MXPA06005370A - Tubular core with polymer plies - Google Patents

Abstract

A tubular core and associated method of manufacture are provided. The tubular core includes at least one inner ply and at least two plastic plies disposed thereon. The inner ply, which can be paper or plastic, has an inner surface upon which identifying indicia are printed, for example, before the tube is formed and while the inner ply is in a flat configuration. The first and second plastic plies are disposed on the inner ply and adhered so that the second plastic ply substantially covers the inner ply and the first plastic ply.

Description

TUBULAR CENTER WITH POLYMER LAYERS BACKGROUND OF THE INVENTION FIELD OF THE INVENTION This invention relates to a tubular center that can be used for winding ribbons, cords, and the like and, more particularly, to a spirally wound tubular center that includes at least one layer of polymer.

DESCRIPTION OF RELATED TECHNIQUES Tubular centers are typically used to support rolled lengths of tape, cord, paper, and the like. Such centers are found in products intended for consumer use, medical applications, manufacturing, and the like. For example, tubular centers are often used to wrap adhesive tape and support the resulting tape roll in a dispenser. A conventional center for adhesive tape is formed by spirally winding a paper layer in a mandrel to form a paper tube. Several layers of paper can be accumulated in the mandrel with an adhesive placed between them in such a way that the resulting tube is rigid. The tube is then cut to form a number of tubular centers, each having a desired length. In addition, the innermost paper layer can be printed before being rolled, for example, with text, other markings, or colors to indicate to the manufacturer of the ribbon, the type of ribbon, and the like. Although widely used, such paper centers are inappropriate or unacceptable for certain applications. For example, the tape for medical applications and clear manufacturing is used in controlled environments where the production of dust associated with the paper centers is undesirable. Paper centers are also generally not clean enough for use in controlled medical environments. In addition, paper centers tend to have no dimensional stability, especially when subjd to stresses or variations of humidity and temperature. Changes in the size of the centers can complicate the winding process, for example, where several paper centers are positioned adjacent to one axis and rotated in unison to roll a ribbon of ribbon at each center. The changes and dissimilarities in the length of the centers can result in a strip of tape that is partially wrapped in more than one center, that is, two adjacent centers, in such a way that the two adjacent centers can not be separated after rolling. Paper centers can also weaken if they are subjd to moisture after rolling. Therefore, the cord or other products rolled in the centers can result in a radial compression load that exceeds the strength of the weakened centers, thus causing the centers to collapse. In addition, many adhesives used for tapes adhere to paper centers. When the innermost end of the ribbon is removed from the center, paper fibers are lifted from the center by the ribbon. Therefore, the end of the tape is generally unusable, and the removal of the tape from the center can cause dust that is unacceptable in some environments. Sometimes extruded or molded plastic centers are used instead of rolls of paper, for example, for adhesive tapes. The plastic centers can be clean and are typically dust-free, even when the tape is completely removed from the center. In addition, plastic centers are generally dimensionally stable along a scale of temperatures and humidity. However, some centers can be difficult to form at precise dimensions by extrusion and injon molding, especially larger centers such as those with an inner diameter of about 76 mm or more. Moreover, it can be difficult to print inside the plastic centers. Therefore, there is a need for a tubular center that can be used to support rolled products such as tape, cord, paper, and the like. The center should be compatible with conventional printing methods so that marks or colors can be placed on it. Preferably, the center should be dimensionally stable when subjd to moisture or other environmental changes. In addition, the center should allow the rolled product to be removed without generating dust or other unacceptable debris.

BRIEF DESCRIPTION OF THE INVENTION The present invention provides a tubular center and the associated manufacturing method. The tubular center includes at least one internal layer and at least two plastic layers placed on it. The inner layer, which can be formed of paper or plastic, has an inner surface on which identification marks are printed, for example, while the inner layer is in a flat configuration. The first plastic layer is placed on the inner layer and adhered to it, and the second plastic layer is placed on the first plastic layer in such a way that the second plastic layer substantially covers the inner layer and the first plastic layer. The plastic layers can reduce or eliminate the creation of dust during the use of the product and can provide a release surface from which the product can be removed. In accordance with one embodiment of the present invention, one or both plastic layers are formed of polystyrene. The plastic layers can be a deformable foam and each have a thickness of about 0.5 mm, for example, with these plastic layers forming about 75-85% of the thickness of the center. The first layer can cover the outer surface of the inner layer, and each of the inner layer and the first plastic layer can define helical seams that are covered by the first and second plastic layers, respectively. In addition, the layers can be adhered by adhesives or welding.

The present invention also provides a method for manufacturing a tubular center for receiving a product rolled therein. A first side of at least one inner layer is imprinted with identification marks, and the inner layer is then spirally wound on a mandrel extending in a longitudinal direction such that the inner layer forms a tubular body. A first plastic layer is spirally wound on an outer surface of the inner layer and adhered thereto. A second plastic layer is spirally wound on an outer surface of the first plastic layer such that the second plastic layer substantially covers the inner layer and the first plastic layer, and the second plastic layer adheres to the first plastic layer. The outer surface of the inner layer can be covered with the first plastic layer and the second plastic layer can at least partially overlap a helical seam of the first plastic layer. The plastic layers can be adhered with an adhesive or by welding.

BRIEF DESCRIPTION OF THE DRAWINGS Having thus described the invention in general terms, reference will now be made to the accompanying drawings, which are not necessarily drawn to scale, and wherein: Figure 1 is a perspective view illustrating a tubular center in accordance with an embodiment of the present invention; Figure 2 is a perspective view illustrating a tubular center formed of a portion of the center shown in Figure 1, and on which tape has been wound; and Figure 3 is an aerial view illustrating the tubular center of Figure 1 during manufacture in accordance with an embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the invention are shown. This invention may, however, involve modalities in different ways and should not be restricted to the modalities set forth herein; rather, these embodiments are provided so that this description is detailed and complete, and will fully convey the scope of the invention to those skilled in the art. Similar numbers refer to similar elements throughout this document. Referring now to the figures, and in particular to Figure 1, a tubular center 10 according to one embodiment is shown. The tubular center 10 can be used for a variety of applications, including supporting a product that is rolled over it. For example, the adhesive tape 50 (Figure 2), paper, other webs, cord, yarn, other textiles and the like can be wound onto the center 10. The center 10 can be provided in a variety of lengths according to the application. Therefore, as shown in Figure 2, the center 10 can be cut into smaller portions, for example, between 3.2 and 101.6 mm in length, to correspond with the width of the adhesive tape 50 or another product that is rolled over the center 10. An inner layer 20 of the center 10 is imprinted with identification marks 22 such as words, symbols, portions of one or more colors, and the like. The identification marks 22 can identify the manufacture of the center 10 or the product provided therein, the type or characteristics of the product, and the like. The inner layer 20 can be formed from a variety of materials including paper, such as paperboard or a multilayer paper laminate. Alternatively, the inner layer 20 may be formed of plastics including, but not limited to, polystyrene, such as polystyrene foam. Each center 10 has at least two plastic layers 30, 40 placed on the inner layer 20. The plastic layers 30, 40 can be formed of numerous plastics such as polystyrene. The thickness of the layers 20, 30, 40 may vary. In one embodiment, the combined thickness of the plastic layers 30, 40 is between about 75% and 85% of the total thickness of the layers 20, 30, 40. For example, as illustrated in Figure 2, the inner layer 20 is paper having a thickness between about 0.23 and 0.30 mm, and each of the plastic layers 30, 40 is formed of polystyrene foam having a thickness of about 0.5 mm.

The plastic layers 30, 40 may be dimensionally stable, that is, the plastic does not expand, contract, or otherwise deform substantially as a result of moisture, temperature variations, and other environmental conditions. However, where polystyrene foam or other expanded polymers are used, the layers 30, 40 may be slightly deformable. Thus, the centers 10 may be compressed or slightly expanded during manufacture and during the subsequent rolling of the product thereon. Further, if the center 10 is subjected to humidity or temperature variations after the tape 50 or other product material is wound on it, and the inner layer 20 or the rolled product expands or contracts, the plastic layers 30 , 40 deformables can be compressed or expanded accordingly. Alternatively, the layers 30, 40 may be formed of plastic that is sufficiently non-deformable to withstand such dimensional changes. The plastic layers 30, 40 can be substantially free of dust and debris. The centers 10 can also be clean enough for use in medical or manufacturing environments. In addition, the second plastic layer 40 can be formed of a plastic from which the product is easily removed in such a way that an outer surface of the layer 40 provides a release layer for the removal of the product. Depending on the requirements of the particular application for the center 10, the inner layer 20 can also be formed of paper or plastic that is substantially free of dust.

Figure 3 illustrates a center 10 during training in accordance with one embodiment of the present invention. The inner and plastic layers 20, 30, 40 can be provided in rolls (not shown) and placed in successive positions on a mandrel 60 having an axis extending in a longitudinal direction. A spiral winding belt 70 can be used to rotate the center 10 around the mandrel, thereby winding the layers 20, 30, 40 in the mandrel 60 and pushing the center 10 in the longitudinal direction along the mandrel 60, this is, to the right as shown in Figure 3. The formed center 10 is continuously pushed towards an end (not shown) of the mandrel 60 during forming. A printing device 64 is provided for printing the identification markings 22 on an inner surface 24 of the inner layer 20 before the layer 20 is spirally wound. The inner layer 20 can be printed together with the winding, as shown in Figure 3, or the layer 20 can be printed at a remote location separate from the winding operation. In any case, the inner layer 20 is printed before it coils the layer 20, for example, while the inner layer 20 is in a flat configuration. Thus, the marks 22 can be printed on the inner layer 20 using conventional printing devices and methods. The marks 22 can be a repeating pattern that is printed in successive places in the layer 20 so that if the center 10 is cut to form a number of shorter centers 10, the information provided by the marks 22 will be in each center 10. The inner layer 20 is spirally wound on the mandrel 60 in such a way that the inner surface 24 is directed towards the mandrel 60 and an outer surface 26 of the inner layer 20 is directed away from the mandrel 60. The first plastic layer 30 it is spirally wound on the mandrel 60 and therefore placed on the inner layer 20 in such a way that an external surface 32 of the first plastic layer 30 is opposite to the inner layer 20. The second plastic layer 40 is also spirally wound on the mandrel 60 and therefore is placed on the outer surface 32 of the first plastic layer 30. The plastic layers 30, 40 are placed in the mandrel 60 in a stepped configuration. For example, an interface or helical seam 28 formed between successive coils of the inner layer 20 can be covered by the first plastic layer 30. Similarly, a helical seam 34 formed between successive coils of the first plastic layer 30 can be covered with the second plastic layer 40. The first plastic layer 30 can be positioned to substantially completely cover the inner layer 20, and the second plastic layer 40 can be positioned to substantially completely cover the inner layer 20 and the first plastic layer 30. The layers 20, 30, 40 shown in FIG. Figure 3 are equal in width, and each is wound on the mandrel 60 without substantial space between successive coils; however, in other embodiments, the layers 20, 30, 40 may have different widths and / or may be wound with gaps or overlaps in the seams of successive windings. Layers 20, 30, 40 adhere to one another, for example, by adhesive or welding. As shown in Figure 3, an applicator 66 is provided to apply a glue or other adhesive to the first plastic layer 30. The applicator 66 can be configured to apply the spray adhesive, rolls or other method to an internal surface 36 of the first plastic layer 30. A second applicator (not shown) may be provided to apply adhesive to the outer surface 32 of the first plastic layer 30 or an inner surface of the second plastic layer 40. Alternatively, the layers 20, 30, 40 may adhere by welding. For example, a heater 68, such as a gas or electric heating device, is provided for heating the second plastic layer 40 while the plastic layer 40 passes therethrough. Therefore, the second plastic layer 40 is softened or partially melted and placed on the first plastic layer 30. In other embodiments of the present invention, the layers 20, 30, 40 can adhere using other configurations of adhesives and solders. Additionally, it is understood that the adhesive can be applied in other ways, for example, to either or both of the adhered surfaces of the layers 20, 30, 40, or as a film placed between the layers 20, 30, 40. The belt Spiral winding 70 can be used to compress the layers 20, 30 40 in the mandrel 60 and push the center 10 along the mandrel 60. As illustrated in Figure 3, each of the layers 20, 30, 40 can be winding on the mandrel upwards of the winding belt 70, that is, towards the left of the belt 70 as shown in figure 3, in such a way that the belt 70 pulls the layers 20, 30, 40 along the mandrel 60 Alternatively, one or more of the plastic layers 30, 40 can be wound onto the mandrel 60 down the belt 70. Before or after the center 10 is pushed from an end (not shown) of the mandrel 60, the tube 10 can Cut into desired lengths. Each resulting center 10 can then be wound with tape, cord, or other products, or used in some other way. Modifications and other embodiments of the invention will occur to those skilled in the art to which this invention pertains having the benefit of the teachings presented in the foregoing descriptions and appended drawings. For example, it is understood that additional layers of paper, plastic, or other materials can be placed on the mandrel 60 during the forming process shown in Figure 3 so that the center 10 includes more than three layers. In addition, each of the layers 20, 30, 40 can be formed from a variety of thermosetting and thermoplastic materials including polystyrene, polyethylene, polypropylene, and the like. Therefore, it should be understood that the invention should not be limited to the specific embodiments described and that modifications and other embodiments are intended to be included within the scope of the appended claims. Although specific terms were used here, they were used in a generic and descriptive sense only and not for purposes of limitation.

Claims (20)

NOVELTIES OF THE INVENTION CLAIMS

1. A tubular center for receiving a product wound thereon, the center comprising: at least one inner layer wound in a spiral about a longitudinal axis to form a tubular body having an inner surface and an outer surface, where the inner surface of the inner layer is imprinted with identification marks; a The first plastic layer wound spirally around the outer surface of the inner layer and adhered to the inner layer, the first plastic layer has an outer surface disposed opposite to the inner layer, wherein the first plastic layer completely covers the surface outside of the inner layer; and a second plastic layer wound in a spiral around 15 the outer surface of the first plastic layer and adhered to the first plastic layer, the second plastic layer substantially covers the inner layer and the first plastic layer.

2. The tubular center according to claim 1, further characterized in that the inner layer and the first and second layers -20 plastics are spirally wound in such a way that each layer defines a helical seam and the second plastic layer at least partially overlaps the seam defined by the first plastic layer.

3. The tubular center according to claim 1 or 2, further characterized in that the inner layer is paper.

4. The tubular center according to claim 1 or 2, further characterized in that the inner layer is plastic.

The tubular center according to claim 1 or 2, further characterized in that at least one of the first and second plastic layers is formed by a polymer foam.

The tubular center according to claim 1 or 2, further characterized in that at least one of the first and second plastic layers is polystyrene.

The tubular center according to claim 1 or 2, further characterized in that the first plastic layer is adhered to the inner layer with an adhesive and the second plastic layer is adhered to the first plastic layer with an adhesive.

The tubular center according to claim 1 or 2, further characterized in that the second plastic layer is adhered to the first plastic layer by welding.

9. The tubular center according to claim 1 or 2, further characterized in that each of the first and second plastic layers has a thickness of at least 0.5 mm.

The tubular center according to claim 1 or 2, further characterized in that the combined thickness of the plastic layers is between about 75% and 85% of the combined thickness of the at least one inner layer and the plastic layers.

11. A method for manufacturing a tubular center for receiving a product wound thereon, the method comprising: printing a first side of at least one inner layer with identification markings; coiling the at least one inner layer on a mandrel extending in a longitudinal direction such that the inner layer forms a tubular body with the first side positioned radially inward to form an inner surface and having an outer surface opposite to the inner surface; coiling a first plastic layer on the outer surface of the inner layer and adhering the first plastic layer thereto, the first plastic layer having an outer surface opposite to the inner layer, wherein the first plastic layer completely covers the surface outside of the inner layer; and spirally winding a second plastic layer on the outer surface of the first plastic layer and adhering the second plastic layer thereto such that the second plastic layer substantially covers the inner layer and the first plastic layer.

12. The method according to claim 11, further characterized in that it comprises providing a paper layer as the inner layer.

The method according to claim 11, further characterized in that it comprises providing a plastic layer as the inner layer.

The method according to claim 11, further characterized in that it comprises providing a polystyrene layer as at least one of the first and second plastic layers.

15. The method according to claim 11, further characterized in that it comprises deforming at least one of the first and second plastic layers during winding.

The method according to claim 11, further characterized in that said second spiral winding step comprises completely covering the outer surface of the inner layer with the first plastic layer.

17. The method according to claim 11, further characterized in that said third step of spiral winding comprises placing the second plastic layer that at least partially overlaps a helical seam of the first plastic layer. The method according to claim 11, further characterized in that said second and third spiral winding steps comprise adhering the first plastic layer to the inner layer with an adhesive and adhering the second plastic layer to the first plastic layer with an adhesive . The method according to claim 11, further characterized in that said second and third spiral winding steps comprise adhering the first plastic layer to the inner layer by welding and adhering the second plastic layer to the first plastic layer by welding. The method according to claim 11, further characterized in that it comprises providing the first and second plastic layers, each having a thickness of at least 0.5 mm.