Wood paste and object made of wood paste
阅读说明：本技术 木糊及由木糊制成的物体 (Wood paste and object made of wood paste ) 是由 多伦·肯恩 迈克尔·拉亚尼 奥代德·舒斯约夫 什洛莫·马格达西 于 2019-01-07 设计创作，主要内容包括：本发明总体上涉及用于建构木质三维结构的多种方法及打印油墨,所述打印油墨包括：木屑/木粉,及植物提取的天然粘合剂。(The present invention generally relates to methods and printing inks for constructing three-dimensional structures of wood, the printing inks comprising: wood chips/flour, and natural binders extracted from plants.)
1. A composition characterized by: the composition comprising at least one woody material, at least one cellulose nanomaterial, and at least one hemicellulose and/or lignin and/or starch, for:
(a) a process of manufacturing a three-dimensional wooden object; or
(b) A process of coating or covering a surface area of an object with the wood material;
wherein the composition is free of formaldehyde, synthetic resins and/or epoxy-based materials.
2. The composition of claim 1, wherein: the composition is in the form of a paste.
3. The composition of claim 1, wherein: the three-dimensional object is formed by casting, molding, extruding, calendaring, injection molding, printing, hand forming, or hand machining.
4. The composition of claim 1, wherein: the compositions include a variety of materials of all natural origin.
5. The composition of claim 1, wherein: the composition is an ink composition.
6. The composition of claim 1, wherein: the at least one wood based material is a natural wood.
7. The composition of claim 6, wherein: the natural wood material is derived from a stem, branch, trunk or bark of a wood.
8. The composition of claim 7, wherein: one form of the natural lumber is selected from the group consisting of wood flour, wood chips, microcrystalline cellulose (CMC), and wood chips.
9. The composition of claim 6, wherein: the woody material is obtained from the stem, branch, trunk or bark of a tree or a shrub selected from the group consisting of basswood, beech, birch, eucalyptus, walnut, hickory, cedar, cherry, elm, gum, hickory, eucalyptus, mahogany, maple, oak, pine, poplar, mahogany, rosewood, satin, sycamore, teak, alder, apple, poplar, chestnut, cotton, cypress, fir, hackberry, hemlock, wintergreen, hawaii, bay, acacia, magnolia, pear, spruce, purple tree and willow.
10. The composition of claim 9, wherein: the tree is eucalyptus.
11. The composition of claim 1, wherein: the at least one wood material is derived from hardwood or softwood.
12. The composition of claim 1, wherein: the at least one cellulose nanomaterial is a material selected from the group consisting of Cellulose Nanocrystals (CNC), nanofibrillated cellulose (NFC), Bacterial Nanocellulose (BNC) and chemical derivatives thereof.
13. The composition of claim 12, wherein: the cellulose nanomaterial is Cellulose Nanocrystals (CNC).
14. The composition of claim 1, wherein: the at least one hemicellulose is selected from the group consisting of xylan, glucuronoxylan, arabinoxylan, glucomannan, galactoglucomannan, and xyloglucan.
15. The composition of claim 14, wherein: the hemicellulose is xyloglucan.
16. The composition of claim 1, wherein: the composition comprises at least one wood material, cellulose nanocrystals, and a hemicellulose or starch or lignin.
17. The composition of claim 1, wherein: the composition includes at least one wood material, a cellulose nanocrystal, and a xyloglucan.
18. The composition of claim 1, wherein: the composition further comprises at least one solvent or a liquid carrier, and/or at least one functional additive.
19. The composition of claim 1, wherein: the composition is in the form of a solid composition, a slurry, a paste, a pseudoplastic liquid or a newtonian liquid.
20. The composition of claim 1, wherein: the polymer body is formed from a material selected from the group consisting of thermoplastic polymers and thermosetting polymers.
21. The composition of claim 20, wherein: the polymer body is a material selected from thermosetting polymers.
22. The composition of claim 21, wherein: the thermosetting polymer is selected from thermosetting silicone polymers and thermosetting organic polymers.
23. The composition of claim 21, wherein: the polymer body is a material selected from thermoplastic polymers.
24. The composition of claim 23, wherein: the thermoplastic polymer is selected from the group consisting of polyolefins, polar thermoplastics, polystyrene, polyvinyl chloride (PVC), acrylonitrile-butadiene-styrene (ABS), styrene copolymers, polyacrylonitrile, polyacrylates, polyacrylamides, vinyl acetate polymers, vinyl alcohol polymers, cellulosics, thermoplastic elastomers, thermoplastic polyurethanes, polyester-based thermoplastic elastomers, thermoplastic polyesters, polyethylene terephthalate, polybutylene terephthalate, compatible thermoplastic blends, polyacetals, polyethers, polyarylates, polycarbonates, polyamides, polyimides, polybenzimidazoles, aromatic polyhydrazides and polyoxadiazoles, polyphenylquinoxalines, polyphenylene sulfides, polyphenylene vinylenes, conductive thermoplastics, conductive thermoplastic composites, poly (arylethersulfones), poly (aryletherketones), poly (arylketones), poly (aryl, Poly (aryl ether ketone-co-sulfone), poly (aryl ether ketone amide), polytetrafluoroethylene, and mixtures thereof.
25. The composition of claim 21, wherein: the polymer body is a material selected from the group consisting of polyvinyl alcohol (PVA), polylactic acid (PLA), Acrylonitrile Butadiene Styrene (ABS) and Polyetherimide (PEI) and other ULTEM polymers, and Polyetheretherketone (PEEK).
26. A hybrid structure, characterized by: the hybrid structure includes a polymeric region associated with at least one printed wood-containing coating or layer or film.
27. The hybrid structure of claim 26, wherein: the shape of the mixed structure is a core-shell structure, a double-layer structure or a multi-layer structure.
28. The hybrid structure of claim 27, wherein: the wood-containing coating or layer or film is composed of a plurality of materials of all natural origin.
29. Use of the composition of claim 1 for printing a two-dimensional pattern or a three-dimensional object.
30. The use according to claim 29, wherein: the printing includes extrusion-based printing or inkjet-based printing.
31. A wooden object characterized by: the wood object is made from the composition of claim 1.
32. The object of claim 31, wherein: the object includes wood, cellulose nanocrystals, and a hemicellulose.
33. The object of claim 32, wherein: the object is composed of wood and a plurality of plant components.
34. The object of claim 32, wherein: the object includes one or more features, elements, portions, regions or surfaces of a material selected from a polymeric material, a photopolymer material, a ceramic material and a metallic material.
35. The object of claim 34, wherein: the object is obtained by post-treating the wood object of claim 29.
36. The object of claim 32, wherein: the object includes one or more flame retardant materials.
Technical Field
The present invention relates generally to a variety of wood objects and methods of producing wood objects.
Background
The wood composite resin is a key factor for realizing digital deposition and processing of wood objects. Of the resins known at present, Urea Formaldehyde (UF) and Phenol Formaldehyde (PF) are the most widely used resins. Formaldehyde in wood composites is strictly regulated to below 0.05ppm by legislation (RAL-UZ 38). Another synthetic resin intended to avoid the use of formaldehyde is methylene diphenyl diisocyanate (MDI). MDI is an allergen and sensitizer for isocyanates. Despite its low vapor pressure, MDI is considered a material that reacts strongly with water and other nucleophiles and is therefore not industrially attractive.
Therefore, there is a need for objects that are free of such substances and other harmful chemicals as described above, such as: furniture and shingles (wood tiles).
Cellulose nanocrystals (Cellulose nanocrystals) are rod-like, nanoscale crystalline components made of Cellulose, which is the main constituent polysaccharide in plant cell walls. Hemicellulose is another major family of polysaccharides entangled in cellulose microfibrils. These materials are used in a variety of applications in the conventional wood resin industry and as a low concentration additive to replace the UF/PF and other resins.
WO 2009/086141[1] describes the use of different types of cellulose microfibrils with nano/micro clays to reinforce adhesives. The binder comprises cellulose/clay in a concentration of 0 to 10 mass percent (wt.%), with the remaining ingredients comprising 90 to 100 mass percent of the binder, the remaining ingredients being selected from industrial chemical resins, such as: formaldehyde based resins, pMDI, and the like.
U.S. patent application No. 2016/0002462[2] discloses the use of Cellulose Nanocrystals (CNC) as an additive to phenolic thermoset resins. The patent proposes a formaldehyde material for reinforcing CNC, which accounts for at most 2 mass percent concentration of the thermosetting resin.
U.S. patent application No. 2016/0355710[3] discloses nanocrystalline cellulose-derived formaldehyde-based binders. The formaldehyde-based binder was invented by using CNC instead of wood flour or materials other than the resin mixture. The CNC is added in an amount of less than 1 mass percent concentration (% w/w), less than 5 mass percent concentration of the added wood flour or equivalent based on the total amount of the resin. I.e. more than 90% of the resin is formaldehyde based.
Chinese patent application No. 105906940[4] discloses a marble or wood 3D printed object made of plastic and printed by a Fused Deposition Modeling (FDM) three-dimensional (3D) printer. The filaments are composed of a polymer (30 to 90 mass percent concentration) with various additives and can produce a "feel" similar to wood, but without the use of solid wood in the filaments.
Reference documents:
[1]WO 2009086141；
[2] U.S. patent application No. 20160002462;
[3] U.S. patent application No. 20160355710; and
[4] chinese patent application No. 105906940.
Disclosure of Invention
In view of the foregoing background, it will be appreciated that all 3D wood structures are "wood-like" in nature in composition and appearance. Wood-like articles known in the prior art consist of synthetic polymers, most of which wood resins contain dangerous and harmful chemicals. Accordingly, there is a need for materials and processing techniques for making three-dimensional (3D) objects composed entirely of wood, which 3D objects are biodegradable and free of hazardous and harmful chemicals. However, despite the ever-increasing demand in industry for truly biodegradable materials and natural materials for additive manufacturing, to date, methods of manufacturing 3D objects comprising 100% wood or wooden material, for example, by printing, have never been realized.
The inventors of the art disclosed herein have for the first time developed a method of manufacturing a natural binder using wood chips/powder and plant extracts, a method thereof, and a printing ink. The composition of the present invention allows free design of 3D structures containing only natural ingredients. These structures may be realized by a printing method, for example.
As disclosed and exemplified herein, 3D objects according to the present invention are wood objects made using a composition (combination) of wood flour and a binder consisting of a plurality of Cellulose Nanocrystals (CNC) and hemicellulose, in the absence (or absence) of any additional resins, formaldehyde and other hazardous materials (e.g., Urea Formaldehyde (UF), Phenol Formaldehyde (PF), diphenylmethane diisocyanate (MDI)).
Thus, in a first aspect, the present invention provides a composition comprising at least one wood material, at least one cellulose nanomaterial and at least one hemicellulose and/or lignin and/or starch.
The various compositions of the present invention are pasty or plasticine-like, i.e. semi-solid which can be kneaded into essentially any shape. The composition can be used in any "handicraft" process for the preparation of decorations, toys or any other functional object. These articles may be manufactured/created by adults and children using any means known in the art. The method of manufacture may be selected from a variety of activities, including the manufacture of articles with their hands or with templates or molds. Manufacturing methods may also include casting, molding, extrusion, calendaring, injection molding, printing, hand forming and hand machining (e.g., with a ceramic wheel) and other similar methods.
In some embodiments, the composition is suitable for use in an additive manufacturing process.
The present invention also provides a composition comprising at least one wood material, at least one cellulose nanomaterial, and at least one hemicellulose and/or lignin and/or starch, the composition being for:
(a) a process of manufacturing a three-dimensional wooden object; or
(b) A process of coating or covering a surface area of an object with the wood material;
wherein the composition is free of formaldehyde, synthetic resins, and/or epoxy-based materials, as disclosed herein.
The composition of the present invention is free of formaldehyde, Urea Formaldehyde (UF), Phenol Formaldehyde (PF), diphenylmethane diisocyanate (MDI), synthetic resins and epoxy-based materials. In some embodiments, the composition is free of formaldehyde and/or synthetic resins and/or epoxy-based materials. In some embodiments, the compositions of the present invention are free of formaldehyde, Urea Formaldehyde (UF), Phenol Formaldehyde (PF), and synthetic resins.
The composition of the invention may be used in or form an ink composition to form a two-dimensional pattern or a three-dimensional object by printing, for example: and (4) digital printing. In some embodiments, the objects are cast into three-dimensional structures rather than machined using a digital printer. In some embodiments, the objects are fabricated into three-dimensional structures by a mold, rather than using a digital printer. In some embodiments, the object is not in the form of a plastic or polymer core that is encapsulated, surrounded, sandwiched, or coated by a wood element provided by the composition of the present invention.
The at least one wood based material is all natural wood, free of non-natural or synthetic additives, such as: resins, stabilizers, and the like. The wood material is present in the composition of the invention in a form suitable for processing, for example: and (7) printing. Thus, the wood material may be processed into a form selected from the group consisting of: wood flour, wood chips, Microcrystalline Cellulose (MC), wood chips, nanofibrillated cellulose (NFC), Cellulose Nanocrystals (CNC), lignin and lignin derivatives, hemicellulose, xyloglucan, arabinoxylan, xylan, starch, and pectin. The woody material can be derived from natural resources (first use) or recycled wood.
In some embodiments, the woody material can be derived from stems, branches, trunks, or barks of wood and processed into a form selected from the group consisting of wood flour, wood chips, and wood chips.
The woody material is obtained from the stem, branch, trunk or bark of a tree or bush (any "wood source"). The tree or bush is selected from the group consisting of basswood, beech, birch, eucalyptus, walnut, hickory, cedar, cherry, elm, gum, hickory, eucalyptus, mahogany, maple, oak, pine, poplar, mahogany, rosewood, satin, sycamore, teak, alder, apple, poplar, chestnut, cotton, cypress, fir, hackberry, hemlock, wintergreen, acacia, bay, acacia, magnolia, pear, spruce, purple tree, and willow.
In some embodiments, the tree is a eucalyptus tree.
In some embodiments, the wood-based material is derived from hardwood or softwood.
In some embodiments, the selection of the wood source depends primarily on the hardness of the wood, the degree of dryness of the wood, the ability to process the wood into particulate form, the desired properties of the final wooden object, the processing temperature, and other similar properties.
In some embodiments, a composition according to the present disclosure may comprise at least one wood-based material as a combination of two or more wood sources, as defined herein.
The at least one cellulose nanomaterial is a material selected from the group consisting of cellulose nanocrystals (CNC, also known as nanocrystalline cellulose (NCC)), nanofibrillated cellulose (NFC), Bacterial Nanocellulose (BNC) and chemical derivatives thereof.
In some embodiments, the cellulose nanomaterial is Cellulose Nanocrystals (CNC).
Cellulose nanocrystals are highly crystalline nanoparticles generated during controlled acid hydrolysis of cellulose fibers, which lead to the degradation of amorphous regions (amorphous regions). Many cellulose nanocrystals are rod-shaped, have a length of 100 to 400 nanometers and a width of 5 to 20 nanometers, and are considered to be super tough materials. A variety of cellulose nanocrystals can be presented in the form of chiral nematic liquid crystal solutions (chiral nematic liquid crystals) in water or organic solvents and self-assemble into highly transparent ordered films (high transparency ordered films) with nanoscale thickness and layered structure. The material can be produced from the cell walls of trees, plants and waste water (e.g., paper mills and municipal sewage sludge), and has recently become commercially available on a commercial scale. Cellulose nanocrystals can be prepared according to any one of the available methods, for example: each of the methods reported in WO2012/014213, WO2015/114630, and U.S. patent applications derived therefrom, are herein incorporated by reference.
The at least one hemicellulose is selected from the group consisting of xylan, glucuronoxylan, arabinoxylan, glucomannan, galactoglucomannan, and xyloglucan. In some embodiments, the hemicellulose is xyloglucan.
In some embodiments, a composition of the invention comprises at least one wood material, cellulose nanocrystals, and a hemicellulose or starch or lignin.
Lignin is an integral part of the cell wall of almost all dry land plants. Lignin is the second most abundant natural polymer in the world, second only to cellulose. Lignin is the only polymer in the plant cell wall that is not composed of carbohydrate (sugar) monomers, and lignin is composed of three different phenylpropane monomers. Thus, lignin may have various forms depending on its natural source. These and all forms and derivatives of lignin are included within the scope of the present invention.
In some embodiments, a composition of the present invention comprises at least one wood material, cellulose nanocrystals, and lignin. In some embodiments, the composition further comprises xyloglucan.
In some embodiments, a composition of the invention comprises at least one woody material, cellulose nanocrystals, and xyloglucan.
In some embodiments, a composition of the present invention further comprises at least one solvent or a liquid carrier, and/or at least one functional additive. The liquid carrier may be selected from water or aqueous solutions, Dowanol solvents of varying boiling points and viscosities (e.g., propylene glycol methyl ether, dipropylene glycol methyl ether, tripropylene glycol methyl ether, propylene glycol methyl ether acetate, dipropylene glycol methyl ether acetate, propylene glycol n-propyl ether, dipropylene glycol n-propyl ether, propylene glycol n-butyl ether, dipropylene glycol n-butyl ether, tripropylene glycol n-butyl ether, propylene glycol phenyl ether, dipropylene glycol phenyl ether, propylene glycol diacetate, dipropylene glycol n-butyl ether adipate, ethylene glycol phenyl ether, diethylene glycol phenyl ether, poly (
In some embodiments, the liquid carrier is water. In other embodiments, the aqueous carrier is not an organic solvent.
A composition of the invention may be in the form of a solid composition, a slurry, a paste, a pseudoplastic liquid, a Newtonian liquid or other form depending on the solvent or liquid carrier or additive used.
In the composition of the present invention, the concentration of cellulose nanocrystals is up to 20 mass percent (wt%) or at least 0.01 mass percent. In some embodiments, the concentration of cellulose nanocrystals may be 0.05 to 20 mass percent concentration, based on the total weight of the composition.
The weight ratio of the at least one hemicellulose and cellulose nanocrystals may be 0:1 to 1: 10.
In some embodiments, the composition includes 50 mass percent concentration of wood flour, 30 mass percent concentration of cellulose nanocrystals, and 10 mass percent concentration of hemicellulose of the total composition. In some embodiments, a composition includes 90 mass percent wood flour, 5 mass percent cellulose nanocrystals, and 5 mass percent hemicellulose of the total composition. In some embodiments, the composition comprises 50 mass percent concentration of wood flour, 20 mass percent concentration of CNC, 5 mass percent concentration of hemicellulose, and 25 mass percent concentration of hyphal fungi of the total composition.
The composition of the present invention is prepared by mixing together at least one woody material, at least one cellulose nanomaterial, and at least one hemicellulose and/or lignin and/or starch under conditions that allow for adequate bonding between the particles of the at least one woody material. Alternatively, the composition may be prepared by first forming a composition comprising at least one cellulose nanomaterial and at least one hemicellulose and/or lignin and/or starch and then merely mixing or applying or contacting the composition or contacting it with the at least one woody material.
In some embodiments, a dispersion of cellulose nanocrystals in water is contacted with at least one wood material (e.g., wood flour or wood chips) while allowing the cellulose nanocrystals to adhere to the surface of the wood flour or wood chips. After the water evaporates, the cellulose nanocrystals act as a binder between the wood chips. In some embodiments, the cellulose nanocrystals are mixed with wood flour or chips to form a homogeneous mixture.
The at least one hemicellulose and/or starch and/or lignin may be introduced with the cellulose nanocrystals or after a homogeneous mixture of the cellulose nanocrystals and wood particles is formed.
As described above, the composition of the present invention can be used as an ink composition for printing, for example: and 3D printing. Since the composition uses solid liquid insoluble materials, for example: wood chips, various methods of creating a pattern or a three-dimensional object by printing may be or involve extrusion-based printing, such as: 3D printing, direct writing and/or inkjet-based printing, for example: 3D printing, adhesive jetting process. In some embodiments, the printing method may be selected from a plurality of inkjet printing methods, for example: continuous inkjet printing (CIJ) or drop on demand (DoD) printing.
In some embodiments, when a DIW (dispenser) is utilized, the composition may be in the form of a pseudoplastic composition, such that the printed material may remain until finally dry. In this method, the defined composition may be mixed with the wood flour, either completely or partially, and then after printing and drying of the liquid carrier (e.g., water), the object is immersed or coated or contacted with another natural binder solution for final hardening.
In some embodiments, when ink-jet printing with a binder, the defined composition must have the properties of an ink-jet ink (i.e., viscosity, surface tension, volatility) and can be printed on pre-treated or untreated wood flour. The wood flour may be laminated in each printed layer during the spraying of the adhesive to improve density and mechanical properties. In this method, fibers can also be used in the ink to induce high mechanical properties.
In some embodiments, a composition is applied during printing, for example: the composition is applied to at least one wood based material by ink jet printing.
In some embodiments, a composition is applied by direct ink writing (direct ink writing).
In some embodiments, an object can be prepared by molding a composition of the present invention.
The compositions of the present invention can provide a two-dimensional pattern on a surface, which can be free-standing, or can be a 3D structure or object. Thus, the present invention also provides objects or wooden structures consisting of wood and plant components only. In other words, the object may comprise or consist of wood and natural materials, as defined herein. In some embodiments, the object may include one or more features, elements, parts, areas or surfaces that are not made of wood or natural materials. One or more of the features, elements, portions, regions or surfaces described above may be a material selected from a polymeric material, a ceramic material, a metallic material and other materials, and may be achieved by post-processing of an all-wood object. Such improved structures or materials enable the fabrication of, for example: a functional object.
In some embodiments, the object is not in the form of a plastic or polymer core that is encapsulated, surrounded, sandwiched, or coated by a wood element provided by the composition of the present invention.
The invention also provides a green additive manufacturing process for producing biodegradable wood objects. This technique can be a separate manufacturing process or can be integrated into existing processes in the wood industry. The completely natural composition of the present invention can also be used as a material replacing conventional wood-like objects while using only natural materials consisting of wood and plant components. As the demand for green materials increases, the present invention eliminates the chemical safety issues currently encountered in current industries such as construction, and furniture.
The multi-material object of the 3D composition, which includes nanoparticles, inorganic, organic and other polymers, can be easily designed and embedded inside or outside of other conventional three-dimensional printed materials.
Thus, the compositions and processes of the present invention can be combined with a variety of manufacturing processes, such as: digital printing processes for floor tiles, industrial designs, exterior walls of buildings, and the like.
The invention also provides a composition comprising at least one woody material, at least one cellulose nanomaterial and at least one hemicellulose and/or lignin and/or starch, for encapsulating or coating or covering a surface area of polymeric material of a plastic or of an object of any non-natural material.
In some embodiments, the composition is a paste-like composition as described herein that is mechanically or manually manipulated to encapsulate, coat or cover a surface area of an object of plastic or polymeric material or any non-natural material.
In some embodiments, the composition is an ink composition. In some embodiments, the ink composition is used to construct two-dimensional or three-dimensional patterns or objects. In some embodiments, the object is not in the form of a plastic or polymer core that is encapsulated, surrounded, sandwiched, or coated by a wood element provided by the composition of the present invention.
The compositions of the present invention can be used as ink compositions for printing or coating on a surface area of a polymeric structure or object or an object made of any material. The object, for example: the polymer object, may be of any shape and size, and need not be completely covered or encapsulated or coated. In some embodiments, for example: the object is formed by printing by applying at least one film or coating or layer of a wood based composition according to the invention on at least one surface area of the object. Alternatively, an object according to the present invention may be formed by using a multi-material printer or digital dispenser. In such multi-material printers, two or more heads (or up to 10 heads) may be used, where each head may be used based on a different dispensing method, for example: FDM/heating nozzles, UV curing nozzles/cooling nozzles, lasers, CNC, etc.
According to the invention, the core, element or feature applied on said surface of one wood based composition may be manufactured by injection moulding or additive manufacturing methods. Thus, one or more extrusion heads for printing the monolithic wood part are combined with (at least one but not limited to) a Fused Deposition (FDM) head for printing a thermoplastic or thermoset polymer. In this case, one print head will print the object material and the other print head can print natural ink based on wood. The formed object may be a complete wood coating or may be composed of parts of wood.
The material forming the object or feature may be selected from thermoplastic polymers and thermosetting polymers.
In some embodiments, where the object is made of a polymeric material, the material may be selected from thermosetting polymers, for example: thermosetting silicone polymers, for example: cured silicone elastomers, silicone gels and silicone resins; and thermosetting organic polymers such as: furan resin, epoxy resin amino resin, polyurethane (polyol and isothiocyanate), polyimide, phenol resin, cyanate resin, bismaleimide resin, polyester fiber, acrylic resin, and the like.
In some embodiments, the polymer body is a material selected from thermoplastic polymers, such as: polyolefins, polar thermoplastics, polystyrene, polyvinyl chloride (PVC), acrylonitrile-butadiene-styrene (ABS), styrene copolymers, polyacrylonitrile, polyacrylates, polyacrylamides, vinyl acetate polymers, vinyl alcohol polymers, cellulosics, thermoplastic elastomers, thermoplastic polyurethanes, polyester-based thermoplastic elastomers, thermoplastic polyesters, polyethylene terephthalate, polybutylene terephthalate, compatible thermoplastic blends, polyacetals, polyethers, polyarylates, polycarbonates, polyamides, polyimides, polybenzimidazoles, aromatic polyhydrazides and polyoxadiazoles, polyphenylquinoxalines, polyphenylene sulfides, polyphenylene vinylenes, conductive thermoplastics, conductive thermoplastic composites, poly (arylethersulfones), poly (aryletherketones), poly (aryletherketone-co-sulfones), poly (arylketone-co, Poly (aryl ether ketone amides), polytetrafluoroethylene, and mixtures thereof.
In some embodiments, the polymer is a material selected from polyvinyl alcohol (PVA), polylactic acid (PLA), Acrylonitrile Butadiene Styrene (ABS) and Polyetherimide (PEI), as well as other ULTEM polymers and Polyetheretherketone (PEEK).
The present invention also provides a hybrid structure comprising a polymeric region associated with at least one wood-containing coating or layer or film. In some embodiments, the hybrid structure is a core-shell structure, wherein the core is polymeric and the shell is a wood composite, as defined herein. In some embodiments, the hybrid structure is a two-layer structure or a multi-layer structure, one layer of the layers being a polymeric material and the other layer being a wood composite material, as defined herein.
Description of the drawings
In order to better understand the subject matter disclosed herein and to illustrate how the invention may be carried into effect, various embodiments will now be described, by way of non-limiting example only, with reference to the accompanying drawings, in which:
fig. 1 depicts the results of Dynamic Light Scattering (DLS) for two different Cellulose Nanocrystals (CNC) used by the experimenter. Size of DLS:
FIG. 2 shows the viscosity versus shear rate at XG: shear thinning properties (shear thinning properties) can be seen in all ink ratios of the CNC.
Fig. 3 shows the results of the embossing test using CNC inks of two different wood flours.
Fig. 4A-4B depict that the modulus (B) increases with the addition of CNC (a) and the maximum compressive load increases with increasing CNC concentration.
Fig. 5A-5B show (a) different XGs for compression testing: a die sample (B) of CNC scaled wood measures the stress-strain curve of the object.
Fig. 6 shows the stress-strain curve of a three-point bending test of a rectangular measuring object as a function of CNC concentration.
Fig. 7A to 7B show three-point bending test of wood flour depending on CNC concentration, (a) modulus (B) breaking stress.
Fig. 8 shows XG compared to the mold sample: CNC: mechanical properties of wood ratio, stress-strain curve of 3D printed cylinder.
Fig. 9A-9D illustrate various examples of 3D printed 100% wood objects by direct ink printing techniques. Fig. 9A to 9D show trunks, cubes, and printed polywood flour (maple and hardwood).
Fig. 10A to 10D show 3D printed 100% wood objects (taiwan T10 com True, each layer printed with 1 liquid) manufactured by binder jet powder printing technique, a: triangle (0.2% CNC), B: biscuit shape (0.1% CNC), C: cylinder (0.2% CNC) and D: japanese carpentry (0.2% CNC).
Fig. 11 shows a 3D printed 100% wood object printed on a 3D printed ABS using a squeeze based technique.
Detailed Description
Description of binder ink:
the binder is composed of a plurality of Cellulose Nanocrystal (CNC) particles dispersed in water. The concentration of CNC can be as high as 20 mass percent (wt%) or as low as 0.01 mass percent. Once mixed with wood flour or chips, the wood flour adheres to the surface of the chips, and the CNC functions as an adhesive between the chips after water evaporates. The deposition process can be carried out by mixing the binder with the wood flour/chips into a homogeneous mixture, for example: the dispenser prints or prints directly on multiple layers of wood flour/chips for use in an adhesive jet/powder printer.
Fig. 1 shows the viscosity of the binder ink without the wood chips. Xyloglucan (XG) can be used as an additive.
Rheology of the ink (Rheology):
CNC suspensions of low surface charge density (size of Dynamic Light Scattering (DLS): 88.37 nm (0.379PdI), fig. 1) prepared via sulfuric acid hydrolysis of kraft pulp board (TEMBEC) and mixed with Xylan (XG) in tamarind seeds (Megazyme) according to the compositions shown in table 1.
TABLE 1
At room temperature (Haake Rheostress 6000 connected to RS6000 temperature controller, lower plate: TMP60, upper plate P60 TiL, Sammer Feishel technologies) was subjected to XG with different values: controlled rate mode rheology measurement of CNC scaled compositions. Four separate 1 ml samples were prepared and evaluated; one representative curve is shown in fig. 2.
Shear thinning behavior (Shear thinning behavior) was seen in all samples. As more XG is added, the initial viscosity will increase while the slope remains the same. This important property of the ink is crucial for direct ink writing 3D printing technology.
Mechanical properties of the mold:
a mould: compression testing
Compression testing of plain CNC based ink:
CNC suspensions of high surface Charge Density (DLS size: 48.34 nm (0.204PdI), FIG. 1), surface Charge Density 0.6eSquare nanometer) prepared by sulfuric acid hydrolysis of kraft pulp board (TEMBEC) and mixed with two types of wood flour (made of cypress and eucalyptus) (table 2).
TABLE 2
Ink name
Distilled water [ g ]]
2.4% CNC [ g ]]
Wood flour g]
0％CNC
4
0
2
0.5％CNC
3.167
0.833
2
1.5％CNC
1.5
2.5
2
2.4
0
4
2
1.5 g of CNC samples of different proportions were dried in a cylindrical mold (D10 mm, H20 mm) at 60 ℃ for at least 48 hours. The samples were evaluated by a compression test using an instron universal tester (model 3345, equipped with a 100 newton load cell, instron corporation) at a rate of 2 mm/min until the sample broke (fig. 3). The results show that with the addition of CNC, the mechanical properties of the samples are significantly improved. The young's modulus increased by an order of magnitude from less than 1 mpa for samples without CNC (0% CNC) to 11 to 17 mpa with 5 mass percent CNC, depending on the source of the wood, with the same increasing trend for the maximum stress load (figure 4). It should be noted that the modulus of the printed samples increased from 1.5 to greater than 20 mpa when small particle wood flour (75 microns) was used.
A mould: compression testing of XG and CNC inks:
CNC suspensions of low surface charge density ((DLS size: 88.37 nm (0.379PdI)) prepared via sulphuric acid hydrolysis of kraft pulp board (TEMBEC) and mixed with Xylan (XG) in tamarind seeds (Megazyme) according to the composition shown in table 3 in preparing inks 4 g of samples with different XG: CNC ratios were mixed with 4 g of Distilled Water (DW) and 2 g of wood flour (eucalyptus).
TABLE 3
A 1.5 g sample of the ink was dried in a cylinder-type mold (D10 mm, H20 mm) at 60 ℃ for at least 48 hours. The samples were evaluated by a compression test using an Instron universal tester (model 3345, equipped with a 100 Newton load cell, Instron Corp.) at a rate of 2 mm/min until the sample broke (FIG. 5).
As shown, as more XG is added, the mechanical properties improve until the threshold reaches XG, CNC 1: 50.
A mould: three point bending
2.5 g of technical hardwood wood flour FIBER-75(LA. SO. LE) were mixed with 10 g of CNC (Table 4) in different weight concentrations for 5 minutes using a planetary centrifugal mixer (Thinky). A 5 gram sample was placed in a rectangular mold (D20 mm, L100 mm) and allowed to dry completely at room temperature for at least 48 hours. The samples were evaluated by a three-point bending method using an Instron universal tester (model 3345, equipped with a 5 kilonewton Instron weighing cell), at a rate of 2 mm/min and a support span (30 mm).
TABLE 4
Ink name
Suspended substance [ g]
Wood flour g]
Triple Distilled Water (TDW)
10
2.5
0.5
10
2.5
1
10
2.5
3
10
2.5
It was found through investigation that the addition of CNC improved the mechanical properties of the samples by at least one order of magnitude significantly (FIG. 6). For example, the bending stress at the break increased from 0.1 million pascals for the triple distilled water sample to over 1.2 million pascals for the 3% CNC sample. (FIG. 7).
Printed sample:
direct write printing (Direct write printing):
the ability to perform 3D printing using dispenser-based techniques depends on the characteristics of the custom ink. The nature of the pseudo-plastic liquid is critical to the deposition of the ink because as the ink is extruded from the nozzle, the ink liquefies and retains its shape after deposition. The plurality of flow printing parameters should also be tailored to the specific ink. First, the rheological properties of the ink and the mechanical properties of the dry ink obtained were investigated by using a die. When the optimal parameters are found, 3D printing of 100% wood structures is performed. Because of the loading and size of the particles, CNC suspensions exhibit shear thinning properties, and these parameters can be used to control the rheology. Since high viscosity inks can be used, the present inventors also investigated the effect of the addition of XG and the effect of XG on the viscosity and mechanical properties of the resulting molded article.
Considering mechanical properties, compression testing and rheology versus XG: dependence of CNC ratio. Once the optimal ink parameters (e.g., viscosity and mechanical properties) are obtained, the ink can be used for 3D printing and characterization of the printed object.
Compression testing of 3D printed samples:
the 3D printed cylinders were printed using a HYREL3D printer fitted with a 10 ml syringe. Two different wood flours were used, home-made ground eucalyptus flour and industrial hardwood flour (FIBER-75, la.so. le), wood flour: CNC: the dry weight ratio of XG is 1: 0.74: 0.06. the samples were subjected to compression testing by an instron universal tester (model 3345, equipped with a 5 kilonewton instron weighing cell) at a rate of 2 mm/min, the measurement was stopped due to the limitations of the weighing cell, and no sample breaks (fig. 8). It was found through research that the mechanical properties of the 3D printed structure are improved by 400% compared to the object prepared in the mold, which is an advantage of the 3D printing process compared to the conventional extrusion and mold manufacturing process.
Examples of 3D printed wood objects:
the 3D printed wooden object can be seen in fig. 9, which is 100% wood showing for the first time a full 3D print made using the direct write technique, and without the addition of a synthetic polymer binder.
Binder jetting/powder printing ink characteristics and results:
the ability to perform 3D printing using inkjet-based technology requires tailoring the properties of the ink. Typical surface tensions and viscosities are about 15 centipoise and 30 millinewtons per meter, respectively (these parameters may vary depending on the type of printer and printhead). Therefore, in order to comply with a typical Drop On Demand (DOD) inkjet printhead, a low density of CNC should be used. The printer's various printing parameters (e.g., frequency) and printer should also be customized for a particular ink. The rheological properties of the ink and the mechanical properties of the dry ink were first investigated by using a die. Once the optimal parameters are found, 100% wood structure 3D printing experiments can be performed.
Examples of 3D printed wood objects:
as shown in fig. 10, when CNC adhesive based jetting is used, various structures can be printed onto the hardwood flour. In this method, a more complex structure can be obtained because the unbound wood flour acts as a support material for the complex structure. The various structures may be immersed in another natural liquid binder solution for final hardening.
ABS panels were coated with 3D printed wood and showed coating/covering/wrapping capability. The ABS was first printed by a Fused Deposition Modeling (FDM) head and then wood ink was extruded/dispensed onto the formed ABS structure. The printing of the hybrid structure may be performed in the same layer, different layers, sequential layers, to form a wood grain structure with an internal plastic body, as shown in fig. 11.
- 上一篇：一种医用注射器针头装配设备
- 下一篇：用于剥离切割工艺用保护性涂层剂的剥离剂