Micro/Nanometer Patterned Injection Molding Tool Surface

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Solution Overview

Problem

Current injection molding techniques are limited in patterning complex geometries and freeform surfaces due to the inherent limitations of patterning stamps prepared outside the molding apparatus and inserted into the tool, which restricts the forms that can be patterned, especially at micro- and nanometer scales below 50µm.

Innovation Solution

A method for manufacturing a micro/nanometer-structured pattern directly on the active surface of an injection molding tool using a micro/nanometer structured imprinting device that is applied within the tool's cavity, allowing for the transfer of patterns on non-planar surfaces without the need for extensive tool preparation or remounting, utilizing techniques like laser-assisted direct imprinting and flexible intermediate members to create air-tight enclosures for pressure changes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If patterning stamps are prepared outside the molding apparatus and inserted into the tool, then the patterning process can be performed, but the available forms that can be patterned are limited due to high pressure and temperature in the injection molding system

Engineering Contradiction:
Improvepatterning process implementationVSAvoidavailable forms that can be patterned
Core Design Contradiction:
Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

The stamp is designed with flexibility to adapt to different mold cavity shapes. The stamp can deform elastically under injection molding pressure to conform to complex geometries and freeform surfaces, enabling patterning of various forms rather than being restricted to rigid predefined shapes

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The stamp material properties are optimized to allow temporary deformation under high pressure and temperature conditions during injection molding, then recover its original shape. This parameter change enables the stamp to accommodate different mold cavity geometries while maintaining patterning precision

Inventive Principle:
Principle #35Parameter changes

2Stability of the object's composition

If a rigid patterning stamp is used in high pressure injection molding, then the stamp structure remains stable, but complex forms and freeform surfaces cannot be effectively patterned

Engineering Contradiction:
Improvestamp structure stabilityVSAvoidcomplex geometries patterning capability
Core Design Contradiction:
Stability of the object's compositionVSAdaptability or versatility

Solution Approach 1:

The patterning stamp is constructed as a flexible thin structure that can conform to complex mold cavity surfaces. The flexibility allows the stamp to adapt to freeform geometries while maintaining sufficient structural integrity to transfer the micro/nanometer pattern accurately under injection molding conditions

Inventive Principle:
Principle #30Flexible shells and thin films

3Ease of manufacture

If patterning is performed on planar surfaces only, then the process is simple, but freeform surfaces and complex geometries cannot be patterned

Engineering Contradiction:
Improvepatterning process simplicityVSAvoidsurface type coverage
Core Design Contradiction:
Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

The stamp design incorporates flexibility that allows it to dynamically adapt to different surface geometries. This enables the same simple patterning process to be applied to planar surfaces, curved surfaces, and complex freeform geometries without requiring different patterning approaches

Inventive Principle:
Principle #15Dynamics

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 efficient and reliable patterning of complex geometries and freeform surfaces within the injection molding tool, allowing for the creation of micro/nanometer patterns on the active surface without extensive tool preparation, enhancing the flexibility and effectiveness of the molding process.

Implementation Method 1

changing the relative pressure between the first and second cavity so as to cause a decrease in the volume of the second cavity by displacing the flexible intermediate member towards the injection molding tool surface and thereby imprinting the micro/nanometer pattern

Methodology Applied
Scientific EffectPressure differential: Pressure Gradient

Implementation Method 2

a flexible intermediate member (5) within the imprinting device (10), the intermediate member comprising a stamp with a micro/nanometer imprinting pattern

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Data Source

PatentEP2483744B1Injection molding tools with micro/nano-meter pattern
Publication Date: 2016.03.30 NIL TECH APS (DK)
  • EP2483744B1 patent drawingFigure 1
  • EP2483744B1 patent drawingFigure 2
  • EP2483744B1 patent drawingFigure 3

AI summary

The present invention relates to methods for embedded a micrometer and/or nanometer pattern into an injection molding tool. In a first main aspect, a micro/nanometer structured imprinting device is applied in, or on, an active surface so as to transfer the micro/nanometer patterned structure to the tool while the imprinting device is, at least partly, within a cavity of the injection molding tool. In a second main aspect, a base plate with a micro/nanometer structured pattern positioned on an upper part is positioned on the active surface within the tool, the lower part of the base plate facing the tool, the active surface receiving the base plate being non-planar on a macroscopic scale. Both aspects enable a simple and effective way of transferring the pattern, and the pattern may be transferred on the active working site of tool immediately prior to molding without the need for extensive preparations or remounting of the tool before performing the molding process.