BAMBOO STEEL

Description

2 Unprocessed bamboo poles from whole culms are therefore suitable up to a certain height for applications such as scaffolding, columns, or posts. The failure modes of bamboo poles are generally caused by splitting along the length of the culm, whereby the parallel fibers separate. Such a failure mode is also evident when fasteners such as bolts are placed through the culm, resulting in poor pull-out performance when bent along the length, making the use of natural bamboo not necessarily a good substitute for wood containing extra cross fibers. To manufacture traditional dimensional construction material, such as timber beams, from bamboo, the bamboo stalk is typically shredded, after which the chips are processed with resins into dimensional timber. However, this shredding destroys the natural fiber orientations and lignin bonds and thereby the natural strength properties of the bamboo stalk, which usually results in materials that are less strong and / or heavier than the natural bamboo stalk.Instead of shredding, bamboo wood is also produced by pressing bamboo fibers. In this case, (giant) bamboo is sawn into long strips. To eliminate parasites and make the bamboo pliable, the strips are boiled in water, after which they are glued together under high pressure. By using multiple layers, the thickness can be varied. By applying the layers diagonally and crosswise, a sheet or plank is created that is, among other things, more resistant to warping. A number of patent publications related to the use of bamboo instead of wood are discussed below. 25USA Patent US10,442,111B1 can be summarized as laminated bamboo timber for the replacement of timber made from trees. The bamboo-laminated timber is formed from laminated bamboo elements that are laminated together to form composite timber components.The laminated bamboo wood consists of a combination of linear bamboo planks, consisting of longitudinally halved halves of wooden bamboo canes that have been flattened and laminated in alternating layers of half bamboo canes in the longitudinal direction of the grain, alternating with half bamboo canes positioned at an angle to them, so that the grain runs at an angle relative to the half bamboo canes positioned in the longitudinal direction. The disadvantage of this solution is that production is complicated and relatively large amounts of bamboo waste are to be expected when making boards of this form of bamboo timber.Finally, it is known on the market for bamboo timber the construction of block-shaped bamboo strips (hereinafter referred to as bamboo elements) in multiple layers, whereby the bamboo elements are placed in a bond known in the construction world as tile bond, in which the bamboo elements of equal width are stacked vertically on top of each other and glued, thereby forming blocks of bamboo elements which are subsequently placed next to and against similar blocks, and thereby forming vertical seams placed between the adjacent blocks. The seams are glued together. Although this has the advantage that planks of different dimensions can be made reasonably efficiently by varying the number of adjacent blocks and the number of layers, this construction inherently has the problem that when stress is applied to a plank made according to this construction, or to a product sawn from this plank, the weakest points of the bamboo timber are, firstly, the seams between the blocks and, secondly, the connection between the different layers.The application of such bamboo timber is therefore usually limited to structures where stress occurs primarily or exclusively in the longitudinal direction of the fibers, where the blocks cannot break in the longitudinal direction or where the layers cannot be separated from each other. 25THEINVENTION The invention concerns a bamboo stem made from a panel of bamboo elements. The panel consists of bamboo processed into block-shaped elements which are placed next to each other in the longitudinal direction of the fibers or veins in at least three layers, whereby the layers are glued together. Vertical longitudinal seams are located between the adjacent and opposing elements. The manner of placing the elements in the longitudinal direction is such that the vertical longitudinal seams of a first layer are staggered relative to the vertical longitudinal seams of a BE2024 / 0032 4 third layer, and preferably also relative to a second layer and a fourth and further layer.Staggering the seams in this manner is also referred to as free bond or wild bond, with the note that it concerns a form of free or wild bond in which careful account is taken to ensure that as few vertical longitudinal seams as possible lie in line with one another, but that in any case no or as few seams as possible of a first course lie in line with a third course. To ensure that the staggering of seams takes place as much as possible in as many courses as possible, bamboo elements of different widths are preferably used. The use of bamboo elements of equal widths leads to an increased chance of a recurring "masonry pattern", in which vertical longitudinal seams of a first course lie in line with a vertical longitudinal seam of a course further above or below, such as, for example, in a half-brick bond.The closer layers with vertical longitudinal joints are to other layers with vertical longitudinal joints lying in line, the greater the chance that a fracture will occur at the location of the joints extending into one another. The joints are, in fact, the most vulnerable point of a timber structure, usually even when the joints are glued. Staggering the joints in this way leads to a bamboo plank construction that is more resistant to stress from multiple directions. The manufacture of the invented bamboo handles from this plank construction therefore leads to handles that are extremely suitable for applications as garden tools and construction tools, as listed above. The manufacturing process is characterized by sawing a beam lengthwise into a cross-section that is just sufficiently sized to subsequently turn it into a round timber. The resulting round timber is therefore much more resistant to stress than bamboo handles currently available on the market, and is at least as resistant to stress as, or better than, tool handles made of conventionally used wood such as beech, ash, or hickory.The invention demonstrates its value in particular in the following application. For ergonomic reasons, tool handles are often manufactured as curved handles. From the end of the handle facing the user, the section without the tool (such as a shovel or spade), an ergonomically sound handle in this case first creates a curvature towards the tool section. Forming a handle in this way presents a challenge in the manufacturing process, as the curve must not compromise the strength and stress resistance of the handle. A widely used technique consists of roughly sawing / milling the shape out of a wooden plank, thus including the curvature. If we view the curved handle with the tool part facing forward in the working position, the curvature is in the vertical plane. The shape being sawn out is sawn out backwards in the horizontal plane if we lay the plank horizontally / flat.If the plank consists of a single cut from one tree trunk, the stem is sawn out as much as possible in such a way that the fibers / veins of the wood structure run in the same longitudinal direction as the stem. However, the problem arises here that the fibers "fly off course" relative to the curved section, or in other words, do not follow the curvature. It is conceivable that points then arise in the material where fracture lines can occur, because stress is not effectively absorbed. Splitting of such a stem lengthwise or breaking in the curved section can therefore occur during prolonged or intensive use. The application of the current plank construction therefore requires very careful planning, the selection of optimal sections of timber to saw out, and consequently leads to a large amount of waste of unusable parts. The same problem arises when using bamboo elements if these bamboo elements are placed in a staggered or corrugated pattern.In the present invention, the place where a stem is sawn out is much less critical, and the curved stem sawn out in this way leads to a much stronger and more reliable product. When sawing production parts from a plank, it is important to make optimal use of the plank, with as little waste as possible. This leads to lower handling costs, such as international transport and more efficient internal logistics flows, less material usage, with obvious positive environmental effects. By using planks constructed according to the invention, such planks can be processed optimally. The so-called nests become easier and smaller spaces can be sawn out to, for example, saw out T-piece handles for the stems, as well as stems with various shapes and dimensions. After the shape of the curved stem has been sawn out of the flat plane, the bamboo stem is, according to the invention, subjected to processes such as turning it into a round piece of wood with a curvature.An important operation that should be mentioned here is tapering the tool at the end of the bamboo handle, so that the handle can be mounted into the socket of, for example, a shovel. The socket is the round, hollow metal part of a metal tool into which the handle can be attached. To make the outside of the handle align with the outside of the socket, the handle must be tapered along the length to be inserted into the socket (leading to a locally slightly smaller diameter of the handle). Tapering usually takes place using a machining technique. Material removed in this way leads to a potential weak point of the handle. Therefore, it is even more important that the bamboo element construction is inherently strong, so that tapering leads to only a negligible reduction in strength.In a first aspect of the invention, the invention consists mainly of block-shaped rectangular elements of bamboo glued together in multiple layers, whereby the elements are placed mainly in the longitudinal direction of the fibers of the elements next to and against each other and whereby the elements are placed next to and against each other in the horizontal plane, thereby forming vertical longitudinal seams between the adjacent and against each other placed elements. Furthermore, at least three layers of the elements are glued together with an adhesive, whereby at least a first layer is glued to a second layer and the second layer is glued to a third layer of the elements. The elements are placed in a bond, whereby the greater part of the vertical longitudinal seams of the first layer are substantially staggered with respect to vertical longitudinal seams of another layer of the at least three layers. The following forms of implementation of the first aspect are proposed.30 The vertical longitudinal joints of each layer are substantially staggered relative to the vertical longitudinal joints of the next adjacent layer. BE2024 / 0032 7 The elements are placed in a bond, whereby the majority of the vertical longitudinal joints of the first layer are substantially staggered relative to the vertical longitudinal joints of the second and third layers. The block-shaped rectangular elements vary by at least two different widths per layer. A bond comprises a bond of the group: - stretcher bond; - random or random bond; - running Klezor bond; 10 bamboo elements of substantially equal dimensions which are placed in a random or random bond or running Klezor bond. The vertical longitudinal joints are glued with the adhesive.Elements of the elements per layer of multiple layers are placed against each other with the end grain, thereby forming vertical width joints 15 between the elements placed against each other, whereby the majority of the vertical width joints of the first layer are substantially staggered relative to the vertical width joints of the second layer and / or the third layer. The vertical width joints are glued with the adhesive. 20 The handle concerns a cutout of a block, a beam or a plank consisting mainly of elements of bamboo placed in the said arrangement. The handle is configured as a round timber or an oval. The handle is suitable for use as a handle for a tool. The tool comprises a tool of the group: rake, shovel, spade, hoe, edger, axe, hammer, fork or rake. The adhesive comprises an adhesive of the group: melamine-based synthetic resin, wood glue (PVA glue), epoxy glue, or polyurethane glue. In a second aspect of the invention, the invention concerns a method for making a handle consisting of bamboo elements. The method comprises the following 30 steps: A.manufacturing elements from bamboo; B. forming a board consisting of multiple layers of elements in a bond according to one of the preceding claims; BE2024 / 0032 8 C. sawing the board into longitudinal sections; D. forming a longitudinal section of the longitudinal sections into round timber by applying a machining technique such as turning or milling. In an execution form of the second aspect, in step C the longitudinal sections are sawn into a relatively long straight section that transitions into a curved section. BRIEF DESCRIPTION OF THE DRAWINGS The attached drawings illustrate various execution forms of the invention. The illustrated element boundaries form an example of the boundaries. It is possible that in some examples one element is designed as multiple elements or that multiple elements are designed as a single element. Elements are not necessarily drawn to scale, but relative dimensions can be indicated with them if relevant. The non-restrictive and non-exhaustive 15 descriptions are described with reference to the following drawings: FIGURE 1 shows a front view, e.g.Cross-section of a bamboo wood construction. FIGURE 2 shows the view of Figure 1 after the material has been cut. FIGURE 3 shows the view of Figure 2 with possible saw cuts. FIGURE 4 shows a sawn-out round timber that can serve as a bamboo handle. FIGURE 5 shows a top view of a bamboo wood construction with possible saw cuts for the manufacture of a round timber or bamboo handle with a curvature. FIGURE 6 shows a detail view of Figure 5. FIGURE 7 shows a front view or cross-section of a bamboo wood construction with cut-out projections of a round timber with a curvature. FIGURE 8 shows a front view or cross-section of a bamboo wood construction with cut-out projections of an oval-shaped round timber. 30 DETAILED DESCRIPTION OF THE DRAWINGS Execution forms of the invention are described in more detail below with reference to the attached drawings in which figures represent similar elements in BE2024 / 0032 9 different figures, and in which example execution forms are shown. FIGURE 1 shows a front view c.g.Cross-section of a bamboo wood construction101. The construction101 is built from bamboo elements placed next to each other and constructed in layers. In the figure, 5 layers can be distinguished (see also figure 2), but more or fewer layers are also possible. The invention assumes a minimum of 3 layers. In the figure, 3 widths of bamboo elements are applied, which are referred to as narrowest width110a,b, middle width111a, and widest112a. The widths used can be found in the following layers, in any composition. By staggering the vertical width seams120, the cohesion between the different layers is strengthened and a fracture line is less likely to occur, since vertical width seams like120 do not reflect vertical width seams and in their extension, at least in two layers further on. 15 To manufacture workable planks from bamboo wood construction 101, parts to the left of the saw cut 190 and to the right of 190 can be shortened. FIGURE 2 shows the view of Figure 1 after the material has been shortened.To identify the layers, reference numbers 131a-e have been added, each representing a layer. 20 FIGURE 3 shows the view of Figure 2, with possible saw cuts 191a, b such that blocks are created from which round wood in cross-section shape 192a, b, c can be manufactured. FIGURE 4 shows a sawn round piece of wood that can serve as a bamboo handle100 according to the invention. Layers 131a-e are made visible, in which the 25 vertical seams per layer are staggered, at least between two layers with a layer in between. To visualize this, virtual dividing lines 19a-d have been drawn. In the optimal case there is not a single vertical seam that lies in the extension of another vertical seam, but to achieve significant reinforcement the invention proposes in any case in every first and third layer in the majority 30 no vertical seams running in line with one another.Another arrangement of the bamboo elements, using a single width of bamboo elements, is the running Klezore bond, in which the vertical width joints in each layer are regularly slightly staggered in the same BE2024 / 0032 10 direction, but such that no two vertical width joints in the same round timber lie in line with each other, at least viewed in a first and third layer. A further arrangement concerns the free bond or random bond, but then in the variation that meets the requirements of the invention. 5 FIGURE 5 shows a top view of a bamboo wood construction101 with a possible saw cut192 for the manufacture of a production part from which round timber or bamboo stem100 with a curvature can be manufactured. FIGURE 6 shows a detailed view of Figure 5. Bamboo elements 110a, 111a and 112 are part of a possible cutout 192. FIGURE 7 shows a front view or cross-section of a bamboo wood construction 101 with cutout projections of a round timber with a curvature.Dotted lines 193a,b show a cross-section 194a, as the round timber from construction 101 would be sawn if it concerned a straight bamboo stalk. Dotted lines 193c,d show a cross-section 194b, as it is followed when the curvature of the production part 192 from which bamboo stalk 1100 can be formed is followed. This visualizes how the different bamboo elements are and remain connected to each other, even in the case of a bamboo stalk with a curvature. FIGURE 8 shows a front view c.q. cross-section of a bamboo wood construction 101 with cut-out projections of a round timber. The dotted line 194c shows a cross-section 194c, as the round timber from construction 101 would be sawn, where an oval round timber is chosen instead of a round cross-section of a round timber as i.