EP3539894A1 - Plastic container with threaded cap - Google Patents

Abstract

A plastic container having a screw cap (20), a container body (2) and a container neck (4) having a container opening (5). On an outer wall (6) of the container neck (4) first threaded portions (7) are provided. The rotary closure (20) has a top surface (21) and a cylindrical shell (22), which protrudes from the top surface (21). Second threaded sections (24) are formed on an inner wall (23) of the jacket (22) of the rotary closure (20). The rotary closure (20) is screwed into engagement with the first threaded sections (7) on the outer wall (6) of the container neck (4) ) are brought. The first threaded sections (7) on the outer wall (6) of the container neck (4) have at least two first threaded passages (8) which are arranged at an angular distance from each other on the circumference of the container neck (4). Each first threaded inlet (8) is associated with a rear rotation lock (9) projecting beyond the outer wall (6) of the container neck (4) and having a radially projecting stop (10). The jacket (22) of the rotary closure (20) is equipped with a tear-off tab (30). The tear-off tab (30) is connected to the jacket via at least one separable web (35) (22). The tear-off tab (30) is arranged on the circumference of the rotary closure (20) in such a manner that a front section (33) of the tear-off tab (30) radially projecting beyond the inner wall (23) of the jacket (22) is adjacent to the stop (10) of the reverse rotation lock (9 ) and in a reverse rotation in abutment with the stop (10) of the reverse rotation lock (9).

Description

The invention relates to a plastic container with a rotary closure according to the preamble of patent claim 1.

The usual in the past containers of white or stained, glass or ceramic are increasingly being replaced by plastic containers. In particular, for the packaging of fluid and / or pasty substances, for example, for household applications, agriculture, industry and commerce, etc., are now mainly plastic containers used. The low weight and the lower costs certainly play a significant role in this substitution. The use of recyclable plastic materials and the overall more favorable overall energy balance in their production also contribute to promoting the acceptance of plastic containers among the users.

Single-layer or multi-layered plastic containers are often produced by the so-called extrusion blow molding method, in particular a tubular blowing method. The extrusion blow molding machines used for the extrusion blow molding process usually have one or more extruders for feeding the required plastic material. The outlet of the extruder is connected to an extruder head, at the outlet opening of which the extruded tube preferably exits in the opening width. The extruded plastic tube can be constructed in one or more layers. The hose exiting the outlet nozzle continuously or quasi-continuously is transferred to a blow molding tool assembly and inflated by overpressure with the aid of a blow mandrel retracted into the mold cavity. Thereafter, the inflated plastic container is removed from the mold cavity.

Plastic containers made of polyethylene terephthalate (PET) and similar materials are usually produced in a so-called stretch blow molding process. In this case, a cylindrical preform is first produced in an injection molding process in an injection mold. Recently, also flow molding processes for the production of preforms have been proposed. The preform has a substantially elongated cylindrical body and is formed closed at one longitudinal end. Usually a so-called support ring separates the body of the preform from a neck section with a pouring opening. The neck portion already has the later shape of the bottle neck and is usually no longer changed in the stretch blow molding process. On the outside of the neck portion already threaded portions or the like can be formed for the determination of a closure part. The preform is demolded after its production and immediately further processed or stored for later processing on a stretch blow molder. Before further processing in a stretch blow molding machine, the preform is conditioned if necessary; then it is introduced into a blow mold of the stretch blow molding machine. In the blow mold, the preform is finally inflated by means of a gas injected with excess pressure in accordance with the mold cavity and usually additionally drawn with a stretching mandrel.

Another production method for plastic containers is the injection blow molding process, in which the blowing process takes place directly after the injection of the preform. The preform remains on the injection core, which can also form a kind of stretching mandrel. The preform is in turn inflated by overpressure according to the mold cavity of a blow mold, which is delivered to the injection core or vice versa, and optionally additionally stretched in the axial direction. Thereafter, the finished plastic container is removed from the mold. This production method is used in particular for smaller plastic bottles and for so-called wide-necked containers.

Pasty masses, such as mayonnaise, mustard, pesto, sugo and the like, but also gherkins, Maiskölbchen, beans and other pickled vegetables and the like are still often kept in glass containers and offered. The glass containers are usually provided with a metal closure which can be screwed onto the glass container. The arrangement of multiple-start threads on the container neck, usually four-start threads allows it to fix the metal closure with an incomplete rotation, for example, in four-start threads with a quarter turn on the container neck or to solve this again ,

The usually hot-filled and / or hot-sterilized contents of the glass container produced on cooling within the first sealed container a negative pressure, through which a slightly deformable central portion of the metal closure is pulled in the direction of the container. The first time unscrewing the metal closure, the consumer hears a "popping noise", which is caused by the return of the central portion of the metal closure in its initial position due to the pressure equalization in the container. This "popping noise" signals to the consumer that the container was properly sealed and has not been tampered with since filling the contents, thus providing a kind of first-hole guarantee.

The production of glass containers is very energy intensive and contributes to the emission of carbon dioxide into the environment. Due to their relatively high weight, the transport of glass containers also causes a considerable excess of carbon dioxide. This applies to the transport of newly manufactured glass containers as well as to glass containers, which are recycled as broken goods. If, however, glass containers are used as reusable containers, the expense of cleaning the containers in the LCA must be taken into account in addition to the transport of the glass containers.

It is therefore an object of the present invention, the glass container for the storage of pasty masses, inlaid with regard to the resulting in consideration of all the above aspects, relatively poor life cycle assessment of glass containers, because of their relatively high weight and also because of the risk of breakage of glass containers To replace vegetables and the like with plastic containers. For the consumer, the handling of the plastic container, in particular the unscrewing and re-screwing a closure, should be feasible in the usual way. Also, the consumer should be offered a simple and incalculable way to detect a first opening of the plastic container. It should thus be provided a visual Erstöffnungsgarantie.

The solution to these problems consists in a plastic container with a screw cap, which has the features cited in claim 1. Further developments and / or advantageous embodiments of the invention are the subject of the dependent claims.

The invention therefore relates to a plastic container with a plastic screw cap, which plastic container has a container body and a subsequent container neck with a container opening. On an outer wall of the container neck first threaded sections are provided with first threaded entries for a positive fixing of a rotary closure. The rotary closure has a cover surface covering the container opening and a cylindrical jacket which protrudes from the top surface and partially overlaps the container neck axially. On an inner wall of the jacket of the rotary closure second threaded portions are formed, which are engageable with screwed rotary closure in engagement with the first threaded portions on the outer wall of the container neck. The first threaded sections on the outer wall of the container neck have at least two first threaded passages, which are arranged at an angular distance from each other on the circumference of the container neck. Each first threaded inlet is associated with a the outer wall of the container neck superior rear-locking, which is approximately wedge-shaped in the circumferential direction of the outer wall of the container neck and has a relative to the outer wall of the neck of the container radially projecting stop. The jacket of the rotary closure is equipped with a tear-off tab, which is arranged in a window-like recess of the jacket open toward a free axial end of the jacket. The tear-off tab is connected via at least one detachable web with a circumferential boundary wall of the recess in the jacket. In this case, the tear-off tab is arranged on the circumference of the rotary closure such that, when the screw cap is screwed on, the front wall of the tear-off tab radially adjoins the inner wall of the pull-tab adjacent to the stop of the reverse rotation lock and comes into abutment against the reverse rotation stop when the rotary closure is turned back.

As a result of the at least two threaded inlets of the rotary closure is very simple, especially in twisted around its longitudinal axis position mounted on the container. The tear-off tab provided on the jacket of the rotary closure cooperates with the rotary closure fitted with the reverse rotation locks associated with each threaded inlet on the container neck and has the function of a freshness seal or a first-opening indicator. If the screw cap is unscrewed, the end portion of the tear-off tab abuts against the stop of the reverse rotation lock and the at least one web which connects the tear-off tab in the recess with the jacket is sheared off. As a result, the tear-off tab loosens from the jacket of the rotary closure. The user can immediately see from the outside whether the tear-off tab is intact and the plastic container has not been tampered with. Thus, the tear-off tab fulfills the function of a freshness crucible, or the rotary closure equipped with the tear-off tab represents a first-opening guarantee. The plastic container is preferably designed as a wide-mouth container. Wide-mouth containers have a very large opening in relation to the body of the container. Typical relationships between the perimeter bounded by the opening and the perimeter defined by the vessel body are about 60% to 120%, with the perimeter of the vessel body being a means for structured vessel bodies. Typically, the contents of the container in wide-necked containers are removed by means of a finger or a spoon.

In one embodiment variant of the invention, the at least two first threaded inlets of the first threaded sections are arranged on the outer wall of the container neck at an angular distance of 180 ° from one another. It follows that the rotary closure can be mounted in a rotated by 180 ° about its longitudinal axis position.

In a further development of the invention, the first threaded sections on the outer wall of the container neck on four first thread entries, which are each arranged at an angular distance of 90 ° from each other. This variant makes it possible to mount the screw cap also in a rotated by 90 ° about its longitudinal axis position.

In a further embodiment variant of the invention, a number of second threaded inlets are provided on the inner wall of the closure lid, which corresponds to the number of first threaded inlets on the outer wall of the container neck. This embodiment of the invention in conjunction with a correspondingly short design of the shell of the rotary closure makes it possible to attach the rotary closure with a rotation of only about 45 ° to the container neck.

A variant of the invention can provide that each reverse rotation lock is designed as a wedge-shaped strip running in the circumferential direction of the container neck and has the largest projection with respect to the outer wall of the container neck on the radially projecting stop. This variant is very easy to manufacture manufacturing technology. The projection of the stop against the outer wall of the container neck can be about 1 mm to 2 mm.

In a further embodiment of the invention, the tear-off tab is connected via two separable webs, which are arranged in the circumferential direction of the tear-off tab at a distance from each other, with the boundary wall extending in the circumferential direction of the recess in the jacket of the rotary closure. The provision of two connecting webs makes it possible to better define the position of the tear-off tab inside the recess in the jacket so that it can interact optimally with the reverse-rotation lock.

A variant of the invention may provide that each web is tapered from a connection to the tear-off tab to a connection to the jacket. By the connecting web is formed thinnest at the connection to the jacket, a defined predetermined breaking point on the jacket is created. If the tear-off tab is disconnected from the jacket when the rotary closure is opened, the bars remain connected to the tear-off tab and can be disposed of together with the tear-off tab if necessary.

In a further embodiment variant of the invention, the tear-off tab on the end section has the largest projection with respect to the inner wall of the jacket of the jacket Rotary closure, wherein the largest supernatant is about 1.5 mm to about 2 mm. At this maximum projection against the inner wall of the shell of the rotary closure reliable opening and locking the tear-off tab on the reverse rotation lock is guaranteed when you open the screw cap. At the same time, however, this supernatant also ensures that the tear-off tab can still slide over the reverse-rotation lock when the plastic container is closed, without damaging the web (s).

A further embodiment of the invention may provide that the tear-off tab is connected at its longitudinal end facing away from the end portion via a film hinge with a boundary wall of the recess extending in the axial direction in the jacket of the rotary closure. The unilateral connection of the tear-off strap with the jacket via a film hinge ensures that the tear-off tab remains connected to the jacket of the rotary closure when the web or severed webs are separated. In general, then the tear-off tab protrudes radially from the shell of the rotary closure, whereby the user is even better an initial opening of the plastic container is already displayed.

The film hinge may have a wall thickness of about 0.3 mm to about 0.8 mm. These wall thicknesses are sufficient for the tear-off tab to remain connected to the jacket of the rotary closure in the case of severed webs. On the other hand, the wall thickness of the film hinge is small enough that the user can very easily separate the tear-off tab from the jacket.

In order to prevent a tear-off can be pushed back despite the severed webs back into the starting position in the recess in the jacket, provides a further embodiment of the invention, that the tear-off at its longitudinal end remote from the front end in addition to the film hinge on a plastic skin with the circumferential direction extending boundary wall of the recess is connected in the jacket. The plastic skin is overstretched and possibly torn during the initial opening and the radial issuing of the tear-off tab and shearing off the connection of the webs to the mantle. This is so opposite to its original one Training injured plastic skin prevents a reset of the tear-off tab in its original position in the window-like recess in the shell of the rotary closure. A Erstöffnung the plastic container can not be hidden.

In order to support a radial issuing of the tear-off tab during the initial opening of the plastic container, in a further embodiment variant of the invention the tear-off tab is designed to be flat at its longitudinal end facing away from the end portion. Advantageously, it has there a wall thickness which is less than a wall thickness of an adjacent region of the jacket of the rotary closure. The smaller wall thickness of the longitudinal section of the tear-off tab facing away from the end section can prevent the longitudinal section from abutting the adjacent area of the jacket, thereby hindering the radial disengagement of the tear-off tab. In one embodiment variant of the invention, the tear-off tab has a wall thickness of about 0.3 mm to about 0.8 mm at its longitudinal end facing away from the end portion.

A further embodiment variant of the invention provides that the jacket of the rotary closure has a wall thickness of about 0.5 mm to about 1.5 mm, preferably about 0.8 mm to 1.3 mm, particularly preferably about 1 mm to about 1.2 mm. With these wall thicknesses, the jacket of the rotary closure has a sufficiently high rigidity in order to ensure a secure closure of the plastic container. On the other hand, the wall thickness is small enough to give the jacket sufficient elasticity, so that the tear-off can slide over the reverse rotation lock when closing.

The rotary closure of the plastic container is preferably produced in an injection molding process. The injection molding of plastics has been well tested and allows a cost-effective production of screw caps with the required dimensional accuracy. The rotary closure comprises as the main plastic component, ie more than 70 percent by weight, a polyolefin, preferably polypropylene.

The plastic container consists of polymers whose main component, ie more than 70 weight percent, at least one material selected from the group consisting of polyolefins, in particular polypropylene (PP), high density polyethylene (HDPE), low density polyethylene (LDPE), polyesters, in particular polyethylene terephthalate ( PET), polyethylene furanoate (PEF), polypropylene furanoate (PPF), polylactides (PLA), styrene polymers, especially styrene-acrylonitrile (SAN), general purpose polystyrene (GPS), high impact polystyrene (HIPS), copolymers and blends of said polymers , The cited plastics have been tested and sufficiently investigated with regard to their use in the food industry.

Preferably, the plastic container is produced in a stretch blow molding from a preferably injection-molded preform. Injection molding of preforms allows adherence to narrow dimensional accuracies, especially in the neck region, which are retained in the subsequent stretch blow molding process, in which the neck region is as a rule no longer altered.

Fig. 1

eine perspektivische Ansicht eines Kunststoffbehälters mit Drehverschluss aus Kunststoff vor dem Verschliessen;

Fig. 2

eine perspektivische Ansicht des Kunststoffbehälters aus Fig. 1 nach dem Abschrauben des Drehverschlusses;

Fig. 3

eine Seitenansicht des Drehverschlusses aus Fig. 1 mit Sicht auf eine Abreisslasche;

Fig. 4

eine Querschnittsdarstellung des Drehverschlusses aus Fig. 3, senkrecht zur Achse des Drehverschlusses;

Fig. 5

eine Detailansicht der Querschnittsdarstellung aus Fig. 4 in vergrössertem Massstab;

Fig. 6

eine perspektivische Ansicht eines die Abreisslasche umfassenden Ausschnitts des Drehverschlusses;

Fig. 7

eine perspektivische Ansicht von unten in das Innere des Drehverschlusses;

Fig. 8

eine perspektivische Darstellung eines Abschnitts des Behälters mit aufgeschraubtem Drehverschluss;

Fig. 9 bis Fig. 11

perspektivische Ansichten des Behälterhalses mit dem Drehverschluss in verschiedenen Zuständen während des Abschraubens; und

Fig. 12

eine perspektivische Darstellung des Behälterhalses mit vollständig abgeschraubtem Drehverschluss.

Further advantages and features will become apparent from the following description of an embodiment of the invention with reference to the schematic drawings. It shows in not to scale representation:

Fig. 1

a perspective view of a plastic container with plastic closure before closing;

Fig. 2

a perspective view of the plastic container Fig. 1 after unscrewing the screw cap;

Fig. 3

a side view of the rotary closure Fig. 1 with view of a tear-off tab;

Fig. 4

a cross-sectional view of the rotary closure Fig. 3 , perpendicular to the axis of the screw cap;

Fig. 5

a detailed view of the cross-sectional view Fig. 4 on an enlarged scale;

Fig. 6

a perspective view of the tear-off comprehensive cutout of the rotary closure;

Fig. 7

a perspective view from below into the interior of the rotary closure;

Fig. 8

a perspective view of a portion of the container with screwed screw cap;

Fig. 9 to Fig. 11

perspective views of the container neck with the screw cap in various states during unscrewing; and

Fig. 12

a perspective view of the container neck with completely unscrewed screw cap.

An inventively designed plastic container, in particular a wide-plastic container, with a plastic screw cap is in Fig. 1 and in Fig. 2 provided with the reference numeral 1 throughout. The plastic container has a container body 2 closed with a container bottom 3, to which a container neck 4 with a container opening 5 adjoins. The container opening 5 may have an inner diameter of, for example, about 45 mm to about 120 mm. On an outer wall 6 of the container neck 4 first threaded portions 7 are formed. The first threaded sections 7 have first thread entries 8 and serve for a positive fixing of a rotary closure 20. Advantageously, at least two first threaded sections 7 with an equal number of first threaded entries 8 are arranged on the outer wall 6 of the container neck 4. In the illustrated embodiment, a total of four first threaded sections 7 are provided with four first threaded recesses 8 on the container neck 4. Because of the perspective view, only two of the uniformly over the circumference of the container neck 4 are arranged first threaded portions 7 clearly visible with first thread enemas 8. From a third first threaded portion 8 is in Fig. 1 or in Fig. 2 only the first threaded inlet 8 visible. A fourth first threaded portion 7 is hidden in the perspective view. The individual first threaded sections 7 and first threaded entries 8 each have the same reference numerals, since they have identical functions with respect to the rotary closure 20. The first threaded sections 7 and the associated first thread entries 8 are uniformly distributed over the circumference of the container neck 4. In the case of two first threaded sections 7 with first threaded inlets 8, the first threaded inlets 8 have an angular spacing in the circumferential direction of approximately 180 °. In the case of four first threaded sections 7, adjacent first threaded entries 8 have an angular spacing in the circumferential direction of approximately 90 °.

Seen in the direction of the container body 2, a reverse rotation lock 9 is formed below each first threaded section 7 on the outer wall 6 of the container neck 4. Each reverse rotation lock 9 is formed in the circumferential direction as an approximately wedge-shaped strip. In this case, each reverse rotation lock 9 projects radially beyond the outer wall 6 of the container neck 4 in the circumferential direction and at its end has a radially projecting stop 10 in relation to the outer wall 6 of the container neck 4. At the radially projecting stop 10, the reverse rotation lock 9 projects beyond the outer wall 6 of the container neck by approximately 1 mm to approximately 2 mm. Each reverse rotation lock 9 is arranged along the circumference of the container neck 4 in such a way that the radial projecting stop 10 is aligned in the axial direction approximately with the end region of the associated threaded section 7 remote from the threaded inlet 8 or at the beginning of the intermediate space between two adjacent threaded sections 7. The term "in Umfangsgsrichtung" means in screwing the lid.

The in Fig. 1 and in Fig. 2 shown rotary closure is provided with the reference numeral 20 and has a container opening 5 covering the top surface 21 and a cylindrical shell 22 which protrudes from the top surface 21. When screwed on rotary closure 20 of the shell 22 engages the container neck 4 partly axially. Out Fig. 9 it can be seen that on an inner wall 23 of the shell 22 of the rotary closure 20 second threaded portions 24 are formed. When the screw cap 20 is screwed on, the second threaded sections are in engagement with the first threaded sections 7 on the outer wall 6 of the container neck 4 (FIG. Fig. 1 ). Out Fig. 9 is further seen that a plurality of second threaded portions 24 are arranged at a uniform angular distance from each other on the circumference of the inner wall 23 of the shell 22. Expediently, the number of second threaded sections 24 corresponds to the number of first threaded sections 7 on the container neck 4. The second threaded sections 24 have second threaded inlets 25, which are arranged at a uniform angular distance from one another. In the case of two second threaded inlets 25, the angular spacing is approximately 180 °. At four second threads 24 with four second thread entries 25, as in FIG Fig. 9 shown, adjacent thread enemas 25 at an angular distance of approximately 90 ° from each other. As in Fig. 1 and 2 are also in Fig. 9 due to the perspective view, not all four second threaded portions 24 with threaded legs 25 visible.

In Fig. 1 and in particular in Fig. 2 It can be seen that the jacket 22 of the rotary closure 20 has a window-like recess 26 open towards a free axial end of the jacket 22. In the window-like recess 26, which has two axial boundary walls 27, 28 and extending in the circumferential direction of the jacket 22 boundary wall 29, a tear-off tab 30 is arranged. The tear-off tab 30 is connected via at least one separable web 35 with the circumferentially extending boundary wall 29 of the recess 26. When in Fig. 1 illustrated embodiment of the rotary closure, the tear-off tab 30 is connected via two webs 35 with the boundary wall 29 extending in the circumferential direction. At its leading in closing direction of rotation of the rotary closure 20 end 31, the tear-off tab 30 is connected via a film hinge 32 with the leading in axial boundary wall 27 of the recess 26 in the shell 22 of the rotary closure 20.

Also in Fig. 2 the plastic container and the associated plastic rotary closure are provided with the reference numeral 1 throughout. The plastic container and the screw cap are identical in terms of based on Fig. 1 explained construction. By difference Fig. 1 shows Fig. 2 the twist lock 20, after being released from the Container neck 4 was unscrewed. The webs 35 were separated from the circumferentially extending boundary wall 29 of the recess 26 in the shell 22. The tear-off tab 30 is only connected via the film hinge 32 with the axial boundary wall 27 of the recess 26 in the jacket 22 and protrudes radially.

Fig. 3 shows a side view of the rotary closure 20. The top surface carries the reference numeral 21, the axially projecting cylindrical cylindrical shell is provided with the reference numeral 22. The tear-off tab 30 arranged in the window-like recess 26 is connected to the jacket 22 via the webs 35 and via the film hinge 32.

Fig. 4 shows a cross section of the rotary closure 20, approximately at half the axial height of the tear-off tab 30 with a view of the top surface 21. From the illustration it can be seen that the tear-off tab 30 protrudes beyond the inner wall 23 of the shell 22 at its end portion 33 facing away from the film hinge 32.

Fig. 5 shows an in Fig. 4 circled detail of the cross-sectional view of the rotary closure 20 in an enlarged scale. Same components bear the same reference numerals as in Fig. 4 , It can be clearly seen that the tear-off tab 30 has the greatest projection d at the end section 33 in relation to the inner wall 23 of the jacket 22. The supernatant d is, for example, about 1 mm to about 2 mm. The film hinge 32 has a wall thickness f of about 0.3 mm to about 0.8. At its end region 31 facing the film hinge 32, the tear-off tab 30 has a smaller wall thickness than the adjoining region of the jacket 22. In particular, the tear-off tab 30 can have a course which is bevelled relative to its outer wall.

Fig. 6 shows a perspective view of the tear-off tab 30 comprising portion of the jacket 22 of the rotary closure. From the illustration it can be seen that the webs 35, over which the tear-off tab 30 is connected to the circumferential boundary wall 29 of the recess 26 in the jacket 22, taper from the tear-off tab 30 to the jacket 22. As a result, a predetermined breaking point of the webs 35 is created at the connection to the jacket 22 and the webs also remain connected to separated tear-off 30 with this. The illustration further shows that the tear-off tab 30 is connected at its longitudinal end 31 facing away from the front end 33 in addition to the film hinge 32 via a plastic skin 34 with the boundary wall 29 of the recess 26 extending in the circumferential direction in the jacket. The plastic skin 34 is at the first opening, in which the tear-off tab 30 issued radially and the connection of the webs 35 to the jacket 22 separated, in particular sheared, overstretched and possibly additionally torn. The plastic cuticle 34 thus injured against its original formation thereby prevents the tear-off tab 30 from being returned to its original position in the window-like recess 26 in the casing 22 of the rotary closure.

Fig. 7 shows a perspective view from below into the interior of the rotary closure 20. The top surface of the rotary closure 20 carries in turn the reference numeral 21. The cylindrical surface 22 axially projecting from the top surface 21 has the inner wall 23. The formed on the inner wall 23 of the cylindrical shell 22 second Threaded portions are provided with the reference numeral 24. In the illustrated embodiment, four second threaded portions 24 are formed on the inner wall 23 of the shell 22, three of which can be seen. The second threaded portions 24 have the same angular distance from each other. Each second threaded portion 24 has a threaded inlet 25. The tear-off tab 30 in the window-like recess in the cylindrical shell 22 is connected via the webs 35 with the jacket 22. At its side facing away from the film hinge 32 end portion 33, the tear-off tab 30 projects beyond the inner wall 23 of the shell 22nd

Fig. 8 is a perspective view of the container 1 with screwed onto the container neck 4 screw cap 20. The container body in turn bears the reference numeral 2. The arranged in the window-like recess 26 in the cylindrical shell 22 tear-off tab 30 is intact.

The pictures Fig. 9 to Fig. 11 serve to explain the function of the tear tab 30 as a tamper evidence. Fig. 9 shows the rotary closure 20, which is screwed onto the container neck 3, which adjoins the container body 2. In this State of the inner wall of the shell 22 superior portion of the end face 33 of the tear-off tab 30 is disposed adjacent to the radially projecting stop 10 of the reverse rotation lock 9. When unscrewing the rotary closure 20 abuts the end face 33 of the tear-off tab 30 against the stop 10 of the reverse rotation lock 9. When further unscrewing the rotary closure 20 an increased force must be expended to the first of the webs 35, over which the tear-off tab 30 with the cylindrical shell 22nd is connected, disconnect or shear. As in Fig. 10 is shown, then the inner surface of the tear-off tab 30 can slide over the reverse rotation lock 9 and is further issued radially, since it remains connected at its opposite longitudinal end on the film hinge 32 with the jacket 22. Just before the rotary closure 20 is removed from the container neck 4, resulting in the Fig. 11 illustrated situation. Both webs 35 ( Fig. 9 ), over which the tear-off tab 30 was connected to the jacket 22, are separated and remain on the tear-off tab 30, which is shown radially farthest.

Fig. 12 shows finally a perspective view of the completely unscrewed from the container neck 4 screw cap 20. The container body in turn bears the reference numeral 2. The radially issued tear tab 30 is still connected via the film hinge 32 with the jacket 22 of the rotary closure 20 and can be completely separated if necessary.

The shell of the rotary closure has a wall thickness of about 0.5 mm to about 1.5 mm, preferably about 0.8 mm to 1.3 mm, more preferably about 1 mm to about 1.2 mm. With these wall thicknesses, the jacket of the rotary closure has a sufficiently high rigidity in order to ensure a secure closure of the plastic container. On the other hand, the wall thickness is small enough to give the jacket sufficient elasticity, so that the tear-off can slide over the reverse rotation lock when closing.

The rotary closure of the plastic container is preferably produced in an injection molding process. The injection molding of plastics has been well tested and allows a cost-effective production of screw caps with the required dimensional accuracy. The rotary closure comprises as the main plastic component, ie more than 70 percent by weight of a polyolefin, preferably polypropylene. The rotary closure can be formed in one piece.

The plastic container consists of polymers whose main component, ie more than 70 weight percent, at least one material selected from the group consisting of polyolefins, in particular polypropylene (PP), high density polyethylene (HDPE), low density polyethylene (LDPE), polyesters, in particular polyethylene terephthalate ( PET), polyethylene furanoate (PEF), polypropylene furanoate (PPF), polylactides (PLA), styrene polymers, especially styrene-acrylonitrile (SAN), general purpose polystyrene (GPS), high impact polystyrene (HIPS), copolymers and blends of said polymers , The cited plastics have been tested and sufficiently investigated with regard to their use in the food industry.

Preferably, the plastic container is produced in a stretch blow molding from a preferably injection-molded preform. Injection molding of preforms allows adherence to narrow dimensional accuracies, especially in the neck region, which are retained in the subsequent stretch blow molding process, in which the neck region is as a rule no longer altered.

The invention has been described with reference to a concrete embodiment. However, the foregoing description is only for the purpose of illustrating the invention and is not to be considered as limiting. Rather, the invention is defined by the claims and the skilled in the art and encompassed by the general inventive concept equivalents.

Claims (18)

Plastic container having a rotary closure made of plastic, which plastic container having a container body and a subsequent container neck with a container opening, wherein on an outer wall of the container neck first threaded portions are provided with first threaded slots for a positive fixing a rotary closure, which rotary closure a container opening covering the top surface and a cylindrical shell which protrudes from the top surface and the container neck partially overlaps axially, and on an inner wall of the shell second threaded portions are formed, which are screwed with screw closure in engagement with the first threaded portions on the outer wall of the container neck can be brought, characterized in that the first threaded portions on the outer wall of the container neck have at least two first thread entries which are at an angular distance from one another at the periphery of the container terhalses are arranged, that each first thread inlet a the outer wall of the container neck superior reverse rotation is associated, which is approximately wedge-shaped in the circumferential direction of the outer wall of the container neck and has a relation to the outer wall of the neck neck radially projecting stop, and that the jacket of the rotary closure with a tear-off which is arranged in a window-like recess of the jacket which is open toward a free axial end of the jacket and is connected in the jacket via at least one separable web to a circumferential boundary wall of the recess, which tear-off tab is arranged on the circumference of the rotary closure, that when screwed screw cap a the inner wall of the shell radially superior face portion of the tear-off to lie in the vicinity of the stop of the reverse rotation lock and in a reverse rotation of the rotary closure in Plant comes to stop the reverse rotation lock. Plastic container with a screw cap according to claim 1, characterized in that the at least two first thread entries of the first threaded portions are arranged on the outer wall of the container neck at an angular distance of 180 ° from each other. Plastic container with a screw cap according to claim 1 or 2, characterized in that the first threaded portions on the outer wall of the container neck have four first thread enemas, which are each arranged at an angular distance of 90 ° from each other. Plastic container with a rotary closure according to one of the preceding claims, characterized in that arranged on the inner wall of the closure lid second threaded portions have a number second thread entries, which corresponds to the number of first thread entries on the outer wall of the container neck. Plastic container with a screw cap according to one of the preceding claims, characterized in that each reverse rotation lock is designed as a wedge-shaped strip extending in the circumferential direction of the container neck and has the largest projection with respect to the outer wall of the container neck on the radially projecting stop. Plastic container with a screw cap according to claim 5, characterized in that the projection of the stop against the outer wall of the container neck is about 1 mm to 2 mm. Plastic container with a rotary closure according to one of the preceding claims, characterized in that the tear-off tab is connected via two separable webs, which are arranged in the circumferential direction of the tear-off tab at a distance from each other, with the circumferentially extending boundary wall of the recess in the shell of the rotary closure. Plastic container with a screw cap according to claim 7, characterized in that each web is tapered from a connection to the tear-off tab to a connection to the jacket. Plastic container with a screw cap according to one of the preceding claims, characterized in that the tear-off tab on the end portion has the largest projection with respect to the inner wall of the jacket of the rotary closure, wherein the largest projection is about 1 mm to about 2 mm. Plastic container with a screw cap according to one of the preceding claims, characterized in that the tear-off tab is connected at its longitudinal end remote from the end portion via a film hinge with a boundary wall extending in the axial direction of the recess in the shell of the rotary closure. Plastic container with a screw cap according to claim 10, characterized in that the film hinge has a wall thickness of about 0.3 mm to about 0.8 mm. Plastic container with a screw cap according to claim 10 or 11, characterized in that the tear-off tab is connected at its end remote from the front end in addition to the film hinge on a plastic skin with the circumferential boundary wall of the recess in the jacket. Plastic container with a screw cap according to one of the preceding claims, characterized in that the tear-off strap at its longitudinal end remote from the end portion has a wall thickness which is less than a wall thickness of an adjacent region of the jacket of the rotary closure. Plastic container with a screw cap according to claim 13, characterized in that the tear-off tab is formed flattened at its longitudinal end remote from the end portion and has a wall thickness of about 0.3 mm to about 0.8 mm. Plastic container with a rotary closure according to one of the preceding claims, characterized in that the jacket of the rotary closure has a wall thickness of about 0.5 mm to about 1.5 mm, preferably about 0.8 mm to 1.3 mm, more preferably about 1 mm to about 1.2 mm. Plastic container with a screw cap according to one of the preceding claims, characterized in that the rotary closure as the main plastic component, ie more than 70 percent by weight comprises a polyolefin, preferably polypropylene, and is produced in an injection molding process. Plastic container with a screw cap according to one of the preceding claims, characterized in that the plastic container consists of polymers whose main component, ie more than 70 weight percent, of at least one material selected from the group consisting of polyolefins, in particular polypropylene (PP), high density polyethylene (HDPE), Low Density Polyethylene (LDPE), Polyesters, especially Polyethylene Terephthalate (PET), Polyethylene Furanoate (PEF), Polypropylene Furanoate (PPF), Polylactides (PLA), Styrene Polymers, Especially Styrene-Acrylonitrile (SAN), General Purpose Polystyrene (GPS) , High Impact Polystyrene (HIPS), whose copolymers and mixtures of said polymers. Plastic container with a screw cap according to one of the preceding claims, characterized in that the plastic container is produced in a stretch blow molding from a preferably injection-molded preform.

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