Controlled Particle Platelets via Segmented Mold Stripping
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Solution Overview
Problem
Existing methods for producing thin flakes with embossed diffraction patterns suffer from stress-cracking and random fracture during deposition and stripping, resulting in incomplete or inadequate replication of the desired shape, leading to reduced brightness and impaired flow characteristics in pigment compositions.
Innovation Solution
A process involving a laminar substrate with a patterned surface of discrete cells, where organic or inorganic material is deposited and then stripped to form particles with controlled dimensions, replicating the cell dimensions and optionally including additional micro-relief patterns for security or optical effects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional embossing methods are used to produce thin flakes with diffraction patterns, then the embossed surfaces can be created, but stress-cracking and random fracture occur during deposition and stripping, resulting in incomplete shape replication
Solution Approach 1:
The substrate is divided into an array of discrete cells, each cell acting as an independent mold cavity. This segmentation allows the deposited material to be formed into individual particles with controlled dimensions, preventing stress-cracking by localizing stress within each cell rather than across the entire substrate. The discrete cell structure enables complete shape replication while maintaining structural integrity during the deposition and stripping processes.
Solution Approach 2:
The invention changes the physical and chemical parameters of the deposited material by controlling deposition conditions (temperature, pressure, material composition) to optimize the balance between shape replication and structural integrity. By adjusting these parameters, the material can be deposited thick enough to replicate the cell geometry completely while remaining flexible enough to avoid stress-cracking and random fracture during handling.
2Manufacturing precision
If the deposited material thickness is increased to improve shape replication, then better embossment is achieved, but stress-cracking and random fracture increase during deposition and stripping
Solution Approach 1:
By segmenting the substrate into discrete cells, the invention allows the deposited material to be formed into individual particles with controlled dimensions. This segmentation prevents stress-cracking by localizing stress within each cell rather than across the entire substrate, enabling complete shape replication while maintaining structural integrity during handling.
Solution Approach 2:
The invention changes the physical and chemical parameters of the deposited material by controlling deposition conditions (temperature, pressure, material composition) to optimize the balance between shape replication and structural integrity. By adjusting these parameters, the material can be deposited thick enough to replicate the cell geometry completely while remaining flexible enough to avoid stress-cracking and random fracture during handling.
3Shape
If conventional embossing methods are used, then diffraction patterns can be produced, but the particles have broad size distribution and poor flow characteristics
Solution Approach 1:
The substrate is divided into an array of discrete cells, each cell acting as an independent mold cavity. This segmentation produces particles with uniform size and shape, as each cell creates identical particles. The discrete cell structure ensures consistent particle dimensions throughout the substrate, resulting in narrow size distribution and improved flow characteristics while maintaining the embossed diffraction pattern.
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
The process produces particles with a narrow size distribution and controlled dimensions, enhancing brightness and flow characteristics while allowing for the incorporation of security features, suitable for use in paints, inks, and security pigments.
Implementation Method 1
stripping the deposited organic or inorganic material from the surface of the substrate
Data Source
AI summary
A process for the preparation of particles with controlled dimensions comprising the steps of: (i) providing a laminar substrate having a patterned surface comprising a micro-relief repeat pattern comprising one or more discrete cells, each cell consisting of a floor portion and walls having a height (HW); (ii) depositing organic or inorganic material onto the patterned surface and into the cells to provide a thickness (T) of the deposited material wherein T≦HW (iii) stripping the deposited organic or inorganic material from the surface of the substrate; and (iv) collecting the particles formed from said organic or inorganic material; and a composition obtainable from said process comprising a plurality of particles (P), wherein the number (n) of particles in said composition is at least 10, wherein said particles (P) are platelets exhibiting a planar geometry which is circular or which is made up of a number (x) of planar (y)-sided polygon(s), wherein x is from 1 to 20 and y is at least 3 wherein if x is greater than 1 then said planar (y)-sided polygons are fused along one or more sides thereof, wherein the width (WP) of the platelets (P) at their widest point is no more than about 250 μm and the thickness of the platelets (P) is in the range of 10 nm to 50 nm.