The invention relates to extruded wood fiber winding cores, and more particularly, to an extruded wood fiber winding core equipped with a rigid paperboard coating.
Wood fiber cores are used to support rolls of various materials. Its limited beam strength and durability, however, have hindered its adoption in some industries like industrial belt winding, were the significant weight of the material wound about a core has traditionally been considered to require a steel core. Such steel cores are custom welded geographically close to the place where they will be used since they are bulky and awkward to transport. They are thus very costly.
Other industries, like light weight high tech non-woven materials have rejected such cores due to the friability of the wood fiber material. Dislodged material may damage the non-woven textile.
What is needed, therefore, are techniques for producing a light weight, non-friable, industrial core with a smooth exterior and high beam strength.
One embodiment of the present invention provides a winding core, the winding core comprising: an extruded wood fiber core member; and at least one preformed paper shell member having a split seam parallel to its major axis, the shell being adhered to an exterior surface of the extruded wood fiber core member.
Another embodiment may provide such a core further comprising a second pre-formed paper shell member. In a further embodiment, the split seam of said first pre-formed paper shell member is offset from a split seam of said second pre-formed paper shell member. In yet another embodiment, such an offset is 180 degrees. In a yet further embodiment, that offset is 90 degrees. In even another embodiment, the first preformed paper shell member is between approximately 90/1000 inch-200/1000 inch thick.
The features and advantages described herein are not all-inclusive and, in particular, many additional features and advantages will be apparent to one of ordinary skill in the art in view of the drawings, specification, and claims. Moreover, it should be noted that the language used in the specification has been principally selected for readability and instructional purposes, and not to limit the scope of the inventive subject matter.
In one embodiment of the present invention, illustrated in
The external shell 14 of one embodiment of the present invention, is, as discussed above, configured from paper laminate, comprising layers of liner board that have been wound and formed into a cardboard like material. Examples of such tubes include those used to pour cement columns and footings. The thickness of the tubes may vary depending on the application, but in one embodiment may be approximately 90/1000 inch-200/1000 inch. Multiple layers of tubes may be applied to provide greater thickness of shells, in some instances up to 500/1000 inch to 600/1000 inch. In such embodiments with multiple layers increases in strength are seen in embodiments with staggered seams. The embodiments with greater demands for hoop strength would be provided with seams that are 180° out of phase as in
The shell may in some embodiments be affixed to the exterior of the core through glue or other chemical fastener. In one embodiment, wood glue is used. It has been found that embodiments using higher viscosity glues work well as they fill gaps in the extruded core. In other embodiments the core can be submersed in a bath of thinner bodied glue or resin to permeate the surface of the core and then the shell is applied. Alternative adhesives, such as epoxies or contact cements, may be used in various embodiments.
In embodiments using glues as adhesives, one or more may be applied to the exterior of the shell. The clamps may take the form of a plurality of hose clamps, a compressed air bag system, or a single vacuum bag enclosing the glued unit until the adhesive sets. An even pressure on the exterior of the shell is, according to one embodiment, used.
A method for manufacturing a winding core configured according to one embodiment of the present invention is illustrated in
The applicant has found that the application of a cardboard or paper tube to the exterior of a wood fiber core member yields a unit with high beam strength and minimal friability.
The foregoing description of the embodiments of the invention has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Many modifications and variations are possible in light of this disclosure. It is intended that the scope of the invention be limited not by this detailed description, but rather by the claims appended hereto.
This application is a divisional of U.S. application Ser. No. 14/865,289 filed Sep. 25, 2015 which claims the benefit of U.S. Provisional Application No. 62/055,164, filed Sep. 25, 2014. This application is herein incorporated by reference in its entirety for all purposes.
Number | Date | Country | |
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62055164 | Sep 2014 | US |
Number | Date | Country | |
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Parent | 14865289 | Sep 2015 | US |
Child | 17060512 | US |