Sheet pile profile, method of manufacturing thereof and method of its installation

Abstract

A sheet pile profile comprising an upper arm (1), which is flat across its entire width, bounded by outwardly inclined slanted arms (2a, 2b), positioned symmetrically relative to a plane perpendicular to the upper arm (1), and a closing element located at the end of each of the slanted arms (3a, 3b), wherein one slanted arm 2b has a female lock 4, and the other slanted arm 2a has a male lock, which further comprises a groove (9) and is made of two types of recyclates, wherein the outer layer is made of a recyclate with higher impact strength, and the core from a recyclate with lower impact strength and a higher content of mineral fillers, wherein the shape of the form-fit joint allows for angular deflections within 15° in both directions.

Description

Field of the invention

[0001] The invention relates to a sheet pile profile comprising male locks, female locks and mounting recesses, as well as a method of manufacturing such a profile and its installation.State of the art

[0002] US6000883A is an American patent disclosing a sheet pile profile, which is a one-piece extrudate, preferably extruded from plastic, wherein the plastic is either virgin or recycled polyvinyl chloride, polyethylene, polypropylene, and polyurethane. The extrusion of the sheet pile profile is reversible, meaning that it can be positioned in a configuration where the upper ends are connected to each other in an interlocking manner, or in a configuration where the upper end is connected to the lower end in an interlocking manner, relative to adjacent sheet pile profile extrusion elements. US6000883A does not disclose the single-orientation stacking of sheet pile profiles, the production of sheet pile profile from two types of recyclates, and the configuration of the co-extruded layer.

[0003] US20210164187A1 is an American patent disclosing a corner filler element for sheet pile profiles. In an exemplary embodiment, this element is formed by extrusion and may be made at least partially from recycled materials, for example recycled PVC. US20210164187A1 does not disclose the single-oriented arrangement of sheet pile profiles, the production of sheet pile profiles from two types of recyclates, and the configuration of the coextruded layer.

[0004] US6033155A is an American patent disclosing a structural panel that is used as a pile to be driven into the ground and to form a continuous barrier that can be used as barrier walls, such as sea walls, dams, pillars, pollution barriers, and the like. The structural panels are extruded and have a uniform size and shape along their entire length, which can range from 2 to 40 feet or more, and which have a uniform cross-section along their entire length and have an elongated Z-shaped cross-section, with opposite distal edges formed as male and female locking edges for connecting adjacent panels together. Each panel includes a pair of opposite flat side sections that are disposed in parallel planes, longitudinally relative to each other. Each structural panel is made of polyvinyl chloride ("PVC"), another suitable synthetic material, or polymer. US6033155A does not disclose the single-oriented stacking of sheet pile profiles, the manufacture of sheet pile profiles from two types of recyclates, and the configuration of the coextruded layer.

[0005] US7025539B2 is an American patent for a structural panel for forming marine walls, barrier walls, and the like, made of a synthetic resin material. Each structural panel is made of a plastic such as polyvinyl chloride, polypropylene, polyethylene, or another suitable synthetic or polymeric material. The structural panel is elongated, has a constant size and shape along its entire length, and is characterized by being longitudinally extruded. In cross-section, the panel includes a center wall section having an inner surface, an outer surface, a first side wall section, and a second side wall section. The male locking member extends laterally from the first side wall section, while the female locking member extends laterally from the second side wall section, wherein the female locking member is configured to slidably receive and retain the male locking member of a duplicate panel. US7025539B2 does not disclose the single-oriented stacking of sheet pile profiles, the production of sheet pile profiles from two types of recyclates, and the configuration of the coextruded layer.

[0006] CN106256965A is a Chinese patent application for an anti-seepage latch connecting sheet pile profiles. The anti-seepage sheet pile profile connecting latch comprises a male lock, a female lock, and a sealing part. CN106256965A does not disclose the single-oriented stacking of sheet pile profiles, the production of sheet pile profiles from two types of recyclates, and the configuration of the coextruded layer.

[0007] US20170030041A1 is an American patent application for watertight sheet pile profiles having an upper side, a lower side, a leading edge, and a trailing edge, wherein the leading and trailing edges include interlocking coupling profiles for connecting multiple sheet pile profiles into a continuous array. The slotted wall preferably comprises cementitious or bentonite material that cures or hardens around or along the sheet pile profile barrier. The sheet pile profile barrier is at least partially submerged or embedded in the slurry wall, or alternatively partially protruding above the slurry wall or ground surface. The sheet pile profiles are made of vinyl, PVC, fiber-reinforced polymer, plastic, polymer, composite, or other polymeric or non-metallic materials. US20170030041A1 does not disclose the single-oriented stacking of sheet pile profiles, the production of sheet pile profiles from two types of recyclates, and the configuration of the coextruded layer.

[0008] RU229055U1 is a Russian utility model for a half-ring-shaped sheet pile profile containing a wall and a head located on the inner central part of the body, and a male and female lock located perpendicular to the radial line. In order to reduce the production costs of sheet pile profiles made of PVC polymer material, a method of manufacturing sheet pile profiles with the addition of recycled PVC raw materials was tested. RU229055U1 does not disclose the single-oriented arrangement of sheet pile profiles, the production of sheet pile profiles from two types of recyclates, and the configuration of the coextruded layer.

[0009] KR200309947Y1 is a Korean utility model for a sheet pile profile manufactured by extrusion molding from 100% polyvinyl chloride, used for water blocking, embankment protection, soil loss prevention walls, etc. KR200309947Y1 does not disclose the single-oriented stacking of sheet pile profiles, the production of sheet pile profiles from two types of recyclates, and the configuration of the coextruded layer.

[0010] US20050042417A1 is an American patent application relating to extruded structural members made of synthetic materials and methods for manufacturing them. In a preferred embodiment, the method comprises the following steps: forming an elongated reinforcing structure from a high-strength material; extruding an outer body from a water-impermeable material adjacent to the reinforcing structure so that the reinforcing structure is completely enclosed within the outer body. The outer body may be made of various plastics, such as polyvinyl chloride, wood flour, etc., which may be resistant to deterioration due to weather conditions such as temperature changes, extreme temperatures, contact with liquid, frozen water, ultraviolet radiation, and abrasion by water, sand, and the like. Each structural member includes a C-shaped female locking member and a protruding male locking member disposed on opposite side edges of the structural member. US20050042417A1 does not disclose the single-oriented stacking of sheet pile profiles, the manufacture of sheet pile profiles from two types of recyclates, and the configuration of the coextruded layer.

[0011] US20040013901A1 is a US patent application describing a composite panel consisting of a substrate sheet and a co-extruded plastic layer covering the substrate. The panel can be used as a retaining panel for a water reservoir in a cantilever wall or an anchored sheet pile profile wall. The retaining panel may include a central portion, two side portions, and two flanges. The retaining panel may also include integral connecting portions. The substrate may be made of a material such as aluminum or steel, while the plastic may be a material such as polyvinyl chloride (PVC). US20040013901A1 does not disclose the single-oriented stacking of sheet pile profiles, the production of sheet pile profiles from two types of recyclates, and the configurations of the coextruded layer as in the present invention.

[0012] JP3385607B2 is a Japanese patent relating to a steel sheet pile profile covered with an anti-corrosion polyethylene film. The sheet is adhered by pressing it onto the steel sheet pile profile using a pressing device such as a roller. JP3385607B2 does not disclose the single-oriented arrangement of sheet pile profiles, the production of sheet pile profiles from two types of recyclates, and the configuration of the coextruded layer as in the present invention.

[0013] DE29504062U1 is a German utility model relating to a coating system for sheet pile profiles based on any chemical composition. The subject of the invention is that a sheet or metal foil made of stainless steel, preferably V steel such as VA steel, is applied to the sheet pile profile. According to the invention, this can be done by thermal welding or bonding. As a result, a type of multi-layer plate or laminated steel sheet pile profile is obtained. DE29504062U1 does not disclose the single-oriented stacking of sheet pile profiles, the production of sheet pile profiles from two types of recyclates, and the configuration of the coextruded layer as in the present invention.

[0014] DE102022000796A1 is a German patent application disclosing a building element (e.g., a sheet pile profile) containing at least one layer that consists of at least one biodegradable material or at least one inorganic material, preferably mineral, or contains at least one material of plant origin. According to an alternative or additional aspect, the earthwork element has at least one additional layer which consists of at least one material resistant to environmental influences, e.g., a polymer. DE102022000796A1 does not disclose the single-oriented stacking of sheet pile profiles, the production of sheet pile profiles from two types of recyclates, and the configuration of the coextruded layer as in the present invention.

[0015] PL3619363T3 discloses the possibility of using plastics for the production of sheet pile profiles. The plastics may be recycled (high-impact vinyl chloride may be recycled from PVC window frames, and PET from recycled bottles). PL3619363T3 does not disclose the single-oriented arrangement of sheet pile profiles and the configuration of the coextruded layer as in the invention in question.

[0016] CN106400780B is a Chinese patent disclosing a decompression and anti-seismic sheet pile profile wall structure, comprising a sheet pile profile wall consisting of several sheet pile profiles arranged in a row, a resilient body, and a base plate. The watertight sheet pile profile is a reinforced concrete structure, which is prepared from the following weight components: 16-23 parts of fine aggregate, 10-20 parts of coarse aggregate, 10-14 parts of cement, 3-8 parts of ash, 2-4 parts of anhydrite, 2-8 parts of silica dust, 0.1-2 parts of diethyl maleate, 0.1-1 parts of vinyl chloride, 2-6 parts of acid clay, 0.1-0.3 parts of magnesium sulfate, 0.1-0.2 parts of polymer adhesive 45 agent, 0.01-0.1 parts of boron nitride, 0.03-1 parts of a hydrophobic agent (e.g., zinc stearate or calcium stearate), 0.05-0.1 parts of a polycarboxylate water reducer, 2-3.6 parts of EVA (ethylene vinyl acetate) resin. CN106400780B does not disclose the single-oriented stacking of sheet pile profiles, the production of sheet pile profiles from two types of recyclates, and the configuration of the coextruded layer as in the present invention.

[0017] PL224574B1 is a Polish patent disclosing a method for manufacturing composite plastic products based on poly(vinyl chloride) using the extrusion method, consisting in mixing 5% of powdered waste poly (polyvinyl chloride) (PVC) obtained from used PVC windows in an amount of 33 to 60.9% by weight in the composite material with modifying additives in an amount of 1 to 4% by weight, maintaining the temperature of the mixed components between 90 and 130°C and causing the modifying additives to be absorbed onto the surface of the powdered waste PVC, after which hemp fibers in an amount of 38 to 58% by weight and 10 EPDM granules (ethylenepropylene-diene terpolymer) in an amount of 0.1% to 5% by weight, and all the components are mixed, leading to homogenization of the powdered waste PVC with the natural filler, after which the composite material mass thus obtained is cooled to a temperature of about 50°C to obtain an agglomerate. The agglomerate is then fed into an extruder, where the material is heated to a temperature of 130 to 180°C and the plasticized material is extruded to form a profile. PL224574B1 does not disclose the single-oriented arrangement of sheet pile profiles and configuration of the coextruded layer as in the present invention.

[0018] DE502014000870D1 is a German patent relating to sheet pile profiles made of plastics, in particular polymer or PVC, also in the form of recycled plastic. The sheet pile profile can be advantageously produced by extrusion using solid or viscous curable compounds. The sheet pile profile has a core made of cheaper plastic, and the surface that is exposed to environmental influences is made of higher quality material. DE502014000870D1 does not disclose the single-oriented stacking of sheet pile profiles and the configuration of the coextruded layer as in the present invention.

[0019] KR102043182B1 is a Korean patent disclosing a sheet pile profile that has high mechanical strength, including tensile strength, bending strength, and impact strength, and also has good flexibility and is easy to cut, so as to improve work efficiency during construction. The sheet pile profile is made of a resin composition, e.g., polyvinyl chloride (e.g., derived from recycled waste); a core and coating structure elastomer; an acrylic copolymer; and a filler (e.g., calcium carbonate, kaolin, aluminum hydroxide, clay, silica, and talc). The sheet pile profile may also contain one or more components such as a heat stabilizer, antioxidant, UV stabilizer, plasticizer, lubricant, and pigment. KR102043182B1 does not disclose the single-oriented arrangement of sheet pile profiles, the production of sheet pile profiles from two types of recyclates, and the configuration of the coextruded layer as in the present invention.

[0020] US9745710B2 is an American patent for a sheet pile profile comprising a top panel and side flanges that can be formed by extrusion, molding, casting, rolling, machining, or otherwise, and may include polyvinyl chloride (PVC), polypropylene, polyethylene, ABS, nylon, steel, aluminum, and / or other plastics, metals, or other materials and / or mixtures or composites thereof. In one exemplary form, the panel and flanges are co-extruded to comprise an outer layer of virgin PVC material and a core of recycled PVC material. US9745710B2 does not disclose the single-oriented arrangement of sheet pile profiles and co-extruded layer configuration as in the present invention.

[0021] KR101917246B1 is a Korean patent relating to a method of manufacturing a sheet pile profile, the core portion of which is continuously formed by melting and extruding plastic waste. The sheet pile profile also includes a mixed layer formed between the core portion and the coating layer, in which waste plastics and reinforced plastics are mixed. In addition, the method includes a step of forming a coating layer, which is then extruded onto the outer peripheral surface of the core portion to prevent it from peeling off from the outer peripheral surface of the core portion. KR101917246B1 does not disclose the single-oriented arrangement of sheet pile profiles and co-extruded layer configuration as in the present invention.

[0022] CN109796699A is a Chinese patent application for a co-extruded profile made of plastic and reinforcing fiber, wherein the plastic comprises PET, HDPE, PVC, at least one of PMMA, PP, and PS, and the reinforcing fiber is at least one of glass fibers, plant fibers, carbon fibers, high-strength steel wire, and nylon fibers. During production, the profile is co-extruded with ASA material to achieve a surface coating effect. PVC, calcium-zinc stabilizer, glass fibers, ACR processing aids, PE wax, and paraffin wax are used in the production. CN109796699A does not disclose the single-oriented stacking of sheet pile profiles and the configuration of the coextruded layer as in the present invention.

[0023] JP1993092514A is a Japanese patent application describing a steel sheet pile profile made of alloy steel, such as carbon steel and stainless steel. In addition, in order to increase the corrosion resistance of steel sheet pile profiles, their ridges and valleys are coated with a coating of zinc, aluminum, chromium, etc., zinc with iron, zinc with aluminum, zinc with nickel, etc. A dispersion coating in which fine inorganic particles such as silica and titanium oxide are dispersed may also be used. JP1993092514A does not disclose the single-oriented stacking of sheet pile profiles, the production of sheet pile profiles from two types of recyclates, and the configuration of the coextruded layer as in the present invention.

[0024] CN212452586U is a Chinese utility model relating to a high-strength steel sheet pile profile for bridge engineering, comprising a steel plate whose outer side is permanently bonded to a first functional layer, and the first functional layer comprises a manganese alloy layer and a polytetrafluoroethylene layer, and the outer side of the first functional layer is permanently bonded to a second functional layer, while the second functional layer comprises a high-manganese steel coating, a polyurethane anti-corrosion coating, and a zinc-rich epoxy coating. CN212452586U does not disclose the single-oriented stacking of sheet pile profiles, the production of sheet pile profiles from two types of recyclates, and the configuration of the coextruded layer as in the present invention.

[0025] US9421742B2 is a US patent application relating to layer laminates produced by co-extrusion of layers, which reduces the cost of laminate production by eliminating the costly bonding process.

[0026] In addition, existing Prolock Epsilon profiles are manufactured in several variants from recycled PVC, with additional seals and protective coatings. They are used to reinforce quays and embankments. The design of the profiles allows them to be stacked in a single-oriented configuration. The existing solution (Prolock profile with a functional width of 735 mm) (Fig. 1) has an additional protrusion that increases the weight of the profile by approximately 300 g per running meter of profile. Converted to a square meter of sheet piling, the increase in weight is approximately 400 g / m 2< . The solution described in this application does not require the use of an additional protrusion.

[0027] With an average price of recycled raw material of EUR 0.85 / kg, the savings resulting from the reduction in weight per square meter of sheet pile profile wall amount to EUR 0.34 / m 2< without compromising the functional parameters of the wall.

[0028] The sheet pile profile with a single-oriented laying function is to be used in large infrastructure projects planned for 2025 / 2026 in Europe. With a total demand for sheet pile profiles of 200,000 m 2< , the savings achieved by reducing the raw material weight will amount to approximately EUR 70,000.

[0029] The introduction of co-extrusion, which enables the production of sheet pile profiles from two types of recyclates, is a significant innovation that has not been used in the production of sheet pile profiles to date. The co-extruded layer known from the prior art is currently approx. 0.5 mm thick and its purpose is to change the external color of the sheet pile profile while increasing its UV resistance. The sheet pile profiles currently in use are made as a monolithic profile from high-impact recycled material or a monolithic profile from high-impact recycled material with a thin co-extruded layer of virgin material.

[0030] With the performance parameters of the sheet pile profile unchanged and average recyclate prices, where the cost of high-impact recyclate is EUR 850 / ton, while the cost of standard recyclate is EUR 650 / ton; the average cost of raw material for the proposed solution (assuming the same density) will be 2.0 / 7.6 x 850 + 5.6 / 7.6 x 650 = EUR 703 / ton. The savings compared to monolithic solutions are therefore EUR 147 / ton.

[0031] With an average sheet pile profile weight of 18.1 kg / m 2< and projects at 200,000 m 2< , the raw material savings amount to EUR 532,140,000 without compromising the functional parameters of the sheet pile profiles.Summary of the invention

[0032] The invention relates to a sheet pile profile comprising an upper arm 1, which is flat across its entire width, bounded by outwardly inclined slanted arms 2a, 2b, positioned symmetrically relative to a plane perpendicular to the upper arm 1, and a closing element located at the end of each of the slanted arms 3a, 3b, wherein one slanted arm 2b has a female lock 4, and the other slanted arm 2a has a male lock 5, wherein it comprises a groove 9 and is made of two types of recyclates, wherein the outer layer is made of a recyclate with higher impact strength, and the core is made of a recyclate with lower impact strength and a higher content of mineral fillers, wherein the shape of the form-fit joint allows for angular deflections within 15° in both directions.

[0033] Preferably, micronized fly ash is used as the mineral filler.

[0034] Preferably, the sheet pile profile includes a seal made of PVC (polyvinyl chloride) or thermoplastic elastomer (TPO).

[0035] Preferably, the outer layer has a thickness of 2x1.0 mm, and the core has a thickness of 5.6 mm.

[0036] Preferably, the functional dimension from the center of the female lock 4 to the center of the male lock 5 is 733-740 mm, and the thickness of the sheet pile profile is in the range of 6.8-12.8 mm.

[0037] Preferably, the outer layer contains stabilizers based on calcium-zinc or tin compounds, and the core contains a lead stabilizer.

[0038] Preferably, the outer layer is made of post-production or post-consumer recyclate from high-impact window joinery, which comprises ground material or regranulates produced from milled packaging waste.

[0039] Preferably, the core is made of post-consumer recyclate, recyclate from panels or pipes, or regranulate.

[0040] Another subject of the invention is a method of manufacturing a sheet pile profile by co-extrusion, in which the technical profile is continuously pulled in selected sections of the profile cross-section, at a haul-off speed below 1 m / min, through a set of dry calibrators 17 and a cooling tank 18, wherein eight caterpillar haul-off units (four pairs) are used for pulling, where two pairs of caterpillars generate the pulling force on the upper arm 1 of the sheet pile profile, and the remaining two pairs of caterpillars generate the force on the inclined arms 2a, 2b of the sheet pile profile, wherein one pair is located near the male lock 5 and the other near the female lock 4, wherein the wall thickness of the locks of the sheet pile profile is adjusted by means of hot air with adjustable temperature, wherein the seal is applied by means of a melt flow channel of the polymer material formed in the body of the extrusion tool 15, where the connection occurs at the material interface, wherein the sheet pile profile is cut in a chipless manner by means of a guillotine with a heated blade, which is synchronized with a transport device moving the cut section of the sheet pile profile away from the cutting area of the heated knife.

[0041] Preferably, the measurement of the dimensions of the polymer melt is carried out continuously by means of a laser sensor, and the measurement signal is used for continuous adjustment of the linear speed of the haul-off driven by servomotors.

[0042] Yet another subject of the invention is a sheet pile profile installation process, in which steel guides (mandrels) 10 are used, which, on the contact surface between the guide and the sheet pile profile, are fully or partially covered with a plastic material with a low coefficient of friction and high abrasion resistance of the PE-100 type (a grade of high-density polyethylene) or UHMWPE (ultra-high-molecular-weight polyethylene).

[0043] Preferably, strips made of PE-1000 are installed in the shelves of the sheet pile profile.Brief description of the figures:

[0044] Fig. 1 shows a Prolock company profile (state of the art). Fig. 2 shows a sheet pile profile together with female and male locks. Fig. 3 shows the shape of a form-fit connection (male lock and female lock) at an angular deviation shown in two positions X) and Y). Fig. 4a shows a sheet pile profile with marked sliding areas (A) and areas that are non-sliding in a standard situation (B). Fig. 4b shows a sheet pile profile with marked sliding areas (A). Fig. 5 shows a sheet pile profile together with a mandrel and marked spacers (C). Fig. 6 shows sheet pile profiles arranged in a stack together with an enlarged view of the connection of the stop shoulder with the installation lock. Fig. 7 shows a diagram of a system for maintaining nominal dimensions of the sheet pile profile by means of changes in haul-off speed (Flowcontrol system) with a marked supply of hot air (D). Fig. 8 shows a diagram of the self-regulation system.

[0045] In the attached drawing, the following reference numerals are used: 1 - upper arm, 2a, 2b - inclined arms, 3a, 3b - closing elements, 4 -female lock, 5 - male lock, 8 - stop shoulder, 9 - groove, 10 - mandrel, A - sliding areas, B - non-sliding areas, C - spacers, 11 - non-contact measuring device of a selected profile segment, 12- PLC controller, 13 - linear haul-off speed control system, 14 - extruder, 15 - extrusion tool, 16 - swollen PVC melt, 17 -dry calibration unit, 18 -cooling tank, 19 - haul-off unit.Detailed description of the invention

[0046] The sheet pile profile (Fig. 2) comprises an upper arm 1, which is flat across its entire width, bounded by outwardly inclined slanted arms 2a, 2b, which are positioned symmetrically with respect to a plane perpendicular to the upper arm 1. The angle between the upper arm 1 and the inclined arms 2a, 2b is from 95° to 105°. At the end of both inclined arms 2a, 2b, the sheet pile profile includes closing elements 3a, 3b, respectively. One of the inclined arms 2b carries a female lock 4, and the other inclined arm 2a carries a male lock 5. Furthermore, the lower part of the female lock 4 and male lock 5 is provided with a groove 9 (assembly recess), while the upper part has a stop shoulder 8 shaped and dimensioned to fit the groove, ensuring greater stability of the stacked profiles during transport (see Fig. 1). The cooperation of the shoulders 8 and grooves 9 prevents the profiles from sliding relative to each other in the lateral or axial direction during transport, so that the entire stack maintains positional stability without the need for additional stabilizing elements. Thanks to this arrangement, during production of the sheet pile profiles by extrusion, there is no need to invert them when stacking, which, for sheet pile profiles up to 16 meters long, would otherwise require additional personnel, equipment, and increased operational space in the production hall. Moreover, during installation of the sheet pile profiles using vibratory hammers, there is also no need to invert them when fitting them onto the steel guide - mandrel 10, which reduces the time and labor required to install a sealed wall from the sheet pile profiles.

[0047] The proposed solution involves the production of a sheet pile profile (Fig. 2) with a nominal thickness of 6.8 mm to 12.8 mm, preferably 6.8 mm to 10.4 mm, more preferably 6.8 mm to 8.5 mm, and most preferably 7.6 mm, wherein the outer layers with a thickness of 0.2 to 2 mm are made of high-impact recyclate (from products with a high content of impact modifiers), and the core with a thickness of 4.8 to 10.4 mm is made of recyclate with lower impact resistance and a higher content of mineral fillers. Suitable fillers include, for example, micronized fly ash. The functional dimension from the center of the female lock 4 to the center of the male lock 5 ranges from 600 to 1200 mm, preferably 600 to 800 mm, and the thickness of the sheet pile profile falls within the range of 6.8 to 12.8 mm. During installation and use of the sheet pile profiles, it is important to ensure adequate impact resistance. Research and development work has confirmed that for solid profiles with wall thicknesses of around 8 mm, it is crucial to use approximately 1 mm thick outer layers of material with guaranteed high impact resistance, such as post-production or post-consumer recyclate from high-impact window joinery. Post-production recyclate from window joinery comprises ground material or regranulates produced from milled packaging waste generated during the manufacture of PVC window joinery. It has two main advantages in terms of sheet pile profile requirements. Due to current ecological regulations, it contains calcium-zinc stabilizers in the outer layer. According to upcoming regulations, the inner layers of profiles (currently made from regranulates from old post-consumer windows containing lead stabilizer) will soon not be allowed to contain more than 0.1% Pb. Therefore, this material provides a source of recycled raw material with a favorable ecological profile. Additionally, it possesses mechanical properties and resistance to external conditions in line with the requirements for sheet pile profiles, for example according to DIN 16456, ASTM D 8427, ITP-PIB-KOT-2023 / 47.

[0048] Ready-made calcium-zinc or tin stabilization systems are produced by specialized companies, such as Reagens, Baerlocher, IKA, and Akzidenz-Chemson. The systems may also include other components known to experts in the field of plastics processing, such as lubricants that improve processing properties.

[0049] There is a trend toward limiting the use of recyclates containing lead-based stabilizers (such stabilizers were commonly used in the second generation of PVC joinery, which is now being widely replaced by joinery with higher thermal insulation performance). The proposed co-extrusion layer configuration covers all sections (including non-visible sections of the sheet pile profile), which is a novel solution compared to co-extruded layers made from virgin PVC. With this configuration, it will be possible to produce sheet pile profiles entirely from recyclates-the core from material containing a lead stabilizer, and the outer layer, for example, from post-production recyclates (waste from the assembly of window joinery) containing calcium-zinc or tin-based stabilizers. The material used for the core may be post-consumer recyclate, recyclate from panels or pipes, or regranulate.

[0050] The dimensions of the form-fit connection of the male lock 5 and female lock 4 (Fig. 3) have been selected to ensure mechanical strength of the connection while allowing a large range of possible angular deviation. The connection of the male lock 5 and female lock 4 at the two extreme deviations X and Y is shown in Fig. 3. The range of deviations may be up to ±15° relative to the neutral position.

[0051] The sheet pile profile further includes a seal made of PVC (polyvinyl chloride) or a thermoplastic polymer (TPO) with a low coefficient of friction, applied via a polymer melt flow channel located in the extrusion head of the sheet pile profile. After exiting the head and before entering the first dry calibration, the PVC melt 16 swells (Fig. 8).

[0052] The present invention also relates to a method of producing a sheet pile profile by co-extrusion. It involves continuously pulling the technical profile in selected sections of the profile cross-section at a haul-off speed below 1 m / min, through a set of dry calibrators 17 and a cooling tank 18 (part of the extrusion tool mounted on the vacuum calibration table) in order to cool the profile and stabilize its geometry (Fig. 8). The extrusion setup further includes a non-contact measuring device for a selected profile segment 11, a PLC controller 12, a linear haul-off speed control system 13, an extruder 14, an extrusion tool 15, and a haul-off unit 19. Eight caterpillar units (four pairs) are used for haul-off, enabling the pulling of large technical profiles in selected sections of the profile cross-section. Two pairs of caterpillars generate the pulling force on the upper arm 1 of the sheet pile profile, while the remaining two pairs generate the force on the inclined arms 2a, 2b of the sheet pile profile, with one pair positioned near the male lock 5 and the other near the female lock 4.

[0053] Conventionally, among sheet pile profile manufacturers, a two-caterpillar haul-off is used, in which the pulling force is generated by clamping the caterpillars on the horizontal, upper arm of the sheet pile profile (Fig. 4a, A). The inclined arms 2a, 2b of the sheet pile profile, as well as the horizontal lower closing elements 3a, 3b of the profile ending with the male lock 5 and female lock 4, are not pulled B. The force required to pull these segments of the sheet pile profile through the calibrators is a derivative of the force generated by the haul-off on the horizontal upper arm 1. In particular, the lock segments of the sheet pile profile are, in the absence of direct pulling, exposed to jamming in the critical area between the extrusion head (where the material is in the form of PVC melt) and the entrance to the first dry calibrator (where the material solidifies due to intensive cooling). Sheet pile profiles are produced from recycled PVC, and during the flow of the melt from the extrusion head, dimensional fluctuations of the extruded profile occur, which, in the absence of sufficient haul-off force, can lead to the material jamming between the head and the first calibrator. Such jamming prevents the material from being pulled through the calibrators (disrupting the continuous extrusion process), requiring the line to be stopped, the jammed material removed, and the extrusion line restarted. Due to the size of the profile, restarting the line can take 6 to 8 hours. Frequent interruptions of production caused by this phenomenon result in a real decrease in production efficiency and an increase in the amount of start-up scrap needing internal recycling. Additionally, personnel involvement (number of employees required to restart the line) is higher when production is interrupted more often due to material jamming.

[0054] When using the developed eight-caterpillar haul-off for production, two pairs of caterpillars generate the pulling force on the horizontal upper arm 1 of the sheet pile profile, and two pairs of caterpillars generate forces on the horizontal lower closing elements 3a, 3b (one pair near the male lock 5 and the other near the female lock 4), which eliminates the above-described production disturbances. Fig. 4b shows the marked haul-off locations.

[0055] During the production of sheet pile profiles, the wall thickness of the male lock 5 and female lock 4 is regulated using hot air with adjustable temperature and flow rate (Flowcontrol system). The Flowcontrol device (Fig. 7) is a patented device from Greiner Extrusion, Austria (patent number DE102011007618 A1), and is used to maintain critical cross-sectional dimensions of the profiles within specified tolerances. The device provides hot air at a defined temperature and flow rate. It works in conjunction with extrusion tools that have an integrated Flowcontrol function: air channels near the critical section of the profile, allowing precise control of the temperature (and thus the flow of the thermoplastic PVC melt) independently of the global tool zone temperature controlled by plate heaters.

[0056] In the context of the present invention, hot air means air at a temperature of 80 to 600°C. The air pressure in the Flowcontrol system during operation ranges from 0.05 to 6 bar.

[0057] The Flowcontrol system works optimally for window profiles with wall thicknesses of about 3 mm. For sheet pile profiles with wall thickness up to approximately 12 mm, produced from recyclates with variable rheology, this solution alone is insufficient. Therefore, it is supplemented by regulating the wall thickness of the sheet pile profile locks through continuous adjustment of the haul-off speed.

[0058] This system works in conjunction with the Flowcontrol assembly through a control loop (non-contact measurement of a reference area of the sheet pile profile) (of the polymer melt) between the extrusion head and the dry calibrator. Proper regulation of the operating speed of the multi-contact haul-off allows achieving dimensional tolerances in the area of the form-fit connection male lock 5 - female lock 4 at a level of ±0.2 mm. Maintaining such precise dimensions ensures the correct functioning of the form-fit connection (both in terms of mechanical strength and the angular deviation range of the connection) as well as the proper functioning of the seal inserted into the female lock 4. The dimensions of the polymer melt are continuously measured using a laser sensor. The measurement signal is processed using appropriate algorithms to continuously adjust the linear haul-off speed driven by servomotors.

[0059] Conventionally, the seal is applied in the female lock 4 in an inline process (during the production of sheet pile profiles by extrusion) in a process referred to as post-coextrusion. This process involves applying the seal via an extruder and extrusion head onto an already calibrated and cooled profile (the seal application assembly is located at the end of the calibration table, after the cooling tank of the extrusion tool, which finalizes the shape and cools the extruded profile). To achieve proper bonding of the plastified seal material (soft PVC or TPO), it is necessary to locally heat the already cooled segment of the female lock 4 using hot air blowers at the point of seal application. This method of applying the seal has the following process limitations: The bond between the seal material and the base sheet pile profile is not optimal in terms of mechanical parameters (peel-off strength is suboptimal), The shape of the seal is neither stable nor repeatable (there is no possibility of calibrating the seal).

[0060] To eliminate these shortcomings of the process, taking into account modifications leading to dimensional stabilization of the female lock 4 area, an innovation was introduced involving the application of the seal via a polymer melt flow channel built into the body of the extrusion tool 15. This solution offers the following advantages compared to the post-coextrusion process: The material bond achieves higher mechanical properties because the connection occurs at a material-to-material interface, where both polymers are in a molten state, After being applied in the extrusion head of the tool, the seal is subsequently calibrated in the dry calibrators 17 and the cooling tank 18, along with the entire sheet pile profile. This allows stabilization of the seal's shape and dimensions.

[0061] Sheet pile profiles are cut chip-free. Chip-free cutting of profiles is commonly used, for example, in multi-chamber PVC window profiles. In the case of single-wall sheet pile profiles, this solution has not been previously applied. Due to increasing ecological awareness and the tendency to eliminate microplastics from the natural environment (classic cutting of sheet pile profiles with a circular saw generates chips and dust, which, due to electrostatic charge, are very difficult to remove from the sheet pile profile surface), chip-free cutting is a desirable function for a sheet pile profile extrusion line. Due to the large mass of the sheet pile profiles and lengths up to 16 m, it is necessary to add a transport device synchronized with the guillotine, used to move the cut section of the sheet pile profile away from the heated blade cutting area. This solution eliminates lateral forces acting on the heated blade caused by the pressure of the cut sheet pile profile, which could lead to blade breakage.

[0062] The sheet pile profile assembly process is also designed to eliminate sources of microplastic generation. Currently, assembling sheet pile profiles using a steel guide (mandrel) can generate microplastics. During assembly, especially of long profiles while pulling the guide, friction occurs between the steel surface and the sheet pile profile under ground pressure. Field observations of dismantled sheet pile profiles confirm the wear of the profile surfaces and, consequently, the generation of polymer dust. To reduce friction forces and dust generation, an innovation has been introduced whereby the contact surface of the guide with the sheet pile profile is partially or fully coated with a low-friction, highly wear-resistant plastic such as PE-100 (high-density polyethylene) or UHMWPE (ultra-high-molecular-weight polyethylene) in the form of profiles, sheets, or films, maintaining the distance C as shown in Fig. 5. The preferred solution is the use of a PE-1000 strip mounted in the shelves of the sheet pile profile.

Claims

1. A sheet pile profile comprising an upper arm (1), which is flat across its entire width, bounded by outwardly inclined slanted arms (2a, 2b), positioned symmetrically relative to a plane perpendicular to the upper arm (1), and a closing element located at the end of each of the slanted arms (3a, 3b), wherein one slanted arm 2b has a female lock 4, and the other slanted arm 2a has a male lock, characterized in that it comprises a groove (9) and is made of two types of recyclates, wherein the outer layer is made of a recyclate with higher impact strength, and the core from a recyclate with lower impact strength and a higher content of mineral fillers, wherein the shape of the form-fit joint allows for angular deflections within 15° in both directions.

2. The sheet pile profile according to claim 1, characterized in that micronized fly ash is used as the mineral filler.

3. The sheet pile profile according to claims 1-2, characterized in that it comprises a seal made of PVC (polyvinyl chloride) or thermoplastic elastomer (TPO).

4. The sheet pile profile according to claims 1-3, characterized in that the outer layer has a thickness of 2×1.0 mm, and the core has a thickness of 5.6 mm.

5. The sheet pile profile according to claims 1-4, characterized in that the functional dimension from the center of the female lock (4) to the center of the male lock (5) is 733-740 mm, and the thickness of the sheet pile profile is in the range of 6.8-12.8 mm.

6. The sheet pile profile according to claims 1-5, characterized in that the outer layer contains stabilizers based on calcium-zinc or tin compounds, and the core contains a lead stabilizer.

7. The sheet pile profile according to claims 1-6, characterized in that the outer layer is made of post-production or post-consumer recyclate from high-impact window joinery, which comprises ground material or regranulates produced from milled packaging waste.

8. The sheet pile profile according to claims 1-7, characterized in that the core is made from post-consumer recyclate, recyclate from panels or pipes, or regranulate.

9. A method of manufacturing a sheet pile profile by co-extrusion, characterized in that the technical profile is continuously pulled in selected sections of the profile cross-section, at a haul-off speed below 1 m / min, through a set of dry calibrators (17) and a cooling tank (18), wherein eight caterpillars (four pairs) are used for pulling, two pairs of caterpillars generating pulling force on the upper arm (1) of the sheet pile profile, and the remaining two pairs of caterpillars generate force on the slanted arms (2a, 2b) of the sheet pile profile, wherein one pair is located near the male lock (5) and the other near the female lock (4), wherein the wall thickness of the locks of the sheet pile profile is is adjusted by means of hot air with adjustable temperature, wherein the seal is applied by means of a melt flow channel of the polymer material formed in the body of the extrusion tool (15), where the connection occurs at the material interface, wherein the sheet pile profile is cut in a chipless manner by means of a guillotine with a heated blade, which is synchronized with a transport device moving the cut section of the sheet pile profile away from the cutting area of the heated knife.

10. The method according to claim 9, characterized in that the measurement of the dimensions of the polymer melt is carried out continuously by means of a laser sensor, and the measurement signal is used for continuous adjustment of the linear speed of the haul-off driven by servomotors.

11. A sheet pile profile installation process, in which steel guides (mandrels) (10) are used, which, on the contact surface between the guide and the sheet pile profile, are fully or partially covered with a plastic material with a low coefficient of friction and high abrasion resistance of the PE-100 type (a grade of high-density polyethylene) or UHMWPE (ultra-high-molecular-weight polyethylene).

12. The method of assembling a sheet pile profile according to claim 11, characterized in that strips made of PE-1000 are installed in the shelves of the sheet pile profile.

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