FI81161C - SKYDDAD TRAESTOLPE ELLER -PAOLE OCH FOERFARANDE FOER FRAMSTAELLNING AV DENNA. - Google Patents

Description

81161 1 Shielded wooden post or pile and method of its manufacture

Interpretation of the type of vehicle and the front of the body of the vehicle 5

The invention relates to a wooden post or pile provided with a protective layer and to a method for manufacturing the same.

JO The traditional outdoor pole has been a wooden pole. The service life of a wooden pole when unprotected is not sufficient. The usual method of protection has been impregnation with anti-rot agents. Wood impregnation plants cause at least some degree of environmental damage and, in addition, the disposal of spent poles is a problem because the incineration of poles containing impregnating agent 15 is not acceptable. Impregnants also do not provide permanent protection against decay and protection against UV radiation is poor. In addition, it can be stated that impregnation methods always treat the whole post and the treatment cannot be applied only to a specific point where protection is needed.

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DE 1 907 476 discloses the use of a sleeve or hose coated with an impregnating agent.

EP 58499 discloses wood treated with a plastic-coated preservative in which the plastic coating is uniform.

The invention relates to a wooden post or pile provided with a protective layer and in which the above-mentioned disadvantages are avoided. A wooden post or pile with a protective layer according to the invention is characterized in that the protective layer is formed by a plastic strip wound on the surface of the wooden post / pile in a molten state, which is cooled by shrinking into a protective layer tightly covering the wooden post / pile surface.

The invention also relates to a method for manufacturing a wooden post 35 or pile with a protective layer. The method according to the invention is characterized in that a plastic strip or strips in a molten state are wound on the surface of a rotating post / pile from one or more extrusion nozzles movable relative to the post / 2 81161 1 pile. the protective layer.

Utilizing the strong shrinkage tendency of melt-extruded plastic films during cooling, according to the invention, a tight protective layer covering the wood post / pile completely or as desired is provided. The properties of the protective layer thus obtained can be influenced in a variety of ways, depending on which properties are particularly desired to be improved. Resistance to light and / or UV radiation can be improved by adding, for example, carbon black or pigment to the plastic material used. The permeability properties of the gases (e.g. water vapor, oxygen) can be changed by the choice of the plastic material. The colors can be obtained by means of color pigments 15 and the wear resistance can be influenced by the choice of the base plastic. One advantage of a wooden post or pile according to the invention is that the protection can also be limited to a smaller area, for example to the area of the length of the post embedded in the ground. In such a case, it may be advantageous to ensure that the starting point of the protective layer is not exposed to rainwater run-off. For example, a recess or groove can be formed in the wood at the starting point of the protective layer, whereby a lip or eaves leading over the rainwater is formed. If desired, longitudinal grooves can be made in the post for the export of cables, etc., before the plastic protection, in which the cables can fit. According to the invention, when the molten plastic strip is twisted and the molten plastic cools and shrinks, the cables remain shielded under the plastic layer. Naturally, bushings and sealing elements known per se can be used for the bushings of cables and wires.

The plastic forming the molten plastic strip may be, for example, a polyolefin such as polyethylene or polypropylene, or polyester or polycarbonate. If a gas-impermeable protective layer is desired, a gas-impermeable plastic grade can be selected, for example, an ethylene-vinyl alcohol copolymer. As mentioned above, the plastic may contain additives that affect the properties and / or appearance of the layer. It is also possible to use several types of molten plastic at the same time, either by coextrusion technique or by using several nozzles, whereby the melting of the molten plastic strip can be carried out simultaneously or in several steps on the wooden post / pile to be protected.

g The wooden post or pile according to the invention can be used wherever posts and piles with a protective layer are required. In this context, a protective layer also means those layers which give the pile or post a certain appearance. This comes into question not only in appearance but also in indoor use, in which case the protective layer 1Q can replace the normally used varnishing or painting treatment.

A great advantage of the method according to the invention is that the post / pile to be protected does not have to be round or regular in shape or constant in dimensions over the entire length of the post. Angular posts / poles can also be protected in accordance with the invention. The molten plastic also protects uneven surfaces when shrinking.

The wooden pole or pile according to the invention can be safely disposed of by incineration because it does not contain toxic anti-rot or 2Q impregnating agents.

The wooden columns with a protective layer according to the invention can be manufactured by utilizing extrusion presses used in the plastics industry, in which the plastic mixture used as a raw material melts and is pressed into the nozzle by the action of a rotating screw. The nozzle may be a conventional slit nozzle for compressing a strip-like product. There may be one or more layers of protective plastic depending on the desired protective properties. The molten plastic strip formed from a single slit nozzle may also include one or more layers (co-3Q extrusion) depending on the number of extruders connected to the nozzle.

The coating of the post with a protective layer takes place, for example, by placing the nozzle part of the extruder close to the surface of the post. As the post to be coated is rotated and at the same time moved past the nozzle, a strip of molten plastic from the nozzle wraps around the post. The rotation speed and conveying speed of the column are suitably selected in relation to the production speed of the extruders.

* 81161 1 The hot-melt plastic tape wrapped around the post shrinks strongly as it cools, thus forming a tight protective layer on the post surface. Due to the manufacturing method according to the invention, it is easy to provide a protective layer either on the entire surface of the post or on the surface of a certain part of the post.

The ends of the post protected according to the invention can be easily protected, for example, by a separate hat part or end patches heat-sealed or glued to the ends, etc. In the post according to the invention, the protective layer can be easily renewed if necessary and the protective layer can be formed anywhere using portable extruders.

The invention is illustrated below with reference to the accompanying Figures 15, in which

Fig. 1 schematically shows a side view of the coating of a pile or post with a molten plastic strip from two melt extruders, Fig. 2 shows a ground-embedded pile according to the invention provided with partial protection and a rainwater trap, and

Figure 3 shows a cross-section of a shielded pile according to the invention in which a longitudinal groove is formed for shielded cables.

In Figure 1, reference numeral 10 the pile, which is moved further in the direction of arrow A, and at the same time is rotated in the direction of arrow B, not shown devices. In the vicinity of the pile 10, a melt-30 extruder 20 is provided, which is provided with a slit nozzle 21. A melt plastic strip 22 is extruded from the slit nozzle 21, which, due to the rotational and advancing movements of the pile 10, is wound into a layer covering the pile 10. Figure 1 further shows a second extruder 30, in which the molten plastic strip 32 coming from the slit nozzle 31 is wound on the melt plastic strip 22 coming from the slit nozzle 35 21. There may, of course, be only one or more molten plastic strips, depending on the intended use of the pile. When the molten plastic strips il 5,81161 1 wound on the pile 10 cool, they shrink strongly and form a tight protective layer on the pile 10.

Figure 2 shows a pile 10, the lower end of which is embedded in the ground 11.

In the case of Figure 2, only the lower end of the pile 10 is provided with a protective layer 32 according to the invention. The pile 10 is milled with a groove or recess 40, the protective layer 32 being arranged starting from the bottom of said groove 40. At the same time, an overflow threshold 41 is formed, which leads along the pile 10 over the starting point of the rainwater protective layer 32.

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Figure 3 shows in cross-section a pile 10 provided with a protective layer 22 in accordance with the invention. A longitudinal groove 50 is milled in the pile 10 to accommodate the cables 51. When the pile 10 is protected in accordance with the invention, the cables 15 51 remain under the protection layer 22.

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Claims (10)

1. Wooden post or pile, son is provided with a protective layer, characterized in that the protective layer is formed by a plastic band (22,32) wound around the surface of the wooden post / pile (10) in a melted state, by means of cooling allowed to shrink into a protective layer that covers the surface of the wooden post / pile (10) tightly. 1 Patent claim Wooden post / post according to claim 1, characterized by Ί0, that the plastic strip (22,32) is made by melt extrusion of plastics belonging to the group of olefin homo- and copolymers, polyesters, polycarbonates and PVC. Wooden post / post according to claim 1 or 2, characterized in that several plastic layers are melt-extruded simultaneously. Wooden post / pile according to claim 3, characterized in that the molten plastic strip has been formed by several layers by coextruding. 20 Wooden post / pile according to claims 1,2,3 or 4, characterized in that the plastic contains additives which improve the adhesion, the durability of light or UV radiation, the wear resistance, the opacity, the gloss or the colors. 25 Wooden post / pile according to any of the preceding claims, characterized in that the pile / post (10) is partially protected. Method for providing wooden posts or piles according to claims 30 to 6 with protective layers, characterized in that one or more plastic strips (22,32) are wound on the surface of a rotating post / pile (10) from a plastic strip (22,32). or several extrusion nozzles (21, 31) moving in relation to the post / pile (10), the surface of the post / pile (10) being covered by a layer of molten plastic which, upon cooling, shrinks into a dense protective layer which covers the surface of the post / pile (10). 9 81161 1 Method according to claim 7, characterized in that a rotating wooden post / pdle (10) is rotated and transported at the same thread past the extrusion nozzles (21,31). g 9. A method according to claim 7, characterized in that the extrusion nozzles (21, 31) are moved and / or wound past a wooden pile / pile (10) which rotates in place and / or progresses forward. 10 15 20 25 30 35