Cup Sidewall Blank With Stepped Corners for Uniform Flat Rims

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Solution Overview

Problem

Paper-based cups with a flat rim for dairy products face issues in forming a uniform rim due to overlapping layers at the side seam, leading to uneven thickness and complicating the flattening process.

Innovation Solution

A blank design with beveled sections and a step at the top corners, combined with a single-side barrier material coating and heat seal lacquer application, allows for forming a side seam with no overlapping layers, facilitating curling and flattening to create a stable flat rim.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If side edges are joined together to form a side seam using conventional blanks, then the cup structure is formed, but overlapping layers result in uneven thickness at the side seam

Engineering Contradiction:
Improveuniformity of sidewall thicknessVSAvoidthickness consistency at side seam
Core Design Contradiction:
Stability of the object's compositionVSManufacturing precision

Solution Approach 1:

The blank is divided into distinct sections with different layer configurations. Specifically, the blank includes a first section with a first number of layers and a second section with a second number of layers, where the numbers differ. This segmentation allows the side seam to be formed in a region with fewer layers (preferably one layer) while other regions have more layers, thereby achieving uniform thickness at the critical side seam area.

Inventive Principle:
Principle #1Segmentation

2Ease of manufacture

If overlapping layers are present at the top edge of the side seam, then the side wall is formed, but the flattening process becomes complicated and produces an uneven rim

Engineering Contradiction:
Improveflattening process simplicityVSAvoidrim uniformity
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The blank is pre-configured with a specific layer arrangement before the flattening process. The side seam is formed in a region with a reduced number of layers (ideally one layer) while adjacent regions have more layers. This preliminary arrangement of layers in the blank ensures that when the top edge is curled and flattened, the side seam area does not create inhomogeneities, thereby simplifying the flattening process and producing a uniform rim without requiring complex adjustments.

Inventive Principle:
Principle #10Preliminary action

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 ensures a uniform flat rim without overlapping layers, reducing material usage and production costs while maintaining structural integrity and stability.

Implementation Method 1

a first surface adapted to form the inside of the cup and a second surface adapted to form the outside of the cup, wherein the first surface is covered with a barrier material coating

Methodology Applied
Scientific EffectBarrier material coating: Coatings

Implementation Method 2

applying a heat seal lacquer in a top portion of the second surface of the blank, the top portion being intended to form the flat rim of the cup

Methodology Applied
Scientific EffectHeat seal: Heating

Data Source

PatentEP4678387A1Blank for forming a side wall of a cup having a flat rim for attaching a cover and method for manufacturing a cup having a flat rim for attaching a cover
Publication Date: 2026.01.14 HUHTAMAKI OY
  • EP4678387A1 patent drawingFigure 1~2
  • EP4678387A1 patent drawingFigure 3a~5
  • EP4678387A1 patent drawingFigure 6~7

AI summary

The invention concerns a blank (100) for forming a side wall (2) of a cup (1) having a flat rim (4) for attaching a cover, the blank (100) including a top edge (121), a bottom edge (122) and two side edges (123, 124) that are arranged between the top edge (121) and the bottom edge (122), wherein the side edges (123, 124) are intended to be joined together to form a side seam (5) of the side wall (2) of the cup (1), wherein each of the side edges (123, 124) meets the top edge (121) in a respective top corner (125, 126) that includes a bevelled section (127), wherein at least one top corner (125, 126), preferably each top corner (125, 126), includes a step (128) between the bevelled section (127) and the top edge (121).