Search

EP-4741333-A2 - SCREW CAP, TOOL AND METHOD FOR SCREWING A CAP ONTO A CONTAINER

EP4741333A2EP 4741333 A2EP4741333 A2EP 4741333A2EP-4741333-A2

Abstract

Screw cap (200), loading piston (300), method for aligning the screw cap (200) and the loading piston (300) in relation to each other and a method for screwing a screw cap (200) onto a threaded neck portion of a packaging container. The screw cap (200) comprises a base portion (210) comprising a top (212) and a bottom surface (214); - an annular portion (220) raised from the base portion (210), the annular portion having an inner (222) and an outer surface (224); - at least one first threaded portion (252) arranged on the inner surface (222) of the annular portion, wherein the base portion (210) comprises engagement means (240), such that the screw cap (200) is configured to engage a tool (300) with at least one complementary engagement means in a process of screwing the cap onto the container with the complementary threaded neck portion.

Inventors

  • BERG, Håkan
  • VIRGILI, Magnus

Assignees

  • Tetra Laval Holdings & Finance S.A.

Dates

Publication Date
20260513
Application Date
20160114

Claims (14)

  1. Screw cap (200) for containers with a threaded neck portion, comprising: - a base portion (210) comprising a top (212) and a bottom surface (214); - an annular portion (220) raised from the base portion (210), the annular portion having an inner (224) and an outer surface (222); - at least one first threaded portion (252) arranged on the inner surface (224) of the annular portion, wherein the base portion comprises (210) at least one engagement portion (240), such that the screw cap (200) is configured to engage a tool with at least one complementary engagement portion in a process of alignment of the screw the cap and a complementary threaded neck portion.
  2. Screw cap according to claim 1, wherein the engagement portion of the base portion are located on the inner surface of the base portion, the inner surface facing a pouring opening of the container defined by the neck portion.
  3. Screw cap according to claim 1, wherein the engagement portion of the base portion are located at the outer surface of the base portion, the outer surface facing away from the pouring opening of the container.
  4. Screw cap according to one the previous claims 1-3, wherein the engagement portion comprises at least one protrusion (242).
  5. Screw cap according to one of the previous claims, wherein the engagement portion comprises at least one protrusion and a recess (244) adjacent to the protrusion.
  6. Screw cap according to claim 5, wherein the at least one protrusion and recess are located in close proximity to each other, such that movement of a tool with at least one shoulder portion complimentary to the recess of the cap during engagement with the at least one engagement portion is reduced.
  7. Screw cap according to one of the previous claims 1-6, wherein one end of the at least one protrusion of the engagement portion is aligned with the starting part of the at least one first threaded portion (252).
  8. Screw cap according to one of the previous claims 1-7, wherein the screw cap engagement means comprise three protrusion and recess pairs arranged along a circular circumference and whose one end is vertically aligned with starting parts of three threaded portions.
  9. Tool for (300) feeding a screw cap to a screw cap holder; comprising: - a body (310) - a top end portion (320) in contact with the body (310), the top end portion (310) being arranged to engage the screw cap,; - at least one engagement portion (324) for engaging at least one complementary engagement portions on the screw cap when rotating the screw cap around the tool or the tool around the screw cap.
  10. Tool according to claim 9, wherein the engagement portions comprises at least one shoulder portion configured to engage a complementary engagement portion arranged on the screw cap.
  11. Tool according to claim 10, wherein the engagement means comprises at least three shoulder portions configured to engage complementary engagement means on the screw cap, wherein the at least three shoulder portions are arranged along a circular circumference of the top end portion and radially aligned with a center of the top end portion.
  12. Packaging container for foodstuffs, comprising: - a body portion - a threaded neck portion of polymer material and a - a screw cap according to one of the claims 1-8.
  13. Method for aligning a threaded screw cap with a complementary threaded neck portion of a packaging container, comprising: - positioning a screw cap holder, such that it faces a screw cap feeding tool; - receiving a screw cap in the screw cap holder from the feeding tool ; - rotating the screw cap holder until engagement between an engagement portion in the screw cap and a complementary engagement portion in the feeding tool; - recording the axial position of the screw cap holder - disengaging the screw cap from the feeding tool.
  14. Method for screwing a screw cap comprising at least one threaded portion onto a neck portion of a packaging container comprising at least one complementary threaded portion, comprising: - positioning a screw cap holder holding a screw cap, such that it faces the threaded portion of a packaging container and such that their symmetry axes are aligned, - rotating the screw cap to a predefined axial position recorded during an alignment step between the screw cap holder and a screw cap feeding tool; - moving the screw cap holder towards the packaging container or vice versa; - rotating the screw cap holder and thus the screw cap in the direction of engagement with the threaded portion of the packaging container , such that the cap is screwed onto the threaded portion.

Description

TECHNICAL FIELD The present invention is related to a screw cap for containers with a threaded neck portion made of polymer material. Furthermore, it is related to a tool for feeding a screw cap onto such a container and a packaging container for foodstuffs. Moreover, it is related to a method for aligning a threaded screw cap with a complementary threaded neck portion of a packaging container. Also, it is related to a method for screwing a screw cap comprising at least one threaded portion onto a neck portion of a packaging container. BACKGROUND Screw caps for containers having a threaded neck portion have been known in the art for a very long time. Usually, both the screw cap and the neck portion are made of polymer material, comprising one or more complementary threaded portions for screwing the cap onto the neck. In the food packaging industry, packaging containers with a bottle-like shape, having a body portion of laminated paper material and a top portion of polymer material including a threaded neck part are well known. Examples of such packaging containers are Tetra Top™, Tetra Evero™ and Tetra Evero Aseptic™ wherein the latter additionally comprises an oxygen barrier in the form of an aluminium foil as part of the laminated paper material for longer storage time of the foodstuff contained in the packaging container. After a web of paper material is laminated with several outer polymer materials, folded and spliced to form a hollow packaging container body, a top portion comprising threaded neck part is injection moulded onto the body, which may be of different material than the top portion as evident from the packaging containers mentioned in the previous paragraph. In the next step, a screw capping unit screws a threaded cap usually made of polymer material and having threads complementary to the threaded neck part is screwed onto the neck part of the packaging container. In the ensuing step, the hollow side of the packaging container is filled with the foodstuff to be contained whereafter the hollow end of the container is folded and sealed. It should be mentioned, that in one possible and known implementation of the capping process, the hollow packaging container body including the injection moulded top portion is fed into a rotating drum and rotated to face a screw cap holder while at a distance a screw cap is fed to the screw cap holder . While both the packaging container and the screw cap holder are locked in their radial positions, the screw cap is rotatingly moved towards the top portion of the packaging container and screwed onto its neck portion. Experience shows that a small percentage of the thus capped package containers display a misalignment between the cap and the neck part of the container. One reason for the misalignment may be storage conditions for the caps, such as temperature and moisture, which may influence the expansion coefficients for the cap material. Another reason may be inaccuracies in the relative position of the screw application tool (chuck) and the screw cap. Such misalignment may lead to a slightly oblique application of the cap to the neck and thus either in a not sufficiently sealed container, damaged threaded portions on the neck part and the cap itself or too easy opening of the bottle. Containers with these deviations need to be discarded. In any case, it would be desirable to solve at least some of the problems mentioned earlier leading to better sealing of the capped packaging container and a lower discard rate. SUMMARY At least some of the problems with existing technology are solved by a screw cap according to claim 1 of the present invention. Preferred embodiments are given in the dependent claims. According to one aspect of the present invention, a solution is provided by a screw cap for containers with a threaded neck portion, where the screw cap comprises a base portion with a top and a bottom surface (214), an annular portion raised from the base portion which has an inner and an outer surface (222), at least one first threaded portion arranged on the inner surface of the annular portion, wherein the base portion comprises at least one engagement portion, such that the screw cap is configured to engage a tool with at least one complementary engagement portion in a process of alignment of the screw the cap and a complementary threaded neck portion. In one embodiment, the engagement portion of the screw cap may be located on the inner surface of the base portion. The inner surface is defined as the surface of the base portion facing a pouring opening of the container defined by its neck portion. In other embodiment, the engagement portion above may be at the outer surface of the screw cap's base portion, where the outer surface is defined as the surface of the base portion facing away from the pouring opening of the container. While the engagement portion may have many variations, in one embodiment of the screw cap, the engagement portion may compris