Dynamic Injection Mold Opening for Perpendicular Filler Orientation

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Solution Overview

Problem

Conventional injection molding processes struggle to control the orientation of fillers in plastic melts, resulting in inadequate property enhancement in directions perpendicular to the flow direction, particularly in thin-walled components, where fillers are predominantly oriented in the flow direction, limiting the ability to optimize material properties for specific applications.

Innovation Solution

The method involves actively influencing the orientation of fillers by performing targeted opening movements of the tool during the injection and holding pressure phases, causing swelling and extensional flows that align fillers perpendicular to the flow direction, thereby optimizing the orientation of fillers in the plastic melt.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If conventional injection molding process is used, then fillers are predominantly oriented in the flow direction, but properties in directions perpendicular to flow cannot be sufficiently enhanced

Engineering Contradiction:

Improvefiller orientation controlVSAvoidproperty enhancement in perpendicular directions

Core Design Contradiction:

Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

The mold is made dynamically adjustable during the injection process. The distance between mold plates can be actively changed by opening movements, transforming the static mold into a dynamic system that can create swelling flows to orient fillers in desired directions perpendicular to flow

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The physical state and flow characteristics of the plastic melt are changed by opening the mold during injection. This parameter change creates swelling and extensional flows that alter filler orientation from the conventional flow-aligned state to perpendicular alignment, enabling property enhancement in previously unachievable directions

Inventive Principle:

Principle #35Parameter changes

2Manufacturing precision

If opening movements are performed during injection phase, then filler orientation perpendicular to flow is achieved, but process complexity increases

Engineering Contradiction:

Improvefiller alignment precisionVSAvoidtool movement control

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The injection process is segmented into distinct phases with the opening movement occurring at a specific timing during injection. This segmentation allows the complex action to be controlled through phased operation rather than continuous complex movement, simplifying control while achieving precise filler alignment

Inventive Principle:

Principle #1Segmentation

3Adaptability or versatility

If fillers are aligned perpendicular to flow direction, then thermal conductivity and heat dissipation are improved, but control over filler orientation becomes more difficult

Engineering Contradiction:

Improvethermal conductivity enhancementVSAvoidorientation control

Core Design Contradiction:

Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The mold opening action is performed preliminarily during the injection phase before the plastic fully solidifies. This preliminary action creates the swelling flows that pre-align fillers perpendicular to flow direction, enabling subsequent thermal conductivity enhancement without requiring additional post-processing steps

Inventive Principle:

Principle #10Preliminary action

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 allows for controlled alignment of anisometric fillers in desired spatial directions, enhancing properties such as thermal conductivity in thermally conductive plastics, enabling more effective heat dissipation and improving material performance in thin-walled components.

Implementation Method 1

At least one opening stroke (132) in the form of opening at least a partial area of the cavity (114) is carried out in such a way that in at least a part of the plastic melt (112) swelling and/or extensional flows, which influence the orientation of the fillers (122) in the plastic melt (112), are caused

Methodology Applied

Scientific EffectSwelling flow:

Implementation Method 2

Methodology Applied

Scientific EffectExtensional flow:

Data Source

PatentEP3317073B1Method for influencing the orientation of fillers in a plastics melt during production of a moulding in an injection-moulding process

Publication Date: 2020.08.05 UNIVERSITAT STUTTGART

Figure 1A~1D
Figure 2A~2B
Figure 2C~3A

AI summary

The present invention relates to a method for influencing an orientation of fillers (122) in a plastics melt (112) during production of a moulding in an injection-moulding process. The method comprises the following steps: a) providing a mould (116), which has at least one cavity (114) for receiving a plastics melt (112); b) introducing the plastics melt (112) into the cavity (114) under pressure; c) applying a pressure to the plastics melt (112) in the cavity (114); d) cooling the plastics melt (112) or allowing the plastics melt (112) to cool in the cavity (114) at least partially while maintaining the pressure, whereby the moulding is formed; and e) demoulding the moulding from the cavity (114); according to the invention, during step b) and/or during step c) at least one opening stroke (132) is performed in the form of opening at least a partial region of the cavity (114) in such a way that laminar and/or stretching flows are induced in at least part of the plastics melt (112) that is present in the cavity (114), with the effect of influencing the orientation of the fillers (122) in the plastics melt (112), and the opening stroke (132) is followed by a pressure being applied to the plastics melt (112) as provided in step c).