A multi-panel system for making a sign blank, comprising: at least a first and a second Pultruded profiles fiberglass sign panels, each panel having: (a) a sign side having a substantially flat sign surface; (b) a back side having a first edge and a second edge that are parallel and located on opposite ends of the backside; (c) a first channel end protruding outwardly from the first edge of the backside forming an angle of about 90° with the back side, wherein a distal end of the first channel protrusion is furthest away from the back side; (d) a second channel end protruding outwardly from the second edge of the backside forming an angle of about 90° with the back side, wherein a distal end of the second channel protrusion is furthest away from the back side; wherein, the first channel end of the first pultruded fiberglass sign panel is fastened substantially adjacent to the second pultruded fiberglass sign panel; the first and the second pultruded fiberglass sign panels are connected lengthwise along the second edge of the first channel end of the first pultruded fiberglass sign panel and the first edge of the second channel end of the second Pultruded profiles fiberglass sign panel forming the substantially flat sign surface on the sign side of the multi-panel system and forming the mounting surface on the distal ends of the first and second channel protrusions.
This invention relates to compositions and methods of making pultruded fiberglass sign panels, in particular, a pultruded fiberglass sign panel having an overall and cross-section designs that are useful for replacing aluminum allow highway signs. The compositions and methods of the current invention produce lighter, stronger, less expansion and contraction, and less expensive sign panels when compared to similar extruded aluminum sign panels, steel panels, or wood sign panels. Additionally, a fiberglass reinforced polymer material that useful for making sign panels can be made from recycled or virgin materials.
Highway Signs. The United States has over 6.3 million kilometers (“km”) of highways crisscrossing the nation's landscape. This number includes about 4.1 million km of paved roads (including 74,406 km of expressways) and about 2.2 million km of unpaved roads. Information signage is located on nearly every kilometer of this immense network of roads, as well as roads in countries around the globe.
Many years ago, the material of choice that was used for highway signage in the United States was wood. However, since the mid 1960's, there has been a shift in the use of signage material toward the current standard of aluminum. This shift was due primarily because an aluminum sign has many superior qualities when compared to a similarly sized wood sign, including increased strength, decreased weight, and longer durability. In contrast, the disadvantages to aluminum signage is the variable cost of aluminum material itself, and the increasing cost of alodizing the aluminum alloys to increase their corrosion resistance and to improve their paint bonding qualities. For example, since 2002, the cost of aluminum has increased about 60% and the cost of Alodizing aluminum has increased more than 25%. Furthermore, aluminum has little or no resistance to impact deformation. There is a need in the highway sign industry to replacement aluminum as a choice material.
Fiberglass reinforced polymers (“ FRP”) are primarily made from glass and resin. Because the glass component can be made from sand or recycled glass, FRP grating is a much cheaper raw material than typical aluminum alloys. Additionally, a finished sign made from FRP requires fewer processing steps when compared to signs made from aluminum, which further reduces the cost of sign manufacturing.
Additionally the current invention comprises a pultruded fiberglass sign panel having a cross-section as shown in FIG. 3B, 3C, 8 A, 9 A, 9 B, or 10 . The construction materials of the pultruded fiberglass sign panel are (a) a glass roving; (b) glass reinforcement matt; and (c) a resin matrix, and the total glass content comprises an amount of glass contained in both the glass roving and the glass reinforcement matt. In a preferred embodiment, the glass content of the pultruded fiberglass sign is about 56% to about 58% by weight or about 38% to about 40% by volume. The glass content of the pultruded fiberglass sign is in the range of about 0% to 100% recycled glass, preferably about 16% by weight or 35% by volume of recycled glass. In a second preferred embodiment, the resin matrix comprises thermoset Isophthalic polyester that is about 42% to about 44% by weight or about 60% to about 62% by volume. The resin matrix of the pultruded Fiberglass mat comprises about 5% to about 50% of a recycled resin matrix, preferably about 7% by weight to about 15% by volume of a recycled resin matrix. The glass reinforcement matt used in the pultruded fiberglass sign panel comprises a hybrid E/A glass reinforcement matt. In a third preferred embodiment, the pultruded fiberglass sign panel has a panel width of about 6 inches to about 36 inches, and a length of about 1 foot to about 50 feet.
Generally, pultrusion is a manufacturing process for producing continuous lengths of fiber reinforced polymers (“ FRP”) structural shapes. Raw materials include a liquid resin mixture (containing resin, fillers and specialized additives) and reinforcing fibers. The process involves pulling these raw materials (rather than pushing as is the case in extrusion) through a heated steel forming die using a continuous pulling device. The reinforcement materials are in continuous forms such as rolls of fiberglass mat or doffs of fiberglass roving. As the reinforcements are saturated with the resin mixture (“wet-out”) in the resin impregnator and pulled through the die, the gelation (or hardening) of the resin is initiated by the heat from the die and a rigid, cured profile is formed that corresponds to the shape of the forming die.
While pultrusion machine design varies with part geometry, the basic pultrusion process structures contain rovings, continuous strand mat, guide plates, resin impregnators, surface veils, preformers, forming and curing dies, pulling systems and cut-off saws.
The creels position the reinforcements for subsequent feeding into the guides. The reinforcement must be located properly within the composite and controlled by the reinforcement guides.
The resin impregnator saturates (wets out) the reinforcement with a solution containing the resin, fillers, pigment, and catalyst plus any other additives required. The interior of the resin impregnator is carefully designed to optimize the “wet-out” (complete saturation) of the reinforcements.
On exiting the resin impregnator, the reinforcements are organized and positioned for the eventual placement within the cross section form by the preformer. The preformer is an array of tooling which squeezes away excess resin as the product is moving forward and gently shapes the materials prior to entering the die. In the die the thermosetting reaction is heat activated (energy is primarily supplied electrically) and the composite is cured (hardened).
On exiting the die, the Pultruded profiles is pulled to the saw for cutting to length. It is usually necessary to cool the hot part before it is gripped by the pull block (made of durable urethane foam) to prevent cracking and/or deformation by the pull blocks. There are at least two distinct pulling systems: a caterpillar counter-rotating type and a hand-over-hand reciprocating type.
In certain applications, a radio frequency (“RF”) wave generator can be used to preheat the composite before entering the die. When in use, the RF heater is generally positioned between the resin impregnator and the preformer. RF is generally only used with an all roving part.
Pultruded structures are high strength components, and are typically stronger than structural steel on a pound-for-pound basis. For example, such parts have been used to form the superstructures of multistory buildings, walkways, sub-floors and platforms. Pultrusions are typically about 20-25% the weight of steel and about 70% the weight of aluminum. Pultruded products are easily transported, handled and lifted into place. Total structures can often be preassembled and shipped to the job site ready for installation. Pultruded products will not rot and are impervious to a broad range of corrosive elements. This feature makes pultrusions a natural selection for indoor or outdoor structures in pulp and paper mills, chemical plants, water and sewage treatment plants, structures near salt water and other corrosive environments. Pultruded products are generally transparent to radio waves, microwaves and other electromagnetic frequencies. The coefficient of thermal expansion of pultruded products is slightly less than steel and significantly less than aluminum. Glass fiber reinforced pultrusions exhibit excellent mechanical properties at very low temperatures, even −70° F. Tensile strength and impact strengths are greater at −70° F. than at +80° F. FRP Pultruded profiles are pigmented throughout the thickness of the part and can be made to virtually any desired custom color. Special surfacing veils are also available to create special surface appearances such as wood grain, marble, granite, etc. Glass reinforced pultrusions can also be manufactured from recycled glass.
In a preferred embodiment, a FRP pultruded sign panel, as shown 200 in FIG. 2A, is one panel of the modular system for forming a sign blank in accordance with this invention. Multiple modular sign panels would be provided and joined together to form as large a sign blank as shown in 203 of FIG. 2B or completed information sign 205 of FIG. 2C.
A cross section of a preferred FRP pultruded sign panel blanks can be produced in different widths. FIG. 3B shows a cross-section of a pultrusion panel having two mounting or fastener channels 220 , which can be produced in different widths (e.g. 6, 12, 24 or 36 inches in width). FIG. 3A show an enlarged view of the sign panel edge. FIG. 3C shows a cross-section of a pultrusion panel having a single mounting or fastener channel 220 , which also can be produced in different widths (e.g. about 3-36 inches in width). FIG. 3D shows a perspective view of a pultrusion panel having two mounting channels, and FIG. 3E shows a perspective view of a pultrusion panel having one mounting channels.
from:freepatentsonline