Rebar Tie Wire with Bonded Coating and Method of Making the Same

This application is filed under 35 U.S.C. § 120 as a divisional of U.S. Patent Application No. 17/822,270, filed on August 25, 2022, which application is incorporated herein by reference in its entirety.

The present disclosure relates to rebar tie wire, and more particularly, rebar tie wire with a coating comprising a bonding agent.

Rebar (short for reinforcing bar), known when massed as reinforcing steel or reinforcement steel, is a steel bar used as a tension device in reinforced concrete and reinforced masonry structures to strengthen and aid the concrete under tension. Concrete is strong under compression, but has weak tensile strength. Rebar significantly increases the tensile strength of the structure. Rebar's surface features a continuous series of ribs, lugs, or indentations to promote a better bond with the concrete and reduce the risk of slippage. The most common type of rebar is carbon steel, typically consisting of hot-rolled round bars with deformation patterns embossed into its surface. A rebar network or cage is formed wherein rebar is arranged in, for example, a plurality of crossing patterns. The various pieces of rebar are secured or tied together with steel wire, sometimes using an electric rebar tier. Once secured, concrete is poured over the rebar cage.

However, since the rebar and the tie wire is typically formed of carbon steel, both are susceptible to corrosion, for example, due to the water content in the concrete or water leakage through the concrete. A common problem among known rebar systems is that corrosion of the uncoated rebar results in corrosion and failure of the rebar tie wire, and thus failure of the entire rebar system. Furthermore, when using epoxy-coated rebar, the steel tie wire cuts into the epoxy coating forming apertures through which water and other corrosive elements can access the steel rebar.

Thus, there is a long felt need for a rebar tie wire that resists corrosion from both the rebar itself and other corrosive elements, and does not damage coated rebar.

The present disclosure is directed to one or more exemplary embodiments of a method of manufacturing a rebar tie wire.

In an exemplary embodiment, the method of manufacturing the rebar tie wire, may comprise heating and mixing a high density polyethylene (HDPE), a bonding agent, and a coloring agent to form a mixture, heating an inner wire portion, coating the inner wire portion with the mixture to form a coated inner wire portion, and quenching the coated inner wire portion.

In an exemplary embodiment, the mixture comprises at least 85% HDPE by weight. In an exemplary embodiment, the mixture comprises at least 85% HDPE by weight, and at least 3% bonding agent by weight. In an exemplary embodiment, the bonding agent is a reactive adhesive. In an exemplary embodiment, the bonding agent is an anhydride modified high density polyethylene.

In an exemplary embodiment, the step of heating the inner wire portion comprises heating the inner wire portion to a temperature in the range of 280°F to 350°F. In an exemplary embodiment, the step of heating the inner wire portion comprises heating the inner wire portion to a temperature in the range of 320°F to 340°F. In an exemplary embodiment, the step of heating the inner wire portion comprises heating the inner wire portion to a temperature of at least 300°F.

In an exemplary embodiment, the method further comprises, prior to the step of heating the inner wire portion, cleaning the inner wire portion. In an exemplary embodiment, the method further comprises, prior to the step of heating the inner wire portion, applying a lubricant to the inner wire portion. In an exemplary embodiment, the lubricant is selected from the group consisting of neat oil, water-miscible solvent, and solution synthetic lubricant. In an exemplary embodiment, the step of coating the inner wire portion with the mixture to form the coated inner wire portion comprises applying the mixture to the inner wire portion at a temperature in the range of 400°F to 500°F.

The present disclosure is directed to one or more exemplary embodiments of a method of manufacturing a rebar tie wire.

In an exemplary embodiment, the method of manufacturing the rebar tie wire may comprise heating and mixing a high density polyethylene (HDPE) and a bonding agent to form a mixture, heating an inner wire portion, coating the inner wire portion with the mixture to form a coated inner wire portion, and quenching the coated inner wire portion.

In an exemplary embodiment, the mixture comprises at least 85% HDPE by weight. In an exemplary embodiment, the bonding agent is a reactive adhesive. In an exemplary embodiment, the bonding agent is an anhydride modified high density polyethylene. In an exemplary embodiment, the step of heating the inner wire portion comprises heating the inner wire portion to a temperature in the range of 280°F to 350°F. In an exemplary embodiment, the method further comprises, prior to the step of heating the inner wire portion, applying a lubricant to the inner wire portion. In an exemplary embodiment, the step of coating the inner wire portion with the mixture to form the coated inner wire portion comprises applying the mixture to the inner wire portion at a temperature in the range of 400°F to 500°F.

The present disclosure is directed to one or more exemplary embodiments of a method of manufacturing a rebar tie wire.

In an exemplary embodiment, the method of manufacturing the rebar tie wire may comprise heating and mixing a high density polyethylene (HDPE) and a bonding agent to form a mixture, wherein the mixture comprises at least 85% HDPE by weight, heating an inner wire portion, and coating the inner wire portion with the mixture to form a coated inner wire portion.

According to aspects illustrated herein, there is provided a rebar tie wire, comprising an inner wire portion including a radially outward facing surface, and a coating arranged on the radially outward facing surface, the coating including HDPE, and a bonding agent.

In some embodiments, the coating further comprises a coloring agent. In some embodiments, the coating comprises at least 90% HDPE by weight, and at least 3% bonding agent by weight. In some embodiments, the coating comprises at least 85% HDPE by weight, at least 3% bonding agent by weight, and at least 3% coloring agent by weight. In some embodiments, the coating comprises 90% HDPE by weight, 5% bonding agent by weight, and 5% coloring agent by weight. In some embodiments, the coating comprises at least 90% HDPE by weight, and at least 3% bonding agent by weight. In some embodiments, the coating is bonded to the inner wire portion. In some embodiments, the coating consists of the HDPE and the bonding agent. In some embodiments, the coating consists of the HDPE, the bonding agent, and the coloring agent. In some embodiments, the bonding agent is a reactive adhesive. In some embodiments, the bonding agent is an anhydride modified high density polyethylene. In some embodiments, the bonding agent is FUSABONDE265 anhydride modified high density polyethylene.

According to aspects illustrated herein, there is provided a rebar tie wire, comprising an inner wire portion including a radially outward facing surface, and a coating bonded to the inner wire portion, the coating comprising HDPE, a bonding agent, and a coloring agent.

In some embodiments, the coating consists of 90% HDPE by weight, 5% bonding agent by weight, and 5% coloring agent by weight. In some embodiments, the coating comprises at least 85% HDPE by weight, at least 3% bonding agent by weight, and at least 3% coloring agent by weight. In some embodiments, the coating comprises 90% HDPE by weight, 5% bonding agent by weight, and 5% coloring agent by weight. In some embodiments, the coating comprises at least 90% HDPE by weight, and at least 3% bonding agent by weight. In some embodiments, the bonding agent is a reactive adhesive. In some embodiments, the bonding agent is an anhydride modified high density polyethylene.

According to aspects illustrated herein, there is provided a method of manufacturing rebar tie wire, comprising heating and mixing a HDPE, a bonding agent, and a coloring agent to form a mixture, heating an inner wire portion, coating the inner wire portion with the mixture to form a coated inner wire portion, and quenching the coated inner wire portion.

These and other objects, features, and advantages of the present disclosure will become readily apparent upon a review of the following detailed description of the disclosure, in view of the drawings and appended claims.

At the outset, it should be appreciated that like drawing numbers on different drawing views identify identical, or functionally similar, structural elements. It is to be understood that the claims are not limited to the disclosed aspects.

Furthermore, it is understood that this disclosure is not limited to the particular methodology, materials and modifications described and as such may, of course, vary. It is also understood that the terminology used herein is for the purpose of describing particular aspects only, and is not intended to limit the scope of the claims.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood to one of ordinary skill in the art to which this disclosure pertains. It should be understood that any methods, devices or materials similar or equivalent to those described herein can be used in the practice or testing of the example embodiments.

It should be appreciated that the term "substantially" is synonymous with terms such as "nearly," "very nearly," "about," "approximately," "around," "bordering on," "close to," "essentially," "in the neighborhood of," "in the vicinity of," etc., and such terms may be used interchangeably as appearing in the specification and claims. It should be appreciated that the term "proximate" is synonymous with terms such as "nearby," "close," "adjacent," "neighboring," "immediate," "adjoining," etc., and such terms may be used interchangeably as appearing in the specification and claims. The term "approximately" is intended to mean values within ten percent of the specified value.

It should be understood that use of "or" in the present application is with respect to a "non-exclusive" arrangement, unless stated otherwise. For example, when saying that "item x is A or B," it is understood that this can mean one of the following: (1) item x is only one or the other of A and B; (2) item x is both A and B. Alternately stated, the word "or" is not used to define an "exclusive or" arrangement. For example, an "exclusive or" arrangement for the statement "item x is A or B" would require that x can be only one of A and B. Furthermore, as used herein, "and/or" is intended to mean a grammatical conjunction used to indicate that one or more of the elements or conditions recited may be included or occur. For example, a device comprising a first element, a second element and/or a third element, is intended to be construed as any one of the following structural arrangements: a device comprising a first element; a device comprising a second element; a device comprising a third element; a device comprising a first element and a second element; a device comprising a first element and a third element; a device comprising a first element, a second element and a third element; or, a device comprising a second element and a third element.

Moreover, as used herein, the phrases "comprises at least one of' and "comprising at least one of' in combination with a system or element is intended to mean that the system or element includes one or more of the elements listed after the phrase. For example, a device comprising at least one of: a first element; a second element; and, a third element, is intended to be construed as any one of the following structural arrangements: a device comprising a first element; a device comprising a second element; a device comprising a third element; a device comprising a first element and a second element; a device comprising a first element and a third element; a device comprising a first element, a second element and a third element; or, a device comprising a second element and a third element. A similar interpretation is intended when the phrase "used in at least one of:" is used herein.

Adverting now to the figures, FIG.is a perspective view of rebar cage. As shown, rebar cagecomprises a plurality of reinforcing bars (i.e., rebar)tied together via a plurality of rebar tie wire or wires.

Reinforcing barsarranged to intersect, forming joints. In some embodiments, reinforcing barsare arranged substantially perpendicular to each other. In some embodiments, and as shown, reinforcing barsvary in diameter. In some embodiments, reinforcing barscomprise a constant diameter. It should be appreciated that, while reinforcing barsare shown having no coating, in some embodiments reinforcing barscomprise a coatings, for example, epoxy.

Each jointcomprises at least two reinforcing barsintersecting. At each joint, reinforcing barsare secured or tied together via rebar tie wire. Rebar tie wireis wrapped around the at least two reinforcing barsand tied, thereby securing the reinforcing bars. This process is repeated throughout rebar cagethereby forming a structure over which concrete is poured. The rebar tie wiremay be tied using an electric rebar tier, for example, a MAX USARB398 rebar tier. In some embodiments, reinforcing barscomprise one or more protrusions and/or textured radially outward facing surfaces.

is a cross-sectional view of rebar tie wiretaken generally along line 2-2 in. Rebar tie wirecomprises inner wire portionand coating. In some embodiments, inner wire portioncomprises carbon steel. In some embodiments, inner wire portion 32 comprises a metal. In some embodiments, inner portioncomprises a metal alloy. In some embodiments, coatingcomprises high density polyethylene (HDPE), a coloring agent (e.g., a colored linear low density polyethylene), and a bonding agent. In some embodiments, coatingconsists of HDPE, a coloring agent, and a bonding agent. In some embodiments, the coloring agent is a colored linear low density polyethylene, for example yellow. In some embodiments, the coloring agent is AVIENT® ONCOLOR YELLOW P7548C PP linear low density polyethylene pellets.

The bonding agent is operatively arranged to bond coatingto inner wire portionwhich prevents the ingress of water therebetween. By bonding it is meant that coatings joined securely to inner wire portionby an adhesive or bonding agent. This differs from current electrical wire, for example, which do not bond the coating to the wire. In some embodiments, the bonding agent is a reactive glue or adhesive. Reactive adhesive means an adhesive that requires a hardener or catalyst in order for the bond to occur and includes, but is not limited to, epoxies, urethanes, and silicones. In some embodiments, the bonding agent is an anhydride modified high density polyethylene, for example, FUSABONDE265 anhydride modified high density polyethylene. In some embodiments, the bonding agent is a functional polymer. In some embodiments, coatingconsists of 90% HDPE by weight, 5% coloring agent by weight, and 5% bonding agent (e.g., FUSABONDE265 anhydride modified high density polyethylene) by weight. In some embodiments, coatingconsists of 90% HDPE by weight, 7% coloring agent by weight, and 3% bonding agent (e.g., FUSABONDE265 anhydride modified high density polyethylene) by weight. In some embodiments, coatingcomprises 90% HDPE by weight, a coloring agent in the range of 0-10% by weight, and bonding agent in the range of 1-10% (e.g., FUSABONDE265 anhydride modified high density polyethylene) by weight.

To manufacture rebar tie wire, inner wire portionis heated, for example using induction heating. Inner portionis heated to a temperature in the range of 280°F to 350°F, for example 300°F, or in the range of 320°F to 340°F. The heated inner wire portionis fed through a crosshead die for crosshead extrusion. In some embodiments, prior to heating, inner wire portionis cleaned, for example, by applying boiling water thereto. In some embodiments, prior to heating, a wire drawing solution or lubricant is applied to inner wire portionto aid in the wire drawing process. The wire drawing solution can be a dry soap lubricant or a liquid lubricant (e.g., neat oil, water-miscible solvent, or solution synthetic lubricant).

The HDPE (e.g., in pellet form), coloring agent, and bonding agent is heated and mixed together to form mixture. Mixture, in liquid (i.e. molten) or substantially liquid form (i.e., colloid), is fed into the crosshead die. Specifically, mixtureis fed into the crosshead die as heated inner wire portionpasses therethrough, and is applied to inner wire portionforming coating. In some embodiments, mixtureis applied to inner wire portionat a temperature in the range of 400°F to 500°F, or in the range of 400°F to 470°F, for example, 450°F. The flow of the mixture can be adjusted to obtain the desired thickness of coating.

shows a cross-sectional view of example crosshead die. As shown, inner wire portionis fed and/or pulled through crosshead die. At the same time, the molten mixture of coating, referred to herein as mixture, is fed through crosshead die. Mixtureis directed via crosshead dieto coat the radially outward facing surface of inner wire portion.

After the now coated inner wire portionexits crosshead die, it is quenched in a bath, for example, in water. This quenching solidifies mixture(i.e., the HDPE) and cures the bonding agent, resulting in coatingbeing bonded to inner wire portion. In some embodiments, after quenching rebar tie wireis air dried. One attribute of this bonding process (i.e., coatingis bonded to inner wire portionvia the bonding agent) is that coatingcannot be easily removed from inner wire portionand prevents the ingress of water and other corrosive materials. Such a feature is not seen in any known coated wires, which are specifically designed to be easily stripped of their coating for electrical connection. Another attribute of the bonding process is that coatingacts as a cushion, or elastic material, that prevents rebar tie wirefrom ripping any epoxy coating on reinforcing bars.

It will be appreciated that various aspects of the disclosure above and other features and functions, or alternatives thereof, may be desirably combined into many other different systems or applications. Various presently unforeseen or unanticipated alternatives, modifications, variations, or improvements therein may be subsequently made by those skilled in the art which are also intended to be encompassed by the following claims.

Rebar cage or system

Reinforcing bars

Joints

Rebar tie wire

Inner wire portion

Coating or casing

Mixture or coating mixture or casing mixture

Crosshead die