The present invention relates generally to stamping methods for forming a part. More particularly, the present invention relates to a method and apparatus for forming via stamping a polycarbonate panel for use with a storm protection system.
Polycarbonate panels for covering a window or other opening to a window to prevent storm damage are known. These panels are created by extruding a plastic or similar material to form a corrugated panel. The extrusion method and apparatus requires expensive dies and extrusion systems to create a panel. Furthermore, the extrusion method does not allow the user to preselect the size of the finished panel.
Corrugated panels, versus flat panels, add strength and resiliency to the panels in the event of high winds, rain, sleet, and debris during a storm. These panels are typically affixed over a window or other building opening to resist the wind, rain, sleet, and debris during a storm. The corrugated panels may be fixed or removable over the building openings.
Thermoforming is also a known method of forming a corrugated panel for a hurricane protection system. However, Thermoforming required high temperatures (250 degrees or more) and does not provide for allowing application or installation of any protection layer.
Accordingly, there exists a need in the art to provide a method and apparatus for creating a corrugated panel having sufficient resiliency and strength to withstand a storm while simultaneously minimizing waste during the manufacturing process.
A method for forming a polycarbonate panel is provided. The method comprising the steps of cutting a flat polycarbonate panel to the desired final dimensions, inserting the panel between the two portions of a die, forming the panel by means of compression between the two portions of the die, overbending the panel between 1-12 degrees to achieve a predetermined angle of bends in the panel and repeating these steps until the panel is fully corrugated. The method further includes the steps of heating the die and/or the panel by means of an electric strip temperature of between 100-110 degrees Fahrenheit.
The die assembly is automatically adjustable and connected to a controller for adjustment. The controller is in communication with the die and an actuator to move and adjust the plate and portions of the die assembly to achieve the desired finished product. The method further includes the step of stretching the polycarbonate within the die to improve strength and resiliency and adding corner pockets and sub-molds in the die. The method further comprising the step of applying polyethylene film to the panel before forming the panel, forming the panel with the polyethylene film positioned thereon. A spring plate may be provided to align the panel and to prevent slipping of the panel during forming. The method may further comprise the step of gas plasma treating the surface of the polycarbonate panel before forming. The lower required temperature for forming (100-110 degrees Fahrenheit) does not (or at least minimally) alter the properties of the polycarbonate thus improving strength and resiliency.
An apparatus is also provided for forming a polycarbonate panel. The panel is adapted for mounting over an opening to a building for protection during inclement weather. The apparatus includes a die where the die includes a first portion and a second portion. The die being automatically adjustable in height and width. The first portion and the second portion movable with respect to each other and the first portion and the second portion operable to compress a panel to form a bend in the panel. A heater is connected to the apparatus operable to slightly raise the temperature of the panel and/or the die to a predetermined temperature slightly above ambient temperature, the heater operable to raise the temperature of the panel and/or the die to between 100-110 degrees Fahrenheit. The first portion and the second portion of the die are both dimensioned 1-12 degrees over than the desired final bend angle of the finished bend in the panel to accommodate for the polycarbonate relaxing when at room temperature. A cooler may also be provided to cool either the die and/or the panel to a predetermined temperature of between 100-110 degrees Fahrenheit. The die may include at least one sub-mold, corner pocket and corresponding protrusion to facilitate stretching of the polycarbonate panel during forming. A spring plate is provided to facilitate alignment of the panel during forming and to prevent slippage of the panel during forming. A plasma treating apparatus may also be provided to apply gas plasma to the die before forming.
The described method and apparatus is unique when used with polycarbonate and polyethylene film. Polycarbonate normally requires a temperature of over 250 degrees Fahrenheit to properly bend. The above mentioned method and apparatus do not require such a high temperature. This high temperature require expending extra energy and time for the panel and/or dies to reach such a high temperature. Overbending of the present invention does not require such a high temperature (the current method only requires a temperature of 100-110 degrees Fahrenheit). The lower temperature requirement, because of the overbending unique to polycarbonate, is less costly and time consuming to the user. Accordingly, this method and apparatus provided for unexpected results when used specifically with polycarbonate (and a polyethylene film).
The present invention provides for a method and apparatus for forming a corrugated panel by using over bending to achieve the desired angle. The method achieves the finished desired angle by over bending the polycarbonate panel by 1 to 12 degrees over the finished desired angle. Heating and/or cooling may be used to adjust the temperature to a temperature of approximately 100 to 110 degrees. Stretching occurs between the press which increases the strength of the polycarbonate panel thus improving performance. Stretching may also occur at the sub-molds or at the corner pockets and corresponding protrusions. A flat piece of polycarbonate material is first cut to the desired finished size and the pressing occurs after the cutting to reduce waste. This allows for customization of the panel size to the user. Rolls of polycarbonate material are obtained in 450 to 650 feet lengths. These rolls are obtained when the polycarbonate is in a flat configuration. The polycarbonate material is then cut to the desired finished size to accommodate the window or other opening within a building and customized to the specific size. Cutting before forming provides for dramatically reduced waste as compared to cutting the panel after the corrugation forming process. Waste on shorter length materials is reduced in the 8 to 10% range, while waste of the 400 to 650 foot rolls is reduced to nearly zero.
As shown by
The second portion 114 includes an upper portion 140 and a lower portion 142. A side portion 144 is also provided configured allowing the pressing apparatus to hold the second portion 114. An interior portion 162 is provided having a surface 148 configured to connect with the surface 132 of the first portion 112. Again, over bending of 1 to 12 degrees is provided in the die to facilitate a correct finished angle of the panel.
A spring plate 150 is provided having an interior cavity 152 and a spring 154. The spring plate 150 is provided having a pressing member 156 in connection with the surface 148 of the second portion 114. The spring plate and spring apparatus is adapted to facilitate removal of the panel from the die 100 after the pressing is complete. In alternative embodiments, the spring 154 may be a hydraulic actuator or other form of spring. The second portion 114 of the die 100 further includes interior surfaces 146 operable to connect with the outer angled surface 122 of the first portion 112 of the die 100. The die 100 also includes submolds or corner pockets 130. The corner pockets 130 are provided at a middle lower portion of the first portion 112 of the die 100 which corresponds to a protrusion 131 of the second portion 114 of the die 100. These corner pockets facilitate stretching of the polycarbonate within the die 100 during pressing. It should be noted that the die may have a plurality of protrusions and depressions such as shown at 130, 131 (submolds) to achieve a corrugated polycarbonate panel in less time. A die having a plurality of submolds will have the same arches, geometry, corner pockets, etc. as adjacent submolds.
The spring plate 150 is operable to create an opposite force of the mold against the polycarbonate panel during the forming process to align the panel and keep the panel from slipping. The protrusions or submolds 130, 131 also facilitate in aligning the panel and keeping the panel from slipping. The spring plate 150 is used in connection with the arch as illustrated at surface 148 to create a planar/flat portion of the finished corrugated polycarbonate panel. As shown in
The apparatus and method includes inserting the panel into the assembly one or more times to achieve the desired radius and profile. Over bending of the polycarbonate is required to achieve the desired final angle. By way of example, a bend in the die 100, or any of the other dies mentioned below, of 85 degrees is necessary to achieve a final radius of 60 degrees in the panel. Greater bending angles can be achieved by pre-arching the polycarbonate in the opposite direction but not to the point that it will permanently set. The pre-arch, as illustrated by surface 148 of
The method includes the steps of cutting a roll of polycarbonate material to the finished size of the shutter to cover a window or other opening of a building. The method then includes the step of heating or cooling the panel and bending the die to the desired stable temperature. The temperature increase/decrease will not drastically but rather only vary within 5 to 30 degrees of the ambient temperature in an effort to keep the system stable. Other methods require increasing the polycarbonate temperature up to 250 degrees and dried of all moisture before forming. The present invention only requires the temperature to be just above ambient at 100 to 110 degrees Fahrenheit. Slightly warming ensures consistent bending. Cold bending of the polycarbonate can cause fractures in the bent area. Furthermore, it is recommended that the material only be radiused to 100 times its thickness.
The present invention only requires a stable temperature of 100 to 110 degrees Fahrenheit. Since the angle of the bend only partially depends on the plastic temperature, the present invention only requires a minimal temperature increase.
The dies as illustrated in
The method may then include the step of plasma treating the surface of the area to be bent before the forming. The plasma surface treating takes place before the bending and before forming changes the surface tension as well as super cleaning the area allowing the empty peaks and valleys to fold within each other and create a fracture free reinforced corner.
The inclusion of a plasma process before, during, or after the die molding process is advantageous. Gas plasma allows for molecular engineering of materials to impart unique characteristics and surface properties without affecting the bulk properties of the whole material. The use of plasma in the forming of polycarbonate panels changes the surface characteristic such as changing in biocompatibility, surface energy, morphology, texture, and absorption.
The next step of the method includes compressing to form ribs or corrugation of the surface of the polycarbonate. The step includes compression of the bent area completely around the radius and/or in specific areas to create one or more compressed ribs thus creating the corrugated look. The compressing/bending requires 50 to 100 tons of pressure. The pressure will add additional heat to the bent/stretched area. This process and method creates a fracture free reinforced bent area. The maximum angle before fractioning and weakening is dependent on the material temperature, die temperature, compressing temperature, thickness of the material, and final desired angle.
The method of the present invention allows a user to make panels with any width panel, height of wave, width of wave, and frequency of the wave. Each of the dies as illustrated in
The amount of deflection that a hurricane panel, such as those illustrated in
The final panel may also include aperture and/or apertures with grommets to reinforce the apertures.
The above described method and apparatus is unique when used with polycarbonate and polyethylene film. Polycarbonate normally requires a temperature of over 250 degrees Fahrenheit to properly bend. The above mentioned method and apparatus do not require such a high temperature. This high temperature require expending extra energy and time for the panel and/or dies to reach such a high temperature. Overbending of the present invention does not require such a high temperature (the current method only requires a temperature of 100-110 degrees Fahrenheit). The lower temperature requirement, because of the overbending unique to polycarbonate, is less costly and time consuming to the user. Accordingly, this method and apparatus provided for unexpected results when used specifically with polycarbonate (and a polyethylene film).
The present apparatus and method allow the user to apply the film to the polycarbonate panel. Traditional stamping methods requires significantly higher temperatures (250 degrees or more). These traditional methods will melt the polyethylene film used for protection on the polycarbonate panel. Since the present invention utilizes overbending and only raising the temperature slightly (100-110 degrees Fahrenheit), the polyethylene film can be applied before forming. Accordingly, the present invention offers significant improvements over the prior art.
The overbending of the panel allows the user to use a lower temperature during forming. The overbending requires the die to be 1-12 degrees over the desired finished angle of the panel. After the panel is allowed to sit for 24 hours, the panel will reach it's final predetermined dimension. By way of example,
The invention is not restricted to the illustrative examples and embodiments described above. The embodiments are not intended as limitations on the scope of the invention. Methods, apparatus, compositions, and the like described herein are exemplary and not intended as limitations on the scope of the invention. Changes therein and other uses will occur to those skilled in the art. The scope of the invention is defined by the scope of the appended claims.
This application claims priority of U.S. Provisional Application 61/836,346 filed Jun. 18, 2013, the contents of which are incorporated herein by reference.
Number | Date | Country | |
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61836346 | Jun 2013 | US |