Technical Field

The present disclosure relates generally to welded wire fabric also known as welded wire mesh or welded wire reinforcement, and more specifically to welded wire fabric with improved ductility, for example suitable for use in reinforced concrete construction, and to continuous web or flow manufacturing methods and apparatus to produce welded wire fabric with improved ductility.

Description of the Related Art

Welded wire fabric (WWF), also known as welded wire mesh (WWM) or welded wire reinforcement (WWR) has been produced for decades as an alternative to hot rolled reinforcement bar (“rebar”) for reinforced concrete construction. Welded wire fabric is generally made from drawn wires, which have been cold worked during the cold wire drawing process. The result is that the wires have elongation values as low as only 2% to 3%. Conversely rebar is hot rolled and has elongation values of around 11 % to 12%, in the Grade 40 material (40,000 psi min yield strength).

Along the west coast of North America and in other regions of the world, higher ductility of the reinforcement (higher elongation) in reinforced concrete construction can improve seismic loading, allowing absorption of energy during cyclic loading during seismic events. Thus, the low ductility of welded wire fabric has been a major impediment to use of such in structural applications, particularly in regions that are prone to seismic events.

BRIEF SUMMARY

Heat treatment of the wires would improve the low elongation. Heat treatment of the individual wires is a costly additional operation and, to the best of Applicant’s knowledge, is not practiced by anyone in the fabrication of welded wire fabric or welded wire mesh.

It may be useful to heat treat weld zones after fabrication of the individual wires into a welded wire fabric or mesh, particularly for cases of higher strength welded wire fabrics or meshes, for instance where there is concern regarding embrittlement resulting from the welding. Such however fails to appreciably address the ductility issue for the welded wire fabric as a whole.

As noted, welded wire fabric has limitations due to poor ductility (e.g., low elongation), which inhibits the use of welded wire fabric, for instance in regions that are prone to seismic events. Hence, the industry continues to use reinforcement bar (/.e., rebar) in concrete structures, even though welded wire fabric could be a more efficient reinforcing option if the welded wire fabric had sufficient ductility.

Described herein are approaches that advantageously employ annealing of the entire welded wire fabric (e.g., the entire lengths of each wire of the welded wire fabric is annealed, in addition to annealing of the welds or weld zones), the annealing performed on the welded wire fabric, for example, in a separate operation after welding of the metal wires to form the welded wire fabric.

Described herein are approaches that advantageously employ annealing of the entire welded wire fabric (e.g., entire lengths of each wire, in addition to the welds or weld zones, after welding) in a continuous web or continuous flow operation, that reduces or avoids additional costs and reduces inefficiencies that might otherwise be incurred if, for example, performed on sheets of welded wire fabric in batch processing.

Described herein are approaches that advantageously perform continuous annealing with a furnace having an entrance, an exit, and a heating zone located between the entrance and exit which allows the welded wire fabric to pass through the furnace as a continuous web or continuous flow annealing operation. Such is in contrast to annealing welded wire fabric via a batch furnace in batch operation. The furnace can advantageously be in-line with welded wire fabric fabricating equipment (e.g., automatic welder).

Described herein are approaches that advantageously perform in-line and/or continual annealing with a fluidized bed furnace having an entrance, an exit, and a fluidized bed heating zone located between the entrance and exit which allows the welded wire fabric to pass through the furnace as a continuous web or continual flow annealing operation. Such is in contrast to annealing welded wire fabric via a batch furnace in batch operation. The fluidized bed furnace is in-line with welded wire fabric fabricating equipment (e.g., welder), in a novel solution to overcoming the problems associated with other heat treating options. Optionally, one or more take- up mechanisms (e.g., roll coiler, motorized take-up spool, shears) can advantageously be located in-line with the exit of the fluidized bed furnace.

In this respect it is noted that welded wire fabric is mainly packaged in sheet form, especially with larger wire sizes/small wire gauges. Each alternating sheet is flipped over so the cross wires of these alternating two sheets both nest together in the same space, saving overall package height. The sheets of welded wire fabric are stacked in bundles of up to 50 sheets per bundle. The length of sheets may vary from 8 ft up to 30 ft, or more. If a batch furnace were employed, such would likely require several bundles to be stacked within the batch furnace together, some on top of each other, and others in the longitudinal direction within the limits of an interior of the furnace enclosure.

Use of batch furnace presents a number of distinct disadvantages as compared to Applicant’s proposed continuous web manufacturing approach.

Use of a batch furnace results in additional labor and material handling to move bundles in and out of the batch furnace. Use of a batch furnace requires additional space for a sufficiently large furnace, plus the area to hold work in process material waiting to go into the batch furnace, and similarly to hold material that has come out of the batch furnace and which needs cooling space before being moved to a warehouse.

Use of a batch furnace places timing requirements on the process. For example, requiring cycle time to heat up, hold at temperature, and to cool down, which could be as low as 2 to 4 hours or 8 hours or longer depending on batch size and treatment required. A single batch furnace would be unlikely to be able to keep up with production from a single fabric welder. Use of a batch furnace also places constraints on welded wire fabric sheet length, which is limited by the interior dimensions of the batch furnace.

With a batch furnace the annealing temperature cannot be varied between various products within the batch. Use of batch furnace results in higher energy costs, for instance because the batch furnace will cool off on each cycle as doors are opened to remove and reload product, and thus the interior needs to be reheated with each batch. Also, higher energy costs can result due to the batch furnace not being able to be fully loaded due to product sizes and quantities. Further, heat transfer in batch furnaces is by thermal convection which is very slow process. Since heat transfer is by thermal convection over a large mass of welded wire fabric, there will be some variability in annealing depending on differences in flow of hot gases throughout the stacks of welded wire fabric. This non-uniform ity will be further exacerbated when the batch furnace is not completely filled, for instance due to various length combinations not fitting into the batch furnace. In such situations, the hot gases can flow through the open areas unimpeded, and cause increased heating of the welded wire fabric nearby.

Use of a batch furnace would also make it difficult to anneal rolls of welded fabric. It is noted that welded wire fabric has further residual stresses at the weld intersections, causing some curvature distortion in the sheets of welded wire fabric in both directions (/.e., across a width of the sheet and along a length of the sheet). Further, with the heat treatment it is unknown what further distortions may arise. With batch processing via a batch furnace there is no way to overcome or correct any such distortions.

Described herein is a continuous web or continual flow annealing and/or manufacturing approach to produce welded wire fabrics with improved ductility, which can, for example, be suitable as reinforcement for concrete structures suitable even for regions that are prone to seismic events. The described approaches can employ in-line annealing or manufacturing operations, for example feeding welded wire fabric from a welder directly to a furnace, with requiring storage, and optionally feed annealed welded wire fabric from the furnace directly to a take-up spindle to create a roll of annealed welded wire fabric having improved ductility. The described approaches can advantageously employ furnaces with an entrance, exit, and a heating zone located between the entrance and the exit. The described approaches can advantageously employ a fluidized bed furnace having a fluidized bed located between an entrance and an exit of the fluidized bed furnace. Such can advantageously improve heat transfer, and hence the ability to anneal faster than in a batch furnace, and even allow matching a throughput of the fluidized bed furnace with an output of the automatic welder that produces the welded wire fabric. The approaches described herein have numerous advantages as compare to batch based approaches. The approaches described herein can advantageously avoid added labor er material handling required of batch furnace based approaches. The approaches described herein can advantageously require less plant or manufacturing floor space. The approaches described herein accommodate the footprint for the continuous web handing furnace (e.g., furnace with entrance and exit and heating zone therebetween, for instance a fluidized bed furnace), which will typically have a much smaller footprint than a batch furnace.

The approaches described herein can advantageously take advantage of the superior heat transfer characteristics of fluidized beds, which is mainly by thermal conduction, which is a very fast process as compared to convection which is the predominate heat transfer mechanism in batch furnaces. The approaches described herein can advantageously reduce time in the furnace to only 1 to 2 minutes.

The approaches described herein can advantageously result in more consistent and more uniform heat treatment across the welded wire fabric.

The approaches described herein can advantageously result in essentially infinite sheet length since the welded wire fabric is continuous and does not need to be cut into sheets at least until after leaving the furnace.

The approaches described herein can advantageously allow annealing temperatures to quickly be adjusted changed between various welded wire fabric configurations or changes in metal wire size or gauge.

The approaches described herein can advantageously result in lower energy cost per sheet of welded wire fabric or per mass of metal (e.g., steel) being processed.

The approaches described herein can advantageously allow the welded wire fabric to be supplied in rolls, with a roll coiler or motorizes spool, and optionally a shear located downstream of the furnace in the manufacturing line.

The approaches described herein can advantageously improve quality and consistency of heat treatment since only one layer of welded wire fabric passes through the furnace at a time. Notably, there will be no other cross wires adjacent, as there would be in stacked bundles of welded wire fabric stacked in a batch furnace. The approaches described herein can advantageously accommodate levelling and flattening rolls or stations along the manufacturing line to correct any distortion in the mesh to produce flat meshes in both directions.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

In the drawings, identical reference numbers identify similar elements or acts. The sizes and relative positions of elements in the drawings are not necessarily drawn to scale. For example, the shapes of various elements and angles are not necessarily drawn to scale, and some of these elements may be arbitrarily enlarged and positioned to improve drawing legibility. Further, the particular shapes of the elements as drawn, are not necessarily intended to convey any information regarding the actual shape of the particular elements, and may have been solely selected for ease of recognition in the drawings.

Figure 1 is a top plan view of a portion of a continuous web of a welded wire fabric, according to an embodiment.

Figure 2 is a top isometric view of a reinforced concrete structure with a slab of concrete and an annealed welded wire fabric (show in hidden line) embedded in the slab of concrete, according to an embodiment.

Figure 3 is an isometric view of a manufacturing line to manufacture a welded wire fabric as a continuous web manufacturing operation, according to an embodiment, including spools of wire, an automatic welder, a furnace with an entrance, and exist and a heating zone, the entrance in-line with the automatic welder, a roll coiler in-line with the exit of the furnace, and an optional automatic shears.

Figure 4 an isometric view of the furnace of the manufacturing line of Figure 3, viewed from an entrance side thereof.

Figure 5 is a flow diagram showing a method of manufacturing welded wire fabric having improved ductility, according to at least one illustrated implementation.

DETAILED DESCRIPTION

In the following description, certain specific details are set forth in order to provide a thorough understanding of various disclosed embodiments. However, one skilled in the relevant art will recognize that embodiments may be practiced without one or more of these specific details, or with other methods, components, materials, etc. In other instances, well-known structures associated with welded wire fabric and machines and techniques to manufacture welded wire fabric technologies have not been shown or described in detail to avoid unnecessarily obscuring descriptions of the embodiments.

Unless the context requires otherwise, throughout the specification and claims which follow, the word “comprise” and variations thereof, such as, “comprises” and “comprising” are to be construed in an open, inclusive sense, that is as “including, but not limited to.”

Reference throughout this specification to “one implementation” or “an implementation” or to “one embodiment” or “an embodiment” means that a particular feature, structure or characteristic described in connection with the implementation or embodiment is included in at least one implementation or at least one embodiment. Thus, the appearances of the phrases “in one implementation” or “in an implementation” or “in one embodiment” or “in an embodiment” in various places throughout this specification are not necessarily all referring to the same implementation or embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more implementation or in one or more embodiments.

As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” include plural referents unless the content clearly dictates otherwise. It should also be noted that the term “or” is generally employed in its broadest sense, that is as meaning “and/or” unless the content clearly dictates otherwise.

The term “aligned” or “in-line” as used herein in reference to two elements along a direction means a straight line that passes through one of the elements and that is parallel to the direction will also pass through the other of the two elements. The term “between” as used herein in reference to a first element being between a second element and a third element with respect to a direction means that the first element is closer to the second element as measured along the direction than the third element is to the second element as measured along the direction. The term “between” includes, but does not require that the first, second, and third elements be aligned along the direction. The term “plurality” as used herein means more than one. The terms “a portion” and “at least a portion” of a structure include the entirety of the structure.

The headings and Abstract of the Disclosure provided herein are for convenience only and do not interpret the scope or meaning of the embodiments.

Figure 1 shows a portion of a continuous web of a welded wire fabric 100 having improved ductility, according to an embodiment.

The welded wire fabric 100 comprises a first plurality of metal wires 102 and a second plurality of metal wires 104.

The metal wires 102a (only one called out for sake of drawing clarity) of the first plurality of metal wires 102 are arranged such that each of the metal wires of the first plurality of metal wires 102 extends substantially along a first direction (doubleheaded arrow 106), the first plurality of metal wires 102 substantially parallel to one another. Each of the metal wires of the first plurality of metal wires 102 is substantially spaced apart from adjacent ones of the metal wires of the first plurality of metal wires 102.

The metal wires 104a (only one called out for sake of drawing clarity) the second plurality of metal wires 104 arranged such that each of the metal wires of the second plurality of metal wires 104 extends substantially along a second direction (double-headed arrow 108), the second plurality of metal wires 104 substantially parallel to one another. Each of the metal wires of the second plurality of metal wires 104 is substantially spaced apart from adjacent ones of the metal wires of the second plurality of metal wires 104. The second direction 108 is non-parallel with the first direction 104, such that the metal wires of the second plurality of metal wires 104 cross or intersect at least some of the metal wires of the first plurality of metal wires 102. In some implementations, the second direction 108 can be perpendicular to the first direction 106. In other implementations the second direction 108 is nonperpendicular and non-parallel with the first direction 106 (e.g., 60 degrees).

The welded wire fabric 100 comprises a plurality of welds 110a, 110b (only two called out for drawing clarity, collectively referenced as 110), wherein each of the metal wires of the second plurality of metal wires 104 is secured to at least some or all of the metal wires of the first plurality of metal wires 102 by a respective one of the welds 110a, 110b of the plurality of welds 110 where the metal wires of the second plurality of metal wires 104 cross at least some of the metal wires of the first plurality of metal wires 102.

Notably, the metal wires of the first plurality of metal wires 102 and the metal wires of the second plurality of metal wires 104 are each annealed along an entire length of the metal wires of the first plurality of metal wires 102 and along an entire length of the metal wires of the second plurality of metal wires 104.

The metal wires of the first plurality of metal wires 102 and the metal wires of the second plurality of metal wires 104 can take a variety of forms. For example, one or more of the metal wires of the first plurality of metal wires 102 and, or, of one or more of the metal wires of the second plurality of metal wires 104 can have a round cross-sectional profile or a rectangular cross-sectional profile (e.g., flattened metal wire). Additionally, one or more of the metal wires of the first plurality of metal wires 102 and, or, of one or more of the metal wires of the second plurality of metal wires 104 can have a number (e.g., a plurality) of indents or depression in an outer surface thereof to increase a “grip” of the metal wire when located in a substrate or composite material. Additionally or alternatively, one or more of the metal wires of the first plurality of metal wires 102 and, or, of one or more of the metal wires of the second plurality of metal wires 104 can have a number (e.g., a plurality) of protrusions that extend from an outer surface thereof to increase a “grip” of the metal wire when located in a substrate or composite material. Additionally or alternatively, one or more of the metal wires of the first plurality of metal wires 102 and, or, of one or more of the metal wires of the second plurality of metal wires 104 can be helical or spiral in shape, which can advantageously increase a “grip” of the metal wire when located in a substrate or composite material and well as increase a resiliency of the metal wires to deformation.

The metal wires of the first plurality of metal wires 102 and the metal wires of the second plurality of metal wires 104 can comprise a variety of materials. For example, one or more of the metal wires of the first plurality of metal wires 102 and, or, of one or more of the metal wires of the second plurality of metal wires 104 can comprise steel or even consist of steel, for example from an SAE 1006 steel up to, for instance, an SAE 1040 steel, although such should not be considered limiting unless expressly recited in a claim.

While the welded wire fabric 100 is illustrated with one set of metal wires extending in a first direction (e.g., first plurality of metal wires 102) overlying the other set of welded metal wires extending in a second direction (e.g., second plurality of metal wires 102), essentially having two parallel “layers” of metal wires which are welded at points of intersection or overlap, other implementations can be employed. For example, the metal wires of one set of metal wires extending in a first direction (e.g., first plurality of metal wires 102) can alternatingly pass over and then under pairs of adjacent metal wires in the other set of welded metal wires that extend in the second direction (e.g., second plurality of metal wires 102), essentially having a woven set of wires, which are welded at points of intersection or overlap. Either of these two implementations can optionally include a plurality of standoffs or feet, for instance formed by respective ones of a plurality of furring bends in at least some of the metal wires, for example as illustrated and described in U.S. patent 8720142 or U.S. patent 9797142 or U.S. patent application publication 2007-0175145. The standoffs or feet (e.g., furring bends) spaces the majority of the welded wire fabric (other than the standoffs or feet themselves) from a surface which distal ends of the standoffs or feet contact when used. While furring bends are formed in the metal wires themselves, the furring bends generally extend from a plane in which a majority of the metal wires lie, for example extending generally perpendicularly therefrom. Additionally or alternatively, one or more stabilizers can be included as part of the welded wire fabric, for example as illustrated and described in U.S. patent 9708816 or U.S. patent 9797142.

Figure 2 shows a reinforced concrete structure 200, according to an embodiment.

The reinforced concrete structure 200 includes a slab of concrete 202 and a welded wire fabric 204 (shown in hidden line) embedded in the slab of concrete 202. While illustrated as a slab, the reinforced concrete structure 200 can take any of a large variety or shapes and forms suitable to a particular construction project.

The welded wire fabric 204 can be an annealed welded wire fabric 204 having improved ductility as compared to conventional welded wire fabrics. The welded wire fabric 204 can, for example, be the same as the welded wire fabric 100 (Figure 1 ). Thus, for example, the metal wires of the welded wire fabric 204 are each annealed along an entire length of the metal, providing for improved ductility over conventional welded wire fabrics. As explained above, it is common to use rebar as the reinforcement, for example in reinforced concrete structures. The common grades and specifications of hot rolled reinforcing bars (rebar) are given in Table 1 , below. Table 1

The common grades and specifications of conventional welded wire fabric used for concrete reinforcement are given in Table 2, below. Table 2

As can be seen from Tables and 1 and 2, welded wire fabrics are generally not available in lower strength Grades (e.g., 40 and 60). However, these grades represent the highest volume of use in the rebar industry. The spread between the ultimate strength and yield strength are smaller for welded wire fabric, as compared to rebar. For safety, engineers prefer to have more strength available between UTS and yield strength, so that if overloading situation occurs, there is prior warning given by cracks appearing and concrete spalling, before sudden failure occurs. With conventional approaches, Grade 80 is the maximum available in welded wire fabric, as compared to Grade 100 for rebar.

Welded wire fabric 102 (Figure 1), 204 (Figure 2) with improved ductility produced using the approaches described herein can advantageously have the ranges and properties set out in Table 3, below.

Table 3

As can be seen from the Tables, lower tensile and yield strengths can be achieved for welded wire fabric as compared to rebar, which is not achieved using conventional approaches to welded wire fabric production. Also, higher tensile and yield strengths can be achieved for welded wire fabric as compared to rebar, which are not achieved using conventional approaches to welded wire fabric production. There is also a greater spread between ultimate strength and yield strength, advantageously providing for an early warning of imminent failure. The approaches described herein can also advantageously provide a greater range of grades for welded wire fabric as compared to hot rolled rebar, which typically available in just 4 grades. There is also a greater range of bar sizes possible with welded wire fabric as compared to the number 3, 4, 5 and 6 sizes up to the % inch size. Elongation for conventional welded wire fabrics is specified as a reduction of area, with a minimum of 30%. However, this level of ductility is inadequate to provide the level of ductility desired in zones that are prone to seismic events. Using the approaches described herein, ductility levels can advantageously be increased to be the equivalent of rebar.

Figure 3 shows a manufacturing line 300 to manufacture a welded wire fabric 302a and an annealed welded wire fabric 302b, as a continuous web manufacturing operation, according to at least one implementation.

The manufacturing line 300 includes an automatic welder 304 and a furnace 306. The furnace 306 has an entrance 308 (Figure 4), an exit 310 and a heating zone 312 (Figure 4) located between the entrance 308 an the exit 310 to allow continuous web annealing operation as described herein. The entrance 308 of the furnace 306 can advantageously be in-line (indicated by double-headed arrow 314) with an output or exit 316 of the automatic welder 304. The automatic welder 304 includes one or more welding heads 318 with welding positons 320 (only one called out) and is operable to weld an array of metal wires at points of intersection thereof to form the welded wire fabric 302a. The welding positions 320 can, for example, include electrically resistive elements, inductive elements or other sources to produce heat. The automatic welder 304 can, for example employ spot or resistance welding, or alternatively employ other types of welding (e.g., tungsten inert gas (TIG) welding, plasma welding, and soldering).

The welded wire fabric 302a created by automatic welder is fed from the output or exit 316 of the automatic welder 304 to the entrance 308 of the furnace 306, either directly or indirectly. One or more conveyors 322 can be positioned to support and/or advance the welded wire fabric 302a from the output or exit 316 of the automatic welder 304 to the entrance 308 of the furnace 306.

As illustrated, the manufacturing line 300 optionally includes one or more supplies of metal wire 324a, 324b, illustrated as two spools 326a, 326b of metal wire 324a, 324b. The metal wire 324a, 324b is are feed to one or more inputs 328 (only one visible in Figure 3) of the automatic welder 304. The metal wire 324a, 324b can be cold drawn metal wire, of can be cold drawn between exiting the spools 326a, 326b and reaching the weld heads 318, for instance just before or on entering the automatic welder 304. While not illustrated the manufacturing line 300 can optionally include one or more cutters to cut the wire into specified lengths, for example based on the lateral dimension of the welded wire fabric 302a or annealed welded wire fabric 302b. While not illustrated the manufacturing line 300 can straighteners positioned just upstream of or at the entrance to the automatic welder 304 to straighten each wire as it enters the automatic welder 304. The straightening may give rise to cold working, which the annealing or heat treating an ameliorate.

The manufacturing line 300 optionally includes a roll coiler or motorized spool 328 that receives the annealed welded wire fabric 302b directly or indirectly from the exit 310 of the furnace 304, and rolls or coils such into a roll or coil 330 of annealed welded wire fabric 302b. The roll coiler or motorized spool 328 can advantageously be in-line 314 with the exit 310 of the furnace 304. The roll coiler or motorized spool 328can include a motor 328a that drives a spindle or spool 328b.

A speed of transit of the welded wire fabric through fluidized bed 400 (Figure 4) of the fluidized bed furnace 306 can advantageously be matched with a speed of take-up of a roll coiler or motorized take-up spindle 328 located downstream of the fluidized bed furnace 306. The manufacturing line 300 can, for example, include one or more transducers (e.g., position encoders, rotary encoders, Reed switches, IR emitter sensor pairs) 334a, 334b, 334c to sense speed of transit through the fluidized bed furnace and/or sense the speed (e.g., rotational speed) of the roll coiler or motorized spool 328. A control system 338 can include one or more circuits (e.g., analog circuits, comparators, microprocessors, microcontrollers) 340 and storage media (e.g., read only memory (ROM) 342, random access memory (RAM) 344) can compare the speeds, including converting rotational speed to translational speed or vice versa, and provide control signals via control lines 346a, 346b to one or more motors, solenoids, pneumatic pistons, hydraulic pistons, valves, or other actuators to adjust speed or operation accordingly, for instance adjusting speed along a conveyor and/or adjusting speed or operation of the welding head 318.

The manufacturing line 300 optionally includes automatic shears 332. The automatic shears 332 can include a blade, knife or sharp edge 332a that cuts the annealed welded wire fabric laterally (e.g., perpendicular to a longitudinal axis) to achieve a roll or coil 330 of annealed welded wire fabric 302b of desired dimensions (e.g.. specified roll diameter, specified length of annealed welded wire fabric 302b on the roll or coil 330). The blade, knife or sharp edge 332a can be driven along a track or rail 332b via an electric motor, solenoid, pneumatic or hydraulic actuator, or some other actuator.

One or more conveyors 334 can optionally be positioned to support and/or advance the annealed welded wire fabric 302b from the output or exit 310 of the furnace 306 to the roll coiler or motorized spool 328.

Figure 4 shows the furnace 306 of the manufacturing line of Figure 3 from the entrance side thereof, the furnace 306 advantageously taking the form of a fluidized bed furnace.

The fluidized bed furnace 306 has a fluidized bed 400 which is a fluidized volume of a solid material typically in suspension from a blown gas (represented by arrows 402, only one called out). As such, the primary thermal transfer mechanism in a fluidized bed is via thermal conduction, although there is thermal transfer via convection as well and thermal transfer via radiant thermal transfer. The efficient heat transfer mechanism facilities annealing while the welded wire fabric 302a (Figure 3) transits the interior of the fluidized bed furnace 306, passing through the fluidized bed 400 itself.

The fluidized bed furnace 306 can include one or more sources of pressurized fluid (e.g., air, inert gas), for example an air intake, fan, blower, and/or compressor 404.

As the welded wire fabric 302a transits (e.g., preferably continuously, or less preferably in start and stop movements) the interior of the fluidized bed furnace 306, the fluidized bed 404 heats the welded wire fabric 302a, for example, to approximately 1200°F or approximately 649°C. This heat treatment stress relieves the metal wires, improving ductility up to approximately 12% to approximately 15%, while still maintaining good tensile strength. Other types of furnaces can alternatively be employed, for example hot air furnaces or radiant furnaces could be utilized, although a fluidized bed furnace has various advantages including speed. In fact, use of a fluidized bed furnace can advantageously allow matching of the speed of the welded wire fabric 302a through the fluidized bed furnace 306 with speed of output of the automated welder 304. Such can eliminate any need to store welded wire fabric 302a while waiting for a furnace to finish an annealing cycle, for instance as would occur with the use of batch furnaces, thus eliminating the need for an accumulating tower or other accumulation structure upstream of the furnace along the manufacturing line 300.

It is also noted that the heat treatment or annealing can advantageously be achieved without galvanizing the welded wire fabric, thereby avoiding the expense associated with a treatment that would have no benefit in certain applications (e.g., using welded wire fabric as reinforcement in concrete structures). The output of the furnace can be an un-galvanized yet annealed welded wire fabric.

Figure 5 shows method 500 of manufacturing welded wire fabric having improved ductility, according to at least one illustrated implementation.

The method 500 starts at 502, for example when turning ON one or more of the various components (e.g., furnace, automatic welder, control system) of a manufacturing line.

At 504, a furnace is heated. For example, a fluidized bed of a fluidized bed furnace is heated, while a pressurized gas is passed through a bed of heated particulate material to create the heated fluidized bed.

Optionally at 506, a first plurality of metal wires is supplied to an automatic welder. The automatic welder is located upstream of the furnace in the manufacturing line or process. The metal wires can be of a variety of grades.

Optionally at 508, a second plurality of metal wires is supplied to an automatic welder.

In some implementations, the automatic welder receives two separate sets of metal wires, one set used to extend along a longitudinal direction of the welded wire fabric that is being created, and the other set to extend along a lateral direction of the welded wire fabric that is being created. In other implementations, the automatic welder receives two separate continuous lengths of metal wire, one length used to create metal wires that will extend along a longitudinal direction of the welded wire fabric that is being created, and the other length used to create metal wires that will extend along a lateral direction of the welded wire fabric that is being created. In such an implementation, the automatic welder can include a knife or blade or other component to cut the continuous lengths of metal wire into individual metal wires. In yet another implementation, automatic welder receives one continuous length of metal wire, used to create both the metal wires that will extend along a longitudinal direction of the welded wire fabric that is being created and to create the metal wires that will extend along a lateral direction of the welded wire fabric that is being created. The metal wire can optionally pass through a straightener to straighten the wires, although such may cold work the metal wire. As noted, the metal wires can be of a variety of grades. The automatic welder can optionally have an adjustable speed, which can, for example, be adjusted to adjust a speed of output of the welded wire fabric from the automatic welder. Such can, for example, be adjusted to match a speed of transit through the furnace.

Optionally at 510, the automatically welder continually welds the second plurality of wires to at least some of the first plurality of wires to create the continuous web of welded wire fabric.

At 512, the continuous web of welded wire fabric is supplied to an entrance of furnace. The continuous web of welded wire fabric can be supplied directly or indirectly to the entrance of furnace. One or more conveyors can be used to supply the continuous web of welded wire fabric to the entrance of furnace. The conveyors can optionally have an adjustable transit speed, which can, for example, be adjusted to match a speed of output from the automatic welder and/or a speed of transit through the furnace.

Optionally at 514, a speed of transit of welded wire fabric through the furnace is matched with a speed of output of automatic welder and/or a speed of the conveyors that convey the welded wire fabric from the automatic welder to the entrance of the furnace. For example, a speed of transit of the welded wire fabric through fluidized bed of the fluidized bed furnace can be set equal to a speed of output of the continuous web of welded wire fabric from the automatic welder or both.

At 516, a continuous web of welded wire fabric is passed through the furnace, for example the continuous web of welded wire fabric passing through the fluidized bed of a fluidized bed furnace. The temperature of the furnace, duration of transit through the furnace, and even a length of transit through the furnace, can be set to achieve a desired amount of annealing. For example, the duration of transit or even length of transit through the furnace (e.g., between entrance and exit) can be set based on a given temperature or range of temperatures to achieve a specified amount of annealing. Also for example, the temperature or range of temperatures can be set based on a specified duration of transit or even length of transit through the furnace (e.g., between entrance and exit). It may be desirable to set the temperature and/or transit time and/or transit length to match the output of the automatic welder, to for instance optimize throughput without requiring intermediate storage between the automatic welder and the furnace, facilitating continuous web manufacturing operation.

At 518, the portion of the continuous web of welded wire fabric that is in the furnace is annealed as that portion of the welded wire fabric passes through the furnace (e.g., fluidized bed furnace).

At 520, the continuous web of annealed welded wire fabric is withdrawn from an exit of furnace. One or more conveyor can optionally be employed to withdraw the continuous web of annealed welded wire fabric from the exit of the furnace. The conveyors can optionally have an adjustable transit speed, which can, for example, be adjusted to match a speed of transit through the furnace and/or a speed of output from the automatic welder or both.

Optionally at 522, a roll of annealed welded wire fabric is formed. For example, a roll of the annealed welded wire fabric can be formed after the annealed welded wire fabric leaves the fluidized bed furnace, for instance via a roll coiler or motorized take-up spool or spindle.

Optionally at 524, a speed of transit of the welded wire fabric through furnace is matched with a speed of take-up. For example, a speed of transit of the welded wire fabric through fluidized bed of the fluidized bed furnace can be matched with a speed of take-up by a roll coiler or motorized take-up spool or spindle that is located downstream of the fluidized bed furnace. A control system (e.g., processor-based) can send drive commands to one or more electric motors, solenoids, or other actuators to adjust speeds.

Optionally at 526, the continuous web of annealed welded wire fabric is sheared, for example via automatic shears. Such can be used to cut the continuous web of annealed welded wire fabric to a desired size, for example to form separate rolls of a continuous web of annealed welded wire fabric. The automatic shear can be located downstream of the furnace and upstream of the roll coiler or motorized take-up spool or spindle in the manufacturing line. A control system (e.g., processorbased) can send drive commands to operate the automatic shearer to cut appropriate lengths of annealed welded wire fabric. While optional forming of rolls is described, in some implementations, the output can be in sheets rather than rolls, the sheets delivered in generally flat configurations with multiple sheets arranged in a stack or bundle of sheets of annealed welded wire fabric. The automatic shears can cut the annealed welded wire fabric into sheets of desired lengths.

The method 500 can terminate at 528. Alternatively, the method 500 can repeat over and over as during operation of the manufacturing line.

The above description of illustrated embodiments, including what is described in the Abstract, is not intended to be exhaustive or to limit the embodiments to the precise forms disclosed. Although specific embodiments of and examples are described herein for illustrative purposes, various equivalent modifications can be made without departing from the spirit and scope of the disclosure, as will be recognized by those skilled in the relevant art.

Many of the methods described herein can be performed with variations. For example, many of the methods may include additional acts, omit some acts, and/or perform acts in a different order than as illustrated or described.

The various embodiments described above can be combined to provide further embodiments. All of the U.S. patents, U.S. patent application publications, U.S. patent applications, foreign patents, foreign patent applications and non-patent publications referred to in this specification and/or listed in the Application Data Sheet, including but not limited to U.S. patent 8720142; U.S. patent 9797142; U.S. patent 9708816; U.S. patent application publication 2007/0175145; and U.S. Provisional Application No. 62/926,346, are all incorporated herein by reference, in their entireties. Aspects of the embodiments can be modified, if necessary to employ concepts of the various patents, applications and publications to provide yet further embodiments.

These and other changes can be made to the embodiments in light of the above-detailed description. In general, in the following claims, the terms used should not be construed to limit the claims to the specific embodiments disclosed in the specification and the claims, but should be construed to include all possible embodiments along with the full scope of equivalents to which such claims are entitled. Accordingly, the claims are not limited by the disclosure.