Removal Element Valve Dynamics for Injection Molding

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Solution Overview

Problem

Current removal elements for injection molding tools face inefficiencies in aftertreatment and fluid flow control, leading to prolonged cycle times and potential damage due to unsuitable vacuum application when no molded part is present in the recording cavity.

Innovation Solution

A removal element with a valve passage system that allows for controlled fluid flow and vacuum application, featuring multiple valve positions to ensure efficient aftertreatment and prevent ambient air ingress when no molded part is ready for removal, including a check valve for fluid supply and evacuation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If vacuum is applied continuously to the fluid channel, then hollow body moldings can be removed efficiently, but ambient air is sucked in when no molded part is present causing inefficiency and potential damage

Engineering Contradiction:
Improveremoval efficiencyVSAvoidambient air ingress
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

The valve passage is designed to dynamically change its state based on the presence of a hollow body molding. When a molding is present, the valve opens to allow vacuum application for efficient removal. When no molding is present, the valve closes to prevent ambient air ingress, thereby adapting the system behavior to current conditions and eliminating the harmful effect while maintaining productivity when needed.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system incorporates a detection mechanism that senses whether a hollow body molding is present in the recording cavity. This detection feedback controls the valve element to open or close the valve passage accordingly. The feedback loop ensures that vacuum is applied only when appropriate, preventing air ingress during idle periods while maintaining removal efficiency when moldings are present.

Inventive Principle:
Principle #23Feedback

2Productivity

If preforms are removed at an early stage to reduce cycle times, then productivity increases, but higher demolding requirements are placed on the removal system

Engineering Contradiction:
Improvecycle timeVSAvoiddemolding reliability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The removal element acts as an intermediary between the injection molding tool and the hollow body molding. It provides a dedicated interface with specific geometric features (such as contact surfaces and vacuum application points) that are optimized for early-stage demolding. This intermediary structure enables reliable removal of soft preforms by distributing forces appropriately and providing controlled vacuum application, thereby meeting the higher demolding requirements imposed by early removal.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The removal system is segmented into distinct functional components: the removal element with its base part and plate, the valve element for fluid control, and the fluid channel for vacuum application. This segmentation allows each component to be optimized for its specific function, with the removal element geometry tailored for early-stage demolding reliability while the valve and fluid channel handle the vacuum control, thereby achieving both high productivity and reliability.

Inventive Principle:
Principle #1Segmentation

3Productivity

If multiple groups of recording cavities are used to extend preform cooling time, then device complexity increases, but cycle times can be reduced

Engineering Contradiction:
Improvecycle timeVSAvoidreceiving plate structure
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The system prepares multiple recording cavity groups in advance, each equipped with removal elements and fluid channels. By pre-configuring these groups, the system can immediately switch between them without additional setup time. The first group can begin cooling a preform while the second group is already prepared to receive the next preform, enabling overlapping operations that reduce overall cycle time without requiring complex real-time control mechanisms.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

Multiple recording cavity groups are designed with identical, standardized structures that can perform the same functions interchangeably. Each group serves as a universal unit capable of receiving, cooling, and removing hollow body moldings. This universality allows the system to use multiple simpler identical units rather than one complex differentiated structure, thereby extending cooling capacity while maintaining relatively simple individual component designs.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 significantly enhances aftertreatment efficiency by nearly 50% and ensures effective cooling and evacuation of hollow body moldings, reducing cycle times and minimizing damage risks.

Implementation Method 1

a fluid channel (53) with a channel input (56) and a channel output (57) arranged such that when the plate (33) is in the retracted position, the channel output (57) opens to the molding interior

Methodology Applied
Scientific EffectFluid flow through pressure differential: Pressure Gradient

Implementation Method 2

the valve element (8) is movable between a first valve position in which the valve passage is opened and a second valve position in which the valve passage is closed, wherein the valve element (8) is movable by the fluid pressure

Methodology Applied
Scientific EffectPressure-driven valve operation: Pressure Gradient

Implementation Method 3

a spring element (4), with which the plate (3) is pressed into its advanced position

Methodology Applied
Scientific EffectSpring force: Spring

Implementation Method 4

when the channel input is connected to a vacuum source, Fluid can be sucked out of the mold part interior via the fluid channel

Methodology Applied
Scientific EffectVacuum suction: Vacuum

Data Source

PatentEP3620287B1Removal element
Publication Date: 2021.04.07 MHT MOLD & HOTRUNNER TECHNOLOGY AG
  • EP3620287B1 patent drawingFigure 1
  • EP3620287B1 patent drawingFigure 2
  • EP3620287B1 patent drawingFigure 3

AI summary

The present invention relates to a removal element for removing a hollow molded part from an injection mold, wherein the removal element comprises a base part and a plate which is movable between a forward position and a retracted position relative to the base part, wherein a fluid channel with a channel inlet and a channel outlet is provided, wherein the channel inlet and channel outlet are arranged such that, when the plate is in the retracted position, the channel outlet opens to the interior of the molded part, so that, when the channel inlet is connected to a vacuum source, fluid can be drawn from the interior of the molded part via the fluid channel, wherein a valve element with a valve passage is arranged between the channel inlet and the channel outlet, wherein in a first valve position the cross-section of the valve passage is larger than in a second valve position.To provide an improved extraction element, it is proposed according to the invention that the valve passage is open in the advanced position and in the retracted position of the plate, wherein the valve element is dimensioned such that in the advanced position, when the fluid pressure at the channel inlet is less than at the channel outlet, the valve element moves into the second valve position, while in the retracted position the valve element is always in the first valve position.