Rotary Foil Cutter Elevations Prevent Material Jamming

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Solution Overview

Problem

Existing rotary die-cutting technologies face issues with material jamming between cutting edges, requiring complex and disruptive detachment methods, and are limited in use with close cutting contour sections or small closed contours, especially when using carrier rollers with suction and blowing air functions.

Innovation Solution

The film cutter or solid knife roller incorporates elevations on its upper side adjacent to cutting edges, designed to prevent material jamming by causing curvature of the punched material, allowing for smooth transfer and reducing the need for high-pressure air usage, with adaptable positioning to accommodate varying cutting contour shapes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If spring-loaded mechanical ejectors are used to release jammed punched parts, then the punched material can be detached from the roller, but the detachment process is disruptive and causes unwanted markings on the product

Engineering Contradiction:
Improvedetachment of punched partsVSAvoidunwanted markings on product
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The invention extracts the harmful mechanical ejection function and replaces it with a pneumatic separation system. The punched parts are detached not by mechanical force from ejectors but by controlled air pressure differences that lift and separate the parts gently from the roller surface without contact that could cause markings.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention replaces the mechanical spring-loaded ejection system with a pneumatic system using air pressure and suction. Instead of mechanical contact and force, air flows are used to detach and transport punched parts, eliminating the harmful mechanical interactions that cause product markings.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Productivity

If multiple spring-loaded ejectors are placed per punched part to handle high processing speed, then detachment capability is improved, but the punched material flutters and machine timing precision is reduced

Engineering Contradiction:
Improveprocessing speedVSAvoidmachine timing precision
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The invention uses pneumatic fields (air pressure and suction) instead of multiple mechanical ejectors. Controlled air flows provide uniform detachment force across the punched material, preventing flutter and maintaining precise machine timing while handling high processing speeds.

Inventive Principle:
Principle #29Pneumatics and hydraulics

3Adaptability or versatility

If the foil knife is made adaptable to accommodate suction and blown air openings, then the suction and blowing air function can be used, but the positioning of ejectors overlaps with air openings making reliable suction difficult

Engineering Contradiction:
Improvesuction and blowing air functionVSAvoidsuction effect
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The invention segments the knife roller surface into distinct functional zones: areas with suction/blown air openings for material handling and areas with elevations for preventing jamming. This spatial segmentation allows both functions to operate reliably without overlap interference.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention applies local quality by creating elevations in specific locations adjacent to cutting edges where jamming occurs, while maintaining open areas for suction and blown air functionality. Each region has optimized properties for its specific function without compromising the other.

Inventive Principle:
Principle #3Local quality

4Reliability

If spring-loaded mechanical ejectors are used, then punched parts can be detached, but the devices are complicated and require disruptive detachment processes

Engineering Contradiction:
Improvedetachment of punched partsVSAvoidejector system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The invention extracts and removes the complex spring-loaded mechanical ejection system entirely, replacing it with a simpler pneumatic separation mechanism that achieves the same detachment function with fewer and simpler components.

Inventive Principle:
Principle #2Taking out (Extraction)

5Reliability

If elevations are added to the film cutter to prevent jamming, then material transfer is improved, but the device complexity increases

Engineering Contradiction:
Improvematerial transferVSAvoidfilm cutter structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The invention introduces elevations with curved or rounded surfaces adjacent to cutting edges. These curved features guide the punched material smoothly and prevent jamming through their geometric shape rather than through complex mechanical mechanisms.

Inventive Principle:
Principle #14Spheroidality (Curvature)

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 solution prevents material jamming during the punching process, enables precise and gentle transfer of punched parts, and allows for efficient use with close cutting contours, reducing noise and air consumption while ensuring reliable suction and blowing air functionality.

Implementation Method 1

the leading cut edge should be gripped with the suction air (otherwise the leading cut edge will flip over at high processing speeds)

Methodology Applied
Scientific EffectSuction: Suction

Implementation Method 2

the snippet must also be detached from the roller after the punching process in order to ensure that the snippet is transferred or passed on more precisely

Methodology Applied
Scientific EffectBlown air: Jet

Data Source

PatentEP2454059B1Flexible rotary cutting die and cutting die cylinder
Publication Date: 2018.11.28 WINKLER & DUNNEBIER GMBH
  • EP2454059B1 patent drawingFigure 1
  • EP2454059B1 patent drawingFigure 2
  • EP2454059B1 patent drawingFigure 3

AI summary

The invention relates to rotary punch, particularly a rotary punch comprising a foil cutter for use on the lateral surface of a carrier roll, wherein the foil cutter comprises a base plate having an underside and a top side, wherein at least one blade is disposed on the top side of the base plate, and wherein the top side of the base plate comprises at least one region that adjoins blades and is partially or completely surrounded by blades, in which region parts of the flat stock to be punched can become jammed during punching. According to the invention, the foil cutter, in the at least one region that adjoins blades and is partially or completely surrounded by blades, comprises at least one elevation disposed on the top side of the base plate, which elevation is disposed, designed and connected to the foil cutter such that it prevents jamming of the punched flat stock or partial regions of the punched flat stock.