Microprismatic Retroreflective Mold Groove Machining

Solution Overview

Problem

The manufacturing of master molds for microprismatic retroreflective sheeting with reduced inactive area (RIA) microprisms is costly and difficult due to the complexity of existing methods, which often result in inaccuracies and high production costs, and can lead to defects such as microscopic gaps and reduced retroreflectivity.

Innovation Solution

A method involving direct machining of a single substrate with intersecting grooves using cutting tools to form RIA microprisms, allowing for continuous cutting without repositioning, thereby simplifying the process and reducing costs, and enabling the production of more stable and efficient microprismatic sheeting.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If existing methods are used to manufacture master molds for microprismatic retroreflective sheeting, then microprisms can be produced, but the manufacturing process is costly and difficult with high complexity

Engineering Contradiction:

Improvemicroprism geometry accuracyVSAvoidmanufacturing process complexity

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The manufacturing process is segmented into two distinct stages: (1) forming V-shaped grooves in a first direction using first cutting tools, and (2) forming V-shaped grooves in a second direction perpendicular to the first using second cutting tools. This segmentation allows each cutting tool to perform a specialized function, simplifying the overall process while achieving complex microprism geometries with reduced inactive area

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The invention transitions from conventional single-direction groove forming to two-dimensional intersecting groove patterns. By forming grooves in both x and y directions on the mold surface, the process creates the complex three-dimensional microprism structures needed for RIA performance, thereby resolving the contradiction between geometric accuracy and process simplicity

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Manufacturing precision

If existing methods are used to manufacture master molds, then microprisms can be formed, but production costs are high

Engineering Contradiction:

Improvemicroprism geometry accuracyVSAvoidmanufacturing cost

Core Design Contradiction:

Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The manufacturing process is segmented into two distinct stages: (1) forming V-shaped grooves in a first direction using first cutting tools, and (2) forming V-shaped grooves in a second direction perpendicular to the first using second cutting tools. This segmentation allows each cutting tool to perform a specialized function, simplifying the overall process while achieving complex microprism geometries with reduced inactive area

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The invention transitions from conventional single-direction groove forming to two-dimensional intersecting groove patterns. By forming grooves in both x and y directions on the mold surface, the process creates the complex three-dimensional microprism structures needed for RIA performance, thereby resolving the contradiction between geometric accuracy and process simplicity

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

3Productivity

If existing methods are used to manufacture master molds, then microprisms can be produced, but inaccuracies and defects such as microscopic gaps occur

Engineering Contradiction:

Improveproduction efficiencyVSAvoidmicroprism quality consistency

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The mold surface is first prepared with a uniform pattern of V-shaped grooves in the first direction before the second set of grooves is formed. This preliminary action ensures that the base structure is established with consistent geometry, and the subsequent perpendicular grooves intersect at precise locations, eliminating microscopic gaps and ensuring uniform microprism formation across the entire mold surface

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The invention transitions from conventional single-direction groove forming to two-dimensional intersecting groove patterns. By forming grooves in both x and y directions on the mold surface, the process creates the complex three-dimensional microprism structures needed for RIA performance, thereby resolving the contradiction between geometric accuracy and process simplicity

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Data Source

PatentUS20240343005A1Microprismatic retroreflective mold, sheet, and article and methods of manufacture thereof

Publication Date: 2024.10.17 AURA OPTICAL SYSTEMS LP

AI summary

Manufacturing an article, including providing a substrate having a surface, forming a first set of first grooves in the surface along a first direction, forming a second set of second grooves in the surface along a second direction substantially perpendicular to the first direction, an intersection of the first and second directions forming an angle of 90±1 degrees. An article including a substrate having a surface with a groove pattern including microprisms thereon. The groove pattern includes a first set of first grooves intersecting with a second set of second grooves. The first grooves are V-shaped having a groove being a sharp or slightly rounded point at the vertex of the V-shaped groove. The second grooves are parallel to each other along a same second direction across the surface, the second direction substantially perpendicular to the first direction.