Abstract:
A method of manufacturing a flexible, laminated sheet operable to receive an ink for use as signage includes mixing solidified polyethylene and at least one solidified ink binder together to form a substantially evenly distributed mixture of the same. The method also includes processing the mixture into a flowable coating layer having a substantially even distribution of the polyethylene and the at least one ink binder. Moreover, the method includes coating the coating layer onto a substrate.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. Provisional Application No. 61/325,770, filed on Apr. 19, 2010. The entire disclosure of the above application is incorporated herein by reference. 
     
    
     FIELD 
       [0002]    The present disclosure relates to a sheet for signage and, more particularly, relates to a sheet for signage that includes polyethylene and other materials and a method of manufacturing the same. 
       BACKGROUND 
       [0003]    This section provides background information related to the present disclosure which is not necessarily prior art. 
         [0004]    Many goods include relatively large sheets of flexible material with inks applied thereto. For instance, billboards and banners are often used for advertising, for decorations, etc. Also, other goods, such as tents, gazebos, and temporary shelters include a flexible sheet that is supported above the ground by a rigid frame, and logos, pictures, and other objects can be printed on these sheets of materials. 
         [0005]    Typically, these printed sheets are manufactured by laminating a substrate sheet with multiple layers in several laminating steps. For instance, a single material can be laminated on the substrate, followed by another layer of another material, and so on until the sheet is completed. Then, the fully laminated sheet can be printed with the desired logos, objects, etc. 
         [0006]    Although these sheets and manufacturing processes have been adequate for their intended purposes, certain disadvantages remain. For instance, because there are separate laminating steps, the manufacturing process can be inefficient. More specifically, manufacturing time can be significant because of the separate laminating steps. Also, manufacturing in this manner can use up significant electricity for powering the separate laminating steps. 
         [0007]    Moreover, use of one or more of the components can have a substantial negative environmental impact. For instance, one of the materials to be laminated on the substrate may be in a liquid form and may solidify during the manufacturing process. Once solidified, it may be impossible to re-melt and/or recycle the material. As such, there can be significant waste produced using these methods. 
       SUMMARY 
       [0008]    This section provides a general summary of the disclosure, and is not a comprehensive disclosure of its full scope or all of its features. 
         [0009]    A method of manufacturing a flexible, laminated sheet operable to receive an ink for use as signage is disclosed. The method includes mixing solidified polyethylene and at least one solidified ink binder together to form a substantially evenly distributed mixture of the same. The method also includes processing the mixture into a flowable coating layer having a substantially even distribution of the polyethylene and the at least one ink binder. Moreover, the method includes coating the coating layer onto a substrate. 
         [0010]    A flexible, laminated sheet operable to receive an ink for use as signage is also disclosed. The sheet includes a substrate and a coating layer that is layered on the substrate. The coating layer has a substantially even distribution of a polyethylene and at least one ink binder throughout. The coating layer provides a surface to which the ink can be received. 
         [0011]    A method of manufacturing a flexible, laminated sheet operable to receive an ink for use as signage is further disclosed. The method includes mixing pelletized low density polyethylene (LDPE), at least one pelletized ink binder, and a pelletized whitener together to form a substantially evenly distributed mixture of the same. The at least one pelletized ink binder is chosen from a group consisting of ethylene vinyl acetate (EVA), polyvinyl acetate (PVA), and ethylene methyl methacrylate copolymer (EMMA). The at least one pelletized ink binder makes up between approximately 5% and 25% of the at least one mixture. Also, the method includes extruding the mixture into a flowable coating layer having a substantially even distribution of the polyethylene and the at least one ink binder. Still further, the method includes coating the coating layer onto a substrate made from woven strips of high density polyethylene (HDPE). Additionally, the method includes treating a surface of the coating layer to at least one of coronal discharge and plasma treatment. 
         [0012]    Further areas of applicability will become apparent from the description provided herein. The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure. 
     
    
     
       DRAWINGS 
         [0013]    The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure. 
           [0014]      FIG. 1  is a flowchart of a method of manufacturing a sheet suitable for use as signage according to various exemplary embodiments of the present disclosure; and 
           [0015]      FIG. 2  is a schematic illustration of a cross section of the sheet manufactured using the method of  FIG. 1 . 
       
    
    
       [0016]    Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings. 
       DETAILED DESCRIPTION 
       [0017]    Example embodiments will now be described more fully with reference to the accompanying drawings. 
         [0018]    Referring initially to  FIG. 2 , a schematic illustration of a flexible, laminated sheet  40  is shown. The sheet  40  is shown in cross section and includes a plurality of laminated layers  50 ,  60   a,    60   b,  each of which will be described. Also, the sheet  40  can be suitable for receiving an ink  70 . The ink  70  can be printed or otherwise applied to the sheet  40 . Thus, as will be discussed, the sheet  40  can be used as signage, for instance, as a billboard, as a banner, as a printed sheet included on a gazebo, temporary shelter, etc. Furthermore, as will be discussed, the sheet  40  can be manufactured in an efficient manner. Moreover, the sheet  40  can be manufactured in a way that reduces negative environmental impact. 
         [0019]    As shown, the laminated sheet  40  includes a substrate  50 , a first coating layer  60   a,  and a second coating layer  60   b.  The first coating layer  60   a  is laminated and layered on a first side  56  (top side) of the substrate  50 , and the second coating layer  60   b  is laminated and layered on a second side  58  (bottom side) of the substrate  50 . The first and second sides  56 ,  58  are opposite each other. The ink  70  can be applied (e.g., by printing) to an outer surface  62  of the first coating layer  60   a,  as shown. In additional embodiments, the ink  70  can be applied to the second coating layer  60   b.  Moreover, in some embodiments, the sheet  40  can include only one of the coating layers  60   a,    60   b.    
         [0020]    Referring now to  FIG. 1 , a method of manufacturing the sheet  40  is shown. Beginning in block  10 , the substrate  50  is prepared. The substrate  50  can be formed from solidified HDPE (e.g., HDPE pellets or beads). This solidified HDPE can be processed to become liquid resin or otherwise flowable, for instance, in a known extrusion process. The HDPE can be extruded into a thin, flat sheet, and the sheet can be cut into a plurality of thin, flat, elongate strips  52 ,  54  ( FIG. 2 ) or tapes. These strips  52 ,  54  can then be woven together to form the substrate  50  into a woven sheet. Specifically, the substrate  50  can be woven in a known manner to include weft strips  52  and warp strips  54  that extend across the length and width of the substrate  50 . 
         [0021]    The substrate  50  can have any suitable dimensions. For instance, the substrate  50  can have a width of up to six feet. Also, the strips  52 ,  54  can have any suitable color, such as black or white. Moreover, preparation of the substrate  50  can include stretching of the HDPE material, either before or after being cut into the strips  52 ,  54 . 
         [0022]    It will be appreciated that the HDPE material of the substrate  50  can have a relatively low environmental impact because HDPE can be recycled, for instance. However, it will be appreciated that the substrate  50  could be made from any suitable material. 
         [0023]    Referring back to  FIG. 1 , the method can continue in block  20 , in which the material used for the coating layers  60   a,    60   b  is prepared. Specifically, polyethylene (e.g., low density polyethylene or LDPE), one or more ink binders, and a pigment (e.g., a white pigment or whitener) are mixed. 
         [0024]    The ink binder(s) included in block  20  can be ethylene vinyl acetate (EVA), polyvinyl acetate (PVA), and ethylene methyl methacrylate copolymer (EMMA). These are known materials that allow the ink  70  ( FIG. 2 ) to bind or otherwise join to the coating layer  60   a.  Only one of these ink binders, a combination of these ink binders, or any other ink binders can be used. Also, the ink binder(s) can make up any suitable percentage of the coating layers  60   a ,  60   b.  For instance, in some embodiments, the ink binder(s) can make up between approximately 5% and 25% of each coating layer  60   a,    60   b.    
         [0025]    The pigment (e.g., whitener) used in block  20  can be of any suitable type for affecting the color of the coating layers  60   a,    60   b.  For instance, the pigment can be titanium dioxide (Ti 0   2 ) that makes the coating layers  60   a ,  60   b  substantially white. Also, block  20  can include adding a UV-resisting material, such as 2-Hydroxy-4-n-octoxy-benzophenone (C 21 H 26 O 3 ) to the mixture such that the sheet  40  will be resistant to degradation due to ultraviolet ray exposure. 
         [0026]    In block  20 , one or more of the ingredients can be in a solid state before and during mixture. Specifically, the LDPE, ink binder(s), whitener, and UV-resisting material can each be supplied in solid pellets or beads (i.e., pelletized). Then, these ingredients can be mixed together (e.g., by a drum mixer or other agitator) such that the ingredients become substantially uniformly mixed and evenly distributed. 
         [0027]    Next, in block  25 , the materials previously mixed in block  20  are processed until the mixture is melted and flowable. Specifically, the mixture can be extruded into a flowable resin. The materials can remain substantially uniformly mixed and evenly distributed throughout this flowable resin. 
         [0028]    Subsequently, in block  30 , the coating layers  60   a,    60   b  can be laminated on the substrate  50 . Specifically, the substrate  50  can be fed relative to an extrusion head while the mixture of the coating layer  60   a  flows onto and coats the surface  56  of the substrate  50 . The coating layer  60   a  can then be cured into a substantially continuous layer covering the substrate  50 , and the substantially even distribution of the LDPE, ink binder(s) and other ingredients can remain within the coating layer  60   a.  The coating layer  60   b  can be applied in a similar fashion to the other surface  58  of the substrate  50 . 
         [0029]    It will be appreciated that the coating layers  60   a,    60   b  can be laminated to the substrate  50  in any suitable fashion. For instance, the coating layers  60   a,    60   b  can be sprayed or jetted onto the substrate  50 . Also, heat and/or pressure can also be applied to the sheet  40  in order to adhere and laminate the coating layers  60   a,    60   b  to the substrate  50 . In other embodiments, the substrate  50  and coating layers  60   a,    60   b  can be laminated together using additional adhesives. 
         [0030]    Next, in block  32 , the sheet  40  can be subjected to coronal discharge, plasma treatment, and/or other procedures for increasing the wettability of the sheet  40 . For instance, the surface  62  of the coating layer  60   a  can be subjected to one or more of these processes. As such, the ink can more readily bind, adhere, or otherwise join to the surface  62  of the sheet  40 . 
         [0031]    The sheet  40  can also be subjected to testing and other procedures. For instance, the sheet  40  can be dyne level tested, strength tested, etc. 
         [0032]    Finally, in block  34 , the ink  70  can be applied to the surface  62  of the sheet  40 . The ink  70  can be of any suitable type, such as solvent, water-based, or UV ink. The ink  70  can be printed or applied otherwise. The ink  70  can be applied in a pattern, to form a picture, words, logo, or other object. In some embodiments, the sheet  40  is manufactured in bulk and stored in rolls and shipped to a customer, and the customer cuts a desired length of the sheet  40  before applying the ink  70 . Accordingly, the sheet  40  can be used to display a message or to display any other printed object as a billboard or banner. Also, the sheet  40  can be subsequently attached to a frame or other support structure to both function as a tent, canopy, or shelter as well as display a logo or other object. 
         [0033]    Accordingly, the sheet  40  can be manufactured fairly efficiently. For instance, manufacturing time can be reduced because the ingredients of the coating layers  60   a,    60   b  can be mixed together when in solid form, and the ingredients can be extruded together as an evenly distributed mixture. Thus, less laminating steps may be needed as compared with the prior art. Also, because the ingredients of the coating layers  60   a,    60   b  are mixed together in solid form, these ingredients can be stable, and fairly easy to handle. Still further, obtaining an even mixture of the ingredients can readily achieved. 
         [0034]    In addition, the sheet  40  can have relatively low environmental impact. For instance, the majority of the materials included in the sheet  40  can be polyethylene (HDPE and/or LDPE), which is highly recyclable. The addition of the ink binder(s), whitener, UV-resisting material, and/or other materials can be included in relatively low amounts, such that the materials remain highly recylable. Also, some of the material of the coating layers  60   a,    60   b  may be left over after the sheet  40  has been formed, yet this material can be re-melted and re-used to make other sheets  40  in the future. 
         [0035]    The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. For instance, it will be appreciated blocks  20  and  25  of  FIG. 1  can occur before, during, or after block  10 . Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.