Patent Application
20190126508
There is described a method of manufacturing glue laminated timber columns.
Wikipedia has the following commentary on glue laminated timber.
“Glued laminated timber, also called glulam, is a type of structural engineered wood product comprising a number of layers of dimensioned lumber bonded together with durable, moisture-resistant structural adhesives. In North America the material providing the laminations is termed laminating stock or lamstock. By laminating a number of smaller pieces of lumber, a single large, strong, structural member is manufactured from smaller pieces. These structural members are used as vertical columns or horizontal beams, as well as curved, arched shapes. Glulam is readily produced in curved shapes and it is available in a range of species and appearance characteristics to meet varied end-use requirements. Connections are usually made with bolts or plain steel dowels and steel plates. Glulam optimizes the structural values of a renewable resource—wood. Because of their composition, large glulam members can be manufactured from a variety of smaller trees harvested from second- and third-growth forests and plantations. Glulam provides the strength and versatility of large wood members without relying on the old growth-dependent solid-sawn timbers. As with other engineered wood products, it reduces the overall amount of wood used when compared to solid sawn timbers by diminishing the negative impact of knots and other small defects in each component board. Glulam has much lower embodied energy than reinforced concrete and steel, although of course it does entail more embodied energy than solid timber. However, the laminating process allows timber to be used for much longer spans, heavier loads, and complex shapes. Glulam is two-thirds the weight of steel and one sixth the weight of concrete—the embodied energy to produce it is six times less than the same suitable strength of steel. Glulam can be manufactured to a variety of straight and curved configurations so it offers architects artistic freedom without sacrificing structural requirements.”
According to one aspect, there is provided a method of manufacturing glue laminated timber columns. In broad terms the method involves forming a glue laminated timber panel as an intermediate step and then cutting the glue laminated timber panel into a selected number of glue laminated timber columns.
According to another aspect, there is a glue laminated timber column made in accordance with the teaching of the method.
The industry is presently doing a custom lay-up for each column manufactured. The method described above, therefore, is a radical departure from industry practices. This enables a dramatic reduction in cost. In addition, the method enables a dramatic increase in the speed with which order can be filled. A plurality of standard glue laminated timber panels can be prepared in advance. As orders are received, the glue laminated timber panels can be rapidly cut to create glue laminated timber columns that meet customer's requirements, with the columns ready for shipment on the same date the order was received.
The adoption of this method has enabled further measures to be taken to reduce cost. The industry practice is to make columns from very high grade and high cost Douglas fir lumber. When Spruce-pine-fir (SPF) lumber is used, the costs are further reduced. As the SPF2100 MSR lumber is a machine stress-rated (MSR) lumber, this substitution can be made while still meeting engineering specifications.
The adhesives currently used in the making of glue laminated timber columns are resorcinol and melamine adhesives. It is preferred that polyurethane adhesives be used. The use of polyurethane adhesives are preferred because they provide the following advantages: they are fast glue curing, require less pressure and are more environmentally friendly.
When the innovation in manufacture is combined with the innovation in the use of polyurethane adhesives and the use of lower cost fibre, the end result is a glue laminated timber column that is significantly lower in cost as compared to a custom glue laminated timber column fabricated by previously known methods.
These and other features will become more apparent from the following description in which reference is made to the appended drawings, the drawings are for the purpose of illustration only and are not intended to be in any way limiting, wherein:
A method of manufacturing glue laminated timber columns will now be described with reference to
Referring to
Referring to
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While the method could be used with high quality Douglas Fir lumber, in order to minimize cost, it is preferred that the boards 18 used are a spruce-pine-fir (SPF2100MSR) lumber. SPF2100MSR is a machine stress-rated (MSR) lumber and can be substituted while still meeting engineering specifications. While the method could be used with any suitable adhesive, it is preferred that the glue used to fabricate the glue laminated timber panel be a polyurethane adhesive. The polyurethane adhesive provides the following advantages: they are fast glue curing, require less pressure and are more environmentally friendly.
While the method could be used with boards 18 of different dimensions, beneficial results have been obtained by the applicant using with 2×6 lumber. Boards 18 are planned prior to use to provide consistent dimensions. After planning each of the boards is 35 mm (1⅜ inches) thick and 133 mm (5.25 inches) in width.
The cross-laminated timber (CLT) press used by the applicant can accommodate a width of 10 feet. However, care must be taken to allow room for pressing. In the result a glue laminated timber panel approximately 8 feet in width is preferred. The cross-laminated timber (CLT) press used by the applicant glue laminated timber panel can be of any length up to 40 feet. Referring to
In this patent document, the word “comprising” is used in its non-limiting sense to mean that items following the word are included, but items not specifically mentioned are not excluded. A reference to an element by the indefinite article “a” does not exclude the possibility that more than one of the element is present, unless the context clearly requires that there be one and only one of the elements.
The scope of the claims should not be limited by the illustrated embodiments set forth as examples, but should be given the broadest interpretation consistent with a purposive construction of the claims in view of the description as a whole.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2984079 | Oct 2017 | CA | national |
