Stained wood and a method of drying and staining wood.

Abstract

A method for drying and staining wood includes supplying green wood with a fluctuating moisture content to an oven and drying the green wood in the oven. The residence time of the green wood in the oven and the oven temperature are selected according to a time and temperature profile based on the moisture content of the green wood before drying, to produce dried surface wood with a moisture content of approximately 15% or less on the dried surface. The method further includes transporting the dried surface wood to a staining booth and staining all sides of the dried surface wood immediately after drying. Systems for carrying out the method and stained wood products produced according to the method are also considered.

Description

Technical Field

[0001] Technical Field The present disclosure generally relates to dyed wood and related methods of drying and dyeing wood.

Background Art

[0002] Background Art Certain dyed wood products and methods of drying and dyeing wood are known. One particular use of such technology is drying and dyeing wood fence boards. A user may purchase a fence board from a supplier or store and install the board as part of a fence. Fence boards available to consumers are typically "green" fence boards recently cut from wood and often have a moisture content of about 20% to 40%. Thus, in order to ensure proper dye adsorption and uniformity, the board must be dried, preferably to a moisture content of 15% or less for most dyes, before applying the dye. One solution to this problem is to install the board as part of a fence and allow the board to dry in the natural environment until the internal moisture content of the board is suitable for dye application. Such an approach is more suitable in hot and dry environments and may be difficult in regions with high humidity, significant rainfall or precipitation, or both, which slow the natural drying process. In some regions, natural drying at the location of the fence board installation is only practical during certain seasons.

[0003] In some cases, fence boards are shipped to a high-temperature, dry environment for natural drying outdoors before being dyed, stacked, and shipped to consumers as pre-dyed boards. However, this process is time-consuming and expensive. Even under ideal conditions, the drying process to reduce the moisture content of green fence boards to a level suitable for dye application can take several weeks. Transporting the boards to and from the high-temperature, dry environment also significantly increases costs. Another solution is to dry the green fence boards in a kiln from their initial moisture content to a preferred moisture content of 15% or less before dyeing and shipping them to consumers. This process is also expensive and time-consuming, especially on a larger scale for the commercial production of fence boards. For example, a typical kiln drying time can be carried out in multiple stages, with each stage lasting at least 8-10 minutes, with several minutes of rest between stages. Special care is taken to dry the wood at a specific temperature to prevent the green fence boards from cracking or burning during the drying process. The above deficiencies and drawbacks of known techniques apply equally to all types of dyed wood, not just fence boards. Therefore, current technology is not always suitable for producing pre-stained wood in specific environments, and it would be advantageous to have stained wood products and methods for drying and staining wood that overcome the shortcomings of known technologies. [Overview of the Initiative] [Means for solving the problem]

[0004] This disclosure generally relates to a method for producing pre-stained wood in a shorter time and at a lower total cost by drying green wood to reduce the surface moisture content of the wood to a level suitable for dye application, and then applying the dye immediately thereafter. Once the dye is applied, the wood naturally releases any remaining internal moisture through the dye over time.

[0005] More specifically, green wood may initially have a fluctuating moisture content, at least partially, depending on the type of green wood, as well as the season and location where the wood was first cut and the ambient humidity in which the green wood is stored. Time and temperature profiles for drying green wood with fluctuating moisture content can be developed based on these and other factors. In a non-limiting example, green wood with a higher initial moisture content may, based on the above, be dried for a longer time and / or at a higher temperature than green wood with a lower initial moisture content. The green wood is left in the oven for a period and oven temperature according to the time and temperature profile to produce dried surface wood with a moisture content of about 15% or less on the dry surface, suitable for dye application. In other words, the residence time in the oven and the oven temperature are modified based on the initial moisture content of the wood to produce dried surface wood. Drying may be carried out in a single continuous processing step, and the interior of the wood generally has a moisture content of about 15% or more after drying. In one non-limiting example, the dye may be applied to all sides of the board immediately after or shortly after the drying step. This is done by placing the dried surface wood into a staining booth immediately after it leaves the drying oven. In this process, the dye can wet the surface of the board and adhere to the dried surface wood before the wood can absorb moisture from both the inside of the board and the surrounding air. Even after the wood has been placed in its final position, the stained board will release internal moisture over time.

[0006] In one or more embodiments, a method for drying and staining wood can be summarized as comprising: supplying green wood having a fluctuating moisture content into an oven; drying the green wood in the oven according to a time and temperature profile based on the pre-drying moisture content of the green wood to produce a dry surface wood having a moisture content of about 15% or less on the dry surface; and staining the dry surface wood after drying.

[0007] In one embodiment, drying the green wood may be a single continuous processing step.

[0008] In one embodiment, the time and temperature profiles vary depending on one or more of the following: the type of raw wood, the ambient humidity in which the raw wood was stored, and the moisture content of the raw wood before drying when it enters the oven.

[0009] In one embodiment, the moisture content of the dried surface wood is measured at the outermost surface of the dried surface wood.

[0010] In one embodiment, the moisture content at the outermost surface of the dry surface wood is measured using a pin meter that is stationary on the outermost surface of the dry surface wood due to its own weight.

[0011] In one embodiment, the internal moisture content of the dried surface wood exceeds approximately 15% after drying, as measured by a pin meter inserted at least 0.08 inches into the wood.

[0012] In one embodiment, drying green wood includes determining the pre-drying moisture content of the green wood based on the humidity content in the oven exhaust, and adjusting the time and temperature profiles based on the humidity content in a closed feedback loop.

[0013] One or more embodiments of a method for drying and dyeing wood can be summarized as including: drying raw wood in an oven to produce dried surface wood, wherein the raw wood is dried in an oven to produce dried surface wood, wherein the moisture content of the outermost surface of the raw wood is about 15% or less; transporting the dried surface wood directly from the oven exit into a dyeing booth; applying dye to all sides of the dried surface wood in the dyeing booth to produce dyed wood; wetting and adsorbing the dye to the surface by transporting the dyed wood on a conveyor for about 30 to about 120 seconds; and bundling the dyed wood for shipment at the end of the process.

[0014] In one embodiment, applying a dye to the dried surface wood further includes transporting the dried surface wood through a dyeing booth at a speed sufficient to coat the dried surface wood to a predetermined aesthetic quality associated with a product code.

[0015] In one embodiment, drying the raw wood involves drying it in an oven according to a time and temperature profile that achieves a surface moisture content sufficient to allow wetting and adsorption of the dye.

[0016] The method may further include loading the bulk green wood onto an inclined table before drying the green wood, separating the bulk green wood into individual pieces, loading the individual pieces onto a second conveyor, and transporting the individual pieces from the inclined table to the entrance of the oven on the second conveyor.

[0017] In one embodiment, applying dye to dry surface wood involves drawing out excess dye from the dry surface wood in the dyeing booth downstream of any nozzle or manifold that may be present in the dyeing booth.

[0018] In one embodiment, the moisture content of the outermost surface of the dry surface wood is measured using a pin meter that is stationary on the outermost surface of the dry surface wood due to its own weight.

[0019] In one embodiment, drying green wood in an oven involves green wood and dried surface wood having an internal moisture content of at least about 15% before and after drying, as measured using a pin meter inserted 0.08 inches into the green wood and dried surface wood, respectively.

[0020] One or more embodiments of a wood product are a wood piece having an inner portion and an outer portion surrounding the inner portion, the outer portion having an outermost surface, the wood piece, and a dyeing layer on the outermost surface of the outer portion of the wood piece, wherein when the dye is applied, the inner portion has an initial moisture content exceeding about 15%, and the outermost surface has a moisture content of less than about 15%, the dyeing layer, wherein the dyeing layer is at least semi-permeable and is configured to release moisture from the inner portion over time to reduce the moisture content of the inner portion from the initial moisture content to a final moisture content of about 15% or less. That is, the dyed board can release moisture over time even after being dyed to reduce the internal moisture to a final moisture content of about 15% or less.

[0021] In one embodiment, the wood piece has a boundary located about 0.08 inches from the outermost surface of the wood piece between the inner portion and the outer portion.

[0022] In one embodiment, the initial and final moisture contents inside the wood piece are measured using a pin meter inserted about 0.08 inches into the wood piece.

[0023] In one embodiment, the moisture content of the outermost surface is measured using a pin meter resting by its own weight on the outermost surface of the wood piece.

[0024] In one embodiment, the dyeing layer is configured to adsorb onto the dry surface wood before the dry surface wood takes in water from both the inner portion of the board and the surrounding air.

[0025] In one embodiment, the wood piece is a fence board, a fence post, or a fence rail.

[0026] Other features and advantages of the present disclosure are provided in more detail below.

[0027] This disclosure will be more fully understood by reference to the following figures, and like reference signs refer to like parts throughout unless otherwise specified. The figures are not drawn to scale and do not limit the scope of the claims.

Brief Description of the Drawings

[0028] [Figure 1] An isometric view of one or more embodiments of a system for drying and dyeing wood according to the present disclosure. [Figure 2] An isometric view of the supply subsystem and drying oven of the system of FIG. 1. [Figure 3] An isometric view of the output from the drying oven of the system of FIG. 1 and the input to the dyeing booth. [Figure 4] An enlarged isometric view of the wood emerging from the dyeing booth onto the transport subsystem of the system of FIG. 1. [Figure 5A] A schematic view of a pin meter for measuring the moisture content of wood according to an embodiment of the present disclosure. [Figure 5B] A schematic view of a pin meter for measuring the moisture content of wood according to an embodiment of the present disclosure. [Figure 5C] A schematic view of a pin meter for measuring the moisture content of wood according to an embodiment of the present disclosure. [Figure 6] A block diagram of a controller suitable for implementing an embodiment of a system that implements at least some of the techniques described in the present disclosure, and various devices connected thereto.

Best Mode for Carrying Out the Invention

[0031] Furthermore, in order to provide additional useful embodiments of this teaching, various features of representative examples and dependent claims may be combined in ways that are not specifically and explicitly enumerated. Also, note that all ranges or representations of values ​​for groups of entities disclose all possible intermediate values ​​or intermediate entities for the purposes of the original disclosure and for the purposes of limiting the claimed subject matter. Also, note that while the dimensions and shapes of components shown in the figures are designed to help understand how this teaching is carried out, in some embodiments they are not intended to limit the dimensions and shapes shown in the examples. In some embodiments, the dimensions and shapes of components shown in the figures are precisely scaled and intended to limit the dimensions and shapes of components.

[0032] This disclosure then describes certain non-limiting examples of wood drying and staining that may be particularly advantageous for the manufacture of fence components such as fence boards, fence posts, and fence rails, but it should be understood that the concepts of this disclosure can be equally applied to any type of stained wood and are not limited to fence components. Furthermore, the concepts of this disclosure can be implemented outside the field of wood drying and staining, including other processes and systems, including drying of materials or substrates and application of coatings such as paints and adhesives to substrates. While it is known and common to preheat substrates before applying coatings to prevent bubbles, cracks, impacts, flash rust, etc., the technique described herein with respect to the use of a heated oven to simply surface dry green wood for use in fences, and then immediately apply dye, has not been implemented previously, as described below.

[0033] Beginning with Figure 1, a system 100 for drying and staining wood is shown, which may be suitable for carrying out the method described herein. The system 100 includes a structural frame 102 supporting a platform 104 above a floor or ground 106 in a warehouse, building, or other indoor space. In one embodiment, the platform 104 is omitted, and the system 100 may be supported directly on the floor or ground 106 with or without the structural frame 102. The system 100 generally includes a supply subsystem 108, an oven 110, a staining booth 112, and a transport system 114, which are arranged in order. Each of the supply subsystem 108, oven 110, staining booth 112, and transport subsystem 114 is positioned on the structural frame 102 and / or platform 104, or at least partially supported by them. For example, the supply subsystem 108, oven 110, and staining booth 112 may be positioned on the platform 104 and supported by the structural frame 102 above the floor 106. The transport subsystem 114 may extend from the platform 112 to the floor 106. In addition to the specific configurations shown herein, other configurations may be used. The platform 104 may be positioned directly on the floor or may be vertically separated from the floor 106 by a selected distance, such as 1 to 12 feet, including all intervening values ​​as a non-limiting example. Positioning the platform 104 above the floor 106 may allow other operations to be performed beneath the platform 104 and / or materials such as dye storage tanks 107 to be stored beneath the platform 104. The raised platform 104 may also improve safety by preventing workers or equipment from unintentionally coming into contact with components of the system 100.

[0034] Each component of system 100, namely the supply subsystem 108, the oven 110, the dyeing booth 112, and the transport subsystem 114, is described in more detail below. In short, green wood 116 is supplied to the supply subsystem 108, for example, using a forklift 118 or other machinery. System 100 may also utilize additional equipment such as a tractor, crane, or forklift 118 to move bundles of wood to various locations, but is not illustrated to avoid obscuring the concepts of this disclosure. The supply subsystem 108 transports the green wood 116 into the oven 110, possibly with the help of an operator. The oven 110 is configured to dry the green wood 116 according to a time and temperature profile to produce dried surface wood with reduced moisture content on the outer surface in a single continuous processing step. The dried surface wood is supplied directly to the dyeing booth 112, which applies dye to all sides of the dried surface wood. The dyed wood leaves the dyeing booth 112 and passes through the transport subsystem 114, which allows the dye to wet the wood and adhere to the wood. At the end of the transport subsystem 114, the pre-stained lumber can be packaged or bundled for shipment.

[0035] Figure 2 provides further details regarding the supply subsystem 108 and oven 110 of system 100. The supply subsystem 108 includes an inclined table 120 communicating with a conveyor 122. The inclined table 120 may be a hydraulic and / or electrically operated assembly for lifting and rotating a green tree 116 from a position below the platform 104, such as the floor 106 or a position above the floor 106 accessible by a forklift 118, and raising the green tree 116 to a position above the platform 104 aligned with the conveyor 122. In one embodiment, the inclined table 120 may include a rotating arm 124A rotatable relative to the horizontal plane and a lift arm 124B translatable or movable along a linear path defined by the rotating arm 124A, to allow movement of the green tree 116 with at least two degrees of freedom. In some examples, the inclined table 120 may be a simple linear or rotary actuator. As shown in Figure 2, once the inclined table 120 aligns the green wood 116 with the end of the conveyor 122, the operator 126 can separate the bulk green wood 116 on the inclined table 120 into individual pieces of green wood 116 on the conveyor 122. The separation process may be performed manually by one or more operators separating the wood into individual pieces spaced apart from each other, or, in some examples, it can be automated with a pick-and-place machine or other similar mechanical device. The conveyor 122 may be a chain or belt conveyor, among other possibilities, and is generally operable to move the separated green wood 116 from the inclined table 120 to the entrance 128 of the oven 110.

[0036] The oven 110 may include a transport device 130, which may be a further conveyor connecting to a conveyor 122 of a supply subsystem 108 for transporting green wood 116 through the oven 110 from the inlet 128 to the outlet 132 in a single continuous step. The transport device 130 may be driven by a drive system including a motor, gears, belt, sprocket, chain, etc., which are not shown. Furthermore, the transport device 130 may have a transport speed that is selectable and controllable to vary the residence time of the green wood 116 in the oven 110. In other words, the residence time of the green wood 116 in the oven 110 can be selected and changed by adjusting the speed of the transport device 130. The oven 110 may include one or more exhaust ports 134 and a housing 136. The housing 136 may correspond to a heating element 138 inside the oven 110, schematically shown by dashed lines in Figure 2. The heating element 138 may be any commercially available heating element 138 currently known or to be developed in the future, including but not limited to burners (i.e., for propane or natural gas) and electric heating elements. The heating element 138 may operate alone to output heat, or it may be used in combination with a convection fan to heat and circulate the hot air inside the oven 110. The exhaust port 134 may be fluidly connected to an external area outside the building to discharge exhaust and other by-products from the heating operation in the oven 110.

[0037] In some embodiments, the oven 110 includes user-operable physical controls, such as buttons and switches, for controlling the operation of the oven 110 and various processing parameters, such as the speed of the transport device 130 and the temperature output by the heating element 138. Alternatively, the oven 110 may be associated with a controller 140 that provides commands for controlling the operation of the oven 110 and processing parameters. The controller 140 is described in more detail with reference to Figure 6. At least one of the exhaust ports 134, for example, the exhaust port 134 located closest to the inlet 128 of the oven 110, may include, or be associated with, one or more humidity sensors 142 for measuring the humidity content of the exhaust passing through the exhaust port 134. In one embodiment, each exhaust port 134 includes at least one humidity sensor 142. The humidity content of the exhaust may share a relationship with the moisture content of the raw wood 116 (i.e., higher moisture content, higher humidity is output to the exhaust and detected by the sensor(s) 142), thereby allowing the oven 110 to adjust the time and temperature profile of the raw wood 116 passing through the oven 110, at least in part, based on the humidity content in the exhaust determined by the humidity sensor(s) 142 in a closed control loop, as further described below, via the controller 140. The raw wood 116 is dried in the oven according to the selected or determined time and temperature profile based on the raw wood's pre-drying moisture content to produce dry surface wood with a moisture content of less than about 15% on the dry surface, thus suitable for dyeing. In one preferred embodiment, it is about 12%. If the surface moisture content of the wood is high, the dye may not spread and adhere sufficiently to the surface, which can lead to uniformity problems, pigment aggregation, and dewetting. This may prevent the finished product from meeting the product code or other industry-set specifications. The time and temperature profiles were chosen not to completely dry the wood, but to create a dry surface on the wood suitable for staining, meaning that the dry surface will have a lower moisture content than the interior of the wood after drying, as will be explained further below.The inventors have found that it is sufficient to dry the wood to a moisture content of less than 15% to a depth of 0.01 to 0.06 inches. A pin meter held at rest by its own weight will not penetrate beyond 0.06 inches into the surface, typically penetrating within the range of 0.01 to 0.05 inches. Having a dry surface to a depth of 0.06 inches is sufficient for the dye to wet uniformly and adsorb onto the substrate. Such a configuration allows for higher throughput and lower costs for drying wood compared to known systems.

[0038] Drying green wood 116 in an oven 110 according to the concept of this disclosure is primarily a function of time and temperature, meaning how long the wood 116 remains in the oven 110 and the temperature inside the oven 110. The temperature inside the oven 110 may be selected from a range of temperatures including and including all intervening values ​​between 350°F and 500°F in Fahrenheit ("F"), or greater or less than those values, and the green wood 116 may pass through the oven 110 from the inlet 128 to the outlet 132 for a time including and including all intervening values ​​between 30 seconds and 240 seconds, or greater or less than those values. Temperatures in the range of 280°F to 450°F are preferred, and care should be taken to keep them below the temperature at which the wood could ignite and thus begin to burn. Since the green wood 116 is preferably heated for a relatively short time (i.e., preferably less than 2 minutes), there is little concern regarding cracking, warping, ignition or burning of the wood. The above drying times and temperatures generally correspond to sufficient drying times and temperatures to reduce the surface moisture content of the wood 116, as described herein, and thus the dried surface wood after drying in the oven 110 is suitable for dye application. The above drying times and temperatures do not completely dry the wood 116, meaning that after drying, the interior of the wood may have a moisture content of more than about 15%.

[0039] As shown in Figure 2, the supply subsystem 108 and the oven 110 may generally be arranged in the longitudinal direction indicated by arrow 144, meaning that the supply subsystem 108 and the oven 110 are aligned with each other along a common direction 144. Referring to Figure 3, the dried surface lumber is output to a further conveyor 146 communicating with the oven 110 and the staining booth 112. The further conveyor 146 and the staining booth 112 may be aligned with each other in the transverse direction indicated by arrow 148 traversing the longitudinal direction 144. In one embodiment, the transverse direction 148 is perpendicular to the longitudinal direction 144, meaning that the dried surface lumber rotates about 90 degrees following the oven 110 for further processing in the staining booth 112. The transport subsystem 114 is similarly positioned along the longitudinal direction 144, parallel to the oven 110 and the supply subsystem 108. Thus, the system 100 has an overall "U" shape or layout that helps save space and enable installation of the system 100 in smaller buildings. The dyeing booth 112 is configured to apply dye to all sides of the dried surface wood. As shown in Figure 3, the dried surface wood may be transported directly from the outlet 132 of the oven 110 to the dyeing booth 112 by the conveyor 146. In some non-limiting examples, the dried surface wood may only be on the further conveyor 146 for short periods of time, such as 5-10 seconds or less and up to 90-180 seconds, so that there is a short time period for the dried surface wood between the oven 110 and the dyeing booth 112.

[0040] During operation, the dry surface wood 150 enters the dyeing booth 112 via an inlet 152 and is transported laterally 148 (Figure 3) through the dyeing booth 112 via a suitable conveyor. The conveyor can be a system of rollers that contact the wood on one or more sides, a tray, a belt, or other suitable conveyor system. The transport speed through the dyeing booth 112 is selected by a controller 140 (Figure 1) and, in some embodiments, can be controlled. The dry surface wood 150 is supported from below by a suitable support that also allows for dyeing. The conveyor moves the dry surface wood 150 through the dyeing booth 112 and applies dye from a dye storage tank 107 (Figure 1). The dye may be a semi-permeable dye available in various colors so that any remaining internal moisture in the wood 150 can be naturally released from the wood over time. In one embodiment, the dried surface wood 150 is transported through the staining booth 112 at a speed sufficient to coat the dried surface wood to a predetermined aesthetic quality associated with a product code, which means the application of a selected number of coats or layers of color or type of dye through the staining booth 112 at a selected transport speed to produce an aesthetic quality that matches the finished product according to the product code. The staining of the dried surface wood 150 produces stained wood 174 that exits the staining booth 112 at an exit 154.

[0041] The staining booth 112 can be any acceptable staining booth capable of uniformly applying an appropriate amount of dye to all sides (top, bottom, left, and right) of the wood in a clean manner, many of which are known in the art. Thus, the staining booth 112 is shown as a general staining setup in which dry surface wood 150 enters and appropriately stained wood 174 comes out.

[0042] As shown in Figure 4, the stained wood 174 is delivered to the landing area of ​​a transport subsystem 114 located at the exit 154 of the staining booth 112. The transport subsystem 114 extends along the longitudinal direction 144 parallel to the oven 110. Thus, the direction of movement of the stained wood 174 along the transport subsystem 114 can be perpendicular to the direction of movement through the staining booth 112. In one embodiment, the system 100 includes a backstop 176 which may have an adjustable position to prevent stained wood 174 of different lengths from falling off the platform 104 after leaving the landing area. Following staining in the staining booth 112, the stained wood 174 is transported along the transport subsystem 114. The transport subsystem 114 may be implemented as a series of sharp chains with pointed ends, or as some other conveyor device, to minimize contact area and avoid marking of the stained wood 174 after application. The transport subsystem 114 provides residence time to allow the dye to wet the surface and adsorb onto the surface, and allows some cooling if the dye is applied at a high temperature. In one embodiment, the transport subsystem 114 extends from the platform 104 to the ground 106 and is therefore arranged at a certain angle to the horizontal (i.e., between 0 and 90 degrees, excluding them and including all intervening values), depending on the height of the platform 104 and the length of the transport subsystem 114. In a non-limiting example, the height of the platform 104 may be about 10 feet, and the length of the transport subsystem 114 can be selected along with the transport speed of the sharp chain such that the drying time (i.e., the length of time it takes for the dyed wood 174 to move from the landing area to the bottom of the transport subsystem 114) is in the range of about 30 to about 120 seconds, including all intervening values. Times greater than 30 seconds are usually preferred, and longer times, e.g., 45 to 90 seconds, have been found to be beneficial. The dye continues to wet the dry surface wood and adhere to it while it cools along the transport subsystem 114.The dye carriers evaporate over time (which can take more than a month to complete), but the final appearance of the boards remains consistent throughout the evaporation process because the raw wood is surface-dried before dyeing. Such a process may be at least partially dependent on time and temperature, and the properties of the transport subsystem 114 (i.e., length, transport speed, etc.) are selected to provide sufficient time for the dye to spread and adsorb onto the substrate. At the end of the transport subsystem 114 is a grading chain 178 that allows the operator 126 to pull the dyed boards 180 and bundle them for shipment.

[0043] Figures 5A to 5C are schematic diagrams of a pin meter 182 for measuring the moisture content of wood according to embodiments of the present disclosure. Wood is generally known to have properties that vary based on many factors. For example, the green wood 116 described herein may have initial surface moisture content and internal moisture content that vary at least based on the type of green wood 116 and the ambient humidity of the air in which the green wood 116 is stored. Ambient humidity may depend at least in part on the location and season in which the wood is stored after it has been cut, as well as the environment in which the log was cut. Therefore, the initial surface moisture content and internal moisture content of green wood 116 may vary between 20% and 40% or more or less, and in any case, are likely to be above about 15%. Referring to Figure 5A, the moisture content of the outermost surface of wood such as green wood 116 (i.e., surface moisture content) can be measured with a pin meter 182 stationary by its own weight relative to the outermost surface of the green wood 116. The pin meter 182 may be a commercially available pin meter typically weighing less than 1 pound (16 ounces), and more commonly less than 1 / 2 pound (8 ounces), such that the test prongs 186 of the pin meter 182 do not substantially penetrate the green wood 116 when the prongs 186 of the pin meter 182 are stationary against the surface of the wood 116 under only the weight of the pin meter 182. The pin depth may be in the range of 0.01 to 0.06 inches, and is usually less than 0.05 inches, where it is stationary under its own weight. The depth is the depth of the dry surface of the wood, which is less than about 15%, so that the dye can be adequately wetted and adsorbed onto the substrate. Higher surface moisture content may hinder the wetting and adsorption of the dye.

[0044] After drying the green wood 116 to produce dried surface wood 150, the dried surface wood 150 includes an inner portion 184A surrounded by an outer portion 184B, as shown in Figure 5B. The outer portion 184B can also be described as a dried surface layer 184B around all sides of the inner portion 184A, which has an outermost dried surface 184C. In one embodiment, the outer portion 184B or dried surface layer 184B has a thickness or depth of less than about 0.08 inches within the dried surface wood 150. The moisture content of the dried surface 184C can be measured again by a pin meter 182 stationary relative to the outermost surface 184C by its own weight. In some embodiments, the moisture content of the dried surface 184C may be less than about 15% after drying the green wood 116. Referring to Figure 5C, the internal moisture content of wood such as green wood 116 or dried surface wood 150 can be measured by inserting the test prong 186 of a pin meter 182 into the wood 116, 150 to a depth of preferably about 0.08 inches or at least 0.08 inches. At this depth, the prong 186 extends beyond the interface between the outer portion 184B or dried surface layer 184B and the inner portion 184A, which may be located at a depth of less than about 0.08 inches in the wood 116, 150 to measure the moisture content of the inner portion 184A. In some embodiments, the moisture content of the inner portion 184B may be higher than the moisture content of the dried surface 184C, such as about 15% or more after drying. Thus, the wood described herein may have an internal moisture content of at least 15% both before and after drying.

[0045] Figure 6 is a block diagram of the controller 140. The controller 140 may be suitable for performing or implementing at least some embodiments or techniques described herein with respect to the system 100.

[0046] The controller 140 includes a processor 188, for example, a microprocessor, a digital signal processor, a programmable gate array (PGA), or an application-specific integrated circuit (ASIC). The controller 140 includes one or more non-temporary storage media, for example, a read-only memory (ROM) 190A, a random access memory (RAM) 190B, flash memory (not shown), or other physical computer or processor-readable storage media that communicate with the processor 188. The non-temporary storage media can generally store instruction words and / or data used by the processor 188 and the controller 140, for example, an operating system (OS) and / or applications. Instructions executed by the processor 140 can execute logic to perform functions of various implementations or technologies of the devices and systems described herein.

[0047] The controller 140 may include a user interface 192 to enable an operator or other user to operate the system 100 as described herein or otherwise provide input regarding the operating state or conditions of the system 100. The user interface 192 may include several user-operable control units, such as toggle switches, keypads or keyboards, rocker switches, or other physical actuators that can be operated to turn the system 100 on and off and / or to set various operating parameters of the system 100, such as overall throughput, temperature inside the oven 110, and others described herein. In some embodiments, the user interface 192 may include a display, for example, a touch panel display. The touch panel display (e.g., an LCD or LED with a touch sensor overlay) may provide both input and output interfaces for the operator or other user. The touch panel display may present a graphical user interface having a variety of user-selectable icons, menus, checkboxes, dialog boxes, and other components and elements that can be selected by the end user to set the operating state or conditions of the system 100. The user interface 192 may also include one or more auditory transducers, e.g., one or more speakers and / or microphones. Such may enable audible alert notifications or signals to be provided to the operator or other user as a result of manual interaction with the user interface 192. Such may also enable the operator or other user to provide audible commands or instructions, either additionally or alternatively. The user interface 192 may include additional components and / or components different from those illustrated or described, and / or some components may be omitted.

[0048] The controller 140 includes a communication subsystem 194, which may include one or more communication modules or components that facilitate communication with various components of one or more external devices, such as personal computing devices, mobile devices, or servers. The communication subsystem 194 may provide wireless or wired communication to one or more external devices and may include wireless receivers, wireless transmitters, and / or wireless transceivers to provide a wireless signal path to various remote components or systems of one or more paired devices. The communication subsystem 194 may include components that enable short-range (e.g., via Bluetooth®, BLE ("Bluetooth® low energy"), near-field communication (NFC), or radio frequency identification (RFID) components and protocols) or long-range wireless communication (e.g., via wireless LAN, low-power wide-area network (LPWAN), satellite, or cellular network), and may include one or more modems or one or more Ethernet® or other type of communication cards or components for doing so. The communication subsystem 194 may include one or more bridges or routers suitable for handling network traffic, including packet-switched communication protocols (TCP / IP), Ethernet®, or other networking protocols.

[0049] The controller 140 further includes a power interface manager 196 that manages the supply of power from the power supply 198 to the controller 140 and various components of the system 100. The power interface manager 196 is coupled to the processor 188 and the power supply 198. Alternatively, in some implementations, the power interface manager 196 can be integrated into the processor 188. The power supply 198 may include, among other things, an external power supply or a rechargeable or replaceable battery power supply. In some embodiments, the power interface manager 196 may include power converters, rectifiers, buses, gates, circuits, etc. In particular, the power interface manager 196 can control, limit, and / or restrict the supply of power from the power supply 198 based on various operating states of the system 100, as will be described in more detail below.

[0050] In some embodiments or implementations, instructions and / or data stored on non-transient storage media, generally used by the processor 188 and controller 140, such as ROM 190A, RAM 190B, and flash memory (not shown), include or provide an application programming interface ("API") that provides programmatic access to one or more functions of the controller 140. For example, such an API may provide a programmatic interface for controlling one or more operational characteristics of the system 100. In this way, the API can facilitate the development of third-party software, such as various different user interfaces and control systems for other devices, plug-ins, and adapters, etc., to facilitate the interactivity and customization of the operation of the system 100.

[0051] In one embodiment, the controller 140 and other device components or modules within the system 100 described herein are implemented using standard programming techniques. For example, the logic for performing the functions of the various embodiments or techniques described herein may be implemented as a “native” executable file that runs on the controller 140, for example, the microprocessor 188, along with one or more static or dynamic libraries. In other embodiments, the various functions of the controller 140 may be implemented as instructions processed by a virtual machine, which runs as one or more programs, with the instructions stored on ROM 190A and / or RAM 190B. In general, various programming languages ​​known in the art, including representative implementations of various programming language paradigms, including but not limited to object-oriented (e.g., Java®, C++, C#, Visual Basic.NET, Smalltalk, etc.), functional (e.g., ML, Lisp, Scheme, etc.), procedural (e.g., C, Pascal, Ada, Modula, etc.), scripting (e.g., Perl, Ruby, Python, JavaScript®, VBScript, etc.), or declarative (e.g., SQL, Prolog, etc.), may be employed to implement such exemplary embodiments.

[0052] In software or firmware implementations, instructions stored in memory, when executed, configure one or more processors of the controller 140, such as a microprocessor 188, to perform the functions of the controller 140. The instructions cause the microprocessor 188 or any other processor, such as an I / O controller / processor, to process information received from one or more sensors or other external devices and to act based on that information to provide the functions and techniques of the system 100 described herein.

[0053] The embodiments or implementations described above may also use well-known or other synchronous or asynchronous client-server computing techniques. However, the various components may be implemented using more monolithic programming techniques, for example, as executable files running on a single microprocessor, or alternatively, they may be decomposed using various structuring techniques known in the art, including but not limited to multiprogramming, multithreading, client-server, or peer-to-peer (e.g., Bluetooth®, NFC or RFID wireless technology, mesh network, etc.), each running on one or more computer systems having one or more central processing units (CPUs) or other processors. Some embodiments may run concurrently and asynchronously and communicate using message-passing techniques. Other functions may also be implemented and / or executed by each component / module, in a different order and by different components / modules, while still achieving the functionality of the controller 140.

[0054] In addition, the programming interface to the data stored on the controller 140 and the functionality provided thereby can be made available through standard mechanisms, such as C, C++, C#, and Java APIs, libraries for accessing files, databases, or other data repositories, scripting languages, or through web servers, FTP servers, or other types of servers that provide access to the stored data. The data stored and used by the controller 140 and the entire system 100 may be implemented as any combination of the above, including one or more database systems, file systems, or any other technology for storing such information, or implementations using distributed computing technology.

[0055] Different configurations and locations of programs and data are intended for use with the technologies described herein. Various distributed computing technologies, including but not limited to TCP / IP sockets, RPC, RMI, HTTP, and web services (XML-RPC, JAX-RPC, SOAP, etc.), are suitable for implementing the components of the illustrated embodiments in a distributed manner. Other variations are also possible.

[0056] Furthermore, in some embodiments or implementations, some or all of the components of the controller 140 and some or all of the components of the system 100 or other devices may be implemented or provided in other ways, such as at least in part, in firmware and / or hardware, including but not limited to one or more application-specific integrated circuits ("ASICs"), standard integrated circuits, controllers (e.g., including microcontrollers and / or embedded controllers by executing appropriate instructions), field-programmable gate arrays ("FPGAs"), complex-programmable logic devices ("CPLDs"), etc. Some or all of the system components and / or data structures may also be stored as content (e.g., as executable or other machine-readable software instructions or structured data) on a computer-readable medium (e.g., as a portable media item to be read by an appropriate drive or via an appropriate connection, such as a hard disk, memory, computer network, cellular wireless network or other data transmission medium, or DVD or flash memory device) so as to enable or configure the computer-readable medium and / or one or more associated computing systems or devices to perform or otherwise use or provide content for performing at least some of the techniques described. In some non-limiting examples, the controller 140 technology described herein may be implemented with control software and / or control logic, such as that from Contrologix, in conjunction with control hardware, such as that from Allen Bradley.

[0057] In one embodiment, the controller 140 communicates with at least one of the following: the conveyor 122 of the supply subsystem 108, the transport device 130 of the oven 110, the heating element 138 of the oven 110, the further conveyor 146 between the oven 110 and the dyeing booth 112, the dyeing booth 112, and a humidity sensor 142 associated with the exhaust port 134. At least a non-temporary storage medium such as ROM 190A and / or RAM 190B may store instructions, when executed by the processor 188, that control the transport speeds of the conveyors 122, 146, the transport device 130, and the throughput through the dyeing booth 112. The transport speeds may be adjustable and selectable to vary the throughput throughout the system 100, as well as the throughput in individual aspects of the system 100. For example, since the throughput through the oven 110 via the transport device 130 is independent of the throughput through the dyeing booth 112, the transport speed of the transport device 130 can be selected to be different from the transport speed through the dyeing booth 112 via an appropriate conveyor system, through input to the user interface 192 and corresponding instructions stored in a storage medium and executed by the processor 188.

[0058] At least non-temporary storage media such as ROM 190A and / or RAM 190B, when executed by processor 188, may store further instructions to control the time and temperature profile through the oven 110 based on information, data, and / or signals received from humidity sensor 142. More specifically, humidity sensor 142 may provide controller 140 with information, data, and / or signals corresponding to a determined humidity level at at least one exhaust port 134 of oven 110. Controller 140 may receive such information, data, and / or signals and compare them with a database of time and temperature profiles for different detected humidity concentrations to determine, in a closed feedback loop, whether to execute further instructions to adjust the residence time of wood in oven 110 (i.e., the transport speed of transport device 130) and / or the temperature of oven 110 (i.e., the fuel and / or power supplied to heating element 138).

[0059] In a non-limiting example, the oven 110 may initially operate at a temperature of 350°F using a transport device that transports the green wood 116 through the oven 110 for a period of 100 seconds, according to a time and temperature profile for a first humidity detected by a humidity sensor 142. If the humidity sensor 142 detects a change in humidity greater than a defined error threshold, such as a change of more than 2% of humidity, among many other possibilities, the controller 140 may compare the second different humidity with a database of time and temperature profiles and execute a command to select a new time and temperature profile corresponding to the second humidity. The controller 140 then executes further commands in a closed feedback loop to change the transport speed of the transport device 130 and / or change the temperature inside the oven 110 according to the second time and temperature profile. The second time and temperature profile may, for example, be a temperature of 400°F and a time of 90 seconds passing through the oven 110, or simply changing the temperature to 400°F while keeping the time of passing through the oven 110 the same at 100 seconds. The time and temperature profiles described herein may generally correspond to any selected values ​​within the range provided herein, including a time of passing through the oven 110 for 30 to 240 seconds at temperatures in the range of 350°F to 450 to 500°F. The time and temperature profiles may be developed, at least in part, based on known or experimental data to achieve a sufficient surface moisture content in the dried surface wood 150 after drying, taking into account different species of green wood 116, ambient humidity, and pre-drying moisture content, thereby enabling wetting and adsorption of the dye to the surface. In one embodiment, a sufficient surface moisture content corresponds to a moisture content of about 15% or less at the outermost surface 184C (Figure 5B) of the dried surface wood 150.

[0060] In one embodiment, the humidity sensor 142 is optionally positioned close to the entrance 128 of the oven 110 and is complemented or replaced by a scanning device 143, such as a line scanning device, which includes an infrared or near-infrared emitter and / or sensor for determining the moisture content of green wood 116 entering the oven 110 and provides the moisture content to the controller 140 in a closed feedback loop of the type described above. In other words, the information, data, and / or signals from the humidity sensor 142 can be complemented or optionally replaced by information data and / or signals from the scanning device 143 in some embodiments to provide the closed feedback loop described above.

[0061] Many other variations are contemplated herein, including, but not limited to, using temperatures higher than those described above for shorter or longer periods, and using the temperatures described above for shorter or longer periods. As described above, the initial surface moisture content can be determined by a pin meter 182 or any other acceptable technique known to be accurate. Time and temperature profiles can then be selected for wood with fluctuating moisture content to produce dry surface wood 150 having a surface moisture content suitable for dye application, i.e., about 15%.

[0062] It should be understood that the above description of System 100 also includes related methods. A non-limiting example of a method may include drying the raw wood 116 in the oven 110 according to a time and temperature profile until the moisture content of the outermost surface of the raw wood 116 is about 15% or less, producing dried surface wood 150. The method further includes transporting the dried surface wood 150 directly from the outlet 132 of the oven 110 via a conveyor 146 to a dyeing booth 112. The dyeing booth 112 applies dye to all sides of the dried surface wood 150 to produce dyed wood 174. The dyed wood 174 is transported along a transport subsystem 114, which may be a conveyor, for a time that may vary, but preferably about 30 to 120 seconds. After the transport period, the dyed wood 180 can be bundled for shipment by the operator 126. The method also includes, among other things, changing the characteristics of the oven 110 (i.e., at least the transport speed of the transport device 130 and the temperature inside the oven 110 via the heating element 138) in a closed feedback loop to dry the wood with a fluctuating initial moisture content based on information received from the humidity sensor 142 and / or the scanning device 143.

[0063] Accordingly, the concepts of the present disclosure provide systems, devices, and methods for drying and dyeing wood, as well as dyed wood produced by such systems, devices, and methods, which can be manufactured at a lower total cost than known technologies. The concepts of the present disclosure generally consider drying the wood for a relatively short time to form a dry surface layer, which reduces drying time compared to known technologies, and further allow the dye to be applied to the dry surface layer and spread and adsorbed onto the substrate. Residual moisture in the wood is released from the board over time, even after the pre-dyed wood has been placed in its final position by the end user. The feedback control loop described herein helps to change the characteristics of the oven to produce consistent results for wood with varying initial moisture content.

[0064] The above description includes certain specific details in order to provide a complete understanding of the various embodiments of this disclosure. However, those skilled in the art will understand that this disclosure may be implemented without these specific details. In other examples, well-known structures associated with the technology are not described in detail in order to avoid unnecessarily obscuring the description of the embodiments of this disclosure.

[0065] Certain words and phrases used herein are as follows: As used throughout this specification, including in the claims, the singular forms “a,” “an,” and “the” include plural references unless otherwise indicated. Any of the features and elements described herein may be singular; for example, “shell” may refer to one shell. The terms “include” and “comprise,” and their derivatives, mean inclusion without limitation. The phrases “associated with” and “associated therewith,” and their derivatives, may mean include, contained within, connected to, encompass, contained within, connected or connected to, joined or coupled to, communicable with, cooperating with, alternating, juxtaposed, adjacent, fixed to or fixed to, having, possessing, etc. Other definitions of certain words and phrases are provided throughout this disclosure.

[0066] The use of ordinal numbers such as 1st, 2nd, 3rd does not necessarily imply a ranked order, but rather may simply distinguish between multiple examples of the same behavior or structure or material.

[0067] Throughout this specification, the claims, and the drawings, the following terms take the meaning expressly associated herein unless otherwise explicitly indicated by context. The term “in this specification” means the specification, claims, and drawings associated with this application. The phrases “in one embodiment,” “in another embodiment,” “in various embodiments,” “in some embodiments,” “in other embodiments,” and other derivatives thereof refer to one or more features, structures, functions, limitations, or characteristics of the disclosure and are not limited to the same or different embodiments unless otherwise explicitly indicated by context. Where used herein, the term “or” is an inclusive “or” operator and is equivalent to the phrases “A or B, or both” or “A or B or C, or any combination thereof,” and lists having additional elements are treated similarly. The term “based on” is not exclusive and, unless otherwise explicitly indicated by context, allows for the basis of additional features, functions, aspects, or limitations not described herein.

[0068] In general, unless otherwise indicated, the materials for fabricating the present invention and / or its components may be selected individually or in any combination from suitable materials such as composite materials, ceramics, metals, various polymers (e.g., thermoplastics, elastomers, plastic compounds), catalysts, and ammonia compounds.

[0069] For illustrative purposes, the foregoing description uses specific nomenclature and formulas to provide a complete understanding of the disclosed embodiments. It should be apparent to those skilled in the art that specific details are not required to carry out the invention. The embodiments are selected and described to best illustrate the principles of the disclosed embodiments and their practical applications, thereby enabling those skilled in the art to utilize the disclosed embodiments as well as various embodiments with various modifications suitable for specific intended uses. Therefore, the foregoing disclosure is not intended to be exhaustive or to limit the invention to the disclosed detailed forms, and those skilled in the art will recognize that many modifications and variations are possible considering the teachings above.

[0070] The terms “top,” “bottom,” “upper side,” “lower side,” “up,” “down,” “upward,” “downward,” “left,” “right,” and other similar derivatives take their general meanings as directional or positional indicators, for example, gravity pulls an object downward, and left refers to a direction toward west when facing north in a cardinal orientation scheme. These terms are not limited to possible orientations that are expressly, implicitly, or essentially disclosed in this disclosure, and any aspect of the embodiments of this disclosure may be placed in any orientation unless otherwise clearly indicated in the context.

[0071] Unless otherwise explicitly indicated in the context, relative terms such as “approximately,” “substantially,” and other derived terms, when used to describe a value, quantity, number, or dimension, are generally interpreted to include the normal tolerance or manufacturing tolerance, and generally refer to a value, quantity, number, or dimension within ±3% of the stated value, quantity, number, or dimension. Any specific dimensions of any component or feature provided herein are for illustrative purposes only with reference to the various embodiments described herein, and therefore, unless otherwise explicitly indicated in the context, it should be further understood that dimensions exceeding or falling below the stated dimensions are expressly considered in this disclosure.

[0072] This application claims priority to U.S. Provisional Application No. 63 / 506,008, filed with the U.S. Patent and Trademark Office on 2 June 2023, the contents and disclosures thereof incorporated herein by reference.

[0073] Further embodiments can be provided by combining the various embodiments described above. These and other modifications can be made to the embodiments in light of the detailed description above. In general, the terms used in the following claims should not be construed as limiting the claims to the specific embodiments disclosed herein and in the claims, but rather as encompassing all possible embodiments, along with the entire scope of equivalents to which rights are granted. Thus, the claims are not limited by this disclosure.

Claims

1. A method of drying and staining wood, Supplying raw wood with a fluctuating moisture content exceeding 20% ​​into the oven, The process involves drying the raw wood in the oven according to a time and temperature profile based on the surface moisture content of the raw wood before drying, thereby producing dried surface wood having a surface moisture content of less than approximately 15% on its surface. A method comprising staining the dried surface wood immediately after the drying.

2. The method according to claim 1, wherein drying the green wood is a single continuous processing step.

3. The method according to claim 1, wherein the time and temperature profiles vary depending on one or more of the type of raw wood, the ambient humidity in which the raw wood was stored, and the moisture content of the raw wood before drying when it enters the oven.

4. The method according to claim 1, wherein the moisture content of the dried surface wood is measured at the outermost surface of the dried surface wood.

5. The method according to claim 4, wherein the moisture content at the outermost surface of the dried surface wood is measured using a pin meter that is stationary on the outermost surface of the dried surface wood by its own weight.

6. The method according to claim 1, wherein the internal moisture content of the dried surface wood is more than approximately 15% after drying, as measured by a pin meter inserted at least 0.08 inches into the wood.

7. The method according to claim 1, wherein drying the raw wood comprises determining the pre-drying moisture content of the raw wood based on the moisture content in the exhaust of the oven, and adjusting the time and temperature profiles in a closed feedback loop based on the moisture content.

8. A method of drying and staining wood, Drying includes drying green wood in an oven until the moisture content of the outermost surface of the green wood is about 15% or less, thereby producing dried surface wood. The dried surface wood is transported directly into the dyeing booth from the outlet of the oven, The process involves applying dye to all sides of the dried surface wood inside the dyeing booth to produce dyed wood, The stained wood is transported along a first conveyor while being exposed to ambient air on the first conveyor for a selected residence time, the residence time being within the range of approximately 30 seconds to approximately 120 seconds. A method comprising bundling the stained wood after the aforementioned transport and shipping it.

9. Applying the dye to the dried surface wood is The method according to claim 8, comprising conveying the dried surface wood through the staining booth at a speed sufficient to coat the dried surface wood to a predetermined aesthetic quality associated with a product code.

10. The method according to claim 8, wherein drying the raw wood involves drying the raw wood in an oven according to a time and temperature profile that achieves a surface moisture content sufficient to allow wetting and adsorption of the dye onto the surface.

11. Before drying the aforementioned green wood, Loading bulk green wood onto an inclined table, The bulk green wood is divided into individual green wood pieces, and these individual green wood pieces are loaded onto a second conveyor. The method according to claim 8, further comprising transporting the individual pieces of green wood from the inclined table to the entrance of the oven using the second conveyor.

12. The method according to claim 8, wherein applying the dye to the dried surface wood includes drawing out excess dye from the dried surface wood in the dyeing booth.

13. The method according to claim 8, wherein the moisture content of the outermost surface of the dried surface wood is measured using a pin meter that is stationary on the outermost surface of the dried surface wood by its own weight.

14. The method according to claim 8, wherein drying the green wood in the oven is such that the green wood and the dried surface wood have an internal moisture content of at least about 15% before and after drying, as measured using a pin meter inserted 0.08 inches into the green wood and the dried surface wood, respectively.

15. It is a wood product, A piece of wood having an inner portion and an outer portion surrounding the inner portion, wherein the outer portion has an outermost surface, The wood piece comprises a staining layer on the outermost surface of the outer portion of the wood piece, When the dye is applied, the inner portion has an initial moisture content of more than approximately 15%, and the outermost surface has a moisture content of less than approximately 15%. A wood product wherein the dyed layer is semi-permeable and is configured to release moisture from the inner portion over time, thereby reducing the moisture content of the inner portion from the initial moisture content to a final total moisture content of approximately 15% or less.

16. The wood product according to claim 15, wherein the wood piece has a boundary between the inner portion and the outer portion located about 0.08 inches from the outermost surface of the wood piece.

17. The wood product according to claim 15, wherein the initial moisture content and the final moisture content of the inner portion of the wood piece are measured using a pin meter inserted approximately 0.08 inches into the wood piece.

18. The wood product according to claim 15, wherein the moisture content of the outermost surface is measured using a pin meter that is stationary under its own weight relative to the outermost surface of the wood piece.

19. The wood product according to claim 15, wherein the staining layer is configured to spread and adsorb onto the dry surface wood before the dry surface wood absorbs moisture from both the inside and surrounding air of the board.

20. The device according to claim 15, wherein the wooden piece is a fence board, a fence post, or a fence rail.

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