Lining reinforced wood-plastic column and beam and preparation method thereof

Abstract

The invention relates to the technical field of wood-plastic material extrusion molding, in particular to a lining reinforced wood-plastic column and beam and a preparation method thereof. The lining reinforced wood-plastic column and beam comprises an outer shell layer, an inner reinforcing layer and a sandwich layer, the outer shell layer and the inner reinforcing layer are respectively and independently extruded and formed, the sandwich layer is contained in the middle of the inner reinforcing layer, and the sandwich layer and the inner reinforcing layer are integrally extruded and formed in a co-extrusion mode. According to the prepared lining reinforced wood-plastic column and beam, the problems that in an existing production technology, extrusion molding is difficult, the production efficiency is low, the structural strength is insufficient, the wall thickness is difficult to control, the cost is high, and the wood-plastic column and beam are difficult to be combined with PA6 engineering plastic and UHMWPE for production are solved.

Description

Technical Field

[0001] This invention relates to the field of wood-plastic composite material extrusion molding technology, and in particular to a lined reinforced wood-plastic column and beam and its preparation method. Background Technology

[0002] Wood-plastic composite materials are a new type of composite material that is usually made of polyolefins such as PE, PP, and PVC and plant fiber powders such as wood, straw, and rice husks as the main raw materials. They are mixed, granulated, and processed into shape by specialized equipment. They combine the excellent properties of wood and plastic and are environmentally friendly, pollution-free, and recyclable.

[0003] Wood-plastic columns and beams are a type of wood-plastic profile with a certain load-bearing structure. Their cross-sections are mostly hollow, and their dimensions are much larger than those of conventional flooring. The inner and outer cavities of ordinary wood-plastic columns and beams are often connected as a whole by connecting ribs. Their mold structure has many mandrels for cooling and shaping during extrusion, making the molding process more difficult and the production speed significantly lower than that of flooring. Unlike solid materials, they cannot achieve uniform extrusion. Uneven cooling of the cavity during extrusion leads to uneven wall thickness between the inner and outer cavities and repeated cracking at the connecting ribs, affecting subsequent use. Furthermore, as a whole material, installation is cumbersome, time-consuming, and labor-intensive. Meanwhile, because it needs to achieve a certain load-bearing strength, its production formula needs to be significantly better than that of conventional floor and wall panels, and it cannot achieve independent reinforcement of the inner and outer cavities, resulting in a significant increase in production costs. PA6 engineering plastic and ultra-high molecular weight polyethylene (hereinafter referred to as UHMWPE) have excellent properties, but PA6 has a high processing temperature and UHMWPE has a high melt viscosity, making it difficult to extrude and mold using conventional methods. Currently, there is a need for an inner-lined reinforced wood-plastic column or beam and its preparation method to solve the problems of difficult extrusion molding, low production efficiency, insufficient structural strength, difficulty in controlling wall thickness, high cost, and difficulty in combining it with PA6 engineering plastic and UHMWPE for production. Summary of the Invention

[0004] To address the aforementioned issues, this application provides a lined reinforced wood-plastic column and beam and its preparation method, thereby solving the problems of difficult extrusion molding, low production efficiency, insufficient structural strength, difficulty in controlling wall thickness, high cost, and difficulty in combining with PA6 engineering plastics and UHMWPE in the existing production technology of wood-plastic columns and beams.

[0005] To achieve the above objectives, this application provides a reinforced wood-plastic composite column or beam, which includes an outer shell layer, an inner reinforcement layer, and a sandwich layer. The outer shell layer and the inner reinforcement layer are extruded and formed independently, and the sandwich layer is contained in the middle of the inner reinforcement layer and is integrally extruded and formed with the inner reinforcement layer by co-extrusion.

[0006] A method for preparing reinforced wood-plastic composite columns and beams includes the following steps: S1. Take 25-35 parts by weight of PE plastic, 3-5 parts of MAPE, 55-65 parts of plant fiber powder, 5-8 parts of filler, 1.5-3.0 parts of lubricant, 1.0-3.0 parts of pigment, and 0.1-0.5 parts of antioxidant, add them to a parallel twin-screw granulator for mixing and granulation to obtain the outer shell layer wood-plastic granules. S2. Pour the outer shell wood-plastic granules into the hopper of a conical twin-screw extruder, extrude, cool and shape, grind and polish, and cut to obtain the outer shell layer; S3. Take 20-30 parts by weight of PE plastic, 10-15 parts of PA6 / PE alloy compatibilizer, 50-55 parts of plant fiber powder, 5-8 parts of filler, 1.5-3.0 parts of lubricant, and 0.5-1.5 parts of pigment, add them to a parallel twin-screw granulator for mixing and granulation to obtain inner reinforcing layer granules. In the above process, the high shear of the parallel twin-screw granulator is used to instantly reach the processing temperature of PA6 engineering plastic, so that it is fully plasticized and the wood fibers are not carbonized.

[0007] S4. Add the inner reinforcing layer granules to the modified conical twin-screw extruder. Take 60-85 parts by weight of the sandwich layer raw materials PE plastic, 5-20 parts by weight of UHMWPE plastic, 5-20 parts by weight of MAPE, and 1-20 parts by weight of modified basalt fiber. Mix and add to the modified single-screw co-extruder. Co-extrude, cool and shape, and cut to obtain the inner reinforcing layer with sandwich layer. In the above process, the modified conical twin-screw extruder is connected to the modified single-screw co-extruder. When the inner reinforcing layer and the sandwich layer are co-extruded in one piece, the co-extruder is started first to extrude the sandwich layer. After the sandwich layer fills the flow channel, the extruder is started to extrude the inner reinforcing layer.

[0008] S5. Align the protrusions or grooves of the inner reinforcing layer with the grooves or protrusions of the outer shell layer, and insert them into the outer shell layer along the length of the wood-plastic column or beam to obtain the inner reinforced wood-plastic column or beam.

[0009] Furthermore, the filler is calcium carbonate or talc.

[0010] Furthermore, the lubricant is at least one of paraffin wax, polyethylene wax, stearic acid, calcium stearate, and zinc stearate.

[0011] Furthermore, the antioxidant is antioxidant 1010 or antioxidant 168.

[0012] Furthermore, the parallel twin-screw granulator described in step S1 has the following process parameters: Zone 1: 80-100℃; Zone 2: 120-150℃; Zone 3: 160-165℃; Zones 4 and 5: 175-180℃; Zone 6: 180-185℃; Zones 7 and 8: 175-180℃; Zones 9 and 10: 150-160℃; main unit current: 200-220A; and main unit speed: 320-380rpm.

[0013] Furthermore, the parallel twin-screw granulator described in step S3 has the following process parameters: Zone 1 165-170℃, Zone 2 190-195℃, Zone 3 170-175℃, Zone 4 190-195℃, Zone 5 170-175℃, Zone 6 190-200℃, Zone 7 170-175℃, Zone 8 190-200℃, Zones 9 and 10 160-170℃, main machine current 200-220A, and main machine speed 320-380rpm.

[0014] Furthermore, in step S2, the mixing section of the conical twin-screw extruder has a groove spacing of 28-30mm and a total length of 48-50mm. The process parameters are: zone 1 and zone 2 175-185℃, zone 3 155-165℃, zone 4 150-160℃, confluence core 140-145℃, die temperature 150-160℃, main engine current 40-50A, vacuum degree >0.08MPa, and main engine speed 12-18rpm.

[0015] Furthermore, in step S4, the modified conical twin-screw extruder has a mixing section with a groove pitch of 25-27mm and a total length of 68-70mm. The process parameters are: Zone 1 and Zone 2 180-195℃, Zone 3 165-175℃, Zone 4 160-170℃, confluence core 145-155℃, die temperature 170-190℃, main engine current 45-55A, vacuum degree >0.08MPa, and main engine speed 8-12rpm.

[0016] Furthermore, the modified single-screw co-extruder described in step S4 has the following process parameters: Zone 1: 170-180℃; Zones 2 and 3: 200-230℃; Combination core: 195-205℃; Main extruder speed: 8-12 rpm.

[0017] Furthermore, the thickness of the sandwich layer is 1.0-3.0 mm.

[0018] Furthermore, the outer shell layer and the inner reinforcing layer have a thickness of 14-20 mm, and the depth of the bumps and grooves is less than 1 / 4 of the thickness of the outer shell layer and the inner reinforcing layer.

[0019] Furthermore, the cross-section of the inner reinforced wood-plastic column is circular or square, and the outer diameter or side length of the outer shell layer is 120-180mm; the cross-section of the beam is rectangular, with the longest side length being 150-200mm and the shortest side length being 40-100mm.

[0020] Furthermore, the number of the protrusions and grooves is at least eight pairs arranged symmetrically.

[0021] Furthermore, the groove and the protrusion are V-shaped or dovetail-shaped with rounded corners, and the distance between the groove and the protrusion is 1.0-1.5mm.

[0022] In summary, this application has the following beneficial effects: Through the special structural design of wood-plastic columns and beams, and the improvement of raw material formulation and preparation methods, the outer shell layer with protrusions or grooves and the inner reinforcement layer are extruded and molded independently. The extrusion process is more stable, avoiding the risk of uneven wall thickness and cracks caused by uneven heating and cooling during extrusion. At the same time, the outer shell layer is produced using a common formula, while the inner reinforcement layer is produced using a formula with added PA6 / PE alloy material. A UHMWPE sandwich layer is set in the middle of the inner reinforcement layer cavity, making the load-bearing performance of the inner reinforcement layer superior. Then, the protrusions or grooves of the inner reinforcement layer are aligned with the grooves or protrusions of the outer shell layer and inserted into the outer shell layer along the length of the wood-plastic column or beam. The positioning connection is achieved through the protrusions and grooves in the structure of the two, resulting in wood-plastic columns and beams with higher production efficiency, easier molding, better load-bearing capacity, lower production cost, and easier installation. Attached Figure Description

[0023] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of the end face structure of the reinforced wood-plastic column and beam of the present invention; Figure 2 This is a schematic diagram of another design end face structure for the reinforced wood-plastic column and beam of the present invention; Figure 3 This is a plan view of the inner reinforcing layer of the inner-lined reinforced wood-plastic column and beam of the present invention penetrating the shell layer; Figure 4 This is a schematic diagram of the granulator screw section for the internally reinforced wood-plastic columns and beams of the present invention. Figure 5 This is a structural comparison diagram of the conventional screw 9a and the modified screw 9b of the extruder for the inner-lined reinforced wood-plastic columns and beams of the present invention. Figure 6 This is a structural comparison diagram of the conventional screw 10a and the modified screw 10b of the single-screw co-extrusion mill for the inner-lined reinforced wood-plastic columns and beams of the present invention. Figure 7This is a schematic diagram of the end structure of a typical wood-plastic composite column and a typical beam.

[0025] The diagram shows: 1. Reinforced wood-plastic column; 2. Reinforced wood-plastic beam; 3. Outer shell layer; 4. Inner reinforcement layer; 5. Sandwich layer; 6. Protrusion; 7. Groove; 8. Granulator screw; 9. Extruder screw; 10. Co-extruder screw; 11. Ordinary wood-plastic column; 12. Ordinary wood-plastic beam; 13. Inner cavity; 14. Connecting rib. Detailed Implementation

[0026] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the embodiments of this application. Obviously, the described embodiments are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this invention.

[0027] The raw materials involved in the specific embodiments of this application are analytical grade.

[0028] Example 1 A reinforced wood-plastic composite column 1 has a circular cross-section with an outer diameter of 180 mm. It includes an outer shell layer 3 with a thickness of 18 mm and an inner reinforcing layer 4 with a thickness of 16 mm. A 2.0 mm thick sandwich layer 5 is located in the middle of the inner reinforcing layer 4. The outer shell layer 3 has a 4 mm deep groove 7 inside, and the inner reinforcing layer 4 has a 3 mm long protrusion 6 on the outside. The protrusion 6 and the groove 7 are V-shaped with rounded corners at the corners, and the distance between the groove 7 and the protrusion 6 is 1.0 mm. The number of them is 8 pairs symmetrically arranged.

[0029] A method for preparing a lined reinforced wood-plastic composite column includes the following steps: S1. Take 30 parts by weight of PE plastic, 4 parts of MAPE, 55 parts of plant fiber powder, 5 parts of calcium carbonate, 2.0 parts of a mixture of stearic acid and polyethylene wax (mass ratio of stearic acid to polyethylene wax is 1:1), 1.2 parts of pigment, and 0.3 parts of antioxidant 1010 and add them to a parallel twin-screw granulator (zone 1 90℃, zone 2 120℃, zone 3 165℃, zones 4 and 5 175℃, zone 6 180℃, zones 7 and 8 175℃, zones 9 and 10 155℃, main machine current 210A, main machine speed 350rpm) to mix and granulate to obtain the outer shell layer wood-plastic granules. S2. Pour the outer shell wood-plastic granules into the hopper of a conical twin-screw extruder (mixing section groove spacing is 28mm, total length is 48mm, process parameters are: zone 1 and zone 2 175℃, zone 3 160℃, zone 4 155℃, confluence core 140℃, die temperature 155℃, main machine current 45A, vacuum degree 0.082MPa, main machine speed 15rpm), extrude, cool and shape, grind and polish (180 mesh sanding belt, pressure 0.3MPa, sanding belt speed 22m / s, feed speed 8m / min), cut to obtain outer shell layer 3; S3. Take 24 parts by weight of PE plastic, 12 parts of PA6 / PE alloy compatibilizer, 50 parts of plant fiber powder, 6 parts of talc powder, 2.0 parts of a mixture of stearic acid and polyethylene wax (mass ratio of stearic acid to polyethylene wax is 1:1), and 0.5 parts of pigment, and add them to a parallel twin-screw granulator (zone 1 170℃, zone 2 195℃, zone 3 175℃, zone 4 195℃, zone 5 175℃, zone 6 195℃, zone 7 175℃, zone 8 195℃, zone 9 and zone 10 165℃, main machine current 215A, main machine speed 340rpm) to mix and granulate to obtain the inner reinforcement layer granules. S4. Add the inner reinforcing layer granules to a modified conical twin-screw extruder (mixing section groove spacing is 25mm, total length is 68mm, process parameters are: zone 1 and zone 2 190℃, zone 3 175℃, zone 4 170℃, confluence core 150℃, die temperature 185℃, main machine current 51A, vacuum degree 0.080MPa, main machine speed 10rpm). Take 70 parts by weight of sandwich layer raw materials PE plastic, 10 parts by weight of UHMWPE plastic, 10 parts by weight of MAPE, and 10 parts by weight of modified basalt fiber, mix and add to a modified single-screw co-extruder (zone 1 175℃, zone 2 and zone 3 220℃, confluence core 200℃, main machine speed 10rpm), co-extrude, cool and shape, cut to obtain the inner reinforcing layer 4 with sandwich layer 5. S5. Align the protrusions 6 or grooves 7 of the inner reinforcing layer 4 with the grooves 7 or protrusions 6 of the outer shell layer 3, and insert the inner reinforcing wood-plastic column 1 into the outer shell layer 3 along the length of the wood-plastic column.

[0030] Example 2 A reinforced wood-plastic composite column 1 has a square cross-section with a side length of 150mm. It includes an outer shell layer 3 with a thickness of 16mm and an inner reinforcing layer 4 with a thickness of 14mm. A 1.5mm thick sandwich layer 5 is located in the middle of the inner reinforcing layer 4. The outer shell layer 3 has a groove 7 with a depth of 3.5mm inside. The inner reinforcing layer 4 has a protrusion 6 with a length of 2.3mm on the outside. The protrusion 6 and the groove 7 are in the shape of a dovetail, and the distance between the groove 7 and the protrusion 6 is 1.2mm. The number of them is 8 pairs symmetrically arranged.

[0031] A method for preparing a lined reinforced wood-plastic composite column includes the following steps: S1. Take 32 parts by weight of PE plastic, 4 parts of MAPE, 60 parts of plant fiber powder, 8 parts of calcium carbonate, 2.5 parts of a mixture of stearic acid and polyethylene wax (mass ratio of stearic acid to polyethylene wax is 1:1), 1.5 parts of pigment, and 0.4 parts of antioxidant 1010. Add them to a parallel twin-screw granulator (zone 1 95℃, zone 2 130℃, zone 3 165℃, zones 4 and 5 178℃, zone 6 185℃, zones 7 and 8 180℃, zones 9 and 10 160℃, main machine current 215A, main machine speed 360rpm) to mix and granulate to obtain the outer shell layer wood-plastic granules. S2. Pour the outer shell wood-plastic granules into the hopper of a conical twin-screw extruder (mixing section groove spacing is 28mm, total length is 48mm, process parameters are: zone 1 and zone 2 180℃, zone 3 165℃, zone 4 160℃, confluence core 140℃, die temperature 160℃, main machine current 48A, vacuum degree 0.082MPa, main machine speed 13rpm), extrude, cool and shape, grind and polish (180 mesh sanding belt, pressure 0.3MPa, sanding belt speed 22m / s, feed speed 8m / min), cut to obtain outer shell layer 3; S3. Take 28 parts by weight of PE plastic, 14 parts of PA6 / PE alloy compatibilizer, 55 parts of plant fiber powder, 8 parts of talc powder, 2.5 parts of a mixture of stearic acid and polyethylene wax (mass ratio of stearic acid to polyethylene wax is 1:1), and 0.8 parts of pigment, and add them to a parallel twin-screw granulator (zone 1 170℃, zone 2 195℃, zone 3 175℃, zone 4 195℃, zone 5 175℃, zone 6 200℃, zone 7 175℃, zone 8 195℃, zone 9 and zone 10 170℃, main machine current 218A, main machine speed 360rpm) to mix and granulate to obtain the inner reinforcement layer granules. S4. Add the inner reinforcing layer granules to a modified conical twin-screw extruder (mixing section groove spacing is 25mm, total length is 68mm, process parameters are: zone 1 and zone 2 195℃, zone 3 175℃, zone 4 170℃, confluence core 150℃, die temperature 190℃, main machine current 55A, vacuum degree 0.082MPa, main machine speed 8rpm). Take 75 parts by weight of sandwich layer raw materials PE plastic, 15 parts by weight of UHMWPE plastic, 15 parts by weight of MAPE, and 15 parts by weight of modified basalt fiber, mix and add to a modified single-screw co-extruder (zone 1 180℃, zone 2 and zone 3 225℃, confluence core 205℃, main machine speed 8rpm), co-extrude, cool and shape, cut to obtain the inner reinforcing layer 4 with sandwich layer 5; S5. Align the protrusions 6 or grooves 7 of the inner reinforcing layer 4 with the grooves 7 or protrusions 6 of the outer shell layer 3, and insert the inner reinforcing wood-plastic column 1 into the outer shell layer 3 along the length of the wood-plastic column.

[0032] Example 3 A reinforced wood-plastic composite beam 2 has a rectangular cross-section with a longest side of 160mm and a shortest side of 80mm. It includes an outer shell layer 3 with a thickness of 18mm and an inner reinforcing layer 4 with a thickness of 16mm. A 2.0mm thick sandwich layer 5 is located in the middle of the inner reinforcing layer 4. The outer shell layer 3 has a groove 7 with a depth of 4.5mm inside, and the inner reinforcing layer 4 has a protrusion 6 with a length of 3.0mm on the outside. The protrusion 6 and the groove 7 are in the shape of a dovetail, and the distance between the groove 7 and the protrusion 6 is 1.5mm. The number of them is 8 pairs symmetrically arranged.

[0033] A method for preparing an internally reinforced wood-plastic composite beam includes the following steps: S1. Take 30 parts by weight of PE plastic, 5 parts of MAPE, 58 parts of plant fiber powder, 6 parts of calcium carbonate, 2.3 parts of a mixture of stearic acid and polyethylene wax (mass ratio of stearic acid to polyethylene wax is 1:1), 1.4 parts of pigment, and 0.4 parts of antioxidant 1010 and add them to a parallel twin-screw granulator (zone 1 90℃, zone 2 125℃, zone 3 163℃, zones 4 and 5 175℃, zone 6 183℃, zones 7 and 8 178℃, zones 9 and 10 157℃, main machine current 212A, main machine speed 353rpm) to mix and granulate to obtain the outer shell layer wood-plastic granules. S2. Pour the outer shell wood-plastic granules into the hopper of a conical twin-screw extruder (mixing section groove spacing is 28mm, total length is 48mm, process parameters are: zone 1 and zone 2 176℃, zone 3 160℃, zone 4 158℃, confluence core 142℃, die temperature 156℃, main machine current 46A, vacuum degree 0.080MPa, main machine speed 15rpm), extrude, cool and shape, grind and polish (180 mesh sanding belt, pressure 0.3MPa, sanding belt speed 22m / s, feed speed 8m / min), cut to obtain outer shell layer 3; S3. Take 26 parts by weight of PE plastic, 13 parts of PA6 / PE alloy compatibilizer, 52 parts of plant fiber powder, 6 parts of talc powder, 2.4 parts of a mixture of stearic acid and polyethylene wax (mass ratio of stearic acid to polyethylene wax is 1:1), and 0.6 parts of pigment, and add them to a parallel twin-screw granulator (zone 1 168℃, zone 2 193℃, zone 3 172℃, zone 4 192℃, zone 5 172℃, zone 6 198℃, zone 7 172℃, zone 8 192℃, zone 9 and zone 10 165℃, main machine current 214A, main machine speed 354rpm) to mix and granulate to obtain the inner reinforcement layer granules. S4. Add the inner reinforcing layer granules to a modified conical twin-screw extruder (mixing section groove spacing is 25mm, total length is 68mm, process parameters are: zone 1 and zone 2 195℃, zone 3 172℃, zone 4 168℃, confluence core 148℃, die temperature 187℃, main machine current 52A, vacuum degree 0.082MPa, main machine speed 9rpm). Take 70 parts by weight of sandwich layer raw materials PE plastic, 20 parts by weight of UHMWPE plastic, 15 parts by weight of MAPE, and 10 parts by weight of modified basalt fiber, mix and add to a modified single-screw co-extruder (zone 1 175℃, zone 2 and zone 3 225℃, confluence core 205℃, main machine speed 9rpm), co-extrude, cool and shape, cut to obtain the inner reinforcing layer 4 with sandwich layer 5; S5. Align the protrusions 6 or grooves 7 of the inner reinforcing layer 4 with the grooves 7 or protrusions 6 of the outer shell layer 3, and insert the inner reinforcing wood-plastic beam into the outer shell layer 3 along the length of the wood-plastic beam to obtain the inner reinforcing wood-plastic beam 2.

[0034] Example 4 The difference between this embodiment and Embodiment 1 is that an inner-lined reinforced wood-plastic column 1 has a circular cross-section with an outer diameter of 160mm. It includes an outer shell layer 3 with a thickness of 18mm and an inner reinforcing layer 4 with a thickness of 16mm. A 2.0mm thick sandwich layer 5 is located in the middle of the inner reinforcing layer 4. The outer shell layer 3 has a 4mm long protrusion 6 inside, and the inner reinforcing layer 4 has a 3mm deep groove 7 on the outside. The groove 7 and the protrusion 6 are V-shaped with rounded corners at the corners, and the distance between the groove 7 and the protrusion 6 is 1.0mm. The number of grooves is 10 pairs symmetrically arranged. The preparation method is the same as in Embodiment 1.

[0035] Example 5 The difference between this embodiment and Embodiment 2 is that an inner-lined reinforced wood-plastic column 1 has a square cross-section with a side length of 120mm. It includes an outer shell layer 3 with a thickness of 16mm and an inner reinforcing layer 4 with a thickness of 14mm. A 1.5mm thick sandwich layer 5 is located in the middle of the inner reinforcing layer 4. The outer shell layer 3 has a 3.5mm long protrusion 6 inside, and the inner reinforcing layer 4 has a 2.3mm deep groove 7 outside. The groove 7 and the protrusion 6 are in the shape of a dovetail, and the distance between the groove 7 and the protrusion 6 is 1.2mm. The number of grooves 7 and protrusions 6 is 12 pairs arranged symmetrically. The preparation method is the same as in Embodiment 2.

[0036] Example 6 The difference between this embodiment and embodiment 3 is that an inner reinforced wood-plastic beam 2 has a rectangular cross-section with a longest side of 180mm and a shortest side of 60mm. It includes an outer shell layer 3 with a thickness of 18mm and an inner reinforcing layer 4 with a thickness of 16mm. A 2.0mm thick sandwich layer 5 is located in the middle of the inner reinforcing layer 4. The outer shell layer 3 has a 4.5mm long protrusion 6 inside, and the inner reinforcing layer 4 has a 3.0mm deep groove 7 on the outside. The groove 7 and the protrusion 6 are in the shape of a dovetail, and the distance between the groove 7 and the protrusion 6 is 1.5mm. There are 16 pairs of them symmetrically arranged. The preparation method is the same as in embodiment 3.

[0037] Compare with Example 1 A common wood-plastic composite column has a circular cross-section with an outer diameter of 180 mm, an outer cavity wall thickness of 18 mm, and an inner cavity wall thickness of 16 mm. The inner and outer cavities are connected by eight connecting ribs 14, and the inner and outer cavities are integrally formed. Its manufacturing method is as follows: S1. Weigh out 30 parts PE plastic, 4 parts MAPE, 55 parts plant fiber powder, 5 parts calcium carbonate, 2.0 parts of a mixture of stearic acid and polyethylene wax (mass ratio of stearic acid to polyethylene wax is 1:1), 1.2 parts pigment, and 0.3 parts antioxidant 1010 by weight and add them to a parallel twin-screw combined granulator (zone 1 90℃, zone 2 120℃, zone 3 165℃, zones 4 and 5 175℃, zone 6 180℃, zones 7 and 8 175℃, zones 9 and 10 155℃, main machine current 210A, main machine speed 350rpm) to mix and granulate to obtain outer shell wood-plastic granules; S2. Pour the outer shell wood-plastic granules into the hopper of a conical twin-screw extruder (mixing section groove spacing is 28mm, total length is 48mm, process parameters are: zone 1 and zone 2 175℃, zone 3 160℃, zone 4 155℃, confluence core 140℃, die temperature 155℃, main machine current 45A, vacuum degree 0.082MPa, main machine speed 15rpm). Use the die to extrude, cool and shape, grind and polish (180 mesh sanding belt, pressure 0.3MPa, sanding belt speed 22m / s, feed speed 8m / min), and after precision cutting, obtain ordinary wood-plastic column 11.

[0038] Compare with Example 2 A common wood-plastic composite beam has a longest side length of 160mm, a shortest side length of 80mm, an outer cavity wall thickness of 18mm, and an inner cavity wall thickness of 16mm. The inner and outer cavities are connected by eight connecting ribs 14, and the inner and outer cavities are integrally formed. Its manufacturing method is as follows: S1. Weigh out 26 parts of PE plastic, 13 parts of PA6 / PE alloy compatibilizer, 52 parts of plant fiber powder, 6 parts of talc powder, 2.4 parts of a mixture of stearic acid and polyethylene wax (mass ratio of stearic acid to polyethylene wax is 1:1), and 0.6 parts of pigment by weight. Add them to a parallel twin-screw granulator (zone 1 168℃, zone 2 193℃, zone 3 172℃, zone 4 192℃, zone 5 172℃, zone 6 198℃, zone 7 172℃, zone 8 192℃, zone 9 and zone 10 165℃, main machine current 214A, main machine speed 354rpm) to mix and granulate to obtain wood-plastic beam granules. S2. The obtained wood-plastic granules are added to a modified conical twin-screw extruder (the mixing section has a groove spacing of 25mm, a total length of 68mm, and process parameters of 195℃ for zones 1 and 2, 172℃ for zone 3, 168℃ for zone 4, 148℃ for the confluence core, 187℃ for the die, 52A for the main extruder, 0.082MPa for the vacuum, and 9rpm for the main extruder). After co-extrusion, cooling, and shaping by a professional die, ordinary wood-plastic beam 12 is obtained by precision cutting.

[0039] Performance testing Functional tests were performed on the products prepared in Examples 1-6 and Comparative Examples 1-2.

[0040] Bending strength test: Take a strip with a length of 80±2mm, a width of 10±0.2mm, and a thickness of 4±0.2mm from the inner cavity or inner reinforcing layer. Test it using an electronic universal testing machine with a strain rate of 0.1% / min. Calculate the bending strength at fracture. Impact strength test: The test was conducted according to GB / T 1843-2008 "Determination of Impact Performance of Plastic Cantilever Beams". The test results are shown in Table 1.

[0041] Table 1

[0042] As shown in Table 1, the reinforced wood-plastic columns and beams prepared in this application have excellent bending strength and impact resistance, which are significantly improved compared to the ordinary wood-plastic columns and beams of the comparative examples. The wood-plastic columns and beams prepared in this application are very different from the ordinary wood-plastic columns and beams prepared in the comparative examples in terms of structure and materials. The molding method of this application is to mold the outer shell layer and the inner reinforcement layer separately and then assemble them, while the molding method of the comparative examples is to mold the inner and outer cavities at one time. The differences in materials, structure and molding method result in the wood-plastic columns and beams prepared in this application having moderate cost, stable extrusion, easy control, good load-bearing capacity, and being difficult to crack and easy to install. Although the ordinary wood-plastic columns prepared in Comparative Example 1 have low cost, the extrusion is difficult to control, the load-bearing capacity is poor, it is easy to crack, and the installation is cumbersome. Although the ordinary wood-plastic beams prepared in Comparative Example 2 have good load-bearing capacity, the cost is high, the extrusion is difficult to control, and the installation is cumbersome. This shows that the wood-plastic columns and beams prepared in this application have excellent effects.

[0043] The above description is merely an example and illustration of the concept of this application. Those skilled in the art can make various modifications or additions to the specific embodiments described or use similar methods to replace them, as long as they do not deviate from the inventive concept or exceed the scope defined in the claims, they should all fall within the protection scope of this application.

Claims

1. A type of reinforced wood-plastic composite column or beam, characterized in that, The reinforced wood-plastic column and beam includes an outer shell layer (3), an inner reinforcement layer (4), and a sandwich layer (5). The outer shell layer (3) and the inner reinforcement layer (4) are extruded independently. The sandwich layer (5) is contained in the middle of the inner reinforcement layer (4) and is extruded integrally with the inner reinforcement layer (4) by co-extrusion.

2. A method for preparing reinforced wood-plastic composite columns and beams as described in claim 1, characterized in that, Includes the following steps: S1. Take 25-35 parts by weight of PE plastic, 3-5 parts of MAPE, 55-65 parts of plant fiber powder, 5-8 parts of filler, 1.5-3.0 parts of lubricant, 1.0-3.0 parts of pigment, and 0.1-0.5 parts of antioxidant, add them to a parallel twin-screw granulator for mixing and granulation to obtain the outer shell layer wood-plastic granules. S2. Pour the outer shell wood-plastic granules into the hopper of a conical twin-screw extruder, extrude, cool and solidify, grind and polish, and cut to obtain the outer shell (3). S3. Take 20-30 parts by weight of PE plastic, 10-15 parts of PA6 / PE alloy compatibilizer, 50-55 parts of plant fiber powder, 5-8 parts of filler, 1.5-3.0 parts of lubricant, and 0.5-1.5 parts of pigment, add them to a parallel twin-screw granulator for mixing and granulation to obtain inner reinforcing layer granules. S4. Add the inner reinforcing layer granules to the modified conical twin-screw extruder. Take 60-85 parts of PE plastic, 5-20 parts of UHMWPE plastic, 5-20 parts of MAPE, and 1-20 parts of modified basalt fiber according to the weight of the sandwich layer raw materials, stir and mix them, add them to the modified single-screw co-extruder, co-extrude, cool and shape, cut, and obtain the inner reinforcing layer (4) with sandwich layer (5). S5. Align the protrusion (6) or groove (7) of the inner reinforcing layer (4) with the groove (7) or protrusion (6) of the outer shell layer (3) and insert it into the outer shell layer (3) along the length of the wood-plastic column and beam to obtain the inner reinforced wood-plastic column (1) and beam (2).

3. The method for preparing an internally reinforced wood-plastic column or beam according to claim 2, characterized in that, The parallel twin-screw granulator described in step S1 has the following process parameters: Zone 1: 80-100℃; Zone 2: 120-150℃; Zone 3: 160-165℃; Zones 4 and 5: 175-180℃; Zone 6: 180-185℃; Zones 7 and 8: 175-180℃; Zones 9 and 10: 150-160℃; Main motor current: 200-220A; Main motor speed: 320-380rpm.

4. The method for preparing an internally reinforced wood-plastic column or beam according to claim 2, characterized in that, The parallel twin-screw granulator described in step S3 has the following process parameters: Zone 1 165-170℃, Zone 2 190-195℃, Zone 3 170-175℃, Zone 4 190-195℃, Zone 5 170-175℃, Zone 6 190-200℃, Zone 7 170-175℃, Zone 8 190-200℃, Zones 9 and 10 160-170℃, main machine current 200-220A, and main machine speed 320-380rpm.

5. A method for preparing an internally reinforced wood-plastic column or beam according to claim 2, characterized in that, The mixing section of the conical twin-screw extruder described in step S2 has a groove spacing of 28-30mm and a total length of 48-50mm. The process parameters are: Zone 1 and Zone 2 175-185℃, Zone 3 155-165℃, Zone 4 150-160℃, confluence core 140-145℃, die temperature 150-160℃, main machine current 40-50A, vacuum degree >0.08MPa, and main machine speed 12-18rpm.

6. A method for preparing an internally reinforced wood-plastic column or beam according to claim 2, characterized in that, The modified conical twin-screw extruder described in step S4 has a mixing section groove pitch of 25-27mm and a total length of 68-70mm. The process parameters are: Zone 1 and Zone 2 180-195℃, Zone 3 165-175℃, Zone 4 160-170℃, confluence core 145-155℃, die temperature 170-190℃, main engine current 45-55A, vacuum degree >0.08MPa, and main engine speed 8-12rpm.

7. A method for preparing an internally reinforced wood-plastic column or beam according to claim 2, characterized in that, The modified single-screw co-extruder described in step S4 has the following process parameters: Zone 1: 170-180℃; Zones 2 and 3: 200-230℃; Combination core: 195-205℃; Main extruder speed: 8-12 rpm.

8. A method for preparing an internally reinforced wood-plastic column or beam according to claim 2, characterized in that, The outer shell layer (3) and inner reinforcing layer (4) are 14-20 mm thick, and the depth of the protrusion (6) and groove (7) is less than 1 / 4 of the thickness of the outer shell layer (3) and inner reinforcing layer (4).

9. A method for preparing an internally reinforced wood-plastic column or beam according to claim 2, characterized in that, The inner reinforced wood-plastic column has a circular or square cross section, and the outer diameter or side length of the outer shell layer (3) is 120-180mm; the beam has a rectangular cross section, with the longest side length being 150-200mm and the shortest side length being 40-100mm.

10. A method for preparing an internally reinforced wood-plastic column or beam according to claim 2, characterized in that, The groove (7) and the protrusion (6) are V-shaped or dovetail-shaped with rounded corners, and the distance between the groove (7) and the protrusion (6) is 1.0-1.5mm.

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