CN1694614A

CN1694614A - Systems, methods, and apparatus for patterned sheeting

Info

Publication number: CN1694614A
Application number: CN 03824992
Authority: CN
Inventors: D·里德
Original assignee: RPM Optoelectronics Inc
Current assignee: RPM Optoelectronics Inc
Priority date: 2002-09-11
Filing date: 2003-09-11
Publication date: 2005-11-09

Abstract

A patterned roller including one or more patterned rings forming an overall cylindrical pattern. The patterned roller may also include one or more spacer rings to form grooves or channels into a surface. The patterned roller may be included in a roller stack as part of a manufacturing system for patterned film. The patterned roller can include a pattern to form full corner cubes of many different sizes and/or geometries in a continuous manner across the width and along the length of a reflective sheet without seams. Methods of manufacture include rolling the cylindrical pattern of the patterned roller into a surface of an extruded sheet. Articles are manufactured utilizing the methods of manufacture including license plates, shoes, highway signs, articles of clothing, pavement markers, automobile reflectors, and bicycle reflectors.

Description

System, method and apparatus for patterned sheeting

David Reed filed U.S. non-provisional patent application claiming priority to U.S. provisional patent application 60/410,206 filed by David Reed (David Reed) on 11/9/2002.

Technical Field

The present invention relates generally to patterned sheeting. In particular, the present invention relates to reflective and retroreflective sheeting.

Drawings

FIG. 1 is a perspective view of a film being pressed between an embossing roll and another roll according to an embodiment of the present invention;

FIG. 2 is an exploded view of a pattern ring or shim and a pair of spaced rings or shims in the patterned roll of FIG. 1;

FIG. 3 is an enlarged view of a portion of FIG. 2;

FIG. 4A is a perspective view of another embodiment of a partially assembled patterned roll;

FIG. 4B is a perspective view of the embossing roll of FIG. 4A with the full pattern rings or shims and/or the spacer rings or shims assembled;

FIG. 4C is an enlarged view of a portion of the embossing roll of FIG. 4A;

FIG. 5 is a perspective view of the patterned ring or shim of the embossing roll of FIG. 4A;

FIG. 6 is an enlarged view of a portion of the embossing roll of FIG. 4A;

FIG. 7 is an enlarged view of a portion of FIG. 6;

8A-8B illustrate a portion of a reflective film having full angle prisms that reflect incident light;

FIGS. 9A-9B are exploded side views of other layers illustrating the orientation of the layers prior to lamination with a reflective film;

FIG. 10 is a schematic view of an illustrative manufacturing system with a roll stack assembly including patterned rolls;

FIG. 11 is a front view of an embossing roll apparatus including an embossing roll;

FIG. 12 is a perspective view of a roll of exemplary reflective film;

fig. 13A-13G illustrate the use of reflective films.

Like reference numbers and designations in the drawings indicate like elements having similar functionality.

Detailed Description

In the following detailed description of the present invention, numerous specific details are set forth in order to provide a thorough understanding of the present invention. However, it is recognized that the invention may be practiced without these specific details. In other instances, well-known methods, procedures, components, parts and devices have not been described in detail so as not to unnecessarily obscure aspects of the present invention.

The reflector may use a series of spherical or spherical lenses made of optical material to reflect the light. In other cases, the reflector may use a series of half-angle prisms made of optical material to reflect light. Sometimes, a half-angle prism may be combined with a spherical or spherical lens to reflect light. In other cases, the reflector may use a series of all-angle prisms made of optical material to reflect the light.

The present invention relates to a method and apparatus for producing retroreflective sheeting or film that can be used as a reflector or as a component of a reflector. The retroreflective sheeting or film may have an optical material surface formed of a series of microstructured half or full angle prisms to reflect light. In one embodiment, the retroreflective sheeting or film of the present invention can be made by an extrusion process using an embossing roll.

The half-angle prism has two interfaces in which incident light rays are reflected twice and returned back to the incident light source. The all-angle prism uses three interfaces in which incident light is reflected three times and returned back to the incident light source. A full angle prism generally provides a large range of angles over which incident light rays can be received and redirected back to the light source. Full-angle prisms can reflect more efficiently than half-angle prisms if the losses in the optical material are low. However, full-angle prisms are more difficult to manufacture. Generally, a reflective film is made of a film embossed with a half-angle prism pattern that naturally reflects incident light at a predetermined angle.

A typical method of making a series of half-angle prisms in a retroreflective sheeting or film is through molding, mechanical cutting, and stamping processes.

The molding process typically requires a mold that is specific to a given pattern. Molten plastic or other similar optical material in liquid form is poured into the mold. The optical material needs a certain curing time in the mold to form a shape having light reflecting properties. The curing time can be quite long. Furthermore, the mold is not suitable for optical materials to form full-angle prisms.

Mechanical cutting processes typically require the use of a machine tool to individually carve patterns into plastic or other optical materials. Patterning one by one is time consuming and therefore not a cost effective way of making a continuous sheet of reflective material.

The stamping process generally requires a rectangular die having a fixed pattern. Soft semi-solid or semi-liquid optical materials such as plastics are stamped by a die into a shape having light reflecting properties. Stamping a limited area with a rectangular die is also slow and not cost effective.

These typical processes often incorporate seams between retroreflective patterns on retroreflective sheeting or film to provide adequate dimensions. The seams break up the reflective pattern and are non-reflective, thereby reducing reflectivity or light intensity efficiency.

These exemplary processes can form a continuous half-angle prism pattern over a limited area, such as a continuous pattern no greater than nine inches by nine inches (i.e., "nine-inch pattern block"), with thirty-six nine-inch pattern blocks in a forty-eight inch by forty-eight inch sheet. In some cases, a nine inch pattern block may limit practical applications to this size, otherwise careful stitching is required to form a larger pattern.

The present invention enables the formation of continuous rolls of microstructured film without seams, thereby providing customers with seamless reflective films that can be of almost any length. By eliminating seams when manufacturing the reflective sheet, reflection efficiency can be improved, and costs can be reduced due to an increase in density of the reflective patterns.

To provide a continuous roll of reflective film, a microstructured cylindrical mold with an optical pattern engraved on its surface is required. Such microstructured cylindrical dies are referred to herein as patterned rolls. Such microstructured cylindrical molds imprint a pattern into a plastic film by continuously imprinting the pattern into a hot optical material, such as a thermoplastic. It is difficult to engrave half-angle or full-angle prism patterns into cylindrical molds using common processes.

The embossing roll provides a tool for the manufacturing process enabling continuous manufacture of microstructured reflective films with half and/or full angle prisms. The precise corner cube recesses can be formed on the three-dimensional surface. Unlike a solid cylinder or roll, the cylindrical pattern of the embossing roll is made up of multiple pieces of sub-patterns. Embossing rolls use one or more narrow rings or shims that are closely packed together to form the entire cylindrical pattern. Each ring or shim is cut individually to form a portion of the pattern. In an embodiment, the width of the ring is less than one millimeter. By using various numbers of rings or shims arranged closely side by side, cylinders of different widths can be formed with the desired pattern.

The embossing roll can provide a large continuous reflective surface with all-angle prisms. That is, the surface of the reflective film or sheet can form a continuous reflective surface of infinite width and length. By using one or more rings or shims to form the entire cylindrical pattern of the embossing roll, the angle of the full angle prism surface can be adjusted, including having each ring have a different angle. Full angle prisms can be formed by alternating the alignment of sub-patterns from ring to ring. As a result, many reflection angles and reflection effects can be formed in the surface of the optical material to reflect or back-reflect incident light. The cube corners (i.e., widening or narrowing) and depth (i.e., shallowing or deepening) of the prisms can be easily adjusted by changing the rings or shims throughout the cylindrical pattern to change their orthogonality, thereby changing the reflective properties of the reflective film and the final product. Larger, deeper prisms can be formed in the surface without loss of reflective quality. The embossing roll is very adaptable in that different reflective sheets or films can be produced with different configurations of the same tool. The entire cylindrical pattern can be modified by simply changing the configuration of the rings or spacers. On one embossing roll, there may be many sizes and kinds of corner cubes coexisting in the range of the embossing roll cylindrical surface to form the entire cylindrical pattern.

The embossing roll comprises a bottom cylinder as a holder for a ring or a shim. The bottom cylinder contains one or more longitudinal guides for properly aligning and securely holding the rings in mutual connection. The outer diameter and shape of the bottom cylinder is similar to the inner diameter and shape of the ring to maintain the position of the ring/spacer and avoid shifting the pattern.

Referring now to fig. 1, a first embodiment of an embossing roll 100A is shown. The embossing roller 100A may also be referred to as an embossing cylinder or a patterned rotating cylinder. The patterned roll 100A includes a cylindrical pattern. In a preferred embodiment, a cylindrical pattern is used to form microstructures in the surface of the material layer.

An optical film or layer may be sandwiched between the patterned roll 100A and another roll 104. In a preferred embodiment, the pattern of patterned roll 100A is formed on the surface of an optical film or layer to create a continuous pattern of reflective film sheet layer 102.

In one embodiment, the optical film or layer is a plastic material that is heated to a soft state between a liquid state and a solid state, so that the cylindrical pattern of the embossing roll 100A is imprinted into the surface of the optical film. In another embodiment, the pattern of the embossing roll 100A is sharp enough to cut into the surface of the optical film in a solid state.

As shown in fig. 1, the emboss roller 100A may comprise: one or more rotatable shafts, spindles or journals 112; n pattern pad (s)/ring 114; m spacer shims/rings (not shown in fig. 1); a pair of end flanges 116; a pair of links 118; a central cylindrical sleeve 120; and one or more fasteners 122 on the end flange 116. The central cylindrical sleeve 120 may also be referred to as a cylindrical core 120. The respective numbers N and M of one or more patterned rings and spacer shims/rings depend on the desired cylindrical pattern of the embossing roll and optical film. In one embodiment, M is N + 1. In another embodiment, M is 0, and thus no spacer/ring is used. The width of the pattern spacer/ring 114 is a function of the desired pattern. The spacer/ring may not contain a cut or formed pattern, but may be of appropriate size to form a pattern of lines, grooves or indentations in the surface of the film. The spacer/ring may be considered to have an edge pattern that may form a pattern of lines, grooves or dimples in the surface.

The patterned roll 100A rotates about one or more shafts 112 while pushing and/or pulling one or more layers of the film material between the patterned roll and the roll 104 to form the reflective film 102. When the embossing roll is rolled over the reflective film 102, a cylindrical pattern of N pattern pads and M spacer pads is formed in the surface of the reflective film 102. The pattern formed in the surface of the film can be considered as a continuous pattern. N pattern shims 114 are disposed around the central cylindrical sleeve 120. A pair of tie bars 118 hold the N pattern pads 114 and M spacer pads (not shown), if any, in fixed positions on patterned roll 100A. The end flange 116 connects the N patterned shims 114; m spacer pads, if any; one or more links 118; and a central cylindrical sleeve 120 sandwiched therebetween. Fasteners 122 at each end flange 116 press the end flanges 116 together and hold the other components sandwiched therebetween together as a unit. In one embodiment, the fastener 122 is a nut and bolt combination.

The N pattern pads and M spacer pads, if any, are slidably coupled to one or more tie bars 118. One or more links 118 are arranged around the patterned roll parallel to shaft 112. One or more links 118 may be disposed on opposite sides of the patterned roll 100A as shown, or angularly spaced from each other around the patterned roll 100A. Fig. 1 shows a pair of links 118 on opposite sides and spaced one hundred and eighty degrees apart from each other. However, there may be one, two, three, four, or more links 118 disposed around the patterned roll 100A to secure the shims.

Referring now to FIG. 2, an exploded view of the pattern pad 114 and a pair of spacer pads 214 is shown. When assembled to the patterned roll 100A, the patterned shim 114 may be sandwiched between a pair of spacer shims/rings 214. Each spacer 214 includes one or more alignment holes 218 for sliding over one or more links 118. Similarly, each pattern shim 114 includes one or more alignment holes 218' for sliding over one or more tie bars 118. Furthermore, each of the spacer pads 214 and the pattern pad 114 includes a central opening 220 for sliding over the central cylindrical sleeve 120.

Referring now to FIG. 3, an enlarged view of a portion of FIG. 2 is shown. Each of the one or more pattern pads 114 includes a sub-pattern 300 around its outer edge. In the case of only one pattern pad 114, the sub-pattern 300 in this one pattern pad 114 may be the entire pattern if the spacer pad 214 is not used to form a portion of the entire pattern. Each sub-pattern 300 in each pattern shim 114 may be similar or unique to complete the entire cylindrical pattern of the patterned roll that is rolled into the surface of the reflective film 102. The sub-patterns 300 may alternate between the odd and even pattern pads 114. The sub-patterns 300 of each pattern pad 114 may be identical, but may be slightly offset from one pattern pad 114 to the next on the patterned roll 100A. The overall cylindrical pattern of patterned roll 100A can be easily changed by replacing pattern shim 114 and any spacer shims with pattern shims and spacer shims of different configurations.

Each pattern pad has a thickness 302 that may vary depending on the sub-pattern selected on a given pattern pad. In comparison, the thickness of spacer 214 is relatively small. For example, in one embodiment, the spacer pads have a thickness that is twenty-five percent of the thickness of the pattern pads. However, the spacer 214 does form its own sub-pattern throughout the pattern. In some cases, spacer 214 may form a groove or a line in the film surface. Although the thickness of the spacer pads 214 is shown in fig. 3 as being relatively small or zero, they may have a greater thickness to further form sub-patterns throughout the pattern.

Referring now to fig. 4A, a second embodiment of patterned roll 100B is shown. The embossing roller 100B may also be referred to as an embossing cylinder or a patterned rotating cylinder. Patterned roll 100B includes many of the features of patterned roll 100A. Patterned roll 100B includes a cylindrical pattern. In a preferred embodiment, a cylindrical pattern is used to form microstructures in the surface of the material layer. However, the pattern shim and the spacer shim are fixed in different ways in each respective embossing roll.

The emboss roller 100B includes: one or two shafts, journals or axles 112; n pattern pad(s) 114'; m gap spacers 214'; a pair of end flanges 116'; a central cylindrical sleeve 120'; and one or more fasteners 122. The central cylindrical sleeve 120 'may also be referred to as a cylindrical core 120'. In the embodiment of the patterned roll 100B, the central cylindrical sleeve 120' includes a guide slot 418. Guide slots 418 engage guide tabs in each pattern spacer 114 ' and each spacer 214 ' to maintain their angular orientation around the central cylindrical sleeve 120 '. End flange 116' differs slightly from end flange 116 of fig. 1 in that guide slot 418 can be used without one or more tie rods 118.

Referring now to fig. 4B, the entire pattern shim 114 'and/or the spacer shim 214' are assembled on the patterned roll 100B to form a cylindrical pattern 400. The details of cylindrical pattern 400 are not shown in fig. 4B and appear to be completely black due to the micro-machined surfaces in one or more pattern shims 114'.

Referring now to fig. 4C, an enlarged view of a portion of patterned roll 100B is shown. The cylindrical pattern 400 may include one or more pattern shims 114 ' and zero or more spacer shims 214 ' between a pair of end flanges 116 '. Spacer pads 214 'may be disposed on both sides of the pattern pad 114'. Alternatively, in some cylindrical patterns 400, the pattern pads 114' may be adjacent. One or more pattern pads 114 'may be disposed on either side of a spacer pad 214'. Alternatively, in another cylindrical pattern 400, the spacer pads 214' may be adjacent.

The sub-pattern 300 of each pattern pad 114' may be formed around the outer circumference or edge of each pad. The sub-pattern 300 may repeat around the outer circumference of the pattern pad. Alternatively, the sub-pattern 300 may be unique along any arc segment or the entire circumference of a given pattern pad 114'.

The sub-pattern 300 may be unique to each shim 114' throughout the cylindrical pattern 400. That is, no two pattern pads 114 may be identical. Alternatively, each pattern pad may be unique within a set of pattern pads 114, and the set of pattern pads 114 repeats from one side of the overall cylindrical pattern 400 to the other. In yet another embodiment, each pattern pad 114' may have identical sub-patterns 300 to form the entire cylindrical pattern 400. In this way, cylindrical pattern 400 is easily modified to form a pattern in the surface of the material.

Referring back to fig. 4B, a drive recess 420 formed in one or more of the shafts 112 is shown. The drive recess 420 is parallel to and near one end of one or more of the shafts 112. On one of the one or more shafts 112 or on one side of the shaft 112, a drive groove 420 may be provided to connect the shaft to a drive gear or motor to rotate the patterned roll 100B. In one embodiment, a key (not shown) may be disposed in the drive recess 420 to connect to a keyway in a gear or other drive coupling. In another embodiment, a gear or other drive coupling may have a coupling tab that slides in the drive groove 420. In yet another embodiment, the drive recess 420 may be designed as a drive key extending outwardly from the cylindrical surface of the shaft.

Referring now to FIG. 5, a perspective view of the patterned shim 114' is shown. The pattern shim 114 'shown in fig. 5 is an illustrative example of N pattern shims 114' in the patterned roll 100B. The pattern shim 114 'includes a central opening 220', guide tabs 518, and a sub-pattern 300. Guide tabs 518 are located on the inner edge of the pattern shim 114 'within the central opening 220'. The central opening 220 ' enables the pattern shim 114 ' to slide over the outer surface of the central cylindrical sleeve 120 '. When the central opening 220 ' slides on the outer surface of the cylindrical sleeve 120 ', the guide tabs 518 of the pattern shim 114 ' slide within the guide slots 418.

The

pattern pads

114 and 114 'and the

spacer pads

214 and 214' are generally annular or donut-shaped. The

pattern pads

114 and 114 'and the

spacer pads

214 and 214' may also be considered to be generally hollow cylindrical with a limited thickness and height. The outer edge or circumference of each pattern pad varies due to the sub-pattern 300. The spacer may be constant or vary around its outer edge or circumference. The inner edges or surfaces of the pattern and spacer shims are shaped to match the shape of the central cylindrical sleeve 120. In one embodiment, the central cylindrical sleeve 120 is a cylinder, and thus the inner edge or surface of each of the spacer and pattern shims is also substantially cylindrical. In other embodiments, the inner edge may be square, rectangular, hexagonal, or otherwise cylindrical to match the shape of the central cylindrical sleeve.

The spacer pads 214 ' and pattern pads 114 ' are assembled on the central cylindrical sleeve 120 ' with the guide tabs 518 of each pad aligned with the guide slots 418.

Referring now to fig. 6, an enlarged view of another portion of the ring/shim in patterned roll 100B is shown. As previously described, the pattern pad 114 'may be sandwiched between a pair of spacer pads 214'. The sub-pattern 300 of each pattern pad 114' is repeated around its outer circumference or edge.

Referring now to fig. 7, there is shown an enlarged view of a portion of the spacer/ring of fig. 6. The sub-pattern 300 extends around the outer edge or circumference of the pattern circle 114'. The sub-pattern 300 may form a corner cube in one region of the reflective film 102. The spacer pads or rings 214 'may form grooves, slots or lines in the reflective film 102 to separate the corner prism columns formed by the sub-patterns 300 of each pattern pad/ring 114'.

The sub-pattern 300 may be machined into the

pattern ring

114 or 114' with a precision cutting tool. Alternatively, the

pattern ring

114 or 114 may be molded or cast to include the sub-pattern 300 along the outer edge. A unique sub-pattern may be formed in each pattern ring. Alternatively, similar sub-patterns may be formed in each pattern circle, but at different angular positions around the cylindrical sleeve. Alternatively, the shape and position of the sub-pattern 300 may vary periodically from one side to the other of the pattern rings 114 or 114' fitted on the emboss rollers 100A and 100B.

Each of the one or more pattern rings 114 or 114 'may be uniquely numbered to identify its position on the cylindrical sleeve 120 or 120' relative to the other pattern rings and any spacing rings. Similarly, each of the zero or more spacing rings 214 or 214 ' may be uniquely numbered to identify its position on the cylindrical sleeve 120 or 120 ' relative to the other spacing rings and the

pattern ring

114 or 114 '.

Referring now to fig. 8A-8D, a portion of the reflective film 102 is shown as reflective film 102'. Fig. 8A is a top view of the reflective film 102'. Fig. 8B is a side view of the reflective film 102'. Fig. 8B is a perspective view of the reflective film 102'. Fig. 8B is a cross-sectional view of the reflective film 102'. Because either embodiment of the embossing rolls 100A and 100B can form patterns in thin films, these embossing rolls are collectively referred to as embossing rolls 100.

As previously described, when the film 102 is pushed or pulled between the patterned roll 100 and the roll 104, the entire pattern is formed in the surface of the reflective film 102. Patterning the reflective film 102 with the patterned roll 100 is not a molding process.

The reflective film 102' includes a plurality of all-angle prisms 800. The reflective film 102' includes a body portion 802 and a microstructure portion 804. A plurality of corner cubes 800 are formed in the microstructured portion 804 of the reflective film 102'. The main portion 802 of the reflective film 102' supports the microstructure portions 804.

In one embodiment of the pattern of patterned roll 100, several full angle prisms 800 are arranged in columns 814A-814F. Each column 814A-814F is separated by a respective line, slot or groove 824A-824G.

Each corner cube 800 has a bottom edge (B), a tail (T), a head (H), a vertex (a), and three surfaces that can reflect light (S1, S2, and S3). The three surfaces (S1, S2, and S3) are joined together to form a tip near the head of each corner cube 800. The tail of each corner cube 800 is opposite to the head. The bottom edge of each corner cube 800 may be flush with the bottom surface of the reflective film. Along each column, the bottom edge of a corner cube 800 may be connected to the bottom edge of the next corner cube. Each corner cube resembles a tetrahedron. That is, each corner cube resembles a triangular pyramid having three triangular side faces and one triangular bottom face. The triangular pyramid shape may be symmetrical or asymmetrical. I.e. the three triangular sides may not be equal to form an asymmetric triangular pyramid or a non-regular tetrahedron.

In each column, each corner cube 800 reverses direction relative to the next corner cube. The direction of the corner cube 800 in each column coincides with the direction of the corner cube in the next column. For example, a corner cube 800 of a column in the reflective film is aligned with the tail on the left and the head on the right. In the next column adjacent thereto, the corner cubes 800 are aligned with the head on the left side and the tail on the right side of the reflective film 102.

The reflective film 102' shown in fig. 8A-8D may be only a portion of a full sheet or roll of reflective film. For the portions shown in fig. 8A-8D, the reflective film 102 ' may be formed from six

pattern pads

114 or 114 ' and seven

spacer pads

214 or 214 ' in patterned roll 100. Each column of corner cubes 814A-814F formed in the reflective film is formed by a corresponding patterned

shim

114 or 114'. Each of the recesses 824A-824G between columns 814A-814F in the reflective film 102 'is formed by a

respective spacer

214 or 214'.

In one embodiment, the corner cubes formed in the surface of the reflective film 102 are male corner cubes. In another embodiment, the corner cubes formed in the surface may be female corner cubes. In either case, the entire pattern rolled into the reflective film 102 can be a seamless continuous pattern.

Referring now to fig. 9A-9B, the reflective film 102 or 102' can be laminated with other layers of material to form a retroreflective laminate sheeting, depending on the particular application desired. Optical microstructures such as full angle prisms cut or imprinted into the surface of the reflective film 102 or 102' can be formed therein to reflect light incident from the front or back side of the optical microstructures.

In FIG. 9A, light ray 910A is coupled to the back side of the optical microstructure and light ray 910B is coupled to the front side of the optical microstructure in the retroreflective layer 102' of the retroreflective laminate sheeting 900A.

In FIG. 9B, light ray 910A is coupled to the back side of the optical microstructure and light ray 910B is coupled to the front side of the optical microstructure in the light reflecting layer 102' of the light reflecting laminate 900B.

Fig. 9A also shows that one or more other materials may be laminated to the top or bottom of the retroreflective layer 102' and both. One or more layers of materials 901A-901N may be laminated together with the light reflecting layer 102' on the first surface. One or more layers of material 902A-902N may be laminated with the light-reflective layer 102' on a second surface opposite the first surface.

Fig. 9B also illustrates that one or more layers of other materials having various widths and various thicknesses may be laminated with the retroreflective layer 102'. For example, layer 911 has a width W1 and a thickness T1. Layer 912 has a width W2 and a thickness T2 that are different from the width W1 and the thickness T1, respectively, of layer 911. The length of these layers may also vary along the laminate film. Moreover, the width, thickness and length of the other layers of material need not be uniform from one side of the retroreflective layer 102' to the other.

Different widths and lengths may be used, for example, to change the reflection efficiency to display text, or may be used to change the color or frequency of light reflected back to the light source. Similarly, different thicknesses may be used to vary the reflection efficiency, or may be related to the amount of material needed to achieve the desired effect. The type of material used to form the retroreflective sheeting 102 may vary the reflective efficiency of the retroreflective laminate sheeting. The type of other materials, their refractive indices, and the location relative to the optical microstructures can also change the reflective efficiency of any retroreflective laminate sheeting. Furthermore, by appropriate selection of the thickness and dimensions of the layers of other materials, the reflection efficiency can be maximized for certain frequencies or colors of light, while minimizing for other frequencies or colors of light. There may be other layers of material that may or may not be transparent to certain wavelengths or frequencies of light desired, but not others.

The retroreflective sheeting layer 102 may be a polymer or plastic layer such as a thermoplastic, or may be other material layer having optical properties that can be cut or embossed with the embossing roll 100. In one embodiment, the light reflecting layer 102 is a transparent semicrystalline polymer.

Examples of other types of material layers that may be laminated with the retroreflective layer 102 include reflective film coatings, pigments, inks, phosphors, silicas, polarizers, sealants, protective coatings, adhesives, substrates, adhesives, and removable release sheet layers. The adhesive layer may be a pressure sensitive adhesive, a heat activated adhesive or a radiation activated adhesive. A removable release sheet layer may be used to protect the adhesive layer until the retroreflective laminate sheet is ready for attachment to a surface.

Silica (silicon dioxide) may be used to fill the voids formed by the optical microstructures to form a more planar surface. One form of silica that may be used is mica.

The layer of protective paint can be used to prevent wear and contamination, such as is encountered with pavement markings that are run over tires. The protective coating layer can also have soil and dew resistance properties that allow the laminated sheet to retain its original reflective efficiency after exposure to moisture, dust or dirt.

The substrate enables the retroreflective laminate sheeting to be mechanically secured to a surface, such as sewn into a garment or shoe. A layer of adhesive or bonding agent may be used to affix the retroreflective laminate sheeting to a surface.

A reflective film such as a metal foil formed with a thin layer of aluminum, brass, red copper, gold, nickel, platinum, silver, or titanium may also be used to reflect light and/or create a difference in refractive index. The reflective film may be laminated or sputtered onto the light-reflecting layer 102. Other materials such as titanium dioxide, zirconium oxide, cobalt/iron mixtures, zirconium dioxide, zinc oxide, white lead, antimony oxide, zinc sulfide, aluminum oxide, and magnesium oxide may also be used to form the reflective film layer.

The other layer may also be a plurality of alternating layers of two polymers, wherein each layer has a thickness of less than one hundred nanometers, the thickness being selected such that the refractive indices do not match to cause constructive interference of light rays.

The layers may be laminated together by applying heat under pressure during the extrusion process. Or a thin layer of adhesive, binder or epoxy may be selectively applied between the layers and the layers laminated and held together by pressure.

Referring now to fig. 10, an illustrative schematic of a processing line, production line, or manufacturing system 1000 is shown. In one embodiment, the manufacturing system 1000 is a coextrusion system for extruding reflective films. In this illustrative manufacturing system 1000, material flows from the left to the right of the page. The manufacturing system 1000 receives a number of pellets, beads, powder, crumb or other forms of raw material 1001 at an input end and forms a roll of reflective film 1002 at an output end thereof.

The illustrative manufacturing system 1000 includes an extruder 1014, an extrusion die 1016, an embossing roll stack assembly 1020, an idler roll ("idler") 1030, a pair of nip rolls 1032, and a take-up roll 1034. Various locations in the illustrative manufacturing system 1000 may also include feeders, agitators, screen packs, gear pumps, feed heads, thickness gauges, slitter machines, and dancers. In addition, for multilayer reflective films, the illustrative manufacturing system 1000 may also include one or more streams of molten or liquefied materials mixed by a feed block. Alternatively, a laminator may be used to laminate together multiple layers of material comprising the reflective film layer 102. In another case, a vacuum former may be used to apply additional layers of material to the reflective film layer 102.

The patterned roll stack assembly 1020 includes a first roll 1022, a patterned roll 100, and a second roll 1024. The patterned roll 100 is driven by a motor to pull the extruded film into a patterned roll stack 1020. The first surface of the extruded film is in intimate contact with the patterned roll 100 so that the cylindrical pattern of the patterned roll 100 can be imprinted or engraved into the first surface. The first roller 1022 at the top of the stacker assembly is pressed against the second surface of the extruded film to squeeze the film between the embossing roller 100 and the first roller 1022. The first roller 1022 may also partially cool the extruded film. Accordingly, the first roller 1022 may also be referred to as a top chill roller. The second roller 1024 at the bottom of the stack may be driven by a motor to pull the reflective film from the patterned roll stack 1020. The second roller 1024 may also cool the extruded reflective film to a solid state. Thus, the second roller 1024 may also be referred to as a bottom cooling roller. The patterned roll stack assembly 1020 can also include a chassis, frame or frame 1026, the first roller 1022, the patterned roll 100, and the second roller 1024 being rotatably coupled to the frame 1026. The frame 1026 supports the position of the rollers and can move one or more rollers together to squeeze and apply pressure to the extruded film.

When the manufacture of the extruded reflective film is started, the raw materials 1001 in the appropriate proportions are fed into the extruder 1014. The extruder 1014 heats the raw materials from a solid state to a liquefied or molten state, mixes the raw materials together, and then pushes out it to become the liquefied or molten raw material 1004.

It is necessary to change the cross-section of the liquefied raw material 1004 to that of a layer or sheet of material. The liquefied raw material 1004 is fed into an extrusion die 1016. The extrusion die 1016 transforms the first cross-section of the liquefied raw material into a thin, wide sheet-like, film-like, or layered cross-section of the extruded film 1006. The extruded film 1006 has a pair of side edges and a top and bottom surface. The side edges of the extruded film 1006 are relatively thin, while the top and bottom surfaces of the extruded film 1006 are relatively wide.

The flattened extruded film 1006 is fed between the first roller 1022 and the patterned roller 100 in the patterned roller stack 1020.

As described above, the patterned roll 100 includes a cylindrical pattern 400 formed by one or more pattern rings 114 or 114 'and/or zero or

more spacer sheets

214 or 214'. The continuous cylindrical pattern 400 of the patterned roll 100 is imprinted, pressed, or engraved into the surface of the extruded film 1006 to form the microstructure of the film 102. In one embodiment, the microstructures in the film are all-angle prisms and film 102 is an extruded reflective film or layer. The continuous cylindrical pattern 400 of patterned roll 100 forms a continuous pattern 800 in the surface of reflective layer 102.

The reflective layer 102 redirects the film 102 around a portion of the second roller 1024 of the patterned roller stack 1020. The second roller 1024 also provides a means for accelerated cooling of the material sheet from a soft state to a hard state. The sheet of material output from the patterned roll stack 1020 is then fed to a take-up roll 1034.

Film 102 is wrapped around idler roll 1030 to change the angle at which the film flows in the manufacturing system. Film 102 is pulled from idler roll 1030 by a pair of nip rolls 1032. Each roll 1032 is a roller driven by a motor. The film 102 is squeezed between a pair of nip rollers 1032 and flows to a take-up roll 1034.

Wind-up roll 1034 receives film 102 and winds the sheet into a roll 1002. Where the film 102 is an extruded reflective film, the roll 1002 is a roll of reflective film of extruded reflective sheeting or film. The take-up roller 1034 is driven to tightly wind the extruded film into a spiral roll. The take-up roll 1034 may include a roll with edges that maintain the alignment of the film 102 as it is wound into a spiral roll.

In general terms, the manufacturing system 1000 includes an extrusion or liquefaction process, a flattening process, an embossing process, and a rolling process. The extrusion or liquefaction process is performed by an extruder 1014. The flattening process is performed by extrusion die 1016. The embossing process is performed by an embossing roll stack 1020. The winding process is performed by a nip roller 1032 and a take-up roller 1034.

Referring now to fig. 11, an exemplary patterned roll assembly 1100 is shown. The patterned roller assembly 1100 includes the patterned roller 100, a pair of bearings 1102, a gear box 1104, and an ac motor 1106 coupled together, as shown in fig. 11. The inner sides of the pair of bearings 1102 provide a support point for the patterned roll 100 connected to the shaft or neck 112. The outer sides of the pair of bearings 1102 may be connected to the frame of the patterned roll stack 1020 to support the patterned roll assembly 1100. The pair of bearings 1102 enable the patterned roll 100 to rotate within the patterned roll stack. Each bearing 1102 may be a roller bearing.

The motor 1106 includes a shaft to drive the gearbox 1104. The gear box 1104 includes gears for making the rotation of the rotation shaft proportional to the rotation of the emboss roller. In one embodiment, the gear ratio of the gearbox reduces the number of motor revolutions imparted to the patterned roll. In another embodiment, the gear ratio of the gearbox 1104 increases the number of motor revolutions imparted to the patterned roll 100. In yet another embodiment, the gear ratio of the gear box 1104 is one, so the number of revolutions of the motor 1106 imparted to the patterned roll 100 is constant. The gear ratio of the gearbox 1104 may be selected to change the rotational speed of the patterned roll 100 similar to a transmission.

Referring now to FIG. 12, a roll 1002 including retroreflective sheeting 1200 is shown. As previously described, other layers of material may be laminated to the retroreflective sheeting 102 to form retroreflective laminate sheeting 1200. The retroreflective laminate sheeting includes retroreflective sheeting 102 and one or more layers of other materials such as layers 1201-1204. 9A-9B, the dimensions of one or more other layers of material may be different and may be disposed on either side of the retroreflective sheeting.

Thus, the roll 1002 may simply be a roll of retroreflective sheeting 102 without additional layers. Alternatively, the roll 1002 may be a roll of retroreflective laminate sheeting 1200, including other layers laminated with retroreflective sheeting 102. The roll 1002 may also contain a central cylindrical core 1210 onto which the reflective sheet 102 or reflective laminate sheet 1200 may be spirally wound. The central cylindrical core 1210 may be a roll with edges that allow alignment of the retroreflective sheeting 102 or retroreflective laminate sheeting 1200 as it is wound onto a take-up roll.

Referring now to fig. 13A-13G, examples of applications for the reflective film 102 are shown. Reflective film 102 may be used in a wide variety of retroreflective applications including, but not limited to, retroreflective signs, pavement markings, sports wear, and safety apparel. The retroreflective bodies and reflective films can be incorporated into the article by a number of means. The retroreflective article may be part of an article, such as a spoke retroreflective article for a bicycle or a tail retroreflective article for an automobile. Alternatively, the retroreflective material may be formed into a sheet or strip of material and then adhered or otherwise attached to the article. For example, retroreflective tape may be added to the garment. Reflective flakes or films may also be added to the pavement marker or logo. The reflective film 102 or retroreflective laminate sheeting may be rolled from a roll 1002 and applied to an article during manufacture.

In fig. 13A, a reflective film 1002A representing a portion of a roll 1002 is added to an automotive license plate 1300A. The letters and numbers may be formed by adding one or more layers of different colored inks to the retroreflective laminate sheet 1200.

In fig. 13B, a reflective film 1002B representing a portion of a roll 1002 is added to a shoe 1300B. The reflective film 1002B may include a substrate to enable it to be sewn to the footwear 1300B and/or an adhesive to enable it to be affixed thereto.

In FIG. 13C, a reflective film 1002C representing a portion of a roll 1002 is added to a highway sign, such as stop sign 1300C.

In fig. 13D, a reflective film 1002D representing a portion of a roll 1002 is added to an article of clothing, such as a vest 1300D.

In fig. 13E, a reflective film 1002E representing a portion of the roll 1002 is added to the pavement marker 1300E. The pavement marker 1300E is secured to the pavement 1352 with an adhesive 1354, as shown in fig. 13E.

In fig. 13F, a reflective film 1002F, representing a portion of a roll 1002, is added to the retroreflective bodies 1300F and 1300F' of the automobile 1360. The reflector 1300F is a side logo or side reflector for the automobile 1360. The reflector 1300F' is the rear reflector or the front reflector of the automobile 1360.

In fig. 13G, a reflective film 1002G representing a portion of a roll 1002 is added to the retroreflective bodies 1300G, 1300G', and 1300G ″ of a bicycle 1370. The reflector 1300G is a spoke or wheel reflector. The reflector 1300G' is a front reflector or a rear reflector of the bicycle. Reflector 1300G "is a foot pedal reflector.

Because the embossing roll functions as a printing roll or a cutting roll rather than as a die, little or no cure time is required for the optically reflective sheeting, thereby providing a method for quickly forming an extruded reflective sheeting. The emboss roller enables the formation of a continuous full angle prism sheet in the surface of one sheet of optical material. By using an embossing roll, the pattern on the continuous web is seamless. The embossing roll may be modified. That is, the pattern formed by the embossing roll can be changed by changing the pattern rings and the spacing rings of another configuration.

While certain exemplary embodiments have been described and shown in the accompanying drawings, it is to be understood that such embodiments are merely illustrative and not restrictive of the current invention, and that this invention not be limited to the specific constructions and arrangements shown and described, since various other modifications may occur to those ordinarily skilled in the art upon reading this specification. For example, the embossing rolls described herein are used to make extruded reflective films. However, the embossing roll may also be used to form other types of structures or microstructures in the surface of a material film or web. The invention is to be defined by the appended claims rather than by the specific constructions and arrangements shown and described herein.

Claims

1. A patterned roll for use in a manufacturing process, the patterned roll comprising:

a shaft lever;

a cylindrical sleeve surrounding the shaft, the cylindrical sleeve being coaxial with the shaft;

one or more patterned rings slidably engageable with said cylindrical sleeve and orthogonal thereto, an outer edge of said one or more patterned rings each having a sub-pattern of said pattern of patterned rollers, an inner edge of said one or more patterned rings shaped to slidably engage said cylindrical sleeve, said one or more patterned rings coaxial with said shaft;

a first end flange and a second end flange sandwiching said cylindrical sleeve and said one or more patterned rings, said first end flange and second end flange being orthogonally connected to and coaxial with said shaft; and

one or more fasteners coupled between the first end flange and the second end flange, the one or more fasteners operable to hold the first end flange and the second end flange in clamping relation to the cylindrical sleeve and the one or more patterned rings.

2. The embossing roll as claimed in claim 1,

the one or more patterned rings, each having the sub-pattern, form the pattern of patterned rolls that can be rolled onto the surface of a sheet of material.

3. The embossing roll as claimed in claim 1,

the one or more fasteners are one or more pairs of interconnected nuts and bolts.

4. The patterned roll of claim 1 further comprising:

one or more spacer rings slidably engageable with and orthogonal to said cylindrical sleeve, an outer edge of said one or more spacer rings each having an edge pattern of said pattern of embossing rollers, an inner edge of said one or more spacer rings shaped to slidably engage said cylindrical sleeve, said one or more spacer rings coaxial with said shaft.

5. The embossing roller as claimed in claim 4,

said one or more patterned rings each carrying said sub-pattern, said one or more spaced rings forming said pattern of embossing rollers which can be rolled onto the surface of a sheet of material.

6. The embossing roller as claimed in claim 4,

a pair of the one or more spaced rings sandwiches a pattern ring of the one or more pattern rings.

7. The patterned roll of claim 1 further comprising:

one or more tie rods parallel to the shaft connected between the first and second flanges, the one or more tie rods slidably engaging the one or more patterned rings and orthogonal thereto; wherein,

the one or more patterned rings each have an opening to slidingly engage the one or more links and maintain a fixed rotational position about the shaft.

8. The embossing roll as claimed in claim 1,

the cylindrical sleeve includes a guide slot parallel to the shaft; and is

The inner edges of the one or more patterned rings each include guide tabs to slidably engage the guide slots and maintain a fixed rotational position about the shaft.

9. The patterned roll of claim 1 further comprising:

a motor driving the embossing roller;

first and second bearings supporting the patterned roll, the first bearing proximate a first end of the shaft and the second bearing proximate a second end of the shaft; and

a gear box connected between the motor and the first end of the shaft, the gear box having a transmission to proportionally rotate the patterned roll under rotation of the motor shaft.

10. A roll stack for forming a pattern in a surface of a film, the roll stack comprising:

a first roller; and

a second roll having a cylindrical pattern that is rollable onto the surface of the film and forms the pattern therein, the second roll comprising,

a rotatable shaft, an

One or more rings connected to the shaft in parallel with each other, the outer edges of the one or more rings each having a corresponding sub-pattern alignable to form the cylindrical pattern; and

the film between the first roller and the second roller, the second roller being depressible against the film surface to form the pattern therein.

11. The roll stack assembly of claim 10 further comprising:

cooling the third roll of film.

12. The roll stack assembly of claim 10 further comprising:

a motor connected to drive said rotatable shaft of said second roller,

first and second bearings supporting the second roller, the first bearing being proximate the first end of the rotatable shaft and the second bearing being proximate the second end of the rotatable shaft; and

a gear box connected between the motor and the rotatable shaft, the gear box having a transmission to proportionally rotate the second roller under rotation of the motor.

13. The roll stack assembly of claim 12, further comprising:

cooling the third roll of film.

14. The roll stack assembly of claim 13, further comprising:

a frame rotatably supporting the first roller, the second roller, and the third roller in parallel.

15. A manufacturing system for manufacturing an extruded film, the manufacturing system comprising:

an extruder receiving a solid raw material, the extruder further capable of heating and extruding a liquefied raw material; and

an extrusion die for receiving the liquefied raw material, the extrusion die further capable of flattening the liquefied raw material into a thin, wide sheet of semi-solid raw material; and

a roll stack assembly receiving the thin and wide sheet of semi-solid raw material, the roll stack assembly comprising:

a first roller and a second roller adapted to receive the thin and wide sheet of semi-solid raw material therebetween,

the second roller is also provided with a cylindrical pattern which is formed by one or more circular rings and is used for rolling the surface of the thin and wide semi-solid raw material sheet and forming a pattern in the surface, and the roller stacking assembly can output the thin and wide solid raw material sheet with the pattern;

a pair of nip rollers for pulling the thin and wide solid raw material sheet for conveyance; and

a wind-up roll receiving the thin wide sheet of solid stock material and rolling it into a roll of sheet.

16. The manufacturing system of claim 15,

the first roller may cool the thin and wide sheet of semi-solid raw material.

17. The manufacturing system of claim 15,

the roll stack assembly further comprises:

and a third roller for cooling the thin and wide sheet of semi-solid raw material into the thin and wide sheet of solid raw material.

18. The manufacturing system of claim 15,

the second roller presses against the surface of the thin and wide sheet of semi-solid raw material to form the pattern therein.

19. The manufacturing system of claim 15,

the second roller further includes:

a rotating shaft which can be rotated is arranged on the rotary shaft,

a motor connected to one end of the rotatable shaft for driving the rotatable shaft,

one or more rings connected parallel to each other to said spindle, the outer edges of said one or more rings each having a corresponding sub-pattern alignable to form said cylindrical pattern of said second roller.

20. A method of manufacturing a patterned film, the method comprising the steps of:

providing a raw material in liquefied form;

forming the raw material in liquefied form into a sheet;

rolling on the surface of the web with an embossing roller comprising one or more rings each having a sub-pattern constituting the cylindrical pattern of the embossing roller; and

winding the sheet into a roll.

21. The method of claim 20, further comprising the steps of:

the sheet is cooled with a first cooling roller and a second cooling roller.

22. The method of claim 20,

the web may be wound into a roll using a wind-up roll.

23. The method of claim 20,

the liquefied raw material can be formed into a sheet by an extrusion die.

24. The method of claim 20,

the raw material in liquefied form can be supplied by means of an extruder.

25. The method of claim 20,

prior to winding the web, the method further comprises:

pulling the sheet.

26. The method of claim 25,

the sheet is pulled using a pair of nip rollers.

27. The method of claim 25,

prior to pulling the sheet, the method further comprises:

the sheet is redirected.

28. The method of claim 27,

the web can be redirected using idler rollers.

29. An extruded film roll formed by the process of:

extruding the raw material in liquefied form;

forming the raw material in liquefied form into a sheet;

rolling on the surface of the web with an embossing roller comprising one or more rings each having a sub-pattern constituting the cylindrical pattern of the embossing roller;

cooling the sheet; and

winding the sheet into a roll.

30. A method of making a reflective film, the method comprising the steps of:

attaching the film to a roll stack assembly;

rolling a corner cube pattern of an embossing roll onto a surface of the film to form the reflective film, the corner cube pattern being comprised of a sub-pattern of one or more patterned circles; and

cooling the reflective film to a solid state.

31. The method of claim 30,

the reflective film may be cooled to the solid state using a cooling roller.

32. The method of claim 30, further comprising the steps of:

pulling the film to the roll stack assembly.

33. The method of claim 32,

the embossing roll can be driven to pull the film into the roll stack.

34. The method of claim 30,

the corner cube pattern of the embossing roll may be rolled onto the film surface using a first chill roll and the embossing roll to form the reflective film.

35. The method of claim 34,

the reflective film may be cooled to the solid state using a second cooling roller.

36. The method of claim 35,

the roll stack assembly includes the embossing roll, the first chill roll and the second chill roll.

37. The method of claim 30, further comprising the steps of:

pulling the reflective film out of the roll stack assembly.

38. The method of claim 37,

the second chill roll can be driven to pull the reflective film from the roll stack assembly.

39. A reflective film formed by the following method:

attaching the film to a roll stack assembly;

cooling the reflective film to a solid state.

40. A roll of retroreflective laminate comprising a layer of reflective film formed by the process of:

attaching the film to a roll stack assembly;

cooling the reflective film to a solid state.

41. An article comprising a portion of a reflective film formed by a method comprising:

attaching the film to a roll stack assembly;

and winding the reflecting film into a roll.

42. The article of claim 41,

the article is one or more of the following:

license plates, shoes, highway signs, clothing, pavement markings, automotive reflectors, and bicycle reflectors.

43. A roll of film comprising:

an optical film wound into a roll, the optical film comprising a first side having:

a plurality of columns of full-angle prisms,

the pattern of the all-angle prisms in each adjacent column is offset from the pattern of the all-angle prisms in the next column, an

A groove between each of the plurality of columns of full angle prisms.

44. The film roll of claim 43,

the optical film further includes a second side having:

an adhesive for affixing the optical film to a surface.

45. The roll of film as defined in claim 44,

the second side of the optical film further has:

a removable release layer to protect the adhesive.

46. The film roll of claim 43,

said all-angle prism at said first side reflecting an incident ray, an

The optical film further includes a second side having:

a reflective layer for further reflecting the incident light.

47. The film roll of claim 43,

said all-angle prism at said first side reflecting an incident ray, an

The first side of the optical film further has:

and the reflecting layer is used for further reflecting the incident light.

48. The film roll of claim 47,

the first side of the optical film further has:

an adhesive for affixing the optical film to a surface.

49. The film roll of claim 43,

the plurality of columns of full angle prisms are seamless therebetween.

50. A reflective film, comprising:

a body portion and an optical portion of optical material, the body portion supporting the optical portion; and

the optical portion has N rows of corner cubes without seams, the optical portion is formed by:

the film surface is rolled with an embossing roll comprising N patterned rings.

51. The reflection film according to claim 50,

the optical portion also has M grooves interspersed between the N rows of corner cubes,

the optical spot is further formed by the patterned roll further comprising M spaced rings.

52. The reflection film according to claim 50,

the optical material is a thermoplastic.

53. A reflector capable of reflecting an incident light source having an angle of incidence at a reflection angle, the reflector comprising:

a laminate sheet having a reflective layer comprising a surface comprised of,

n rows of full angle prisms without seams, each of said full angle prisms being of triangular pyramidal shape, an

M grooves, each groove separating two columns of full angle prisms without seams.

54. The retroreflective article of claim 53, wherein the retroreflective article comprises,

each all-angle prism includes a base, a head, a tail, and three reflective surfaces joined at an apex.

55. The retroreflective article of claim 53, wherein the retroreflective article comprises,

the full-angle prism is a male corner cube.

56. The retroreflective article of claim 53, wherein the retroreflective article comprises,

the full angle prisms are aligned in columns.

57. The retroreflective article of claim 56, wherein the retroreflective article comprises,

the all-angle prisms in even columns are aligned in columns from end to end, and the all-angle prisms in odd columns are aligned in columns from end to end.

58. The retroreflective article of claim 53, wherein the retroreflective article comprises,

the laminate sheet also includes an adhesive layer for attaching the reflective film to a surface.

59. The retroreflective article of claim 53, wherein the retroreflective article comprises,

the N columns of full angle prisms without seams and the M grooves are formed by,

the film surface is rolled with an embossing roll comprising N patterned rings and M spaced rings.

60. The retroreflective article of claim 53, wherein the retroreflective article comprises,

the reflector is one or more of license plate, shoes, highway sign, clothes, pavement marker, automobile reflector and bicycle reflector.

61. The retroreflective article of claim 53, wherein the retroreflective article comprises,

each of the full-angle prisms is shaped as an asymmetric triangular pyramid.

62. The retroreflective article of claim 53, wherein the retroreflective article comprises,

each of the full-angle prisms is shaped as a symmetrical triangular pyramid.