Patent Application
20210170624
The present disclosure relates generally to lumber and more particularly to laminated veneer lumber that has been specifically treated after assembly and a related method for making the same.
Laminated veneer lumber (LVL) is an engineered wood product that uses multiple layers of thin wood assembled with adhesives. LVL is typically used for headers, beams, rafters, rim board and edge-forming material. LVL can be preferred over typical milled lumber in many instances. For example, LVL is manufactured to controlled specifications. In this regard, LVL can be manufactured to be stronger, straighter and more uniform as compared to conventional solid milled lumber. Further, due to its composite nature, LVL is much less likely than conventional lumber to warp, twist, bow or shrink.
While LVL can be useful in many applications a need still exists in the art to provide improvements. For example, LVL is typically installed in interior environments that are not exposed to weather. In addition, a need exists to provide a straighter, stronger and more consistent lumber solution that is simpler to make and can be readily applied to a wider range of applications.
The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
A method of making treated laminated veneer lumber (LVL) according to one example of the present disclosure includes obtaining assembled LVL. The assembled LVL comprises a plurality of layers of veneer wood assembled together with adhesive. The LVL is loaded into a pressure chamber. A vacuum is created in the pressure chamber thereby removing air from the plurality of layers of veneer wood of the LVL. Inorganic solution is added into the pressure chamber. The pressure chamber is pressurized to force the inorganic solution into the wood creating the treated LVL.
According to additional features, a predetermined amount of time is passed subsequent to pressurizing the pressure chamber to allow the inorganic solution to sufficiently absorb into the LVL. In one example, the predetermined amount of time is greater than 30 minutes. In another example, the predetermined amount of time is greater than 35 minutes. In still other examples, LVL can be successfully penetrated through the thickness of the LVL during pressure treatment in less time, such as but not limited to, 6 minutes. The inorganic solution is removed from the pressure chamber subsequent to waiting the predetermined amount of time. A vacuum is created in the pressure chamber subsequent to removing the inorganic solution from the pressure chamber.
In other features, the treated LVL is removed from the pressure chamber and placed onto a concrete pad for drying. Adding the inorganic solution can include adding a solution that includes at least one of micronized copper azole (MCA), copper azole (CA), ammoniacal copper quaternary (ACQ), ammoniacal copper zinc arsenate (ACZA) and chromatid copper arsenate (CCA). In one example, adding the inorganic solution comprises adding a solution that comprises all of the MCA, CA, ACQ, ACZA and CCA. In still other examples, the inorganic solution can additionally or alternatively include other vacuum pressure waterborne inorganic chemicals.
A treated laminated veneer lumber (LVL) according to the present disclosure is provided. The treated LVL comprises an assembled LVL treated with an inorganic solution in a pressure chamber. The inorganic solution is penetrated through an entire thickness of the assembled LVL. In some examples, the inorganic solution comprises a solution that includes at least one of micronized copper azole (MCA), copper azole (CA), ammoniacal copper quaternary (ACQ), ammoniacal copper zinc arsenate (ACZA) and chromatid copper arsenate (CCA). In one example, the inorganic solution comprises all of MCA, CA, ACQ, ACZA and CCA. The CA can comprise type A and B. The ACQ can comprise type B and C. The CCA can comprise type A, B and C.
The present disclosure will become more fully understood from the detailed description and the accompanying drawings, wherein:
As will become appreciated from the following discussion, the present disclosure provides a treated LVL that is created using a novel method. While not so limited, the treated LVL disclosed herein is particularly useful in outdoor applications, such as but not limited to, deck framing. While traditional LVL has been successfully used in many applications such as indoor framing, such LVL is not particularly suited for outdoor use where weather elements such as moisture and sun can degrade the LVL over time. Moreover, other treated LVL offerings incorporate organic treatments and involve multiple steps for treating each layer of wood prior to assembly.
With initial reference to
Turning now to
Turning now to
Each veneer 102A, 102B, 102C, 102D and 102E is dried and graded. In most examples, the higher graded veneers are used for the face of the LVL while lesser graded veneers are arranged near the core. Once the veneers 102A, 102B, 102C, 102D and 102E are dried they are individually passed under a curtain or roll coater where resin is applied. The resin can be phenol-formaldehyde (PF) or urea-formaldehyde (UF) or other material suitable for joining the veneers 102A, 102B, 102C, 102D and 102E together. Once resin is applied to each individual veneer 102A, 102B, 102C, 102D and 102E, the veneers are arranged in a stack 110 and fed into a hot press where the stack of veneers 110 are pressed into a solid billet thereby forming the assembled LVL. In some examples the solid billets may be rip cut into numerous strips 120A, 120B according to customer specification. By way of example, some LVL strips can be formed to beam length sections having 1 and ¾ inch by 11 and ⅞ inch cross-sections. Again, the description of the method of forming assembled LVL above is merely exemplary and other methods may be used for forming the assembled LVL within the scope of the present disclosure.
With reference to
With particular reference now to
With continued reference to
The pressure chamber 210 is then filled with solution at 322. According to one example, the solution is inorganic solution that fully impregnates the assembled LVL with waterborne preservatives such as, but not limited to micronized copper azole (MCA), copper azole, type A and B (CA), ammoniacal copper quaternary, type B and C (ACQ), ammoniacal copper zinc arsenate (ACZA) and chromatid copper arsenate, type A, B and C (CCA). In still other examples, the inorganic solution can additionally or alternatively include other vacuum pressure waterborne inorganic chemicals. Next, the pressure chamber 210 is pressurized to force the solution through the assembled LVL at 324. The pressure chamber 210 is pressurized for an amount of time required to sufficiently penetrate the solution through the thickness of the LVL. In some examples, the LVL is pressurized for greater than 30 minutes, such as 35 minutes to ensure full penetration of the solution through the thickness of the LVL. In other examples, the LVL can be successfully penetrated through the thickness of the LVL during pressure treatment in less time, such as but not limited to, 6 minutes. After the assembled LVL has been submerged with solution and pressurized for a period of time, the solution is removed (drained) from the pressure chamber 210 at 330. In some examples the solution is returned back to a work tank where it can be used again. At 332 a final vacuum is introduced to the vacuum chamber 210 to remove excess solution. The treated LVL 120C is then removed from the vacuum chamber 210 at 334. In some examples the treated LVL 120C can be placed on a concrete pad for a designated amount of time. The method ends at 340.
The foregoing description of the examples has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular example are generally not limited to that particular example, but, where applicable, are interchangeable and can be used in a selected example, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.
