.1 g, while the weight of the closure 30 (made of HDPE) can reach a value comprised between 0.75 g and 1.2 g.

[0158] In practice, an optimal but not exclusive sizing of the neck finish 10 according to the first version may result in an exemplar 10' that has all the sizes explicitly shown in Figure 7.

[0159] In particular, the exemplar 10' of Figure 7 has all of the following characteristics (as sizes expressed minus any tolerances such as those discussed above): T=29.41 mm, E=27.40 mm, C=25.10 mm, B=27.40 mm, PL=0.6 mm; S=1.34 mm; P=1.62 mm; D=8.20 mm; X=12.60 mm.

[0160] Second version of the neck finish according to the invention

[0161] In some preferred embodiments of the second version, the diameter T is comprised between 25.10 and 26.60 mm.

[0162] More preferably, a size of the diameter T is comprised within the range 26.40±0.13 mm. Even more preferably, the diameter T is 26.44 mm (regardless of any processing tolerances such as those discussed above).

[0163] In the second version, the external threaded portion 16 consists of only one single thread 18.

[0164] In the preferred and illustrated embodiments of the second version, the thread 18 has discontinuities 19, similar to those discussed above for the not shown configuration of the first version. However, not shown configurations in which the single thread 18 is continuous are also conceivable.

[0165] In some embodiments of the first version, the thread pitch P is comprised between 1.5 mm and 1.8 mm or, more preferably, between 1.6 mm and 1.65 mm.

[0166] In particularly preferred embodiments of the second version, the pitch P may be greater than 2.2 mm. Even more preferably, the pitch P is 2.3 mm.

[0167] Even in the case of the second version, the above-discussed values of the pitch P can be obtained by appropriate sizing of the valleys of the external threaded portion 16, for example by reducing the width U to a value of about 0.8 mm.

[0168] In the second version, the second vertical distance S is, preferably, strictly greater than 1.5 mm.

[0169] More preferably, the first vertical distance S is comprised between 1.55 and 1.75 mm. Even more preferably, the first vertical distance S of the second version is equal to 1.65 mm.

[0170] In this way, an appropriate selection of the second vertical distance S allows to make the second version in a simple way, avoiding unnecessary thickenings to protruding portions similar to the one which, in Figure 1A, is designated by the reference numeral 108.

[0171] Advantageously, in the particularly preferred embodiments of the second version, the single thread 18 winds helically around the annular wall 12 for about 570°, for example 568°.

[0172] In practice, in the flattened extension of Figure 13, the length Lf of the single thread 18 extends about 570°.

[0173] In this way, the second version can have a considerably lower weight with respect to some known neck finishes (in particular, of the 26 / 22 type), where the external threaded portion extends for more than 600°.

[0174] In some preferred embodiments of the second version, the diameter E of the neck finish 10 has a value comprised between 23.00 mm and 23.80 mm, more particularly between 23.10 and 23.70 mm.

[0175] More preferably, a size of the diameter E lies in the range 23.44±0.15 mm. In other words, minus tolerances, the diameter E may measure about 23.40 mm (for example: 23.44 mm).

[0176] In addition or alternatively, in some preferred embodiments of the second version the diameter B has a value comprised between 23.20 mm and 24 mm.

[0177] In embodiments of the second version that are particularly advanced from the point of view of optimizing geometries and masses, a size of the diameter B may correspond to that of the diameter E.

[0178] Also in the second version, a minimization of the weight of the neck finish 10 can be achieved by a reduction in the thickness of the annular wall 12, for example proximate to the thread starting section 20.

[0179] In particular, in the second version, the half-difference between the diameter E and the diameter C (i.e.: (E-C) / 2) is preferably less than 1 mm.

[0180] For example, in Figure 13 the thickness of the annular wall 12 proximate to the thread starting section 20 (calculated as (E-C) / 2) is 0.85 mm. In some preferred embodiments of the second version, the halfdifference between the diameter T and the diameter E is comprised between 1.37 and 1.63 mm. For example, in Figure 13 the half-difference between the diameter T and the diameter E is 1.50 mm.

[0181] In practice, an optimal but not exclusive sizing of the neck finish 10 according to the second version may result in an exemplar 10” that has all the sizes explicitly given in Figure 13.

[0182] In particular, the exemplar 10” of Figure 13 has all of the following characteristics (as sizes expressed regardless of any tolerances such as those discussed above): T=26.44 mm; E=23.44 mm; C=21.74 mm; B=23.44 mm; PL=0.8 mm; S=1.65 mm; P=2.3 mm; D=10.59 mm; X=15.06 mm.

[0183] Assembly comprising closure and neck finish

[0184] In some embodiments, the neck finish 10 is part of an assembly 70 which further comprises the closure 30 in addition to said neck finish 10.

[0185] In the preferred and illustrated embodiments, the closure 30 is a screw capsule.

[0186] In each assembly 70, the closure 30 has an internal threaded portion 34.

[0187] In turn, the internal threaded portion 34 can be screwed onto the external threaded portion 16 of the neck finish 10, for example in the manner suggested by the arrows Fl and F2 shown in Figure 16.

[0188] In practice, the internal thread 34 allows the closure 30 to be screwed onto the neck finish 10.

[0189] For example, in Figure 17 the external threaded portion 16 is engaged by the internal threaded portion 34.

[0190] Although not clearly visible from all the figures mentioned, the vertical direction Z represents not only a longitudinal axis of the neck finish 10 but also an axis of rotation of the closure 30 with respect to the neck finish 10, as suggested by the curvilinear arrow F2 visible in Figure 16.

[0191] In Figures 15-17, the tamper-evident ring 32 is integral with the closure 30 by means of a plurality of breakable bridges 38.

[0192] In Figure 17, the tamper-evident ring 32 is accommodated within the groove 26.

[0193] Moreover, the inlet section 14 is engaged by an internal ring (or plug) 36 provided in a head portion 31 of the closure 30.

[0194] Accordingly, in Figure 17 the closure 30 is screwed onto the neck finish 10 so as to seal the neck finish 10.

[0195] Preferably, the internal thread 34 of the closure 30 comprises a proximal portion 34A, which is closer to the tamper-evident ring 32, and a distal portion 34B, which is farther from the tamper-evident ring 32.

[0196] Advantageously, each thread 18 of the internal threaded portion 34 of the closure 30 may have a greater angular extension than a respective thread of the external threaded portion 16 of the neck finish 10. In other words, each thread 18 of the external threaded portion 16 of the neck finish 10 may have a smaller angular extension with respect to an angular extension of a respective thread of the internal threaded portion 34 of the closure 30.

[0197] In practice, the threaded portion of the closure 30 (i.e., the internal threaded portion 34) may have more windings than the threaded portion of the neck finish 10 (i.e., the external threaded portion 16).

[0198] In particular, when each thread 18 of the external threaded portion 16 has an angular extension of 135°, the angular extension of each thread of the internal threaded portion 34 can be at least 150°.

[0199] For example, the angular extension of each thread of the internal threaded portion 34 can be comprised between 180° and 250°, preferably between 180° and 220°.

[0200] More preferably, the angular extension of each thread of the internal threaded portion 34 is about 219°.

[0201] In practice, in Figure 17 the distal portion 34B engages the external threaded portion 16 (as shown by Figure 17B), while the proximal portion 34A constitutes a so-called “excess thread,” i.e., a portion of thread that does not engage any complementary thread when the closure 30 is closed onto the neck finish with the breakable bridges 38 still intact.

[0202] In Figures 17 and 17 A, the presence of an excess thread results in the proximal portion 34A facing a region of the annular wall 12 that lacks an external threaded portion.

[0203] The presence of excess thread in the internal threaded portion 34 is particularly useful and practical for keeping the closure 30 level with respect to the inlet section 14, both in the first steps of an operation for mating the closure 30 to the neck finish 10 and in the first steps of the unscrewing of the closure 30 starting from said condition of use.

[0204] In practice, the excess thread on the closure 30 makes it possible to significantly reduce the risk of a loss of horizontality between the closure 30 and the neck finish 10 during the screwing or unscrewing of the closure 30. This aspect is particularly important if the closure 30 is unscrewed starting from said condition of use, in which a misalignment of the internal ring 36 with respect to the inlet section 14 can cause early loss of the hermetic seal.

[0205] For example, in Figure 17, the presence of the excess thread significantly reduces the risk that, during the unscrewing of the closure 30, the loss of hermetic seal may occur before the breakage of the bridges 38.

[0206] The beneficial effects arising from the presence of the excess thread in the internal threaded portion 34 are particularly evident when the closure 30 is used in combination with a neck finish that has a smaller thread pitch than the thread pitch of known neck finishes while the other neck finish dimensions, in particular the dimensions T, C and D, are equal.

[0207] For example, when the assembly 70 comprises the first version of the neck finish according to the invention, the pitch P can be 1.624 mm, while T, C, and D can be, respectively, 29.41 ±0.13 mm, 25.10±0.13 mm, and 8.20±0.1 mm (with, possibly, PL=0.6 mm and S=1.34±0.1 mm).

[0208] In particular, a more intimate meshing between the external threaded portion 16 and the internal threaded portion 34 allows to have a firmer engagement between the neck finish 10 and the closure 30, and this reduces the risk of tilting the closure 30 during screwing / unscrewing and also increases the hermetic tightness of the assembly formed by the neck finish 10 and the closure 30.

[0209] Moreover, the presence of both a relatively small thread pitch P and one extra thread with respect to known neck finishes (in particular, for equal values of T, C and D with respect to known 29 / 25 neck finishes) allows to obtain an external threaded portion 16 that has a larger lateral surface, which can offer not only an increase in grip force but also a greater resistance to axial loads.

[0210] The latter aspect is particularly useful and practical when considering that, since bottles are typically stored as groups of pallets stacked on top of each other, the neck finishes of bottles must be capable of withstanding axial compression loads without plastically deforming or breaking.

[0211] Moreover, the more intimate meshing between the external threaded portion 16 and the internal threaded portion 34 is particularly advantageous in the case of pressurized bottles. In this case, in fact, the increased grip force results in a greater resistance to the pressure exerted by the gas contained within the bottles, and this greater resistance is achieved without having to increase the weight of the neck finish and / or the weight of the closure.

[0212] In Figures 16 and 17, the neck finish 10 corresponds to the one shown in any of Figures 1 through 7. However, embodiments (not shown) in which the neck finish 10 of the assembly 70 corresponds to the one shown in any of Figures 8 through 13 are also conceivable.

[0213] In practice it has been found that the present invention fully achieves the intended aim and objects, since the neck finish thus conceived allows to exceed the qualitative limitations of the background art.

[0214] The invention thus conceived is susceptible of numerous modifications and variations, all of which are within the scope of the accompanying claims; by way of non-limiting example, the person skilled in the art effortlessly understands that embodiments that are alternative to those shown may also be provided.

[0215] Except where otherwise indicated, the various embodiments described herein may be combined to provide additional and / or alternative embodiments.

[0216] Although the first and second versions of the neck finish according to the invention have been conceived in particular for 29 / 25 necks and 26 / 22 necks, respectively, the beneficial effects of the present invention may still be used, more generally, for necks having other sizes.

[0217] All the details may furthermore be replaced with other technically equivalent elements.

[0218] In practice, the materials used, so long as they are compatible with the specific use, as well as the contingent shapes and dimensions, may be any according to the requirements and the state of the art.

[0219] To conclude, the scope of the protection of the claims must not be limited by the illustrations or preferred embodiments shown in the description by way of example, but rather the claims must comprise all the characteristics of patentable novelty that reside in the present invention, including all the characteristics that would be treated as equivalents by the person skilled in the art.

[0220] The disclosures in Italian Patent Application No. 102024000003934 from which this application claims priority are incorporated herein by reference.

[0221] Where technical features mentioned in any claim are followed by reference signs, those reference signs have been included for the sole purpose of increasing the intelligibility of the claims and accordingly, such reference signs do not have any limiting effect on the interpretation of each element identified by way of example by such reference signs.

Claims

CLAIMS1. A neck finish (10; 10'; 10") for a bottle (60), for a container for liquids (50), or for a bottle or container preform (40), said neck finish (10; 10'; 10") comprising an annular wall (12) extending around a vertical axis (Z) from an inlet section (TOF, 14), said annular wall (12) comprising: a horizontal parting line (22); a flash-free annular sealing portion (24), said flash-free annular sealing portion (24) being comprised between said inlet section (TOF, 14) and said horizontal parting line (22); and an external threaded portion (16), said external threaded portion (16) being composed of a number of threads (18) greater than or equal to one, each thread (18) wrapping around said annular wall (12) in a helical manner, each thread (18) starting from a thread starting section (20) arranged below said horizontal parting line (22); characterized in that:- said horizontal parting line (22) is spaced by more than 0.3 mm from said inlet section (14);- said external threaded portion (16) has a thread pitch (P) of less than 2.4 mm, and- the product of the helical extension of each thread (18) and the number of threads (18) of said external threaded portion (16) is strictly less than 600°.

2. The neck finish (10; 10'; 10") according to claim 1, wherein a width (U) of each valley that exists between two consecutive thread crests (18A-B, 18B-C, 18C-D, 18D-A; 18) of said external threaded portion (16) is less than 0.95 mm.

3. The neck finish (10; 10'; 10") according to any one of preceding claims, wherein each thread (18; 18A-D) extends away from said inlet section (14) starting from a vertical distance (S) of at least 1.24 mm from said inlet section (14).

4. The neck finish (10; 10'; 10") according to any one of the preceding claims, wherein a half-difference between a first diameter (T) and a second diameter (E) is comprised between 0.7 mm and 1.5 mm, said first diameter (T) corresponding to the "Thread crest diameter" according to the ISBT Threadspecs™ nomenclature, and said second diameter (E) corresponding to the so-called "Thread root diameter" according to said ISBT Threadspecs™ nomenclature.

5. The neck finish (10; 10') according to claim 4, wherein a size of said second diameter (E) lies in the range 27.40±0.30 mm.

6. The neck finish (10; 10') according to any one of the preceding claims, wherein said external threaded portion (16) consists of four threads (18A-D).

7. The neck finish (10; 10') according to any one of the preceding claims, wherein said thread pitch (P) is comprised between L5 mm and 1.8 mm, preferably between L60 mm and 1.65 mm.

8. The neck finish (10; 10') according to any one of preceding claims, wherein a distance (PL) between said horizontal parting line (22) and said inlet section (14) along said vertical direction (Z) measures at least 0.4 mm, preferably 0.6 mm.

9. The neck finish (10; 10') according to any one of the preceding claims, wherein each thread (18A-D) winds around said annular wall (12) for about 135°.

10. The neck finish (10; 10') according to any one of preceding claims, wherein said neck finish (40) is of the so-called "29 / 25" type.

11. The neck finish (10; 10") according to any one of claims 1 to 4, wherein said external threaded portion (16) is single-threaded.

12. The neck finish (10; 10") according to any one of claims 1 to 4 or 11, wherein said neck finish (10) is of the so-called "26 / 22" type.

13. The neck finish (10; 10") according to claim 11 or 12, wherein said thread pitch (P) is 2.3 mm, said horizontal parting line (22) beinglocated 0.8 mm away from said inlet section (14).

14. The neck finish (10; 10") according to claim 3 and one of claims 11 to 13, wherein said vertical distance (S) is 1.65 mm.

15. The neck finish (10; 10") according to any one of claims 11 to 14, wherein said external threaded portion (16) winds helically around said annular wall (12) for about 570°.

16. The neck finish (10; 10") according to any one of claims 11 to 15, wherein a thickness of said annular wall (12) at said thread starting section (20) is 0.85 mm.

17. An assembly (70) comprising: a neck finish (10) according to any one of the preceding claims; and a closure (30), said closure (30) being screwable or screwed onto said neck finish (10) by means of an internal threaded portion (34) of said closure (30); wherein each thread (18) of the external threaded portion (16) of said neck finish (10) has an angular extension that is smaller than an angular extension of a respective thread of said internal threaded portion (34).

18. A bottle (60) comprising a neck finish (10) according to any one of claims 1 to 16.

19. A preform (40) comprising a neck finish (10) according to any one of claims 1 to 16.

20. A mold (100) shaped to make either a preform (40) according to claim 19 or a neck finish (10) according to any one of claims 1 to 16.

21. A method for making a preform (40) by injection molding using the mold (100) according to claim 20.

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