Rotating Cup Shoulder Forming for Leak-Resistant Side Seams

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Solution Overview

Problem

Existing methods for producing containers with stacking shoulders often result in poorly defined contours and side seam leaks, particularly at the stacking shoulder region, which complicates destacking and leakage issues.

Innovation Solution

A method involving a rotating form tool and static mandrel to form a container's stacking shoulder, ensuring a well-defined edge and minimizing side seam damage during the forming process, allowing for improved leak resistance and easier tool movement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a reciprocating form tool is used to form the stacking shoulder, then the stacking shoulder can be formed into the sidewall, but the stacking shoulder does not have a sharp, well defined contour and the side seam leaks particularly in the region of the stacking shoulder

Engineering Contradiction:
Improvestacking shoulder contour definitionVSAvoidside seam leak resistance
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The form tool is made to rotate continuously or at least temporarily during the forming process instead of reciprocating linearly. This dynamic rotational motion allows the forming means to smoothly engage and disengage from the sidewall, preventing locking on the side seam while maintaining continuous material contact for proper contour formation.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The forming action is transitioned from purely linear reciprocating motion to rotational motion around the cup's axis. This adds a tangential dimension to the forming process, allowing the tool to move over the material more smoothly and include the side seam without locking, while still forming the stacking shoulder contour.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Device complexity

If the form tool reciprocates without rotation, then the tooling structure is simpler, but the tool locks on the cup at the side seam and cannot be pulled back off

Engineering Contradiction:
Improveform tool structureVSAvoidtool removal from cup
Core Design Contradiction:
Device complexityVSEase of operation

Solution Approach 1:

The form tool incorporates rotational capability that allows it to dynamically adjust its engagement with the cup. The rotation enables the tool to smoothly pass over the side seam region during reciprocation, preventing the tool from locking onto the cup and facilitating easy removal without requiring complex release mechanisms.

Inventive Principle:
Principle #15Dynamics

3Device complexity

If the form tool moves up the cup without rotation, then less mechanical complexity is introduced, but there is increased load required to push the form tool up the cup and more material drag

Engineering Contradiction:
Improveform tool mechanismVSAvoidforming load and material drag
Core Design Contradiction:
Device complexityVSForce

Solution Approach 1:

The rotational motion of the form tool reduces friction and material drag during the forming process. The rotation allows the forming means to glide over the sidewall material more efficiently, distributing the forming load and reducing the force required to push the tool up the cup compared to pure linear reciprocating motion.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The rotational motion introduces a dynamic element that reduces material drag and friction during forming. This mechanical motion pattern helps the tool move more smoothly over the material, reducing the overall force required for the forming operation.

Inventive Principle:
Principle #18Mechanical vibration

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The method produces containers with enhanced stacking shoulder definition and improved leak resistance, facilitating easier destacking and reduced material drag, while simplifying the form tool design and reducing the load required for forming the shoulder.

Implementation Method 1

a form tool and a mandrel, wherein the sidewall is wrapped around the mandrel and the form tool reciprocates between a remote- and a forming position. In the forming position, forming means, for example an edge in the form tool cooperates with forming means at the mandrel and hence form the stacking the shoulder into the sidewall of the cup

Methodology Applied
Scientific EffectMechanical deformation: Deformation

Data Source

PatentEP2962842B1Method to form a stacking shoulder into the sidewall of a cup with a rotating tool
Publication Date: 2018.09.05 HUHTAMAKI OY
  • EP2962842B1 patent drawingFigure 1
  • EP2962842B1 patent drawingFigure 2
  • EP2962842B1 patent drawingFigure 3~4

AI summary

The present invention relates to a method for the production of a container having a bottom and a first sidewall attached to the bottom, wherein a stacking shoulder is formed into the first sidewall (3) by means of a form tool and a mandrel, wherein the form tool reciprocates along its center axis from a remote to a forming position and wherein the form tool rotates around its center axis at least temporarily during forming of the stacking shoulder.