Patent Application
20100299984
The present application relates generally to reflective and retroreflective signs, and more particularly, to signs including interlocking mechanical fasteners.
The term “sign” as used herein refers to a stand-alone article that conveys information, usually by means of alphanumeric characters, symbols, graphics, or other indicia, and that in use is mounted to an object such as a post, bracket, wall, or similar body. Specific examples include signs used for traffic control purposes (STOP, YIELD, speed limit, informational, roadside markers, etc.), street signs, and vehicle license plates. The term “retroreflective” as used herein refers to the attribute of reflecting an obliquely incident light ray in a direction antiparallel to its incident direction, or nearly so, such that it returns to the light source or the immediate vicinity thereof.
Two known types of retroreflective sheeting are microsphere-based sheeting and cube corner sheeting. Microsphere-based sheeting, sometimes called “beaded” sheeting, employs a multitude of microspheres typically at least partially imbedded in a binder layer and having associated specular or diffuse reflecting materials (e.g., pigment particles, metal flakes, vapor coats) to retroreflect incident light. In contrast, cube corner retroreflective sheeting comprises a body portion typically having a substantially planar front surface and a rear structured surface comprising a plurality of cube corner elements. Each cube corner element comprises three approximately mutually perpendicular optical faces that cooperate to retroreflect incident light.
Typically, a sign 10 (shown schematically in
In an alternative manufacturing process, retroreflective sheeting is attached to a sign blank by screws, rivets, or nails that are drilled or driven through one or more of the retroreflective sheeting and the sign blank.
The present application relates to a sign including: (1) a sign blank having opposed first and second major surfaces and a first fastener component on the first major surface of the sign blank; and (2) a sheeting having opposed first and second major surfaces and a second fastener component on the first major surface of the sheeting; wherein the first and second fastener components are capable of matably engaging one another and of holding the sign blank and the sheeting together.
The present application also relates to a sign including: (1) a sign blank including multiple first interlockable members; and (2) sheeting including multiple second interlockable members; wherein the first and second matable members interlock with one another to hold the sign blank and the sheeting together.
The present application also relates to a sign blank including: a piece of rigid material; and a first matable fastener attached to the piece of rigid material. The sign blank may further include a sign sheeting attached to a second matable fastener wherein the second matable fastener is capable of matably attaching to the first matable fastener.
The present application also relates to a sign sheeting including optically active (e.g., retroreflective or reflective) sheeting; and a second matable fastener attached to the optically active sheeting. The sign sheeting may further include a piece of rigid material having a first matable fastener attached to the piece of rigid material wherein the second matable fastener is capable of matably attaching to the first matable fastener.
Conventional traffic signs have some disadvantages. For example, the PSAs or other adhesives used to attach the optically active (e.g., reflective or retroreflective) sheeting to the sign blank can (1) exhibit shock failure in cold temperatures; (2) exhibit sheer or creep in hot temperatures; (3) wrinkle in humid climates; (4) exhibit liner curling or instability during fabrication; and (5) ooze into undesired locations causing edge tackiness, all of which can result in poor sign performance. Further, PSAs and other adhesives can have limited positionability because of their inherent tackiness. As a result, a minor error in placement of the sheeting onto the sign blank can destroy the entire sign, resulting in increased manufacturing cost. Manufacturing cost is also relatively high because of the cost of the release liner, which is waste, as it is not used in the final sign.
The inventors of the present application recognized these disadvantages and also recognized a continuing need to improve the performance, reduce the cost, and/or to simplify the manufacture of retroreflective signs. The inventors recognized that the typical sign blank-sheeting attachment system and method has various disadvantages that can be minimized or eliminated by an improved sign blank-sheeting attachment system and method.
One improved sign blank-sheeting attachment system is shown schematically in
The specific type of first interlockable members 102 shown in
The specific type of second interlockable members or fastener components 110 of
Another improved sign blank-sheeting attachment system is shown schematically in
Fastener component 212 is preferably positioned to create a space between the tops of geometric structures 208 and fastener component 212, which facilitates the total internal reflection of light off of geometric structures 208. When sign blank 200 and prismatic retroreflective sheeting 206 are matably coupled, first and second interlocklable members interlock with one another to hold sign blank 200 and prismatic retroreflective sheeting 206 together, thereby forming a sign.
The above-described embodiments are examples of the signs, attachment systems, and methods of the present application. Many modifications to these examples can be made while still falling within the inventive concept of the present application. For example, the sheeting attached to the sign blank can be, for example, retroreflective sheeting (e.g., prismatic or beaded), reflective sheeting, or any other type of optically active sheeting. Those of skill in the art will appreciate that when non-prismatic sheeting is used, a space for total internal reflection may not be necessary. Also, the sign blank can be any rigid substrate suitable for mounting in the intended end use application including, for example, a rigid mass of metal, wood, plastic, a composite substrate, or the like.
The first and second interlockable members can be any members capable of interlocking or mating that do not require puncturing of either the sign blank or the sheeting including, for example, hook and loop fasteners (e.g., Scotchmate™ brand fasteners sold by 3M Company of St. Paul, Minn. and VELCRO™ brand fasteners sold by Velcro Industries N.V. of the Netherlands). Additionally, any method or means of attaching the interlocking or mating fasteners to each of the sign blank and the sheeting can be used including, for example, incorporating the interlockable fasteners into the sign blank or sheeting construction using 3M™ Dual Lock™ Reclosable Fasteners, use of heat lamination, or use of adhesives, including, for example, PSAs. Further, the interlockable fasteners on either the sign blank or the sheeting can cover the entire sign blank or sheeting surface or can cover only a part of the sign blank or sheeting surface. In one exemplary implementation, the first fastener component is on at least 50% of the first major surface of the sign blank and the second fastener component is on at least 50% of the first major surface of the sheeting. The interlocking members can be placed on the sign blank or sheeting surface in an array, in a design, randomly, only on the outer edges, in a matrix, etc. In at least one preferred implementation, the number of interlockable members on at least one of the sign blank or the sheeting are at least 5 interlockable members per inch of sheeting or sign blank. The nature of the interlockable fasteners can be such that the attachment of the sign blank to the sheeting is either permanent or temporary.
In at least one preferred implementation, the edges of sign 100 or 200 are edge or perimeter sealed to prevent water, dew, etc. from accessing the internal portion of the sign and to reduce the risk of tampering with the sign by removal of the sheeting. This sealing can be accomplished by, for example, applying tape around the perimeter of the sign, using thermal stitching, or applying a putty filling compound such as, for example, Scotch-Weld™ Structural Void Filling Compound 3550 B/A FST, 3M™ Lightweight Body Filler, or 3M™ Premium Body Filler Gold QBA. Alternatively or additionally, where the interlockable fasteners are formed of thermoplastic materials, the attached sign blank and sheeting can be exposed to at least one of temperature and pressure to melt the interlockable elements together, thereby furthering the bond strength between the sign blank and sheeting and effectively sealing the perimeter of the sign.
Some potential advantages of the attachment method and system of the present application include (1) less expensive manufacturing; (2) more environmentally friendly manufacturing due to the elimination of the PSA layer, which requires the use of potentially harmful solvents; (3) increased shock sensitivity of the resulting sign; and (4) more ergonomic and easier installation.
The following examples describe some exemplary constructions of various embodiments of the signage articles and attachment systems described in the present application.
A sign (8 inches by 6 inches (20.3 cm by 15.2 cm)) consisting of retroreflective sheeting adhered to a substrate by means of fastener components was prepared. The substrate was an 0.080 in. (0.2 cm) thick aluminum sheet available from Vulcan, Ala., USA. The retroreflective sheeting was “Diamond Grade DG3 Reflective Sheeting Series 4000” available from 3M Company, St. Paul, Minn., USA. Two types of fastener components were used: “Scotchmate Reclosable Fastener Hook SJ3572” (first fastener component) and “Scotchmate Reclosable Fastener Loop SJ3572” (second fastener component), both available from 3M Company. The fastener components were of the type hook and loop and included an adhesive layer protected by a release liner.
The fastener components were cut into 8 in. by 6 in. (20.3 cm by 15.2 cm) rectangles. Upon removal of the release liner, the first fastener component was adhered to a major surface of the substrate and manually pressed against the substrate to promote adhesion. In a similar fashion, the second fastener component was adhered to the non-optically active (back side) of the retroreflective sheeting and manually pressed against it to promote adhesion.
The substrate was placed on a flat surface with the first fastener component facing upward. The retroreflective sheeting, with the second fastener component facing downward, was visually aligned with the substrate and manually pressed against it to interlock the first and second fastener components.
A sign was prepared as described in Example 1, except the substrate was a fiber reinforced polypropylene honeycomb core sandwich composite, available from Plascore, Mich., USA, under the trade designation “PPSLICE05.”
After interlocking the first and second fastener components, the edge of the honeycomb substrate was filled with a curable adhesive, available from 3M Company under the trade designation “Scotch-Weld Structural Void Filling Compound 3550 B/A FST,” using a pneumatic gun available from 3M Company. The adhesive was allowed to cure at room temperature for 48 hours to seal the edges of the sign, therefore preventing water, dirt, etc. from accessing the internal portion of the sign.
A sign was prepared as described in Example 2, except that the fastener components were stems with mushroom shaped tops, available from 3M Company under the trade designation “Dual Lock Reclosable Fasteners SJ3756 Type 170.”
Various modifications and alterations of the present disclosure will become apparent to those skilled in the art without departing from the spirit and scope of the disclosure. The scope of the present disclosure should, therefore, be determined only by the following claims.
