Leaf-like Trim Ejector for Rotary Steel Rule Die Waste Reduction

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Solution Overview

Problem

The paperboard die-cutting industry faces significant waste due to excessive trim around the carton's pattern, which current rotary steel rule die apparatuses struggle to minimize effectively.

Innovation Solution

A trim ejector system comprising a leaf-like body with a trim-ejecting surface and a compressible biasing member is integrated into the rotary steel rule die apparatus, allowing for efficient ejection of trim by utilizing tension from the sheet to push the trim out of the cutting gap when the sheet exits.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If extra sheet width is provided beyond the rules to prevent centring problems and help ejecting trim, then ease of operation is improved, but loss of substance (trim waste) increases

Engineering Contradiction:
Improveease of operationVSAvoidtrim waste
Core Design Contradiction:
Ease of operationVSLoss of substance

Solution Approach 1:

The trim ejector is extracted as a separate functional element from the die board, positioned adjacent to the rule but independent from it. This allows the ejector to specifically target and remove trim without requiring extra sheet width beyond the rule boundaries, thus reducing trim waste while maintaining ease of operation

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The trim ejector acts as an intermediary mechanism between the rule and the trim. It utilizes the tension from the sheet to push the trim out of the cutting gap, serving as a mediating force that enables efficient trim ejection without requiring additional sheet width beyond the rules

Inventive Principle:
Principle #24Intermediary (Mediator)

2Loss of substance

If a trim ejector is added to the rotary steel rule die apparatus, then loss of substance (trim waste) is reduced, but device complexity increases

Engineering Contradiction:
Improvetrim wasteVSAvoiddevice complexity
Core Design Contradiction:
Loss of substanceVSDevice complexity

Solution Approach 1:

The trim ejector is constructed as a flexible, leaf-like body that can bend and deform elastically. This flexible structure allows the ejector to conform to the trim shape and apply pushing force effectively without requiring a complex rigid mechanism, thus reducing device complexity while maintaining trim waste reduction efficiency

Inventive Principle:
Principle #30Flexible shells and thin films

Solution Approach 2:

The trim ejector utilizes changes in physical state and mechanical properties, specifically the elastic deformation of the leaf-like body. The compressible biasing member changes the physical state of the ejector from a relaxed position to a tensioned state, enabling automatic trim ejection without adding complex control systems

Inventive Principle:
Principle #35Parameter changes

3Loss of substance

If the leaf-like body is made flexible to push trim effectively, then loss of substance (trim waste) is reduced, but strength decreases

Engineering Contradiction:
Improvetrim wasteVSAvoidstrength
Core Design Contradiction:
Loss of substanceVSStrength

Solution Approach 1:

The leaf-like body is designed as a flexible element that can bend and deform elastically to push trim effectively. This flexibility allows the ejector to conform to the trim shape and apply pushing force without requiring a rigid, complex structure, thus reducing trim waste while maintaining sufficient strength through the elastic properties of the material

Inventive Principle:
Principle #30Flexible shells and thin films

Solution Approach 2:

The trim ejector is made from a composite structure combining a flexible leaf-like body with a compressible biasing member. This composite design provides both the flexibility needed to push trim effectively and the structural strength required to withstand the operational forces, resolving the contradiction between flexibility and strength

Inventive Principle:
Principle #40Composite materials

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 reduces the extra sheet width required beyond the rules to 1/8 inch, significantly minimizing trim waste and enhancing ejection efficiency, resulting in substantial carton savings and reduced waste in subsequent cuttings.

Implementation Method 1

a compressible biasing member secured to the leaf-like body on a side thereof opposite the trim-ejecting surface; the compressible biasing member being for forcing the leaf-like body to a neutral position, corresponding to no tension being applied to the stem portion

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

when the sheet in the sheet receiving gap causes the rule to cut a trim from the sheet, the sheet exerts the tension on the stem portion and the biasing member is compressed

Methodology Applied
Scientific EffectTension: Tension

Data Source

PatentEP2073964B1Trime jector for ejecting the trim produced by a rule of a rotary steel rule die apparatus or the like
Publication Date: 2014.05.14 PRODEN INC
  • EP2073964B1 patent drawingFigure 1
  • EP2073964B1 patent drawingFigure 2~3
  • EP2073964B1 patent drawingFigure 4

AI summary

A trim ejector for ejecting the trim produced by a steel rule of a rotary steel rule die apparatus comprising a die cylinder including a die board provided with the rule and an anvil roll positioned parallel to the die cylinder so as to define a sheet receiving gap therebetween is described herein. The trim ejector comprises a leaf-like body defining a trim-ejecting surface extending between an ejecting edge and a stem portion, an anchor portion connected to the stem portion of the leaf-like body for securing the leaf-like body to the die board so that the ejecting edge of the leaf-like body is positioned adjacent the rule parallel therefrom; and a compressible biasing member secured to the leaf- like body on a side thereof opposite the trim-ejecting surface. The compressible biasing member is provided for forcing the leaf-like body to a neutral position, corresponding to no tension being applied to the stem portion, when the leaf- like member is moved away from the neutral position under a passage of a sheet in the sheet receiving gap. The trim ejector according to the present invention provides a relatively powerful and fast ejection of the trim around the pattern defined by the rules, which minimizes the bringing of trim and carton's waste in the subsequent cuttings. It has been found that the use of a trim ejector according to the present invention allows yielding an extra width of only about 1/8" (3.2 mm) on the sheet beyond the rules for example. This results in important savings in sheet material.