FI126050B - Three-dimensional structures - Google Patents

Description

Three-dimensional constructions The present invention relates to three-dimensional constructions, according to the preamble of claim 1, which contain at least one rigid disk.

The invention further relates to a method according to the preamble of claim 15 for the manufacture of three-dimensional structures.

Larger basins and containers are usually made of metal or concrete, which in these applications has completely replaced wood-based materials. Concrete base beds are usually cast on site due to the large weight. Concrete is cheaper than metal, but the difficulties in recycling the material when the containers are taken out of use are greater.

While metal is susceptible to corrosion and in a separate manufacturing stage must be coated with polymeric materials e.g. For corrosion-resistant applications, the concrete is affected by strong temperature changes and is sensitive to frost damage which over time can lead to cracks in and degradation of the material. Metals are also affected by temperature changes, which should be taken into account, among other things. when designing the pipe systems connected to tanks or wells.

There is a need for building materials that can be used in larger constructions but which are economically more advantageous than metal and less sensitive to variations in ambient temperature than metal and concrete.

In technical applications, thermoplastic materials have several advantages over wood and metal, especially in terms of, among other things. recovery and resistance to corrosion and rot caused by microorganisms. For design purposes, larger constructions consisting wholly or to a predominant part of thermoplastic materials have so far not been available. The containers made have a maximum diameter of about 3 - 4 m and have been limited to cylindrical shapes. However, open basins and other non-pressurized applications may well be built up by rigid boards if they can be reliably coupled to provide dense structures.

Rigid boards for various construction purposes are usually made up of thin solid boards that are stiffened with beams, e.g. beams with an L- or I-shaped cross-section or the like. The plate structures are manufactured by cutting larger slices and then modifying them with bending stiff beams of the aforementioned type. A typical double-wall structure thus comprises two rigid discs spaced apart which form the surfaces of the structure and which are joined by intermediate, longitudinally or transversely extending beams. In sandwich designs, stiffening layers of hive model are also used.

In practice, if it is desired to manufacture polymeric double-wall panels of significant dimensions in thermoplastic material by extrusion, double-wall structures cannot be made thick, because only a limited amount of heat can be taken from the beams in the double-wall structures that bond the surface layers. Since the beams cannot be cooled down quickly and controlled, it is very difficult to manufacture said stiff boards of uniform quality and thus strength-specific properties. The uneven and slow heat dissipation leads to unfavorable production costs as well as internal stresses in the material and thus the discs twist and bend.

The object of the present invention is to remedy at least some of the disadvantages related to the prior art and to provide new solutions for basins, tanks and similar structures.

The invention is based on the idea of building a three-dimensional structure using a sheet material having a double-wall structure and consisting of elongated hole profiles which have substantially straight and parallel center axes and which abut against and are joined together to form said double electrical wall structure.

Such boards according to the invention can be provided primarily from thermoplastic materials, but they can also be made of metal or of various thermosets.

Rigid sheets of thermoplastic provide a possibility for joining via welding, and the invention therefore relates to a new method for producing three-dimensional structures by joining at least two rigid sheets consisting of a disk-shaped thermoplastic material, formed of elongated tube profiles, each of which exhibits a substantially straight center axis and which tube profiles abut against and are welded to each other to form a double wall structure, welding the sheets together to form a three-dimensional structure.

More specifically, the three-dimensional constructions of the invention are characterized by that set forth in the characterizing part of claim 1. The method of manufacturing three-dimensional constructions of the invention is characterized by that which is set forth in the characterizing part of claim 15.

Significant advantages are achieved by the invention. An essentially unlimited number of the present double-wall designs can easily be joined to three-dimensional designs of freely chosen design. If desired, the double-wall structure can also be bent to produce curved elements. The boards have a good bending stiffness and are therefore also suitable for applications where concrete and stiffened metal walls have been used so far.

Since the boards are formed of hollow profiles, if desired, the structure can be reinforced and anchored by filling the cavities e.g. with reinforcing iron or with concrete pulp. The cavities can also be used for electric cables and even as pipelines for liquid media. By using hole profiles of different colors, striped structures can be constructed.

According to a particularly preferred embodiment, several thermoplastic or metal sheets of the present type are joined by welding to three-dimensional structures, such as basins and tanks.

In addition to good bending stiffness and the possibility of recovery, the present thermoplastic sheets - and thus also the three-dimensional constructions produced by them - exhibit good resistance to corrosion, to rot and to mold. Because the structures are made up of pipe profiles, they are durably colored and UV-protected. The structures are easy to repair or modify. In relation to their mechanical properties, the weight is low, especially when comparing the structures with the corresponding structures made of reinforced concrete.

In the following, preferred embodiments will be considered in more detail with the aid of the accompanying drawings.

Figures 1a and 1b schematically show how extrusion welding of pipe profiles can be carried out according to an embodiment of the invention, wherein figure 1a shows a side view and figure 1b corresponding top view, figures 2a and 2b show in cross-section the section for structures according to two different embodiments. Figure 3 indicates the welding directions of a clamped stack from the front, Figures 4a and 4b show a welded stack of weld joints from the front (Figure 4a) and cross-section from the side (Figure 4b), and Figure 5 shows an open culvert consisting of a plurality of rigid, flat disks and rigid, curved discs which are welded to each other to form an arch-like structure, suitable for smaller tunnels under roads and railways.

The present technology encompasses the manufacture of new 3-dimensional designs of sheets having a double-wall structure and having a considerable bending stiffness.

These boards are in turn manufactured by joining together a plurality of hole profiles, which are placed side by side or stacked on one another to obtain a uniform horizontal row or vertical stack (hereinafter "stack" is used for both cases). Preferably, the stack is arranged in the upright position.

The hole profiles in the disc preferably have parallel center axes and are so straight that they can be pressed against each other along their entire length. The stack of hole profiles therefore has two large, typically flat, opposite sides parallel to the center shafts. The width of the flat sides corresponds to the total width of all hole profiles.

The disc-shaped structure is typically made up of hollow profiles consisting of thermoplastic material, of thermosetting material or of metal. In the accompanying drawings, which will be described in more detail below, various embodiments of the manufacture of double wall structures are first shown. In particular, the drawings relate to sheets made of thermoplastic material, which represent a particularly preferred embodiment. Then the discs are considered in more detail and then their use.

The manufacturing technique is described in more detail in our pending application entitled "Process for the production of a slab-shaped structure with a double-wall structure".

By "disc" in the present context is meant a limited, substantially flat piece, the extent of which in two dimensions is substantially larger than its third dimension. In practice, this means that the piece has a much larger side than its thickness.

Typically, the present discs have a ratio of the area of one of the flat sides of the disc to the thickness of the disc amounting to more than 50 [length units2]: 1 [length unit], in particular the ratio is about 75 to 100,000 [length units2]: 1 [length unit , usually about 100 - 50,000 [length units]: 1 [length unit.

"Three-dimensional constructions", on the other hand, are structures that have a significant extent in space. In practice, the area of one side is at least 1/10, preferably at least 1/8 of the surface of the next smallest page. Typically, the present three-dimensional structures form or define an open or enclosed space in which the rigid plate (s) forms at least one wall.

Typical examples of three-dimensional designs are tanks, containers, basins, booths, cabins, cabinets, boxes, containers, wells, tanks and culverts. These will be discussed in more detail below.

For the sake of order, it should be noted that the following description applies mutatis mutandis to the manufacture of three-dimensional structures consisting of rigid sheets with double-wall structures of also other materials are thermoplastics, although all the advantages obtained with the use of precisely thermoplastics are not possible for e.g. metals and thermosets. As a difference, it can be noted that thermosetting composite profiles are usually glued rather than welded. Reinforced thermoplastic profiles, which are also included in the scope of protection, on the other hand can be joined with e.g. extruder welding

The production of rigid discs

Figures 1a and 1b show a standing bar consisting of hole profiles. In the case of the figures, the stack consists of six thermoplastic pipe profiles with a generally rectangular cross section. These have been given the reference numbers 1-6.

Generally, the number of pipe profiles can vary freely, from 2 to 100, usually 2 to 50 or 3 to 30, depending on the predetermined width of the double-wall structure.

The stack is immobilized which can be achieved, for example, by the adjacent hole profiles being clamped together at the end of the hole profiles. Another possibility is to arrange the hole profiles in a separate frame that temporarily holds them together.

According to a preferred embodiment, the welding of the stack is carried out as extrusion welding with welding nozzles arranged on opposite sides of the pipe stack and which is connected to a source of molten thermoplastic material. This is shown in more detail in Figures 1a and 1b where reference numerals 7, 8 and 11 and 9, 10 and 12 respectively refer to two welding devices (extrusion welds) consisting of extruders with screws 7, 9 and funnel 8, 10, which feed molten plastic mass through a nozzle 11 , 13 into the joint between adjacent hole profiles 3, 4 so that two welds 12, 14 are formed.

The same joint is welded simultaneously from opposite directions. This solution can avoid the formation of uneven heating of the material. For this purpose, the extrusion welds are 7, 8, 11; 9, 10, 12 in the cases 1a and 1b are arranged symmetrically on each side of the pipe profile stack.

Figure 3 shows a similar stack of pipe profiles 31-36 which are stacked horizontally. The directions of welding are indicated by arrows. The relative movement between the stack and the welds can be achieved in various ways. In a first embodiment, the welding is performed with permanently mounted welding nozzles by displacing the stack longitudinally ie. along the center axes of the hole profiles. For this purpose, the stack can be arranged on a conveyor capable of moving the stack horizontally past the welding nozzles. However, the welding can also be performed with movably arranged welding nozzles which are displaced longitudinally (horizontally) along the stack.

Similarly, the welding is performed by a stack of pipe profiles, which are placed in a standing position (where the joints between the profiles are vertical), by moving the welding nozzles vertically or by moving the stack itself vertically or horizontally in case the welding nozzles are fixedly mounted.

After complete welding of a joint, the welding site is moved to the following joint. According to a preferred embodiment, where the stack is arranged with horizontal joints between the profiles, the welding site is moved downwards to the following joint.

According to a preferred embodiment, the joint surface is prepared separately before the welding itself to ensure a good welding quality. This can be done e.g. by mechanically machining the joint in a first sweep along the stack, e.g. by (chip) cutting machining and then by a second sweep add the molten plastic mass. By machining, any dirt or oxidized surface layers are removed from the welding surfaces.

It is also possible to apply radiant heat or convection heat (eg through hot air) to the joint from a separate nozzle simultaneously with the welding of the previous joint. Preferably, the joint is preheated simultaneously from both sides.

It is particularly desirable to heat the material in the joint edges separately prior to welding, preferably to a temperature above about 50 ° C. For this purpose, IR heaters can be used. Conveniently, the extrusion welding device is provided with a nozzle for blowing hot air at the welding site immediately before welding.

If the hole profiles have surface layers of different materials (eg functional layers on one side, see below), it is advisable to use different welding materials on different sides.

Figures 2a and 2b show the use of different types of profiles to form the double wall structure. In Figure 2a, the joining of generally rectangular, mutually similar profiles 21, 23 shows, whereby plastic melt is injected into the joints 22, 24, which can be formed into weld beads 24 which are, in cross-section, roughly wedge-shaped.

However, in a preferred embodiment, the weld bead is adapted to the surface next to it so that a weld joint can be formed which together with the side of the pipe profile forms a substantially flat and even surface for the sheet.

The structures of Figure 2a thus have two substantially parallel smooth surfaces.

In Figure 2b, the corresponding structure shows where the pipe profiles 25, 26, 27 and 28 together form a flat surface on one side of the stack. The profiles are joined together in the same way as above with the sealant in the joints 30 and melt in weld beads 29. Three of the pipe profiles 25 - 27 are similar while one is wider 28. The wider profile gives a greater bending stiffness in the longitudinal direction of the profiles and construction and thus forms a kind of reinforcing elements for the entire structure.

Generally, for the manufacture of the present double wall structures, hollow profiles which are formed of tubular profiles are used, preferably hollow profiles of thermoplastic material consisting of one or more layers.

For thermoplastic pipe profiles, the welding is carried out with a thermoplastic material, preferably with the same thermoplastic material as that of the pipe profiles.

The term "profile" is used interchangeably with "pipe" (ie an elongated object having an open cross-section).

The thermoplastic profile has 1-5 layers. If it contains multiple layers, according to one embodiment, it constitutes one of these inner layers of the profile and one outer layer of the profile. This is especially the case where there are functional layers in the multilayer wall of the profile, as it is preferable to arrange the functional layer separately in the outer wall (eg a conductive layer) or in the inner wall (eg a layer of good abrasion resistance). ). Typically, the tube profile is comprised mainly or solely of a conventional thermoplastic, e.g. a polyolefin, such as polyethylene, in particular HD-PE, or polypropylene, polyacrylonitrile butadiene styrene (ABS), polyamide (PA) or any other thermoplastic material.

Possible functional layers may be ultra high molecular weight PE (EIHMWPE) or e.g. of antistatic materials. A material of the latter type may consist of a thermoplastic material made permanently conductive. In this case, the thermoplastic material may be the same as used in the body profile of the tube profile. This device achieves good inter-layer compatibility.

The pipe profiles have a substantially rectangular cross section, with the sides of the pipe profiles facing each other constituting at least 1/10 of the casing surface of the pipe profiles. The term "rectangular" also includes the cases where the pipe profiles in cross-section are square or substantially square.

In the pipe profiles, the ratio of width to height is preferably 1: 1 - 1:10, the ratio between the minimum thickness of the pipe wall and the height of the cross section of the pipe profile in particular being about 1: 100 - 1: 4, especially about 1:50 - 1. : 5th

According to a preferred embodiment, plastic profiles of a type which can also be used for the manufacture of plastic tubes by coil winding are used. Such plastic profiles are described i.a. in U.S. Patents 5,127,442, 5,411,619, 5,431,762, 5,591,292, 6,322,653, and 6,939,424.

Usually, the surfaces of the pipe profiles are smooth. However, some or all of the pipe profiles may be rib reinforced, in particular they may have one or more longitudinal ribs on the inside or outside or on both sides of the pipe profile. In case the pipe profiles are made of a thermoplastic, any rib reinforcements are preferably formed of the same material.

Rigid thermoplastic sheets

In general, a method of the above mentioned type can be made of boards whose flat surfaces have dimensions (height x length) from about 100 mm x 100 mm to about 10,000 mx 20,000 m. Typical maximum dimensions of the boards are about 7,500 mm x 5,000 mm, in particular about 5,000 mm x 3,500 mm, and the minimum dimension is about 500 mm x 1000 mm.

Figures 4a and 4b show a finished sheet consisting of six substantially square tube profiles 41-46 which are welded to a uniform, dense sheet by means of molten thermoplastic material in the joints 47.1 in the case of the figure, the profiles are joined to the narrower side walls in each other. A stiffer, but columnar construction is achieved by turning the profiles 90 degrees and joining them with the wider side walls towards each other.

A disc of the type shown in Figures 4a and 4b is straight and rigid. However, it can be bent to take a curved shape, such as an arched portion, which bend can be fixed.

The present disc is self-supporting at span widths of up to 5,000 mm transverse to the central axes of the pipe profiles and up to 20,000 mm in the direction of the central axes.

The use of the double wall structures

A plastic sheet of the kind described above can be used as a substance in the manufacture of composite structures. Such a plastic sheet can be cut to predetermined dimensions before making the composite structure.

However, the plastic sheet can be joined together with other similar plastic sheets to form large uniform flat surfaces consisting of a plurality of individual plastic sheets.

Figure 5 shows an open culvert 51 consisting of four joined discs, 52 - 55. Of these discs, two are flat / straight discs, namely 52 and 53, which form the vertical portion of the culverts after installation, while the arched portions 54 and 55 forms the ceiling. The arched portions can be readily made of similar rigid sheets as the straight sides 51 and 52 by bending in a jig, if necessary, during simultaneous heating.

The boards are edged together by welding e.g. in the same way as the individual pipe profiles

A number of examples can be given of the use of either single discs or joined discs. Such are e.g. open containers and basins, such as Process basins for water and wastewater treatment, basins for chemical processes, basins for fish care and fish farming, and collection basins under conventional basins and tanks.

Of course, these few examples are by no means exhaustive, but the present technology can be applied to virtually any open reservoir, basin and tank.

Similarly, closed containers of various kinds of tanks and silos are exemplified for dry material, sludge, liquid and gases. Cylindrical dryers can also be manufactured according to the present technology.

Other three-dimensional examples are wells, rectangular tanks above and in the earth, open culverts. booths, cabins, cabinets, drawers, containers.

As is evident from our parallel patent application, "Process for making a sheet-shaped structure with a double-wall structure", parts which are essentially two-dimensional can also be manufactured for these three-dimensional structures, ie. the boards may form only part of the structure even though it is three-dimensional, and the other sides then comprise conventional sides and materials.

Examples of this latter are tank roofs, silo bottoms, structural foundations, horizontal tank tanks, partition walls in tanks, both horizontal and vertical, tank tanks for standing tanks, which ends can be weighted and reinforced with concrete mass. Furthermore, the disks can be used as protective barriers, protective surface constructions in port facilities; shock absorbers, pylon covers, molds, sliding surfaces. Other examples are security barriers, e.g. as wall surfaces at community buildings - noise walls and protective walls at roads.

Other essentially flat designs are represented by floating manhole hatches.

A special area of use is heat exchangers for air / gases and heat exchangers for water / liquids. In these applications, the fact that the rigid disks exhibit a large number of parallel cavities can be utilized.

Structures can also be built up by combining the present straight sheets with corresponding sheets bent in arched form. As an example of such, open culverts may be mentioned.

Another particularly interesting area of application includes straight and arched plates for boatbuilding, decks and hulls.

In the case that the sheets are made of thermoplastics, the joining of a plurality of sheets into larger three-dimensional assemblies can be effected by welding, usually after the edges of the sheets to be joined are first chamfered.

Claims (15)

A three-dimensional structure comprising an open or a closed space, comprising at least one rigid plate forming at least one wall having a double-wall structure and having elongated hole profiles (1-6, 21, 23, 25-27; 31-). 36; 41-46) having substantially straight and parallel central axes adjacent to each other and interconnected to form a double-wall structure, the sheet being formed from tubular profiles (1-6; 21, 23, 25-27; 31-35) of thermoplastic material; ; 41-46) connected by welding such that the tube profiles are welded to each other, characterized in that the tube profiles (1-6; 21, 23, 25-27; 31-36; 41-46) are substantially rectangular and the opposite sides of the tube profiles form at least 1/10 of the surface of the shell of the tube profiles. The structure according to claim 1, characterized in that the plate is substantially flat or curved. A structure according to claim 1 or 2, characterized in that the structure comprises at least two rigid plates which are connected at right angles to each other. The structure according to any one of the preceding claims, characterized in that the plates have at least one substantially planar surface parallel to the central axes of the tube profiles (1-6; 21, 23, 25-27; 31-35; 41-46). Structure according to one of the preceding claims, characterized in that the sheets consist of 2-100, in particular 3-40, parallel-arranged hole profiles (1-6; 21, 23, 25-27; 31-35; 41-46). Structure according to one of the preceding claims, characterized in that the hole profiles consist of tubular profiles (1-6; 21, 23, 25-27; 31-35; 41-46) made of a single or multilayer thermoplastic material. A structure according to any one of the preceding claims, characterized in that the pipe profiles (1-6; 21, 23, 25-27; 31-35; 41-46) have a rectangular cross-section and a width-to-height ratio of 1: 1-1. Wherein the ratio between the minimum wall thickness of the tube and the height of the cross-section of the tube profile in particular is about 1: 100-1: 4, in particular about 1:50 to 1: 5. A structure according to any one of the preceding claims, characterized in that at least a portion of the tube profiles are reinforced with longitudinal flanges, in particular having one or more longitudinal flanges inside or outside the tube profile or on both sides. A structure according to any one of the preceding claims, characterized in that the pipe sections are made of a thermoplastic material, whereby any flange reinforcements are made of the same material. Structure according to one of the preceding claims, characterized in that the pipe profiles (1-6; 21, 23, 25-27; 31-35; 41-46) comprise functional or conductive layers. The structure according to any one of the preceding claims, characterized in that the three-dimensional structure is a reservoir, well, container or space in which the rigid plastic sheet forms a self-supporting part, the three-dimensional structure is for heat exchanger air / gases or heat exchanger water / liquids. Structure according to one of the preceding claims, characterized in that the three-dimensional structure comprises a container end consisting of a rigid plate, a dividing wall in horizontal or vertical containers or a container end in a standing container, possibly weighted and reinforced, e.g. Structure according to one of the preceding claims, characterized in that it comprises rigid plates which are bent in the transverse direction towards the central axes of the pipe profiles to form arcuate sections (54, 55) in the structure (51). Structure according to claim 13, characterized in that the arcuate portion (54, 55) is connected by at least one straight plate (52, 53). 15. A method for manufacturing three-dimensional structures comprising open or closed spaces by joining together at least two rigid sheets (1-6), characterized in that - providing at least two sheets (1-6) consisting of a sheet-like thermoplastic material consisting of elongated sheets. tubular profiles, each having a substantially straight central axis, and the tubular profiles facing each other and welded to each other to form a double wall structure, wherein the tubular profiles (1-6) are substantially rectangular in cross-section and the half profiles of the tubular profiles (12) together to form a three-dimensional structure (1-6).