EP2903898A1

EP2903898A1 - Plastic receptacle, in particular plastic bottle, having no support ring

Info

Publication number: EP2903898A1
Application number: EP13762406.0A
Authority: EP
Inventors: Robert Siegl
Original assignee: Alpla Werke Alwin Lehner GmbH and Co KG
Current assignee: Alpla Werke Alwin Lehner GmbH and Co KG
Priority date: 2012-10-04
Filing date: 2013-09-11
Publication date: 2015-08-12
Also published as: CH707062A1; EP3187430A1; EP3187430B1; WO2014053212A1

Abstract

Described is a plastic receptacle (1) which has no support ring and comprises a receptacle member (2) and a receptacle shoulder (4) that extends from the receptacle member (2) and that has a pouring orifice (20). Fastening means (6) for positively securing a closure are provided in an outer wall (6) of the plastic receptacle (1), in the vicinity of the pouring orifice (20). An at least partially circumferential, blow-molded groove (10) is formed in the receptacle shoulder (4), in a region close to the fastening means (6) for positively securing a closure part.

Description

Supportless plastic container, in particular plastic bottle

The invention relates to a supportless plastic container, in particular a plastic bottle, 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 substances, for example, for household applications, agriculture, industry and commerce, etc., recently mainly plastic containers are 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 in the so-called extrusion blow-molding process, in particular a tubular blowing process. 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 is preferably adjustable in the width of the outlet, the extruded tube emerges. 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 preform is first produced by injection molding in an injection mold. Recently, extrusion or extrusion blow molding processes have also been used for the production of preforms. been hit. The preform has a substantially elongated preform body and is formed closed at its one longitudinal end. At the other end of the preform body, a neck portion adjoins, which is provided with a Ausgiessöffhung. The neck portion already has the later shape of the bottle neck. On the outer side of the neck portion, therefore, threaded portions or the like protrusions are usually already formed for fixing a closure part. In many cases, a so-called snap ring is provided on the neck portion, which protrudes radially from the circumference. The snap ring serves as an abutment for a detachable guarantee strip of a screw-on screw cap for a plastic container stretched out of the preform or in the case of oil bottles or the like for fixing the lower part of a commonly used hinge closure. In most of the known preforms, the preform body and the neck portion are separated by a so-called support ring. The support ring protrudes radially and serves for the transport of the preform or of the plastic container produced therefrom and for the support of the preform on the molding tool or of the plastic container during the closure.

The preform is demolded after its production and hot processed immediately in a one-step stretch blown or immediately cooled in a two-stage stretch blown for a spatially and / or temporally separate further processing on a stretch blow and stored. Prior to further processing in the stretch blow molder, the preform is conditioned if necessary, i. The preform is impressed on a temperature profile. Thereafter, it is introduced into a blow mold of the stretch blow molding apparatus. In the blow mold, the preform is finally inflated by means of a gas injected with overpressure, usually air, according to the mold cavity and additionally axially stretched with a stretching mandrel. An injection blow molding process is also already known, in which the blowing process takes place directly after the injection of the preform. The preform remains on the injection core, which at the same time forms 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 thereby stretched by the mandrel. Thereafter, the finished plastic container is removed from the mold.

The extrusion blown, injection blown or stretch blown plastic containers are usually transported immediately after demolding to a filling plant and filled. After filling, the plastic containers are automatically closed with screw caps or snap closures. These are either screwed on, bounced or snapped.

For reasons of an improved life cycle assessment but also for reasons of cost, plastic containers, in particular plastic bottles, are becoming ever lighter and thinner-walled. As a result of the resulting reduced mechanical strength of the plastic container, the torques, bouncing and snap forces occurring during closing can only be absorbed inadequately by the bodies of the plastic containers or undesirable deformations can occur. This problem can also occur in supportless plastic containers, which are stretch-blown from supportringless preforms, as described for example in WO

2006/027092 AI are described for wide-mouth containers. In conventional stretch blown plastic containers, the closure is applied to the relatively thick-walled, non-stretched neck portion. A usually arranged between the container body and the container neck support ring is used when closing the previously filled container for receiving the forces occurring. Due to the relatively large wall thickness in this area, the forces can be easily absorbed, although the unstretched material has a lower strength than the stretched. If the support ring is missing and the rest of the container body is very thin-walled with respect to the unstretched neck portion, problems may arise during the application of the closure.

In the case of plastic containers produced by the so-called "lost-neck method", the application of the closure can also lead to problems due to the absence of the support ring Following the blowing process, the neck portion of the plastic container located above the blown-off means for positive locking of the closure is severed having large opening diameter is then transported to the filling station to be filled there and then to be provided with the closure. However, after the neck portion has been severed, this wide neck container does not have a support ring which could serve as an abutment when the closure is applied.

Object of the present invention is therefore to remedy the problems described, which can occur when applying a closure part on supportringlose plastic containers. A supportringless plastic container is to be created, which allows an optimization with regard to the container weight and, despite reduced wall thicknesses and a lack of a support ring, permits a problem-free automatic closing of the plastic container. The existing automatic closing devices should continue to be usable without complex redesigns.

The solution to these problems consists in a supportless plastic container, in particular a plastic bottle, which have the stated in the characterizing portion of claim 1 features. Further developments and / or advantageous embodiments of the invention are the subject of the dependent claims.

The invention provides a supportringloser plastic container is provided which has a container body and extending from the container body container shoulder with a Ausgiessöffhung. In the vicinity of the pouring opening fastening means for the positive fixing of a closure are provided in an outer wall of the plastic container. The fastening means for the positive fixing of a closure may be, for example threaded sections, a thread or bayonet-like projections or grooves. In the container shoulder an at least partially circumferential groove is formed, which is produced in a blow molding process.

The at least partially encircling groove in the container shoulder, in the vicinity of the fastening means, assumes the function of a support ring in the case of a supportless plastic container. The partially circumferential groove allows the coupling of a torque occurring when unscrewing a twist lock or bayonet closure or the absorption of the bounce or snap forces in a bouncing or snapping a closure part. The at least partially encircling groove is arranged in a structurally stronger region of the plastic container and thus relieves the rest Container body, which may be formed according to thin-walled. The at least partially circumferential groove in the container shoulder of the plastic container is designed such that devices, such as transport, holding or Verschliesseinrich- lines, which are actually intended for plastic containers with usually injected support ring, can continue to be used.

The inventive design of the plastic container can be provided in bottle-like shaped plastic containers as well as plastic containers, which are made by the Lost-Neck method.

The at least partially encircling groove having container shoulder is structurally stronger than the rest of the container body, which may be formed correspondingly thin-walled.

The at least partially circumferential groove is expediently arranged within the first third of the axial extension of the container shoulder from the container neck to the container body. In this area, the plastic container is less strongly radially and axially stretched, and the plastic container in this area usually also has a greater wall thickness than in the following sections of the container shoulder or the container body.

A measured in the axial direction width of the groove is about 2 mm to about 20 mm. The groove has a depth measured in the radial direction which is about 2 mm to about 20 mm. In the case of these dimensions of the groove, it is ensured that the inflated plastic container, which may be additionally stretched axially in the stretch blow molding process, is easily demoldable and the majority of the automatic closing devices normally used can be reused without redesigning.

A variant of the invention provides that the groove is formed as a circumferential annular groove. This facilitates the detection of the plastic container from the holding and closing devices in particular in that no radial orientation of the holding and closing devices to the plastic container is necessary. So that a torque occurring when turning a screw cap can be better absorbed, the boundary surfaces of the annular groove can be formed at least partially with a greater roughness than the adjacent outer wall. Additionally or alternatively, one or more abutments may be formed for torque take-up within the annular groove.

The abutment (s) may extend radially outward or toward the interior of the container from a radial boundary surface of the annular groove. In this case, each abutment is formed as a projection or as a notch-like depression. The abutments facilitate the absorption or support of the torque that can occur through the closure device when turning a rotary closure onto the container neck provided with threaded sections.

A further embodiment of the invention provides that in the vicinity of the at least partially encircling groove or to the circumferential annular groove, above and / or below the same in the adjacent outer wall, one or more abutment are formed for torque take-up. The abutments are formed, for example, as projections relative to the adjacent outer wall or as notch-like depressions in the adjacent outer wall. Preferably, the protrusions or notches have a radial extent of from about 1 mm to about 10 mm. Their axial extent corresponds approximately to the axial width of the annular groove. When applying, in particular unscrewing the closure on the container neck, the abutment can cooperate with appropriately designed holding devices on the Verschliesseinrichtungen to absorb the occurring torque and / or the occluding closing forces.

The abutments for torque absorption are like the at least partially encircling groove or the annular groove produced during the blowing process in a correspondingly shaped mold cavity of a blow mold.

The features according to the invention prove to be advantageous for supportringless plastic containers which are produced by extrusion blow molding or by stretch blow molding. Particularly expediently, they are found in plastic containers, in particular fuel bottles made from supportringless preforms in a stretch blow molding process. This can be a single-stage stretch blow molding process in which a previously produced preform is stretch-blown immediately following its production to the desired plastic container. However, the plastic container can also be produced in a two-stage stretch blow molding process in which the preform is stretch-blown after its production in a plastic injection molding or in a flow molding process temporally and / or spatially separated from the desired plastic container, in particular to a plastic bottle. The invention is particularly advantageous in plastic containers, which are produced by the lost-neck process.

Further advantages and features will become apparent from the following description of exemplary embodiments of the invention with reference to the schematic drawings, which are not shown to scale. Fig. 1 shows a partially sectioned view of a supportringlosen

Plastic container, in particular a plastic bottle;

Fig. 2a - Fig. 2c show schematic cross sections through an annular groove in

a container shoulder;

Fig. 3 a and 3b show two further cross sections through the annular groove; and

4 shows a view of a plastic container, which after a release

Neck procedure is made.

Fig. 1 shows schematically a partially cut in the container neck representation of a total provided with the reference numeral 1 plastic container, such as a plastic bottle. The plastic container 1 is manufactured in a blow-molding process, for example in an extrusion blown process from an extruded plastic tube or in a stretch blow molding process from a preform previously produced, for example by injection molding or in a flow-compression process, and consists of the plastic materials commonly used for these processes, e.g. PE, in particular

ADJUSTED SHEET 1 p example, plastic materials used for these methods, such as PE, especially HDPE, PP, PET, PEN, PS, PLA, PA, as well as copolymers of these materials. It can be constructed in one or more layers.

The plastic container 1 has a container body 2 which is closed by a container bottom 3. About an approximately conical container shoulder 4, the container body 2 is integrally connected to a container neck 5. On an outer wall of the container neck 5 fastening means 6 are formed, which are formed in the present exemplary embodiment as threaded portions 6 or the like projections. The fastening means 6 are used for the positive fixing of a closure part, not shown. In the case of a plastic container produced in a stretch blow molding process, the threaded sections 6 are already finished on a preform previously produced in an injection molding or flow molding process and are not further changed during the subsequent blow molding process. In the extrusion blow molding method, the container neck with the external thread is first formed in the mold cavity of a blow mold on an inserted section of an extruded plastic tube. In many cases, as in the case of the plastic container 1 shown in FIG. 1, which is produced in particular from a supportless preform in a stretch blow molding process, a circumferential snap ring 7 is formed on the container neck 5. The snap ring 7 serves as an abutment for a detachable guarantee strip of a screw-on screw cap or in Olflaschen or the like for fixing a lower part of a commonly used hinge closure. In this case, ensures the below the snap ring 7 to the container neck 5 subsequent container shoulder 4, which widens conically in the direction of the container bottom 3, that the detachable guarantee strip of the screw can not be levered over the snap ring 7.

In a region of the brackets adjacent to the threaded sections 6, shoulders 4, approximately in the first third of the axial extension of the container shoulder 4 in the direction of the container body 2, are formed with a groove 10 in the boundary wall 9 of the container shoulder 4 by blow molding. The groove 10 is formed at least partially circumferentially. According to the illustrated embodiment, the groove 10 is formed as a circumferential annular groove whose cross-section extends approximately perpendicular to an axis A of the plastic container 1. In the radial direction, the annular groove 10 by a radial Limiting surface 1 1 limited. The annular groove 10 has a width w measured in the axial direction, which is about 2 mm to about 20 mm. A measured in the radial direction depth d of the annular groove 10 is about 2 mm to about 20 mm. The surfaces bounding the annular groove 10 may have a greater roughness than the surface of the remaining boundary wall 9 of the container shoulder 4.

2a, 2b and 2c show schematically different cross-sectional contours of the annular groove 10. In this case, the cut surface runs approximately in the middle of the width w through the annular groove 10 and perpendicular to the container axis A. Fig. 2a shows the contour of the radial boundary surface 1 1 of the annular groove 10 at a rotationally symmetrical plastic container 1. The indicated in Fig. 2b and 2c cross-sectional contours of the annular groove 10 each show two abutment 16 for torque absorption. In Fig. 2b, these abutments 16 are formed by two projections 12 which extend within the annular groove 10 from the radial boundary surface 1 1 to the outside. Preferably, the projections 12 do not project beyond the annular groove 10. However, the projections 12 may be flush with the boundary wall 9 of the container shoulder 4 (FIG. 1). An inner wall of the radial boundary surface 11 extends into the projections 12. This is a consequence of the production of the projections 12 in a blowing process. The abutment 16 shown in Fig. 2c are formed as notches-like depressions 13 which extend from the radial boundary surface 1 1 of the annular groove 10 radially in the direction of the container interior. A radial length 1 of the recesses 13 or the projections 12 corresponds approximately to the radial depth d of the annular groove 10. Their axial Erstrek- kung corresponds approximately to the axial width w of the annular groove 10th

In the exemplary embodiments illustrated in FIGS. 3 a and 3 b, the abutments 16 for torque absorption are arranged in close proximity above and / or below the encircling annular groove 10. Fig. 3a shows two projections 14 which project above and / or below the annular groove 10 substantially radially from the boundary wall 9 of the container shoulder 4. According to FIG. 3b, the abutments 16 are formed by two notch-like depressions 15, which extend inwards and / or below the annular groove 10 substantially radially from the boundary wall 8 of the container shoulder 4 inwards. The projections 14 or depressions 15 have a radial extension 1, which is about 1 mm to 10 mm. Their axial extent corresponds approximately to the width w measured in the axial direction w of the annular groove 10. The at least partially encircling groove 10 in the container shoulder 4 in the vicinity of the threaded portions 6 or the like projections on the container neck 5 assume the function of a support ring in a supportless plastic container 1. The partially encircling groove 10 allows the coupling of a torque occurring when a screw cap is screwed on, or the absorption of the bounce or snap forces during a bouncing or snapping-on of a closure part. The at least partially encircling groove 10 is arranged in the region of the structure stronger container shoulder 4 and thus relieves the rest of the container body 2, which may be formed correspondingly thin-walled. Additional abutment 16 for torque support support the coupling of a torque occurring when turning a rotary closure on the container neck 5 in holders of a closing device. While always two abutments 16 are shown in the figures, more or only one abutment 16 may be provided. It can also recesses 13, 15 and projections 12, 14 may be provided in combination as an abutment 16. These can be arranged within the groove 10 or annular groove and / or above and / or below it.

4 is a schematic representation of a plastic container made by a lost-neck process. In turn, the plastic container carries the reference number 1. It is produced in a blow molding process, for example in an extrusion blown process from an extruded plastic hose or in a stretch blow molding process from a preform previously produced, for example, in an injection molding process or in a flow molding process plastic materials used for these methods, such as PE, especially HDPE, PP, PET, PEN, PS, PLA, PA, as well as copolymers of these materials. It can be constructed in one or more layers. The illustrated in Fig. 4 separated neck portion 30 is intended to indicate the production in the Lost-Neck process. At its outer wall close to the pouring opening 20, the plastic container is in turn equipped with fastening means 6 for the form-fitting fixing of a closure part. In contrast to bottle-like plastic containers, the fastening means 6 are designed for the form-fitting fixing of a closure part in a blow molding process. The plastic container 1 has a container body 2 which is closed by a container bottom 3. In the vicinity of the fastening means 6 for the positive fixing of the closure part is in the adjacent outer wall 9 by blow molding a groove 10 formed. The groove 10 is formed at least partially circumferentially. According to the illustrated embodiment, the groove 10 is formed as a circumferential annular groove whose cross section is approximately perpendicular to an axis A of the plastic container 1. The dimensions and the special design of the groove 10 correspond to those of the embodiment explained with reference to FIGS. 1 to 3 for plastic bottles.

The invention provides, in particular, a supportringless plastic container 1 which has a container body 2 and a container shoulder 4 extending from the container body 2 with a pouring opening 20. In the vicinity of the pouring opening 20, fastening means 6 are provided in an outer wall 6 of the plastic container 1 for the positive fixing of a closure. In the container shoulder 4, in a region close to the fastening means 6 for the form-fitting fixing of a closure part, there is formed an at least partially encircling groove 10, which is produced by a blowing process. The invention is not limited to the specific variants described in the preceding exemplary embodiments, but also encompasses all equivalent embodiments resulting for the person skilled in the art from the description of the figures and the claims.

Claims

claims

1. Supportless plastic container with a container body (2) and extending from the container body container shoulder (4) to which a container neck (5) with a Ausgiessöffhung (20) adjoins the outer wall in the vicinity of the Ausgiessöffhung (20) fastening means (6) are arranged for positive fixing of a closure part, characterized in that in the container shoulder (4) an at least partially circumferential groove (10) is formed, which is produced in a blow molding process.

2. Plastic container according to claim 1, characterized in that it is made in a lost-neck process.

3. Plastic container according to claim 1 or 2, characterized in that it is designed like a bottle.

4. Plastic container according to one of the preceding claims, characterized in that the groove (10) within the first third of the axial extent of the container shoulder (4) from the container neck (5) to the container body (2) is arranged.

5. Plastic container according to one of the preceding claims, characterized in that the groove (10) has an axial width (w) which is about 2 mm to about 20 mm.

6. Plastic container according to one of the preceding claims, characterized in that the groove (10) has a radial depth (d), which is about 2 mm to about 20 mm.

7. Plastic container according to one of the preceding claims, characterized in that the groove (10) is designed as a circumferential annular groove.

8. Plastic container according to one of the preceding claims, characterized in that the annular groove (10) has boundary surfaces which at least partially have a greater roughness than an adjacent outer wall (9).

9. Plastic container according to claim 7 or 8, characterized in that within the annular groove (10) at least one abutment (16) is designed for Drehmomentaufnahrne.

10. Plastic container according to claim 9, characterized in that the at least one abutment (16) extends from a radial boundary surface (11) of the annular groove (10) in the direction of an adjacent outer wall (9).

1 1. Plastic container according to claim 9, characterized in that the abutment (16) extends from a radial boundary surface (1 1) of the annular groove (10) in the direction of the container interior.

12. Plastic container according to one of the preceding claims, characterized in that in the vicinity of the at least partially encircling groove or the circumferential annular groove (10), above and / or below the same in an adjacent outer wall (9) one or more abutments (16 ) are designed for torque absorption.

13. Plastic container according to claim 12, characterized in that each abutment (16) as a projection (14) opposite the adjacent outer wall (9) is formed.

14. Plastic container according to claim 12, characterized in that each abutment (16) is designed as a notch-like depression (15) in the adjacent outer wall (9).

15. Plastic container according to claim 13 or 14, characterized in that each projection (14) or each notch-like depression (15) opposite the adjacent outer wall (9) has a radial extent (1) of about 1 mm to about 10 mm.

16. Plastic container according to one of the preceding claims, characterized in that the abutments (16) are made for torque absorption in a blow molding process.

17. Plastic container according to one of the preceding claims, characterized in that it is made of a supportringlose preform in a one- or two-stage stretch blow molding.