Retroreflective cube corner sheeting mold and sheeting formed therefrom

A method of manufacturing a lamina for use in a mold suitable for use in forming retroreflective cube corner articles, the lamina having opposing first and second major surfaces defining therebetween a first reference plane, the lamina further including a working surface connecting the first and second major surfaces, the working surface defining a second reference plane substantially parallel to the working surface and perpendicular to the first reference plane and a third reference plane perpendicular to the first reference plane and the second reference plane, comprising:

• forming a first groove set including one V-shaped groove in the working surface of the lamina, the groove defining a first groove surface and a second groove surface that intersect to define a first groove vertex;
• forming a second groove set including one V-shaped groove in the working surface of the lamina, the groove defining a third groove surface and a fourth groove surface that intersect to define a second groove vertex, the third groove surface intersecting the first groove surface substantially orthogonally to define a first reference edge;
• and
• forming a third groove set including three parallel V-shaped grooves in the working surface of the laminae, each such groove defining a fifth groove surface and a sixth groove surface that intersect to define a third groove vertex, the fifth groove surface of one of tile three parallel grooves intersecting substantially orthogonally with the first and third groove surfaces to form a first cube corner element disposed in a first orientation.

A method of manufacturing a plurality of laminae for use in a mold suitable for use in forming retroreflective cube corner articles, each lamina having opposing first and second major surfaces defining therebetween a first reference plane, each lamina further including a working surface connecting the first and second major surfaces, the working surface defining a second reference plane substantially parallel to the working surface and perpendicular to the first reference plane and a third reference plane perpendicular to the first reference plane and the second reference plane, comprising the steps of:

• orienting a plurality of laminae to have their respective first reference planes parallel to each other and disposed at a first angle relative to a fixed reference axis;
• forming a first groove set including a plurality of V-shaped grooves in the working surface of the laminae, the respective grooves defining a first groove surface and a second groove surface that intersect to define a first groove vertex;
• orienting the plurality of laminae to have their respective first reference planes parallel to each other and disposed at a second angle relative to the fixed reference axis;
• forming a second groove set including a plurality of V-shaped grooves in the working surface of the laminae, the respective grooves defining a third groove surface and a fourth groove surface that intersect to define a second groove vertex, the respective third groove surfaces intersecting the first groove surfaces substantially orthogonally to define a first reference edge;
• and
• forming a third groove set including a plurality of V-shaped grooves in the working surface of the laminae, the respective third grooves defining a fifth groove surface and a sixth groove surface that intersect to define a third groove vertex, the fifth groove surfaces intersecting substantially orthogonally with the first and third groove surfaces to form at least one cube corner element disposed in a first orientation.

A mold assembly comprising a plurality of laminae, the laminae including opposed parallel first and second major surfaces defining therebetween a first reference plane, each lamina further including a working surface connecting the first and second major surfaces, the working surface defining a second reference plane substantially parallel to the working surface and perpendicular to the first reference plane and a third reference plane perpendicular to the first reference plane and the second reference plane, the working surface of a plurality of the laminae including:

• a first groove set including a plurality of parallel adjacent V-shaped grooves in the working surface of each of the laminae, a plurality of such grooves defining a first groove surface and a second groove surface that intersect to define a first groove vertex;
• a second groove set including a plurality of parallel adjacent V-shaped grooves in the working surface of each of the laminae, a plurality of such grooves defining a third groove surface and a fourth groove surface that intersect to define a second groove vertex, the third groove surface intersecting the first groove surface substantially orthogonally to define a first reference edge;
• and
• a third groove set including a plurality of parallel V-shaped grooves in the working surface of the laminae, the third grooves defining a fifth groove surface and a sixth groove surface that intersect to define a third groove vertex, the fifth groove surface intersecting substantially orthogonally with the first and third groove surfaces to form at least one cube corner element disposed in a first orientation.