Rotational Moulding Control Using Thermal Profiles and Feedback

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Current rotational moulding systems face challenges in achieving economically viable large-scale production of high-quality rotation moulded products due to variability in resin and manufacturing conditions, leading to inconsistencies in product properties such as wall thickness, internal stress, and material characteristics.

Innovation Solution

A system and method that determine suitable temperature-time and motion-time programs based on predetermined rotational moulding thermal characteristics of raw materials, using sensors for real-time feedback and adjustments, and a computer simulation system to optimize mould design and process parameters, allowing for improved control and reproducibility.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If traditional rotational moulding systems are used without advanced control, then the system is simpler and easier to operate, but product quality consistency and reproducibility deteriorate due to variability in resin and manufacturing conditions

Engineering Contradiction:

Improveproduct quality consistencyVSAvoidcontrol system complexity

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent implements feedback control by measuring actual mould cavity temperature using sensors and comparing it to the target temperature-time profile. The control system then adjusts heating power and motion parameters in real-time based on this feedback, ensuring consistent product quality despite variations in resin properties or manufacturing conditions.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The patent replaces traditional mechanical trial-and-error mould design methods with computer simulation technology. The simulation system uses thermal models to predict temperature distribution and optimize mould design before physical manufacturing, improving product consistency without requiring multiple physical prototypes and manual adjustments.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Loss of time

If trial-and-error methods are used for mould design and material selection, then the process is simpler to initiate, but time consumption and resource waste increase significantly

Engineering Contradiction:

Improvemould design timeVSAvoidmould design simplicity

Core Design Contradiction:

Loss of timeVSEase of manufacture

Solution Approach 1:

The patent applies preliminary action by performing computer simulations of the rotational moulding process before actual manufacturing. The simulation predicts temperature distribution, identifies potential quality issues, and optimizes mould design parameters in advance, eliminating the need for time-consuming trial-and-error physical testing.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent creates a virtual copy of the rotational moulding process through computer simulation. This digital twin allows engineers to test and optimize mould designs, material selections, and process parameters in the virtual environment before committing to physical manufacturing, significantly reducing development time and resource waste.

Inventive Principle:

Principle #26Copying

3Reliability

If real-time feedback control is implemented, then product quality and reproducibility improve, but the complexity of the control system and measurement requirements increase

Engineering Contradiction:

Improveprocess reproducibilityVSAvoidtemperature measurement complexity

Core Design Contradiction:

ReliabilityVSDifficulty of detecting and measuring

Solution Approach 1:

The patent uses an intermediary approach by implementing temperature sensors that measure mould cavity temperature and feed this data to a control system. The control system acts as a mediator, processing the temperature data and adjusting heating/motion parameters accordingly, ensuring reliable process control while keeping the measurement system relatively simple.

Inventive Principle:

Principle #24Intermediary (Mediator)

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 enables more precise control over the rotational moulding process, improving product quality and reproducibility by adapting to material and process variations, and reducing the need for trial-and-error methods in mould design and material selection.

Implementation Method 1

a mould heating and cooling system at least partly integrated with the mould wall and provided for applying a temperature-time program to the mould

Methodology Applied

Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 2

a target mould cavity temperature-time profile for the at least one raw material

Methodology Applied

Scientific EffectThermal diffusion: Conduction (thermal)

Data Source

PatentEP3656526B1System and method for controlling a rotational moulding process

Publication Date: 2023.06.07 AMS BELGIUM

Figure 1
Figure 2a~2b
Figure 3a~3b

AI summary

Rotational moulding system configured for determining at least one suitable temperature-time program and at least one suitable motion-time program for the rotational moulding of an object by means of the rotational moulding system on the basis of a predetermined rotational moulding thermal characteristic of a raw material to be used for the rotational moulding of the object. Computer-implemented method for using the rotational moulding system.