Method for producing composite wood-like material and material obtained by this method

Abstract

FIELD: wood-polymer composite materials.SUBSTANCE: method for producing a composite wood-like material is proposed, which includes preparing a binder, which is a thermosetting or thermoplastic polymer resin with pigments and functional additives, wherein UV stabilizers are introduced into the binder in an amount of 1.0-3.0% by weight of the binder, preparing a filler, which is unidirectional natural or artificial fibers, and molding a blank by a method of controlled layer-by-layer or spiral build-up of the composition on a rotating core with varying the thickness of each layer in the range of 0.5-20 mm to simulate annual rings, wherein the filler fibers are oriented primarily along the longitudinal axis of the blank; and a composite wood-like material obtained according to the proposed method.EFFECT: 100% visual and tactile identity of natural wood with increased strength, UV and bio-resistance, density of 500-1200 kg / m3.12 cl, 2 dwg, 5 ex

Description

[0001] SECTION 1. TECHNICAL FIELD

[0002] The invention relates to the field of materials science, in particular to technologies for the production of wood-polymer composite materials intended to replace natural wood in construction, architecture, furniture production, shipbuilding and interior design.

[0003] SECTION 2. BACKGROUND

[0004] Currently, various methods for producing materials that imitate natural wood are known in this field. Natural wood is widely used, but has a number of disadvantages: it is susceptible to rot, requires regular maintenance (painting, impregnation), has defects (knots, cracks), is limited in size, and some species are expensive. Traditional wood-polymer composites (WPCs) are produced primarily by extrusion or pressing. Their disadvantages include the lack of realistic internal structure, growth rings, pores, and rays, as well as limited anisotropy of mechanical properties.There are methods for winding composite materials, additive technologies (3D printing) and technologies for the layer-by-layer creation of layered structures, but none of the known methods simultaneously ensures a realistic reproduction of all the main visual and structural features of natural wood (annual rings, open and closed pores, medullary rays of arbitrary shape and complexity, curling, subsurface light scattering) with high productivity and waste-free production.

[0005] SECTION 3. SUMMARY OF THE INVENTION

[0006] The objective of the present invention is to create a highly efficient automated method for producing a composite material that is free from the aforementioned disadvantages, has a realistic volumetric structure of natural wood and is economically feasible.

[0007] The technical result consists of producing a composite wood-like material with a three-dimensional layered structure imitating the annual rings of natural wood and with anisotropic mechanical properties, offering increased strength and resistance to rot, moisture, UV radiation, and biological factors. Specific embodiments additionally reproduce open and closed pores, medullary rays, the effect of subsurface light scattering, and the grain characteristic of certain wood species.

[0008] The specified technical result is achieved by the fact that in the method for producing a composite wood-like material, including the preparation of a binder, filler and molding of the product, the molding is carried out by a method of controlled layer-by-layer or spiral build-up of the composition on a rotating core with a variation in the thickness of each layer in the range of 0.5-20 mm to simulate annual rings, while unidirectional natural or artificial fibers oriented primarily along the axis of the workpiece are used as a filler.

[0009] Thermosetting (epoxy, polyester, polyurethane, etc.) or thermoplastic (polyethylene, polypropylene, PVC, PET, etc.) polymer resins with pigments and functional additives are used as binders. UV stabilizers are added to the binder at a rate of 1.0-3.0% by weight. Flame retardants, plasticizers, and glass or polymer microspheres may also be added.

[0010] Color transitions are formed by dynamically dosing pigments through 4 (RGB+W) independent channels. Open pores are simulated by introducing and then removing anti-adhesive tubular elements with a diameter of 0.4-1.5 mm. Closed pores are simulated by introducing fiber bundles in the form of a roll material. Core rays of arbitrary shape and complexity are formed by any known method, including laser ablation, mechanical stamping, milling, or engraving, followed by filling the resulting channels with a binder differing in color and / or optical properties. The effect of subsurface light scattering is achieved by introducing optical diffusers (0.5-8% by weight). The curly effect is achieved by wavy laying of highly reflective fibers with a diameter of 5-30 μm. Production waste is crushed and returned to the cycle.

[0011] The composition is applied through a universal head (5) with quick-release modules (Fig. 1): for thermoplastic compositions - with heating at 180-250°C and auger feed, for thermosetting ones - with separate dosing of components and cooled walls. Each subsequent layer is applied after partial polymerization of the previous layer when using a thermosetting binder or continuously when using a thermoplastic binder. The diameter of the workpiece over 200 mm is usually 200-2000 mm, the length is 3-6 m or more. After curing, the workpiece is sawn into boards, beams or lamellas similar to natural wood and subjected to standard mechanical processing.

[0012] The invention is explained by drawings, where:

[0013] Fig. 1 - general view of the installation for layer-by-layer molding;

[0014] Fig. 2 - a product with end, radial and tangential cuts, with open and closed pores and medullary rays;

[0015] The installation (Fig. 1) contains:

[0016] 1 - Laser guides

[0017] 2-drive for height adjustment

[0018] 3 - Laser head

[0019] 4 - blank

[0020] 5 - Universal polymer feed head

[0021] 6 - fluoroplastic tube feeder.

[0022] 7 - Roll material feeder

[0023] 8 - Height adjustment of the frame

[0024] 9 - Laser height sensor

[0025] 10 - workpiece servo drive

[0026] The resulting artificial tree (Fig. 2) has:

[0027] 11 - tangential cut

[0028] 12 - radial cut

[0029] 13 - end cut

[0030] 14 - medullary rays on the end cut

[0031] 15 - medullary rays on a radial section

[0032] 16 - medullary rays on a tangential section

[0033] 17 - growth rings

[0034] 18 - pores

[0035] SECTION 4. EXAMPLES OF CARRYING OUT THE INVENTION

[0036] Example 1 (thermosetting binder, imitation teak).

[0037] Binder - ED-20 epoxy resin with NEPA hardener in a ratio of 100:1.0 wt. parts, filler - sisal fiber 50% by weight, glass microspheres 6%, UV stabilizers Tinuvin 328 + Tinuvin 770 - only 2% by weight. Layers are 2-4 mm thick, color transitions are formed by dynamic dosing of four pigments (brown, dark brown, red, yellow). Imitation of open pores was carried out using PTFE tubes with a diameter of 1.0 mm, followed by extraction after partial polymerization. The resulting material had a density of 850 kg / m 3 , bending strength over 60 MPa, water absorption over 24 hours less than 0.5%. The appearance and tactile properties are completely consistent with natural teak wood.

[0038] Example 2 (thermosetting binder, oak imitation).

[0039] Two-component polyurethane system (component A - polyol, component B - isocyanate) in a ratio of 100:45, filler - jute fiber 45%, microspheres 5%. Reaction temperature: 60°C. Color transitions are formed by color variations from light brown to dark brown. The core rays are created by laser ablation on a 3D model, followed by filling the channels with polyurethane resin with the addition of light beige pigment. The resulting material had pronounced radial rays, a density of 910 kg / m3. 3 , Brinell hardness 52 N / mm 2 .

[0040] Example 3 (thermoplastic binder, imitation merbau, budget option).

[0041] PVC plastisol grade PD-1, filler - 50% jute fiber, plasticizer - 35% DOP, pigments - iron oxide red and brown. Extrusion head temperature was 1.85-195°C. Application was carried out continuously on a rotating core without intermediate polymerization. Layer thickness was 3-10 mm. The resulting material had a density of 1050 kg / m3. 3 , bending strength 55 MPa, water absorption less than 1%.

[0042] Example 4 (thermoplastic binder, imitation pine).

[0043] Polypropylene homopolymer grade Kaplen 01030 (MFI 3 g / 10 min), filler - flax fiber 45%, glass microspheres 4%, UV stabilizer Chimassorb 944 - 1.5%, pigments - titanium dioxide, ocher, umber. Extrusion head temperature 190-21.0 ° C. Continuous application, layer thickness 1.5-12 mm. After cooling the workpiece, the material had a density of 780 kg / m 3, flexural strength of 58 MPa, water absorption in 24 hours less than 0.8%. The appearance and texture are completely consistent with natural pine.

[0044] Example 5 (combined version, imitation walnut).

[0045] Polyester resin with 30% styrene, filler - a mixture of sisal (30%) and glass fiber (20%), 5% microspheres. The core rays and grain were formed by mechanical roller stamping, followed by filling the channels with resin with a high content of optical diffusers. The effect of subsurface light scattering was enhanced by the addition of 7% glass microspheres. The resulting material had a pronounced grain and complex radial rays, a density of 920 kg / m3. 3 , Brinell hardness 48 N / mm 2 .

Claims

1. A method for producing a composite wood-like material, which includes preparing a binder, which is a thermosetting or thermoplastic polymer resin with pigments and functional additives, wherein UV stabilizers are introduced into the binder in an amount of 1.0-3.0% by weight of the binder, preparing a filler, which is unidirectional natural or artificial fibers, and molding a workpiece by a method of controlled layer-by-layer or spiral build-up of the composition on a rotating core with a variation in the thickness of each layer in the range of 0.5-20 mm to simulate annual rings, wherein the filler fibers are oriented predominantly along the longitudinal axis of the workpiece.

2. The method according to paragraph 1, characterized in that the color transition in the annual rings is formed by dynamic dosing of pigments through 2-4 independent channels.

3. The method according to paragraph 1, characterized in that the imitation of open pores is carried out by introducing and then removing anti-adhesive tubular elements with a diameter of 0.4-1.5 mm.

4. The method according to paragraph 1, characterized in that the imitation of closed pores is carried out by introducing fiber bundles in the form of a roll material.

5. The method according to claim 1, characterized in that the core rays are formed by laser ablation or mechanical stamping, followed by filling the resulting channels with a binder that differs in color and / or optical properties.

6. The method according to paragraph 1, characterized in that the effect of subsurface light scattering is achieved by introducing optical diffusers into the binder composition in an amount of 0.5-8% by weight of the binder.

7. The method according to paragraph 1, characterized in that the curling effect is achieved by wavy laying of high-gloss fibers with a diameter of 5-30 microns.

8. The method according to paragraph 1, characterized in that glass or polymer microspheres are additionally introduced into the binder composition.

9. The method according to paragraph 1, characterized in that the diameter of the workpiece is 200-2000 mm.

10. The method according to paragraph 1, characterized in that the resulting workpiece is sawn into boards, beams or lamellas similar to natural wood.

11. The method according to paragraph 1, characterized in that sisal, jute, flax, banana, coconut, palm, basalt, glass, carbon fiber or combinations thereof are used as filler.

12. A composite wood-like material containing a polymer binder with pigments, functional additives and UV stabilizers in an amount of 1.0-3.0% by weight of the binder and a filler in the form of unidirectional natural or artificial fibers oriented primarily in the longitudinal direction of the material, while a layered structure of layers 0.5-20 mm thick is formed throughout the volume of the material, located around the longitudinal axis of the material and forming a pattern on transverse, radial and tangential sections that imitates the annual rings of natural wood.

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