Field

The present invention is directed to a method to achieve a malleable material. Further, the application of a malleable material and the use thereof is disclosed.

Backg round

Bendable, malleable material is well known in technological fields as long as mankind exists. Ever since metal was discovered by the ancestors, hammering, smithing, casting, bending and other methods are well known. Wood has been deformed by carving, bending (after watering or steaming), cutting and further methods. In later times, plastic materials have been invented. Plastics can be formed by a wide variety of application that are left to the reader to determine.

Wood has increasingly been reintroduced in house construction, overstretching areas in large public halls, but also modern furniture. Wood is a naturally grown base material that meets demands in environmental preservation.

In the 1920s, the production of soft, pliable wood was described, as published in GB 275,058. Disclosed is the production of soft pliable wood by boiling or steaming pieces of wood and piling, i.e. applying pressure to the same in the direction of the fibers until the completion of evaporation, as also the provision of devices for carrying the improved method into effect.

The wood is exposed to heat, preferable supplied by steam or boiling water, some 100°C at normal pressure conditions. The wooden workpiece is then compressed and shrinked by up to 20% in the longitudinal direction. This disrupts the fiber structures and makes the wood bendable without reasonable force. And it remains flexible after cooling and drying.

The German patent DE 946 479 C discloses the procedure to grant a more even bendability over the whole length of the wooden workpiece.

US 2,030,819 A discloses that placing a thin piece of wood into an alkali solution in a certain procedure to retain the structural look of natural wood but retains the optical structure and the characteristic grain thereof. This procedure is named chemical softening. It is possible to transform thin wood sheets or woods into a soft, flexible condition by all processes for cellulose production, as long as the treatment is not extended too far. Especially good results may be obtained by the alkali softening, which results in a thorough swelling and loosening of the wood structure. The soft flexible structure, however, only lasts as long as the wood contains enough water. It gradually loses these properties by air-drying, and the dry product finally again becomes hard and brittle.

In order to cause wood, which has been softened, to be more resistant to environmental impact, it must be impregnated with materials of low vapor pressure, which are suited to stabilize the condition of loosening and swelling. Experiments have shown that two groups of substances come into consideration for such an impregnation. The first group contains substances at low vapor pressure which are water soluble and perhaps water attracting, such as glycerol, monoacetin and lactates. These substances act themselves as swelling and softening preservatives. The second group contains water insoluble but emulsifiable substances, such as liquid, dissolved or emulsified hydrocarbons, fats, oils and soaps, known emulsifying agents, such as sulfo- and oxy fatty acids and their derivatives (Turkey red oil, or similar products such as alkali salts of sulfonated castor oil).

Other methods are known, as described in DD 284 189 A5, where layers of wooden particles and thermoplastic and/or duroplastic material are combined in a way to have a bendable piece of wood available. Disclosed is the limitation of the thermoplastic used in those areas of the work piece where the bending actually is applying deformation forces. According to the invention in the manufacture of a three-layer wood particle material, the particles of the middle layer in a conventional manner by addition of a thermosetting adhesive, the particles of the two layers on the other hand bound with a thermoplastic. The thermoplastic is the outer layer particles added either in solid form or in a dispersed form.

Another method is described in AR 213.508 from 1979: A method for introducing in wood frame glasses or neutral or optical glass for all types of spectacles, characterized by the steps of heating kerosene to between 30 and 80 degrees approximately, add wax in a proportion of 10 to 30% of the volume of kerosene, introducing into the mixture obtained by a wooden frame space of between about 5 and 30 minutes for softening, remove it and leave for 5 to about 30 minutes before introducing the glass or glass and then proceed to drying. EP 1 037 732 Al, showing a priority of 1997, discloses a method of isostatic pressure on a wooden workpiece and making it bendable and pliable to a high extent. The invention relates to a process for greatly increasing the elasticity and bendability of diffuse-porous wood and comprises the following steps: a) supplying a specimen of diffuse-porous wood; and b) isostatically pressing the specimen in a) with a pressure of at least 500 bars. The rigidity is increased once again by immersing the wood specimen in a liquid for up to 2 hours, after which the specimen is dried. This can be utilized when producing shaped products made of diffuse-porous wood.

Further, a scientific article in a periodical "Ingenieria Investigacion y Tecnologia, volumen XVI (niimero 1), enero-marzo 2015: 105-112 ISSN en tramite FI-UNAM" has been published on 7 March 2015 at httPSi //doi.orQ/10.1016/S 1405-7743f 15)72111-6. A composite material is disclosed of sawmill-dust and PET where the properties of such a material are investigated and published.

Summary

The above-mentioned documents have certain defects. Either, in case of pliable wood, the wood remains pliable till the end of its days. Or, if such a pliable wood is achieved by soaking, impregnation or saturation of wood with water, steam or the disclosed liquids, this liquid must be or is by principle removed from the wood piece and thus the wood loses its bendability. Other publications describe sawmill-powder or wooden particles that don 't show the typical structures of naturally grown wood.

The problem underlying the present invention is to provide an improved or ameliorated method of forming a malleable material that avoids the above disadvantages.

The problem can be solved by the subject matter of the present invention exemplified by the description and the claims.

The malleable material in accordance with this invention may allow to produce workpieces with a high degree of a predictable result. Raw wood appeals by its substantially parallel fibers. The workpiece can easily be formed by a wide variety of technologies, one of them may be deep-drawing and further swaging. Wood can usually be formed by milling a structure out of a compact piece of wood. This, however, can result in unpredictable results because the inner structure of a solid piece of wood cannot be determined prior to a process step. Further, the consumption of wood can be considered high, at least the wood chips that result of a machining process can be considered lost for further production steps and can be dealt with as garbage that has to be taken care of disposal. The densified wood can maintain its visible structure. Thus, it can be known how a piece of densified wood looks like, no unexpected structure defects can appear. A piece of densified wood however can show a very high flexibility and a lack of structural strength. Therefore, an organic agent (impregnating agent) can be impregnated to the densified wood and thus can add one or multiple feature(s) to the densified wood. The new material that can be formed by the densified wood and the impregnating agent can experience features that can be considered suitable for a wide variety of forming methods that have not been experienced before.

The present invention relates to a method to produce a piece of malleable material comprising the steps of providing a sheet of densified wood . This sheet of densified wood can be impregnated. An impregnation can be applied to the wood at least to its surface, however, also the full or partial soaking of the wood with an impregnating agent. The workpiece produced in the described way can then comprise a high degree of flexibility in two dimensions - the one along the majority of the fibers, the other crosswise, thus allowing a three-dimensional shaping or forming of the workpiece. This is disclosed in further detail below.

The impregnation can have the result that an increased flexural strength is achieved. The malleable material that has been undergone the above method can be malleable and/or ductile as known by the person skilled in the art. The densified wood can be impregnated in more than one steps, as an exemplifying sample, the wood can first be impregnated with an oil, which can make the densified wood even more bendable than without the impregnation. It may then be formed and in a further step be impregnated with a nother material, for instance a thermoplastic resin. After cooling of the workpiece, the workpiece may have a property of being stiff in ambient temperature conditions, or somewhat flexible. Depending on the impregnating agent, as in the example, the shape of the formed workpiece may be re-shaped by a further step of heating and forming. It should however be understood that the impregnating agent may solidify under the initial imposement of heat and at a later stage cannot be re-shaped again. The person skilled in the art will know that various sorts of resins can be applied to achieve the properties required in a specific application.

The densified wood can be penetrated by an impregnation agent and thus comprising improved properties: on the one hand, the appealing appearance of wood is maintained, on the other hand, due to the physical effect that the majority of the fibers are deflected, shows no visible cracks if the wood is bent far beyond what is possible with a non-densified wood. After having impregnated the densified wood as described in this invention, a new composite material is resulted. The composite material is named "malleable material", because the composite material can be malleable and can manifest new physical features. Dependent from the application and from the type of the impregnating agent, the malleable material can remain malleable in ambient atmosphere. If a thermoplastic material is used as an impregnating agent, the malleable material may be solid in ambient atmosphere, while it can be repeatedly reshaped under heat and/or pressure. With other thermoset material, like a duroplast would constitute, the malleable material may be malleable only once and be unable to reshaping later on. In this respect, what the malleability of the malleable material regards, the physical properties may follow the properties of the impregnating agent with the limitations of the densified wood.

The malleable material is a material made from two or more constituent materials with significantly differing physical or chemical properties that, when combined, produce a material with characteristics different from the individual components. The individual components remain separate and distinct within the finished structure, differentiating composites from mixtures and solid solutions.

The composition of a densified, flexible and bendable piece of naturally grown wood with an impregnating agent combines the advantages of wood with the flexibility and wide variety of thermoplastic materials.

The expression "densified wood" shall be understood as a piece of wood that has been compressed in an apparatus that is known in the art. The wood is compressed usually by hydraulic force. Other source of power can be applied if desirable. The piece of wood that has been compressed in the manner as described above can after compression be released and further can be pulled to a desired length. The measures accompanied in this procedure are described below. The densified wood can after the process of compression and subsequent straining have a less density than the original piece of deciduous wood. For clarity reasons, the phrase "densified wood" is anyhow maintained to distinguish it from the initial piece of wood.

Because of the flexibility that is immanent to the workpiece in the described manner, the workpiece is accessible to a large variety of forming methods. Most of these methods are known to the person skilled in the art of wood forming. Wood that has not been treated in the above described way could however not be drawn without causing structural damage or visible defects to the workpiece. The malleable material according to the above explanations however offers additional forming methods, like drawing and rolling. The workpiece can even be undergone a deep- drawing process. Other forming processes may be performed, like swaging or curling or any combination of the forming processes known in the industry.

The wood as to the present invention can be taken from natural sources, usually can be naturally grown and has been harvested from a deciduous tree. Certainly, as known in the art, fresh cut wood can be dried to a defined or desired grade of humidity. This can be done by resting a lumber log or after having cut the lumber into sheets.

The wood material can be wood with a substantially constant density, wherein the wood material in the undensified status can have a ratio flexural strength to density of at least 35 Nm/g and at most 650 Nm/g, preferably at least 100 Nm/g and preferably at most 300 Nm/g, most preferably in a range of about 140 Nm/g to about 270 Nm/g. These values are derived from industry standards and can be undershot or overstepped if certain sorts of wood or other preferences can be met better.

Usually, the wood that is intended to be formed into a piece of densified wood can be assembled in bars comprising edge lengths of some 13 cm x 13 cm but other measures can be utilized if required. The grade of densification and/or compression and/or pre- densification and/or pre-compression can be at least 5%, preferably at least 10%, more preferably at least 30%, most preferably at least 50% and at most 70%, preferably at most 50%, more preferably at most 30%, even more preferably at most 20%.

After the compression process the densified wood can be torn or pulled lengthwise. The stretching can be to at least 31% of the length before densification, more preferably to at least 70% of the original length, even more preferably to at least 120% of the original length and at most to at most 200% of the original length, preferably at most 160% of the original length, more preferably at most 130% of the length before densification, most preferably about 100% of the length before densification.

The densified wood produced with the method described above can then be cut into sheets comprising thicknesses of as low as 0,05 mm, preferably at least 1 mm, more preferably at least 2 mm, most preferably at least 5 mm and at most 15 cm, preferably at most 8 cm, more preferably 10 mm, most preferably between 2 mm and 5 mm.

The workpiece can further be laminated to a second material . Such second material can be at least one of metal, keratin, ceramic, resin, densified or undensified wood or a sheet of the workpiece. This lamination can further extend to multiple layers of materials. The material can be homogeneous but also be formed as a grid or other structured surface. Further, a material with the properties of rubber can be applied. As the workpiece can be flexible in all dimensions, a push button or similar can be constructed with the feature of showing a wooden surface to the button.

The impregnating agent may be a fluid, a powder or a layer. The application of the impregnating agent to the densified wood can be by multiple methods, such as vacuum- pressure method, also in the oscillating process alternative. Further, the fluid may be heated to increase rheologic properties to allow the impregnating agent to easier enter the densified wood. The impregnating agent, if a solid agent is selected, can liquify by the application of heat. The application of a solid or semi-solid layer may be used simultaneously with the forming process, specifically during the deep-drawing process.

The impregnating agent may have several functions. One can be the strengthening of the workpiece. Another function can be to increase resistivity against environmental influence. The flexural strength of the malleable material can be at least 3% above the corresponding flexural strength of the densified wood. The strengthening of the flexural rate can rise further to 6% and even 18%. In some cases, the flexural strength of the malleable material can reach the flexural strength of the impregnating agent. It varies from the application of the malleable material and is left to the technician to select the suitable impregnating agent to determine the physical properties of the malleable material. In case that flexibility is required, an impregnating agent with a high flexibility at ambient temperature is selected. It should be kept in mind that the densified wood can be considered flexible and it is the impregnating agent and its properties to determine the properties of the malleable material. The densified wood itself can follow the properties of the impregnating agent in wide ranges.

The impregnation process may be applied repeatedly for various reasons. One reason, as explained above, can be to intermediately increase the bendability or flexibility of the workpiece, form it and then impose the workpiece to another impregnating agent to increase the flexural strength.

Exemplifying, but not excluding other impregnating agents, the impregnating agents are discussed below.

Such an impregnating agent can be a solid, semi-solid or liquefied polymer. The polymer, if solid or semi-solid, can impregnate the densified wood by being heated or imposed to considerable pressure. Also microwave heating and/or heating by a chemical process can be applied. For instance, the densified wood can be brought in contact with a sheet of polymer and optionally with any second material, like another sheet of wood. Under pressure and heat, the polymer liquifies and thus impregnates the densified wood and thus forms the malleable material that forms a three-dimensional workpiece.

The forming may be elastic deformation or plastic deformation. Further, any forming process can be applied on the malleable material, like cutting, bending, milling, sawing, drawing, and further forming methods known to the person skilled in the art. Further, forming methods, like rolling, deep-drawing or other forming processes may be performed, like swaging or curling.

Other polymers to act as impregnating agent may be any organic agent, like one of a plastic material, thermoplastic resin, a liquefied acetate, a cellulose-based liquid and/or a glue. Its dependent from the application that is to be formed. In some cases, the workpiece shall be formed once and never again shall be re-shaped. In this case, a duroplastic resin can be used.

As known in the art, an acetate as an impregnating agent can be re-shapeable if the workpiece is exposed to a temperature of about 90°C, in some cases up to 150°C. Certain thermoplastic materials require up to 550°C.

Further, natural resin materials can be applied, either as an intermediate impregnating agent to alter the bendability or ductability of the densified wood. However, also differing features may be applied, for instance, one side of the densified wood for decorative purpose, the other side for another technical property, like fortifying the structure or supplying gluing property to attach to a second material.

The impregnating agent may further be selected from a cellulose-based liquid, as can be cellulose acetate, cellulose acetate butyrate, celluloid and/or cellulose propionate or any combination thereof.

The malleable material produced after the disclosed method can be bent durably, provided the impregnation agent is one of the thermoplastic product family. The densified wood as a component of the workpiece can be bent without visual fractures by at least 5°, preferably at least 10°, more preferably at least 20°, more preferably at least 45°, more preferably at least 90°. The following examples of application of the material received after having applied the steps of the disclosed method may comprise interior appliance for a car, a mobile home, an airborne vehicle, a boat or a ship.

Further, also for interior appliance for inhouse use or music instruments, furniture or appliance for furniture such a workpiece can be advantageous.

Luxury goods may be packed with packaging material of the disclosed workpiece. Even luxury articles themselves can be manufactured from or with the malleable material . The housing of a watch, a ring, a necklace, just to exemplify some ideas where such workpiece can find use.

Further, eyewear and/or accessories for fashion like a handbag can be considered.

Drawings

The skilled artesian will understand the drawings, described below, are for illustration purposes only. The drawings are not intended to limit the scope of the present teaching in any way.

Fig. 1 shows a flow diagram how the method to handle the malleable material according to the invention.

Fig. 2 depicts a sample of the surface of the malleable material produced after the method as disclosed.

Fig. 3 depicts a further example how the malleable material can be shaped.

Fig. 4 depicts an apparatus that can conduct a deep-drawing step of method.

Embodiments

While the disclosure has been illustrated and described in detail in the drawings and foregoing description, such illustration and description are to be considered illustrative or exemplary and non-restrictive; the disclosure is thus not limited to the disclosed embodiments. Variations to the disclosed embodiments can be understood and effected by those skilled in the art and practicing the claimed disclosure, from a study of the drawings, the disclosure, and the appended claims. As used herein, including in the claims, singular forms of terms are to be construed as also including the plural form and vice versa, unless the context indicates otherwise. Thus, it should be noted that as used herein, the singular forms "a," "an," and "the" include plural references unless the context clearly dictates otherwise.

The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to fulfill aspects of the present invention. The present technology is also understood to encompass the exact terms, features, numerical values or ranges etc., if in here a relative term, such as "about", "substantially", "ca.", "generally", "at least", "at the most" or "approximately" is used in this specification, such a term should also be construed to also include the exact term. That is, e.g., "substantially straight" should be construed to also include "(exactly) straight". In other words, "about 3" shall also comprise "3" or "substantially perpendicular" shall also comprise "perpendicular". Any reference numerals in the claims should not be considered as limiting the scope.

In the claims, the terms "comprises/comprising", "including", "having", and "contain" and their variations should be understood as meaning "including but not limited to" and are not intended to exclude other components. Furthermore, although individually listed, a plurality of means, elements or method steps may be implemented. Additionally, although individual features may be included in different claims, these may possibly advantageously be combined, and the inclusion in different claims does not imply that a combination of features is not feasible and/or advantageous. In addition, singular references do not exclude a plurality.

Whenever steps were recited in the above or also in the appended claims, it should be noted that the order in which the steps are recited in this text may be the preferred order, but it may not be mandatory to carry out the steps in the recited order. That is, unless otherwise specified or unless clear to the skilled person, the order in which steps are recited may not be mandatory. That is, when the present document states, e.g., that a method comprises steps (A) and (B), this does not necessarily mean that step (A) precedes step (B), but it is also possible that step (A) is performed (at least partly) simultaneously with step (B) or that step (B) precedes step (A). Furthermore, when a step (X) is said to precede another step (Z), this does not imply that there is no step between steps (X) and (Z). That is, step (X) preceding step (Z) encompasses the situation that step (X) is performed directly before step (Z), but also the situation that (X) is performed before one or more steps (Yl), ..., followed by step (Z). Corresponding considerations apply when terms like "after" or "before" are used.

It will be appreciated that variations to the foregoing embodiments of the invention can be made while still falling within the scope of the invention can be made while still falling within scope of the invention. Features disclosed in the specification, unless stated otherwise, can be replaced by alternative features serving the same, equivalent or similar purpose. Thus, unless stated otherwise, each feature disclosed represents one example of a generic series of equivalent or similar features.

Use of exemplary language, such as "for instance", "such as", "for example", "exemplifying" and the like, is merely intended to better illustrate the invention and does not indicate a limitation on the scope of the invention unless so claimed. Any steps described in the specification may be performed in any order or simultaneously, unless the context clearly indicates otherwise.

All of the features and/or steps disclosed in the specification can be combined in any combination, except for combinations where at least some of the features and/or steps are mutually exclusive. In particular, preferred features of the invention are applicable to all aspects of the invention and may be used in any combination.

The ratio of flexural strength to density can be considered to normalize values that apply to many wood materials and thus make them comparable.

Numerical values regarding the properties of the wood material are based on DIN 68364 as issued in 05.2003.

Where the density of wood is mentioned, the gross density or bulk density is addressed.

Description of the figures

Fig. 1 depicts a flow diagram of one embodiment. A piece of massive wood S10, harvested from a deciduous tree, has been brought to the properties in accordance with the further process. The flexural strength of the wood material may be normalized to a value to represent an approximate average value that corresponds with the type of wood. The wood is assumed to have substantially constant density, i.e., not comprising knotholes, no foreign objects comprised or any other irregularities. The compact piece of wood can be compressed by a compressive force S22 in their length and comprises tattered and/or inflected fibers. The wood by densifying S20 becomes bendable to a high degree. The technology is known at least since the 1920 ^' s.

The densified wood can further be pulled opposite to the prior affected compression direction. Thus, the piece of wood keeps its flexibility but the density of the wood can be adjusted to the needs of the further process.

The wood at this stage may be cut to the measures as required for the further process S30. For instance, milling, lathing and/or punching may be performed.

At step S40, the piece of compressed wood may be modified by impregnating the piece of densified wood with an impregnating agent. Various possibilities to insert an impregnating agent to at least the surface of the piece of wood can be considered .

One possibility may be a vacuum-pressure S42 method, which first imposes a vacuum to the sheet of wood and then under high pressure inserts the impregnating fluid to the wood, at least to the surface. Dependent from the flowability of the impregnating agent, this procedure can be carried out repeatedly.

The material composed from densified wood and the impregnating agent forms a malleable material S50.

The impregnating agent S44 rules the further properties of the malleable material. If a thermoplastic agent is used, the malleable material can keep the malleability ever since the workpiece made of this material is heated to the temperature that is necessary to melt. Such a workpiece can be re-shaped repeatedly.

In case a thermoset material, like duroplast, is used for impregnating the densified wood, the workpiece after an initial forming under the application of heat stiffens and under normal conditions cannot be re-shaped .

A further step S60 of forming by milling, similar to step S30, can be carried out at this stage. However, as an addon, also drawing and/or rolling can be conducted to the malleable material.

In dependency of the impregnating agent, the malleable material can further be re-shaped to form another sized body or to adjust the shape to individual necessities. The represented steps S70 and S72 exemplify the methods of shaping or reshaping of the malleable material. This can be done by either applying heat to the workpiece or by exerting considerable pressure.

A readily formed piece of semi- or end-product at S80 may be the result of the prior method steps.

Fig. 2 represents an example how the malleable material can be formed. The contour lines indicate, for instance, a larger slope at location 10 and relatively flat regions at locations 20 and 30. As long as the slope isn ^' t to large, the malleable material can be brought into any shape as required. The risk may exist that at a too large slope the malleable material might tear. The risk of tearing may be dependent on the wood material, the impregnating agent, the applied heat and the applied pressure.

Fig. 3 further shows a conically shaped sample that could form a lampshade. Referral number 10 indicates a location with a high (large) slope, while 20 shows a substantially flat region. As is obvious to the person skilled in the art, the measures of the minimum slope and the maximum of a drawing depth will have to be determined by try and error. Wood is a natural product with a wide variety of properties, thus final values cannot be given and must be left to the practitioner on site.

Fig. 4 shall represent a deep-drawing machine in a way that concentrates on the portions that matter in the present application. Box 100 is the steering and supply portion of the machine that carries the switches to control the machine, further the hydraulic pressure is produced and provided to the hydraulic actuator 200.

With the referral number 800 a sheet of malleable material is depicted, shortly before it is located to the exact position where it must be placed to produce the desired workpiece, in this case a cone shape. The male portion of the mold 400 is then lowered by hydraulic force 200 into the direction of the female portion 500 of the mold. The malleable material by this movement is jammed between the mal 400 and the female 500 molding elements. The hydraulic force can be supported by the application of heat.

Horizontal bar 300 represents the anchor for the upper part of the press exerting the deep- drawing process. In the case that the malleable material is ready assembled, thus the densified wood and the impregnating agent have already been integrally formed, the heat and the pressure soften the malleable material and brings it into the required shape as defined by the form of the mold. In the case that the densified wood has been layered with an impregnating agent, a firm material or in powder form, the heat causes the impregnating agent to be liquified and under the pressure is then impregnating the densified wood .

Several layers can be inserted to achieve the properties as required.