MANUFACTURING AN ASSEMBLY OF A FIRST AND A SECOND OBJECT

Abstract

A method of manufacturing and assembling a first and a second object wherein the first object is made by bringing a flowable compound into a first object shape and then subjecting the flowable compound to a hardening process that results in a change of a chemical composition of the flowable compound, thereby creating the first object or a part thereof. Then, the first object is positioned relative to a second object, and a flow portion of the hardened article of the modified compound is caused to become flowable by an input of energy. An interpenetration zone of the flow portion and structures of the second object is created, and the flow portion is allowed to re-solidify, whereby the interpenetration zone between the re-solidified flow portion and the structures of the second object secures the first and second objects to each other.

Claims

1. A method of manufacturing an assembly of a first and a second object, the method comprising the steps of: providing a flowable compound; subjecting the flowable compound to a hardening process that results in a change of a chemical composition of the flowable compound, thereby creating a modified compound; subjecting the modified compound to a thermal shaping process to create a hardened article of the modified compound, which article constitutes at least a part of the first object; providing the second object; positioning the first object relative to the second object, the second object is optionally also formed from the flowable compound; causing a flow portion of the modified compound to become flowable by an input of energy; and generating an interpenetration zone of the flow portion and structures of the second object; and allowing the flow portion to re-solidify, whereby the interpenetration zone between the re-solidified flow portion and the structures of the second object secures the first and second objects to each other.

2. The method according to claim 1, wherein prior to the thermal shaping process, the modified compound is provided as a granulate or powder.

3. The method according to claim 1, wherein the thermal shaping process is a thermomechanical process.

4. The method according to claim 3, wherein the thermal shaping process is an injection molding or additive manufacturing process.

5. A method of manufacturing an assembly of a first and a second object, the method comprising the steps of: providing a flowable compound; bringing the flowable compound into a first object shape; while the flowable compound is in the first object shape, subjecting the flowable compound to a hardening process that results in a change of a chemical composition of the flowable compound, thereby creating a hardened article of a modified compound having the first object shape, said hardened article constituting at least a part of the first object; providing the second object, the second object being formed from the flowable compound; positioning the first object relative to the second object; causing a flow portion of the hardened article of the modified compound to become flowable by an input of energy, and generating an interpenetration zone of the flow portion and structures of the second object; and allowing the flow portion to re-solidify, whereby the interpenetration zone between the re-solidified flow portion and the structures of the second object secures the first and second objects to each other.

6. The method according to claim 5, wherein the step of bringing the flowable compound into the first object shape comprises filling the flowable compound into a cavity in a mold, the cavity at least partially having the first object shape.

7. The method according to claim 5, wherein the step of bringing the flowable compound into the first object shape comprises casting, or molding, 3D printing.

8. The method according to claim 1, wherein in the step of causing the flow portion to become flowable by the input of energy, portions of the modified compound remain solid.

9. The method according to claim 8, wherein the portions remaining solid constitute more than 50% of the modified compound.

10. The method according to claim 1, wherein in the step of causing the flow portion to become flowable by the input of energy, only a local flow of material is caused and the first object essentially keeps its shape.

11. The method according to claim 1, wherein the energy is mechanical vibration energy.

12. The method according to claim 1, wherein the energy is electromagnetic energy.

13. The method according to claim 1, wherein in the step of causing the flow portion to become flowable by the input of energy, at least a portion of the energy impinges on the first object until the flow portion becomes flowable, and the flow portion is caused to penetrate into structures of the second object.

14. The method according to claim 13, wherein the structures of the second objects comprise pores of the second objects, wherein the pores are pre-existing pores or pores generated during the step of causing the flow portion to penetrate into the structures of the second object.

15. The method according to claim 13, wherein the first object is a connector or reinforcement element, and the method comprises connecting a further object to the second object via the connector.

16. The method according to claim 1, wherein at least a portion of the energy is coupled into the second object, and material of the first object is caused to flow into pre-made structures of the second object.

17. The method according to claim 16, wherein the second object is a connector or reinforcement element, and the method comprises connecting a further object to the first object via the connector.

18. The method according to claim 1, wherein the second object comprises a thermoplastic material different from the modified compound, and wherein in the step of causing the flow portion to become flowable by the input of energy, near an interface between the first and second objects portions of the thermoplastic material become flowable, resulting in an interpenetration zone between the thermoplastic material and the flow portion.

19. The method according to claim 1, wherein during the step of causing the flow portion to become flowable by the input of energy, the first and second objects are pressed against each other.

20. The method according to claim 1, wherein after the step of allowing the flow portion to re-solidify, the first and second objects are secured to each other by a positive-fit connection in the interpenetration zone.

21. The method according to claim 1, wherein after the step of allowing the flow portion to re-solidify, the flow portion adheres to material of the second object in the interpenetration zone.

22. The method according to claim 1, wherein the first object consists of the hardened article.

23. The method according to claim 1, wherein the hardening process takes place at room temperature or at a temperature the compound reaches when the process takes place without input of thermal energy.

24. The method according to claim 1, wherein the hardening process comprises drying, a chemical reaction, percolation, a hydraulic reaction, or adsorption.

25. The method according to claim 24, wherein the chemical reaction is a curing, especially a polymerization.

26. The method according to claim 1, wherein the flowable compound comprises a solvent a binder and a filling material.

27. The method according to claim 26, wherein the flowable compound comprises further additives.

28. The method according to claim 26, wherein the solvent is water or an aqueous solvent.

29. The method according to claim 26, wherein the binder is a protein glue.

30. The method according to claim 26, wherein the filling material is a natural fiber.

31. The method according to claim 30 wherein the natural fiber is chosen from the group consisting of: wood fibers, cellulose fibers, fibers of corn, bamboo fibers, hemp fibers, fibers made of hazelnut shells, and cotton.

32. The method according to claim 27, wherein the additive is a hygroscopic agent.

33. The method according to claim 32, wherein the hygroscopic agent is chosen from the group consisting of: cellulose, calcium chloride, magnesium chloride, zinc chloride, ferric chloride, carnallite, potassium carbonate, potassium phosphate, ferric ammonium citrate, ammonium nitrate, potassium hydroxide, and sodium hydroxide.

34. Use of a material which comprises or is obtained by mixing together: 10-60% per weight of a binder; 5-50% per weight of a filling material; 2-50% per weight of an additive, and up to 83% per weight of a solvent for manufacturing a connector or reinforcement element.

35. A connector or reinforcement element obtained by mixing together: 10-60% per weight of a binder; 5-50% per weight of a filling material; 2-50% per weight of an additive, and up to 83% per weight of a solvent.

36. The connector or reinforcement element according to claim 35, wherein the connector comprises a surface portion of a material being a modified compound obtained from subjecting the mixture to a hardening process.

37. The connector or reinforcement element according to claim 35, comprising a coupling-in face for receiving mechanical vibration energy, and further comprising an energy director formed of the modified compound.

38. The connector or reinforcement element according to claim 35, comprising a non-liquifiable portion such as a core, the core preferably comprising at least one of natural fibers, wood, a biodegradable material, a metal, ceramic material, a thermosetting polymer or any combination thereof.

39. A method for making a connector or reinforcement element comprising the step of: mixing together 10-60% per weight of a binder; 5-50% per weight of a filling material; 2-50% per weight of an additive, and up to 83% per weight of a solvent.

40. The method according to claim 39 further comprising a hardening process.

41. Use of a connector as defined in claim 35, wherein the material of the connector is at least partially liquefied.

42. Use according to claim 41, wherein the liquefaction is caused by mechanical energy transferred to the connectors.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0122] The invention and embodiments thereof are described in further detail in connection with the appended drawings that are all schematical. Same reference numbers refer to same or analogous elements. In the drawings:

[0123] FIGS. 1-4 illustrate steps of the first stage of a method according to the first aspect, the manufactured first object being a connector;

[0124] FIGS. 5-7 depict the second stage for an example of the first, second, and third group of embodiments, respectively;

[0125] FIG. 8 shows a detail of an interface produced in accordance with FIG. 7;

[0126] FIGS. 9 and 10 show steps of the first stage of a method according to the second aspect; and

[0127] FIG. 11 shows a combined first stage/second stage of a method according to its second aspect.

[0128] FIGS. 12A-12C show a second stage of a method wherein the first object is a reinforcement element.

[0129] FIGS. 13A-13C show a second stage of a method wherein the first object is a connector having two flow portions.

DESCRIPTION OF PREFERRED EMBODIMENTS

[0130] FIG. 1 illustrates the step of composing the flowable compound 1. Liquid constituents 12 and possibly solid constituents 11 (see the description of the material above) are illustrated to be mixed in a vessel 10 until a desired composition is achieved, for example with desired parameters such as viscosity, temperature etc.

[0131] In FIG. 2, a quantity of the flowable compound 1 is filled into a cavity 25 of a mold. The mold is illustrated to have two mold halves 21, 22.

[0132] FIG. 3 very schematically illustrates the hardening process. During this process, the flowable compound 1 remains in the cavity 25, which cavity is for example completely closed (closure 26). The hardening process may optionally include material removal (arrows 32) for example if the hardening process includes drying, such as allowing a solvent to diffuse into the mold, which then has the necessary absorbing capacity, for example by being porous. The hardening process may in addition or as an alternative include that energy impinges, such as for example in the form of UV irradiation (arrows 31). It is not excluded that the process may include material reception, for example by an initiator or similar being supplied via the mold.

[0133] The hardening process results in the first object (or an article supplemented by a further constituent to become the first object) being manufactured. FIG. 4 illustrates an example of the first object 41. The first object is a connector having a connector shaft portion 44 and a connector head portion 45, whereby the shaft portion (or at least a distal (in FIG. 4 lower) part thereof may be anchored in the second object, while a further object is secured to the second object. If the connector has the shape illustrated in FIG. 4, such further object may have a sheet-like or plate-like portion with a through hole through which the shaft extends, so that the sheet-like or plat-like portion is clamped between a proximal (upper) surface of the second object and a distal (lower) surface of the head portion—similar to a screw with a screwhead or nail with a nail head securing an item to a wall.

[0134] Other shapes of connectors, including connectors with another dedicated connecting structure, such as an inner or outer thread, an undercut coupling structure etc. are readily possible.

[0135] The first object 41 of FIG. 4 has energy directing structures for the subsequent second stage. The energy directing structures include a distal tip 42 as well as a plurality of ribs 43 which are illustrated to extend axially along an outer surface of the shaft portion 44.

[0136] In FIGS. 2-4, the first object 41 is illustrated to be cast of the flowable compound and to consist of it. It would be possible also that the first object in addition to having portions of the flowable compound also has portions of a further constituent. For example, a constituent of a different material, for example of a metal, may be placed in a defined position in the mould cavity during the casting process, and/or a constituent of a different material may be affixed to the moulded article after the hardening process to yield the first object.

[0137] FIG. 5 illustrates the second stage for an example of the first group of embodiments. The first object 41 of the kind illustrated in FIG. 4 is shown together with an example of a second object 51, which second object has a proximally facing surface and an opening 52 being a blind hole, the opening having a mouth in the proximally facing surface. The second object is, at least in a vicinity of the opening, of a material that is penetrable by the flow portion in the above-described sense. An example of a material of the first object is a wood or wood composite.

[0138] For securing, the first object 41 is placed relative to the second object 51, with the shaft portion partially inserted in the opening 52. Then, a sonotrode 60 is used to press the first object 41 against the second object 51 while mechanical vibration energy is coupled into the first object 41 via a proximally facing coupling-in face (upper surface in the figure) of the first object 41 until a flow portion 48 of the modified compound becomes flowable and flows into structures of the second object to yield, after re-solidification, an anchoring of the first object in the second object.

[0139] The second stage may be substantially as described in WO 98/42988 (for example as described referring to FIGS. 1-4) or in WO 00/79137 (then possibly without the opening 52; for example based on the principle as described referring to FIG. 1) or in WO 2006/002569 (then with the energy impinging indirectly on the first object, via a further object to be connected to the second object, for example substantially as described referring to FIGS. 1-11) or in WO 2015/181300 (then with the shaft portion and the opening adapted to each other for a press-fit; as described for example referring to FIGS. 1 and 5) or in WO 2008/034276 (then for example with an additional counter element being used, for example as described referring to FIG. 4). Other possibilities include the possibility causing the flow portion to be made flowable not in direct contact between the first and second objects and due to friction between these objects but in contact between the sonotrode and/or a counter element and the modified compound, for example as described in WO 2009/052644, for example as described referring to FIG. 1 or FIG. 3 or FIG. 5. An even further variant is shown in WO 2018/172 385 where the second object in a region has a material of low density which is penetrated and possibly compressed by the first object—for example a fibrous material. All these documents mentioned above are incorporated herein by reference.

[0140] FIG. 6 illustrates an example of the second group of embodiments. The first object 141 shaped in the first stage and including the modified compound is a functional part having a structure dictated by its function. The second object 151 is for example a connector and is of a material that does not liquefy at the temperature at which the modified compound becomes flowable.

[0141] The second object 151 is illustrated to have a head portion and a shaft portion 154 for a similar function as the connector constituting the first object in the previous embodiment. The second object moreover has pre-made structures 153—here illustrated to include recesses along the shaft portion—into which the flow portion can flow during the second stage.

[0142] For seconding, a sonotrode 60 is used to press the second object 151 against the first object 141 while mechanical vibration energy is coupled into the second object 151 until a portion of the second object penetrates into material of the first object 141 and causes a flow portion thereof to become flowable and flow into the pre-made structures 153. With respect to the direction in which the second object is pressed relative to the first object, the structures form an undercut, so that the re-solidified modified compound secures the first and second objects to each other by a positive-fit connection.

[0143] In embodiments of the second group, the second stage and/or the structure or shape of the second object may be substantially as described in WO 2016/071335, which is incorporated herein by reference.

[0144] FIG. 7 shows an example of the third group of embodiments. In FIG. 7, the first object 41 is illustrated to be similar to the first object of FIG. 5. The second object 241 is a thermoplastic part having a shape and structure dictated by its function.

[0145] For securing, a sonotrode 60 is used to press the first object against the second object while mechanical vibration is coupled into the first object, until a flow portion of the modified compound as well as a thermoplastic material portion of the second object become flowable, and a heterogeneous mixture of material portions of the first and second objects results so that after re-solidification, an anchoring of the first object in the second object is achieved. FIG. 8 very schematically illustrates the according interface.

[0146] In embodiments of the third group, the roles of the first and second objects may be interchanged, i.e. it is possible to provide the second object (having the for example conventional thermoplastic material) as a connector and the first object (having the modified compound) to be a functional part, and to cause the vibration energy to impinge on the second object instead of on the first object.

[0147] FIG. 9, again very schematically, illustrates the principle of the first stage of the method according to its second aspect. A flowable compound 1 is composed as in FIG. 1 and is then used to prepare a granulate of the modified compound. In the illustrated embodiment, the flowable compound 1 is conveyed in an extruder 310, and then an extruded portion 301 is subject to the hardening process, where after a mechanical device—here schematically illustrated to be a rotating knife 311—is used to hackle the extruded and hardened modified article of the modified compound to yield the granulate 341. The skilled person will readily come up with alternative set-ups producing a granulate or powder used for the second sub-stage. It is possible that some additives, such as common biodegradable polymers, can be added to the flowable compound being within the extruder.

[0148] Then, in a second sub-stage, illustrated in FIG. 10, the article constituting the first object or a part thereof is manufactured in a thermomechanical process. Such thermomechanical process may be an injection moulding process, in which the granulate or powder is first molten and then introduced into a cavity of a mould in a flowable state. FIG. 10 illustrates an alternative in which the granulate 341 is initially solid and melting takes place due to heat input on the mould halves 321, 322 while at the same time a pressing force is used to close the mould. The article constituting the first object can be blended with another component such as another thermoplastic polymer or another modified compound. The amount of the added component can be up to 50% but is preferably in the range of 10 to 30%.

[0149] FIG. 11, finally, illustrates a special embodiment of the second aspect, in which the article is shaped in situ during the securing step. The first object includes a sheath 401 of a material not liquefiable at temperatures at which the modified compound becomes flowable. It is placed relative to the second object 51 (which may have a configuration similar to the first group of embodiments of the first aspect described above), and then serves as a vessel for the granulate. The vessel is accessible from proximally, and a sonotrode 60 is used to couple mechanical vibration energy into the granulate, which at the same time is shaped to at least partially fill the vessel and is pressed through holes into the surrounding material of the second object (flow portion 48) to yield the anchoring.

[0150] FIGS. 12A-12C show the second stage an embodiment wherein the first object is a reinforcement element. FIG. 12A shows a schematic drawing of a second object 80 having pores 82 and a hole 81 wherein another object should be fixed. FIGS. 12B and 12C outline the steps of reinforcement of object 80. Therefore, a reinforcement element 83 made of a modified compound is introduced into the hole 81. A sonotrode 60 is used to liquefy the material of the reinforcement element. This material flows into the pores of object 2 causing a reinforcement of object 2 within the vicinity of the hole. Subsequently a third object may be anchored to object 2 within the hole.

[0151] FIGS. 13A-13C show the aspect that the first object is part of a connector having two flow portions and being designed in a way suitable for connecting two objects (a second object and a third object). FIG. 13A shows a schematic drawing of a second object 80 having pores and a hole 81. FIG. 13B shows a connector 84 having a first portion 92 being made of the modified compound. This first portion may have the shape of a pin. The outermost part 91 of this first region can serve as a flow portion. The connector contains a second portion 90 which is also made of a modified compound which may be identical to the material of the first region 92. The second region may have a thread and/or may have a second flow portion. FIG. 13C shows the connector 84 after fixation within the second object 80. The flow portion 91 has been liquefied, penetrated into the second object 80 and was re-solidified. Thus, a penetration zone 92 can be created. The connector 84 is not fixed to the second object 80. The second portion 90 of the connector can be used to attach or secure a third object to the connector and to the second object.

[0152] The invention is not restricted to these embodiments. Other variants will be obvious for the person skilled in the art and are considered to lie within the scope of the invention as formulated in the following claims. Individual features described in all parts of the above specification, particularly with respect to the figures may be combined with each other to form other embodiments and/or applied mutatis mutandis to what is described in the claims and to the rest of the description, even if the features are described in respect to or in combination with other features.