Pin Valve Actuation Sequences for Injection Moulding Colour Changes

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Solution Overview

Problem

The existing injection moulding systems face inefficiencies in colour change processes, leading to prolonged production shutdowns and significant waste of plastic material due to manual and inefficient control of pin valve movements during colour changes, especially in large-scale production of articles like vehicle panels.

Innovation Solution

An optimized colour change method is implemented, where the electronic control unit programmatically controls the pin valves to invert the typical injection cycle by fully opening injectors that dispense less material and keeping those that dispense more material closed, minimizing the number of moulding operations required for colour changes, and automating the process based on parameters like article dimensions and injector geometry.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If manual control of pin valves is used during colour changes, then the operator can adjust the process, but production shutdown time is prolonged and material waste increases

Engineering Contradiction:

Improvemanual control flexibilityVSAvoidproduction shutdown time

Core Design Contradiction:

Ease of operationVSLoss of time

Solution Approach 1:

The patent replaces manual mechanical control of pin valves with an automated electronic control system. The electronic control unit receives commands and automatically actuates the pin valves according to predetermined sequences, eliminating the need for manual operation while reducing changeover time and material waste during colour changes.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent implements automated control parameters for pin valve actuation sequences. By pre-programming the opening and closing sequences of multiple pin valves, the system automatically optimizes the colour change process, reducing both shutdown time and discarded material while maintaining operational effectiveness.

Inventive Principle:

Principle #35Parameter changes

2Ease of manufacture

If standard sequential injection cycle is used for colour changes, then the process is simple to implement, but the number of moulding operations required is high (tens of operations)

Engineering Contradiction:

Improveprocess simplicityVSAvoidnumber of moulding operations

Core Design Contradiction:

Ease of manufactureVSProductivity

Solution Approach 1:

The patent segments the injection process by controlling multiple pin valves independently according to different sequences. Instead of using a single standard sequential cycle, the system divides the injection points and applies customized opening/closing sequences to each pin valve, enabling more efficient colour changes in fewer moulding operations.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent introduces dynamic control of pin valve actuation sequences through an electronic control unit. The system can adaptively adjust the opening and closing timing of each pin valve based on predetermined sequences, transforming the static standard cycle into a dynamic, optimized process that reduces the number of moulding operations required for colour changes.

Inventive Principle:

Principle #15Dynamics

3Stability of the object's composition

If pin valves are opened in standard sequential order, then the injection process is stable, but material waste during colour changes is significant

Engineering Contradiction:

Improveinjection process stabilityVSAvoiddiscarded plastic material

Core Design Contradiction:

Stability of the object's compositionVSLoss of substance

Solution Approach 1:

The patent implements preliminary automated sequencing of pin valve actuation. Before the colour change begins, the electronic control unit is programmed with optimized opening and closing sequences for each pin valve. This preliminary configuration allows the system to minimize material waste during the transition by precisely controlling when each valve opens and closes, reducing discarded material while maintaining process stability.

Inventive Principle:

Principle #10Preliminary action

4Ease of operation

If colour change cycle is manually evaluated and set, then the operator can use discretion, but additional production shutdown time is required

Engineering Contradiction:

Improveoperator discretionVSAvoidproduction shutdown time

Core Design Contradiction:

Ease of operationVSLoss of time

Solution Approach 1:

The patent implements a self-service automated control system where the electronic control unit independently manages the colour change process. The system stores multiple predetermined actuation sequences and automatically selects and executes the appropriate sequence based on the colour change requirements, eliminating the need for manual evaluation and setting by operators, thereby reducing production shutdown time while maintaining operational effectiveness.

Inventive Principle:

Principle #25Self-service

Data Source

PatentUS10807289B2System and method for injection moulding of plastic materials

Publication Date: 2020.10.20 INGLASS SPA

AI summary

A system and method for the injection moulding of plastic material through a plurality of injectors each having a pin valve displaceable in a controlled fashion between a closing position and an opening position by a respective actuator of an electronic control type, in which there is provided prompt activation of a preset function of changing a colour of the plastic material to be injected, actuated according to an optimized sequence which minimizes a number of moulding operations required to change the colour.