Interfolded Sheet Stack Separation With Pre-Folded Grippable Flap

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Solution Overview

Problem

Existing interfolding machines struggle with low productivity and cannot produce packs of interfolded sheets with an end sheet partially folded to create a grippable flap for easy extraction, limiting the efficiency and functionality of the separation process.

Innovation Solution

A method and apparatus utilizing a pair of independently movable support tables, a separating board, and separator elements to facilitate high-production separation of interfolded sheets, allowing for the formation of a grippable flap by partially folding the end sheet, with the support tables handling hanging sheets during separation to enable simultaneous support of the next stack.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If traditional separation means are used to separate successive stacks of interfolded sheets, then the separation process can be performed, but productivity remains low and no grippable flap is formed

Engineering Contradiction:
Improveproduction efficiencyVSAvoidease of sheet extraction
Core Design Contradiction:
ProductivityVSEase of operation

Solution Approach 1:

The end sheet is partially folded on itself in advance during the separation process to pre-form the grippable flap, so that when the pack is delivered, the flap is already ready to facilitate easy extraction of sheets without requiring additional operations

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The support tables are divided into multiple independent movable elements that can operate separately - one table supports the formed stack while another handles the hanging strip, allowing simultaneous independent operations that increase productivity while forming the flap

Inventive Principle:
Principle #1Segmentation

2Ease of operation

If the end sheet is folded to create a grippable flap, then ease of sheet extraction is improved, but the separation process becomes more complex

Engineering Contradiction:
Improveease of sheet extractionVSAvoidseparation process complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The support tables perform multiple functions: they support the formed stack, support the hanging strip, and simultaneously fold the end sheet to create the grippable flap. This multi-functionality avoids adding separate dedicated folding mechanisms, thereby limiting the increase in device complexity

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Productivity

If support tables are used to handle hanging sheets during separation, then productivity is enhanced through simultaneous operations, but device complexity increases

Engineering Contradiction:
Improveproduction efficiencyVSAvoidapparatus structure complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The support tables are designed to be independently movable rather than fixed, allowing them to dynamically adjust positions to support different components (formed stack or hanging strip) at different times. This dynamic capability enables simultaneous operations that boost productivity without requiring an entirely separate complex apparatus for each function

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP4440971B1A method and apparatus for separating two successive stacks of interfolded sheets of a type joined by a pre-tear or perforation line and for obtaining a pack of interfolded sheets wherein an end sheet of the pack is folded to define a grippable flap for a facilitated extraction of the sheets from the pack
Publication Date: 2025.11.19 OT LUCCA SRL
  • EP4440971B1 patent drawingFigure 1A~1E
  • EP4440971B1 patent drawingFigure 2A~2B
  • EP4440971B1 patent drawingFigure 2C~2D

AI summary

The method for separating two successive stacks (PA, PB) of interfolded sheets comprises: once having released the formed stack (PA) on a conveyor (O), moving the two support tables (11, 12), one following another, in such a way as to fold the strip (S) of sheets hanging below the successive stack (PB) under formation supported by the pair of separator elements (14, 15), in such a way that, when the two support tables (11, 12) are brought to face one another or moved towards one another to support the successive stack (PB) under formation, an end flap (F3) of the lower sheet of the successive stack (PB) under formation is partially folded and hanging between the two support tables to form a grippable flap (L) for a facilitated extraction of the sheets from the pack (P) which is obtained once the formation of the successive stack (PB) is completed.