Paper Roll Core Cutting Accuracy via Laser Measurement

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Solution Overview

Problem

Existing methods for cutting paper roll cores suffer from inadequate accuracy, leading to inaccuracy in roll separation, dust formation issues, and safety concerns due to uncontrolled dust dispersion and burr formation during the sawing process.

Innovation Solution

The method involves reversing the direction of core rotation and saw blade operation to ensure cutting occurs on the outer and then inner surfaces, minimizing dust dispersion and burr formation, using a band-type measuring element for precise longitudinal positioning, and compensating for blade wear to enhance accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a mechanical limit is used to determine cutting length, then the core can be positioned, but cutting accuracy deteriorates due to core rotation and end shape deviations

Engineering Contradiction:

Improvecore positioningVSAvoidcutting accuracy

Core Design Contradiction:

Ease of operationVSManufacturing precision

Solution Approach 1:

The patent replaces the mechanical limit system with an optical measurement system (laser). The laser measures the position of the core end face without physical contact, eliminating the problems caused by mechanical contact during rotation. This substitution allows accurate measurement of the core's longitudinal position while the core rotates, solving the contradiction between ease of positioning and cutting accuracy.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Productivity

If the core is rotated during cutting, then the cutting operation can be performed, but cutting accuracy deteriorates due to axial displacement from non-straight end face

Engineering Contradiction:

Improvecutting operation capabilityVSAvoidcutting accuracy

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The patent uses optical measurement (laser) instead of mechanical measurement to track the core position during rotation. The laser can accurately measure the position of the rotating core end face without being affected by the rotation, allowing the core to rotate during cutting while maintaining high cutting accuracy.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Object-generated harmful factors

If the mechanical limit does not cover the core end entirely, then dust removal can be achieved, but cutting accuracy deteriorates due to uncontrolled dust dispersion

Engineering Contradiction:

Improvedust removal capabilityVSAvoidcutting accuracy

Core Design Contradiction:

Object-generated harmful factorsVSManufacturing precision

Solution Approach 1:

The patent replaces mechanical dust collection methods with optical measurement that is not affected by dust. The laser measurement system can accurately determine core position even in the presence of dust, eliminating the need to compromise between dust removal and accuracy.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

4Device complexity

If conventional measuring techniques are used, then the system is simple, but accuracy deteriorates due to wear and measurement errors

Engineering Contradiction:

Improvemeasuring system simplicityVSAvoidlongitudinal positioning accuracy

Core Design Contradiction:

Device complexityVSMeasurement precision

Solution Approach 1:

The patent replaces mechanical measuring techniques with optical measurement (laser). The laser measurement system has no moving parts that wear, providing high precision longitudinal positioning without the wear and measurement errors associated with mechanical systems. The increased device complexity is offset by the significant improvement in measurement precision.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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 approach significantly improves cutting accuracy, reduces uncontrolled dust, eliminates burr formation, and enhances safety by directing dust into a controlled recovery system, allowing for precise and efficient core cutting.

Implementation Method 1

a laser is used for measuring the position of the core end face

Methodology Applied

Scientific EffectLight reflection/scattering: Reflection

Implementation Method 2

The amount of uncontrolled saw dust is substantially reduced, because the dust spray can be directed more accurately

Methodology Applied

Scientific EffectSuction: Suction

Data Source

PatentUS7770497B2Method and apparatus for cutting a core

Publication Date: 2010.08.10 RAUMASTER PAPER

AI summary

The invention relates to a method and an apparatus for cutting a sleeve to a predetermined length. The sleeve is first moved the direction of the longitudinal axis through a distance corresponding to the required cutting length, a rotating saw blade is driven through the outer surface of the sleeve but not through the inner surface, the sleeve is rotated through a first revolution whereupon the direction of rotation of the sleeve is set to be the same as the direction of rotation of the blade, the blade is driven through the inner surface of the sleeve and the sleeve is rotated until the cut extends around the sleeve.