Paper Straw End Sealing Using External Tongue-Fold Bonding

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Solution Overview

Problem

Existing methods for sealing the end opening of paper-based drinking straws are technically complex and time-consuming, making them expensive and inefficient.

Innovation Solution

A method involving cutting a tongue-shaped section from the end of a paper straw, folding it over the opening, and gluing it to the outside wall to create lateral openings, using a fast-setting hot melt adhesive, which simplifies the process and forms openings without requiring additional drilling or punching steps.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If adhesive is applied inside the hollow straw to seal the opening, then the sealing is reliable, but the process becomes technically complex and time-consuming

Engineering Contradiction:
Improvesealing reliabilityVSAvoidprocess complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

Instead of applying adhesive inside the hollow straw as in conventional methods, the invention inverts the approach by applying adhesive to the outside of the straw. The tongue-shaped section is folded over the opening and glued to the external surface, eliminating the need for internal adhesive application while achieving reliable sealing.

Inventive Principle:
Principle #13The other way round (Inversion)

Solution Approach 2:

The invention extracts the adhesive application step from the internal hollow space of the straw and relocates it to the external surface. This extraction simplifies the process by eliminating the need for precise internal positioning while maintaining sealing effectiveness through external bonding of the folded tongue section.

Inventive Principle:
Principle #2Taking out (Extraction)

2Reliability

If adhesive is applied inside the hollow straw to seal the opening, then the sealing is reliable, but the manufacturing time and cost increase

Engineering Contradiction:
Improvesealing reliabilityVSAvoidmanufacturing efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The invention inverts the adhesive application location from internal to external, allowing for faster and more cost-effective manufacturing. The tongue-shaped section is glued to the outside surface, which is significantly simpler from a process engineering perspective and can be carried out more efficiently.

Inventive Principle:
Principle #13The other way round (Inversion)

Solution Approach 2:

The tongue-shaped section itself serves as both the sealing element and the bonding substrate. By folding this section over the opening and gluing it externally, the structure uses its own geometry to facilitate the bonding process, eliminating the need for separate internal adhesive application steps.

Inventive Principle:
Principle #25Self-service

3Reliability

If the tongue-shaped section is folded over completely to close the opening, then the sealing is effective, but no lateral openings are created for sensory drinking

Engineering Contradiction:
Improvesealing effectivenessVSAvoiddrinking experience functionality
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The invention applies local quality by creating different functional zones: the tongue-shaped section provides sealing where needed, while lateral openings are created in specific areas to allow liquid flow. This localized differentiation enables both effective sealing and sensory drinking functionality to coexist.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

Instead of completely closing the opening with the folded tongue section, the invention uses partial action by leaving lateral openings. The tongue section is folded over to provide sealing while intentionally leaving gaps for liquid to pass through, achieving both sealing and flow functionality.

Inventive Principle:
Principle #16Partial or excessive 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

This method simplifies and speeds up the manufacturing process, making it more cost-effective and efficient, while providing a reliable bond and customizable opening sizes for a pleasant drinking experience.

Implementation Method 1

glue the tongue-shaped section to the outside of the straw wall

Methodology Applied
Scientific EffectAdhesive bonding: Adhesive

Data Source

PatentEP4115776B1Method for at least partially closing a main orifice of a drinking straw
Publication Date: 2026.02.11 HENKEL KGAA
  • EP4115776B1 patent drawingFigure 1~3
  • EP4115776B1 patent drawingFigure 4~6

AI summary

The invention relates to a method for sealing the end of a paper-based drinking straw (1), comprising the following steps: - Providing a tubular paper-based drinking straw (1); - Cutting an end section of the drinking straw (1) to form a tongue-shaped section (4); - Folding the tongue-shaped section (4) over the opening (3a) of the drinking straw (1) to form two lateral openings (10); - Bonding the tongue-shaped section (4) to the outside of the wall (2) of the drinking straw (1).