Inking Unit Temperature Control for Printing Speed Transients

Solution Overview

Problem

In lithographic offset printing presses with short inking units, such as anilox units, temperature changes are sluggish, limiting the ability to quickly adjust printing speed without affecting coloration, and existing methods result in step changes that can negatively impact the printed image.

Innovation Solution

A method where a control computer calculates and adjusts the target temperature and printing speed to achieve desired coloration and speed changes, allowing for maximum acceleration within tolerance limits to minimize color deviations and prevent unsalable waste, considering properties of ink, press, and printing material.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the printing speed is changed quickly, then the productivity is improved, but the coloration deviates from the target value

Engineering Contradiction:

Improveprinting speedVSAvoidcoloration

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The control computer calculates the required target temperature in advance based on the desired printing speed and target coloration. This preliminary temperature calculation allows the system to prepare the inking unit at the optimal temperature before the speed change is fully implemented, enabling quick speed changes while maintaining coloration within tolerance limits.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The control computer continuously monitors the actual coloration and compares it with the target coloration. Based on this feedback, the system dynamically adjusts the temperature setpoint to compensate for coloration deviations caused by rapid speed changes, ensuring the printed product meets quality requirements.

Inventive Principle:

Principle #23Feedback

2Manufacturing precision

If the temperature is adjusted to compensate for speed changes, then the coloration is maintained, but the response time is too long

Engineering Contradiction:

ImprovecolorationVSAvoidtemperature response time

Core Design Contradiction:

Manufacturing precisionVSLoss of time

Solution Approach 1:

The system calculates the required target temperature in advance based on the desired printing speed and target coloration. This preliminary temperature calculation allows the system to prepare the inking unit at the optimal temperature before the speed change is fully implemented, enabling quick speed changes while maintaining coloration within tolerance limits.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The control system dynamically adjusts the temperature setpoint based on the current printing speed and target coloration. The temperature is not fixed but continuously adapted to match the dynamic conditions of rapid speed changes, allowing the inking unit to respond more effectively to changing conditions.

Inventive Principle:

Principle #15Dynamics

3Manufacturing precision

If the printing speed is changed in steps, then the coloration remains relatively stable, but the production time increases

Engineering Contradiction:

ImprovecolorationVSAvoidproduction time

Core Design Contradiction:

Manufacturing precisionVSLoss of time

Solution Approach 1:

The control computer calculates the required target temperature in advance based on the desired printing speed and target coloration. This preliminary temperature calculation allows the system to prepare the inking unit at the optimal temperature before the speed change is fully implemented, enabling quick speed changes while maintaining coloration within tolerance limits.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system changes the temperature parameter continuously rather than in discrete steps. By smoothly adjusting the temperature setpoint throughout the acceleration process, the system maintains coloration within tolerance limits while achieving faster speed changes compared to step-based adjustment.

Inventive Principle:

Principle #35Parameter changes

4Loss of time

If the acceleration is maximized, then the time to reach target speed is reduced, but the coloration deviates beyond tolerance limits

Engineering Contradiction:

Improveacceleration timeVSAvoidcoloration

Core Design Contradiction:

Loss of timeVSManufacturing precision

Solution Approach 1:

The control computer calculates the required target temperature in advance based on the desired printing speed and target coloration. This preliminary temperature calculation allows the system to prepare the inking unit at the optimal temperature before the speed change is fully implemented, enabling quick speed changes while maintaining coloration within tolerance limits.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The control computer continuously monitors the actual coloration and compares it with the target coloration. Based on this feedback, the system dynamically adjusts the temperature setpoint to compensate for coloration deviations caused by rapid speed changes, ensuring the printed product meets quality requirements.

Inventive Principle:

Principle #23Feedback

Solution Approach 3:

The system dynamically adjusts the acceleration profile based on real-time coloration measurements. If coloration deviates beyond tolerance limits during acceleration, the system automatically reduces the acceleration rate to bring the coloration back within acceptable ranges, balancing speed and quality.

Inventive Principle:

Principle #35Parameter changes

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

Enables quick speed changes while maintaining acceptable coloration, reducing the production of unsalable products by optimizing temperature and speed adjustments within defined tolerance limits, ensuring consistent ink density and quality.

Implementation Method 1

the inking unit only reacts sluggishly to temperature changes; it takes much longer to attain a desired temperature than to change the printing speed

Methodology Applied

Scientific EffectTemperature compensation:

Implementation Method 2

the control computer calculates the required target temperature that is necessary to attain the predetermined actuating variable at a desired printing speed

Methodology Applied

Scientific EffectThermal control:

Implementation Method 3

the press can continue to run at the maximum acceleration. If the desired printing speed is attained during this acceleration, the acceleration process is stopped

Methodology Applied

Scientific EffectAcceleration control:

Data Source

PatentUS8869699B2Method of controlling inking units in case of printing speed changes

Publication Date: 2014.10.28 HEIDELBERGER DRUCKMASCHINEN AG

AI summary

A method controls a printing speed and a temperature of a printing press to attain a predetermined actuating variable. The printing press includes a control computer. The method is characterized by calculating a target temperature to attain the predetermined actuating variable at a desired printing speed and initiating the adjustment operations to attain the target temperature by the control computer. The actual printing speed is changed via a first acceleration within a tolerance limit with respect to fluctuations about the predetermined actuating variable. The first acceleration process is stopped if the desired printing speed is attained in the process. The first acceleration is changed if the tolerance limits are reached and the desired printing speed has not been attained yet. The printing speed is ran at a modified second acceleration along the tolerance limits until the desired printing speed is attained.