BR102017001437A2 - wax injection mold production process and uses - Google Patents

Abstract

Production process of wax injection molds and uses. The present invention relates to a process of producing lost wax injection molds from silicone molds for the production of wax replicas with great perfection, precision and quality of general technical parts of any size and shape. For this purpose, the conventional two-part silicone mold is first produced and then the two-part rigid resin or polyurethane or polymer mold is generated.

Description

(54) Title: PROCESS OF PRODUCTION OF MOLDS FOR INJECTION OF WAX AND USES (51) Int. Cl .: B29C 45/00; B29C 45/06; B29C 33/40; B22C 7/00; B22D 2/23; (...) (73) Holder (s): UNIVERSIDADE DE SÃO PAULO - USP (72) Inventor (s): BENEDITO DE MORAES PURQUÉRIO; LETÍCIA HATSUE MAKI; VICTOR TAMASSIA NOPPENEY (85) National Phase Start Date:

24/01/2017 (57) Abstract: PROCESS OF PRODUCTION OF MOLDS FOR INJECTION OF WAX AND USES.

The present invention relates to a process of producing molds for injection of lost wax from silicone molds intended for the production of replicas in wax with great perfection, precision and quality of technical parts in general of any sizes and shapes. For this purpose, the production of the conventional silicone mold in two parts is carried out first, and then the polymeric mold or polyurethane or rigid resin is generated, also in two parts.

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PROCESS OF PRODUCTION OF MOLDS FOR INJECTION OF WAX AND USES

Field of the invention:

[001] The present invention falls within the field of application of metallurgy, more specifically in the area of molding in foundries, since it refers to a process of obtaining molds for injection of lost wax from silicone molds, aiming at making rigid polymeric or polyurethane or resinoid molds for the production of wax replicas of pieces of the most varied types, shapes and sizes.

Fundamentals of the invention:

[002] In Metallurgy, casting is one of the processes for manufacturing metal parts, basically consisting of pouring liquid metal into a ceramic or non-refractory mold that has the desired geometry for the part. The foundry is widely used in parts of simple geometry and for production in low series. However, the foundry generally delivers parts with low surface quality when compared to machined metal parts. In addition, the traditional foundry works with relatively rough parts, such as combustion engine blocks and electric motor housings. It is difficult to register small parts made from traditional casting.

[003] For wax injection casting, ceramic molds that will receive liquid metal are obtained from parts manufactured in wax. These wax pieces are covered by a suspension containing ceramic powder; after drying, a mold is obtained for casting with its cavities filled with wax. So, this ceramic mold is heated

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2/27 for the melting of this wax, which is finally poured out of the mold, and therefore, the name “lost wax”. Then, the ceramic mold, with the internal cavities unobstructed, can receive liquid metal. After the metal has cooled and solidified, the ceramic mold is destroyed (mechanically or by attack of an appropriate solution), leaving only the metal parts.

[004] This lost wax casting process generates metal parts with better surface quality, since the surface of the wax parts is copied with a high degree of fidelity by the ceramic mold. Therefore, it is possible to manufacture wax parts with different geometries to obtain metallic parts with the same geometries. To this end, one of the processes currently employed in the industry is the wax injection, which consists of preparing a mold with the desired geometry for the wax pieces and the injection channels (used both for wax and, later, for molten metal) ) and then inject liquid wax under pressure into this mold. After cooling and solidifying the wax, the mold is opened and the wax pieces, ready to go through the process of creating the previously described ceramic mold, are removed.

[005] To manufacture the wax parts by the lost wax injection process, currently use is made of metal molds manufactured on CNC machining machines. Such a process constitutes one of the obstacles to lost wax casting, as access to CNC machines is relatively restricted, in addition to requiring specific technical knowledge for its operation. In addition, the process of machining these molds is very time consuming and some molds must be

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3/27 manufactured with special metals, due to their use.

[006] In order to solve the technical problems presented, the present invention proposes a process for the production of molds for injection of lost wax from silicone molds, aiming at making rigid polymeric or polyurethane or resin molds, intended for the production of replicas in wax of pieces of the most varied types, shapes and sizes.

[007] In this way, the process described here simplifies the process of manufacturing non-metallic molds for wax injection, effectively replaces the corresponding metallic molds for wax injection and enables the improvement of the surface quality of the molded parts, since this characteristic is of paramount importance for the manufacture of precision and safety parts such as, for example, precision machine parts, prosthetic components, orthoses and bone implants.

[008] In addition, the proposed process is easy to obtain molds for wax injection using reusable materials that are easy to acquire and handle, reducing the time of making the mold by at least ten times, compared to its corresponding metallic material that lacks machining processes for your production.

[009] In this way, the process now proposed heals the negative situations offered by the current techniques for producing metallic molds for wax injection now used.

[010] Therefore, the present invention opens new doors for industrial users, prosthetics and researchers who need to make molds for

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4/27 wax injection to produce high quality and precision parts. Users who are unaware of molding techniques and need to produce wax replicas perfectly can also use these new techniques with great ease of application and high quality, in order to promote the making of wax injection molds that produce identical wax replicas. matrices or models.

State of the art:

[011] Some state-of-the-art documents describe various processes for obtaining lost wax injection molds.

[012] Document DE4022653 (A1) describes a process for injection of lost wax, plastic or metal using vulcanized silicone rubber molds.

Unlike the present invention, said process is only about molding jewelry pieces using high temperature. In addition, the proposed invention meets any technical part, for any application, limiting only to the production of silicone molds or resin for lost wax, at low temperature.

[013] EP1101783 (A2) emphatically describes the production of resin composites and atomized reinforcers for the production of high performance molds for use in various molding processes, such as injection, compression, vacuum molding, high molding pressure and foam injection, but not in the specific lost wax injection process.

[014] CN102248125 (A), on the other hand, describes a conventional process of injection of lost wax through resin molds. In contrast, the present invention

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5/27 describes a process for obtaining silicone or resin molds, describing and illustrating the molding steps, regardless of the silicone rubber itself or the resin itself or any material itself, the modeling now presented, for product and process , it uses optimization of the consumption of silicone rubber, the consideration of supports of the part to be molded in silicone or any other material that will be integrated into the mold, and the forecast and simultaneous generation of rubber injection channels still in the liquid phase associated with the air exhaust channels (bubbles) that associated make the mold easy to obtain, economical, efficient and of high precision.

[015] Therefore, none of the state-of-the-art documents describes a process for the production of molds for injection of lost wax from silicone molds, with a view to making polymeric molds (thermoplastic and or thermoset polymers) or polyurethanes (elastomeric polymers or rubber) or resinoid (thermoset polymers), rigid, for the production of wax replicas of pieces of the most varied types, shapes and sizes, as proposed by the present invention.

Brief description of the invention:

[016] The present invention relates to a process of producing molds for injection of lost wax from silicone molds intended for the production of replicas in wax with great perfection, precision and quality of technical parts in general of any sizes and shapes. Thus, the new molding process was given an original and unprecedented feature, with a view to improving the use and efficiency in relation to the current methods applied for the

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6/27 manufacture of metal molds for injection of lost wax. First, the conventional silicone mold is produced in two parts and then the polymeric or resin mold is generated, also in two parts.

Brief description of the figures:

[017] In order to obtain a total and complete visualization of the object of this invention, the figures to which reference is made are presented, as follows.

[018] Figures 1 AF are seen from the articulated eight ring orthosis, assembled, showing the proximal ring (1) and the distal ring (2) coupled, used as a model to illustrate the figures, where (A) is a front view , (B) is a top view, (C) is a left side view, (D) is a perspective view of the articulated ring eight orthosis, (E) is a perspective view of the proximal ring (1), and (F ) is a perspective view of the distal ring (2).

[019] Figure 2 is a perspective view of the male (7), consisting of branches (3, 4, 5, 6), conical and / or cylindrical, in polymeric, metallic or similar material, which form the tree or bunch , used to generate the feeding channel of the silicone mold.

[020] Figures 3 AD are seen from the male (7) in polymeric material, metallic or similar, with the proximal rings (1) coupled, used to generate the feeding channel of the silicone mold, where (A) is a side view, in section; (B) a top view; (C) is a front view, in section; and (D) a perspective view.

[021] Figures 4 A-D are seen from the male (7) with the proximal (1) and distal (2) rings, with their respective proximal (9) and distal (10) taps and air outlet pins

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7/27 (8), coupled, used to generate the feeding channel of the silicone mold, where (A) is a side view, in section; (B) a top view; (C) a side view, in section; and (D) a perspective view.

[022] Figures 5 AC are seen of the mounting of the tap (7) with the proximal rings (1) and their respective proximal taps (9) coupled, on silicone buttons (11), inside the molding enclosure formed by angles (12), on the molding base (13), with its guide pins (14), in which (A) is a side view, in section; (B) a top view; and (C) a front view, in section.

[023] Figures 6 AC are seen showing the silicone spilled around the male (7) of channels, proximal rings (1), proximal rings (9), distal rings (2), distal males (10) and outlet pins of air (8), coupled, and guide pins (14), to form the first half (15) of the silicone mold, in the molding shell, where (A) is a side view, in section; (B) a top view; and (C) a front view, in section.

[024] Figure 7A is a side view, in section, showing the silicone spilled on the first half (15) of the silicone mold to form the second half (16) of the silicone mold, in the molding shell.

[025] Figures 7 B-C are seen showing the silicone spilled on the first half (15) of the mold

silicone and in surrounding of male (7) of channels, rings proximal ( 1 ) and distal (2) with your related males proximal ( 9) and distal (10) , and pins outgoing air (8), coupled, and pins guide (14), to form the Monday

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8/27 half (16) of the silicone mold, where (B) is a top view; and (C) a front view, in section.

[026] Figure 7D is a side view, in section, showing the silicone mold with its two parts (15, 16), with their respective half channels (24, 25) for injection and holes (21) for pins. guides, ready to receive the silicone injection (32), to generate a male of silicone channels.

[027] Figure 7E is a top view showing the bottom part (15) of the silicone mold with its respective channel (24) for injection, ready to receive the silicone injection (32), to generate a male of silicone channels .

[028] Figures 7 F-H are views showing the silicone core (26) to generate the injection channels in the resin mold, where (F) is a side view, in section; (G) a top view; and (H) a front view, in section.

[029] Figure 7I is an exploded perspective view, showing the silicone mold with its two parts (15, 16), with their respective half channels (24, 25) for injection and holes (21) for guide pins (14), ready to receive the silicone injection (32), to generate a male of silicone channels, and the silicone male (26) generated.

[030] Figures 8 AC are seen showing the polymeric resin spilled on the first half (15) of the silicone mold and on the silicone male (26), around the guide pins (14), to form the first half (17) of the resin mold, in the molding casing formed by the angles (12), on the molding base (13), where (A) is a side view, in section; (B) one

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9/27 top view; and (C) a front view, in section.

[031] Figures 9 AC are seen showing the polymeric resin spilled on the second half (16) of the silicone mold and on the silicone male (26), around the guide pins (14), to form the second half (18) of the resin mold, in the molding casing formed by the angles (12), on the molding base (13), where (A) is a side view, in section; (B) a top view; and (C) a front view, in section.

[032] Figure 10A is a bottom view of the upper half (17) of the resin mold showing the upper half (19) of the wax injection channel and holes (29) for guide pins.

[033] Figure 10B is a side view, in section, showing the resin mold with its two parts (17,18), with their respective half channels (19.20) for injection and holes (29) for pins. guides, ready to receive the wax injection, to generate a bunch of lost wax.

[034] Figure 10C is a top view of the lower half (18) of the resin mold showing the lower half (20) of the wax injection channel and holes (29) for guide pins.

[035] Figures 10 DE are seen showing the resin mold, with its two parts (17,18), with their respective channels (19.20) for injection, ready to receive the wax injection, to generate a bunch of lost wax, where (D) is a front view, in section; and (E) is a perspective view of the open split resin mold.

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10/27 [036] Figure 11A is a bottom view of the upper half (17) of the resin mold showing the upper half (19) of the wax injection channel, with the proximal males (22), distal males ( 23) silicone and holes (29) for guide pins.

[037] Figure 11B is a side view, in section, showing the resin mold with its two parts (17,18), with their respective half channels (19.20) for injection and holes (29) for pins. guides.

[038] Figure 11C is a top view of the lower half (18) of the resin mold showing the lower half (20) of the wax injection channel, with the proximal males (22) of silicone, distal males (23) of silicone and holes (29) for guide pins.

[039] Figure 11D is a front view, in section, showing the resin mold with its two parts (17,18), with their respective channels (19.20) for injection, proximal cores (22) of silicone and distal males (23) of silicone, ready to receive the injection of wax, to generate a bunch of lost wax.

[040] Figure 12A is a side view, in section, showing the resin mold with its two parts (17, 18), with their respective half channels (19, 20) for injection, ready to receive the wax injection (31), to generate a bunch of proximal and distal rings in lost wax.

[041] Figure 12B is a top view showing the lower part (18) of the resin mold with its respective half channel (20) for injection.

[042] Figures 12 C-G are seen showing the

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11/27 bunch of proximal and distal rings in lost wax, where (C) is a side view, in section; (E) is a top view; (F) a front view, in section; and (G) a perspective view.

Detailed description of the invention:

[043] The present invention relates to a process of producing molds for wax injection from silicone molds, aiming at making polymeric molds (thermoplastic and or thermoset polymers) or polyurethanes (elastomeric polymers or rubbers) or resinoid (thermoset polymers), rigid, intended for the production of wax replicas of pieces of the most varied types, shapes and sizes.

[044] To this end, the referred process comprises the

steps of: The) To define one piece o u model (35) a to be reproduced; B) Prepare the model set (36) in the center of wrapper molding; ç) Prepare the casing of molding; d) Accomplish the production of silicone mold in fur minus two parts (bipartite); and) Accomplish the production of replicas in silicone; and f) Accomplish the production of resin molds. [045] At step a said piece < u model (35) refers to any parts or models obtained per

rapid prototyping, multi-axis CNC machining or other process for the manufacture of precision components in general, such as machine elements, medical and dental devices, orthoses in general, implants and

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12/27 surgical prostheses, all of the most varied types, shapes and sizes, which are possible to obtain the geometric shape and functionality of the pieces to give rise to the silicone (24) and resin (32) molds.

[046] In step b, the said model set (36) consists of the coupling of the parts of the chosen part to the groove cores (7) consisting of branches (3, 4, 5, 6), conical and / or cylindrical, in material polymeric, metallic or similar, which form the tree or bunch, and tap holes (9, 10) on the silicone buttons (11), which are fixed on a mounting base (13) in the center of the molding shell. The coupling of the parts of the part will depend mainly on the geometry of the part and the functionality of each of its surfaces.

[047] Said molding casing is formed by angles (12) selected from the groups consisting of metallic, polymeric or similar, in the desired perimeter shape for the silicone mold; they have equidistant dimensions so that the replica to be reproduced is in its center with a distance that varies 5.0mm to 10.0mm from the walls, base and top edge of the molding shell.

[048] Thus, in step co, the said frame molding enclosure (12) is mounted around the entire model set (36) described in step b, which is fixed with any product indicated for sealing cracks and holes that prevent penetration of liquid, such as caulk. Subsequently, at least two guide pins (14) of the silicone mold are attached to the base (13) between the walls of the molding casing.

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13/27 angles (12) and the model set (36). Said guide pins (14) are necessary to facilitate the correct assembly for making the mold, avoiding deformations of the replicas, since after the cured silicone acquires the solid state, the guide pins are fixed and positioned in the side of the mold for perfect separation.

[049] After assembling the model set (36) and the molding casing, in step d the production of the split silicone mold is carried out.

[050] It is worth mentioning that the referred silicone mold must always be formed by at least two parts (bipartite), or alternatively, it can be tripartite, quadripartite, or as many parts as necessary, depending on the complexity of the piece (as for example, a skull or jaw). In this way, the wax pieces can be easily removed and unnecessary deformation is avoided.

[051] To this end, step d comprises the substeps of:

d.1) Pour the liquid silicone into the molding casing to half the total volume available;

d.2) Wait for the first half of silicone to cure or solidify;

d.3) Coating the resulting silicone surface with release agent;

d.4) Fill the remaining half of the molding shell with liquid silicone;

d.5) Wait for the second silicone half to cure or solidify; and

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d.6) Remove the impression casing and model assembly (36).

[052] In substep “d.1” the liquid silicone is poured inside the molding housing of angles (12), involving the lower half of the model set forming the first half (15) of the silicone mold, in the molding housing .

[053] Said liquid silicone consists of a mixture of silicone rubber and catalyst in the proportion that ranges from 10.0: 0.9 to 10.0: 1.1, preferably 10.0: 1.0. In this way, the poured silicone fills all the accidents on the surfaces of half of the model set (36) and up to half of the molding shell. Thus, the liquid silicone of this half (15) of the silicone mold penetrates into simple and deep holes, grooves and chamfers of the model set (36).

[054] In substep “d.2”, the silicone is cured of the first half (15) of the silicone mold in a period of time that varies from 12 to 24 hours, preferably 24 hours.

[055] After curing the silicone of the first half (15) of the silicone mold, in substep “d.3” the release agent coating of the resulting silicone surface is carried out, where the amount of release agent must be the minimum possible fully cover the surface to be coated.

[056] Next, in substep “d. 4 ”a new amount of liquid silicone in its liquid form, is poured into the inside of the angle molding casing (12), surrounding the other (upper) half of the set

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15/27 model (36) to form the second, upper half (16) of the silicone mold in the molding shell.

[057] Thus, after curing the silicone of the second half (16) of the silicone mold performed in substep “d.5” over a period of time ranging from 12 to 24 hours, preferably 24 hours, in substep “d. 6 ”the angles (12) of the molding shell are removed and the silicone mold formed by the two halves (15, 16) is detached from the molding base (13). Also in substep “d.6”, the model set (36) is removed from the silicone mold. In this way, the silicone mold with its molding cavity consisting of the two halves, the upper (25) and lower (24), is ready for the molding of silicone replicas and also, if it is necessary to produce several molds with the technique described here.

[058] The production of resin molds for injection of lost wax from silicone molds is made possible through the initial molding of male replicas or models of the parts to be obtained also in silicone, to be used in the production of cavities of the resin molds sought.

[059] Thus, after the preparation of the silicone mold, in step “e” the production of silicone replicas is carried out, which comprises the substeps of:

e.1) Prepare the mold by coating it with release agent on the surface of the cavities of each half of the silicone mold;

e.2) Close the silicone mold, insert guide pins (14) and position this mold appropriately for

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16/27 molding;

e.3) Prepare the liquid silicone rubber with catalyst and pour it into the inlet channel of the mold prepared in the previous step;

e.4) Wait for the silicone to cure or solidify;

e.5) Open the mold by removing the guide pins (14) and remove the silicone part from inside; and

e.6) Clean the inside of the mold.

[060] Firstly, in substep “e.1”, the silicone mold obtained in step “d” is prepared, coating it with release agent on the surface of the cavities of each half of the silicone mold. Said release agent is preferably petroleum jelly, in which the necessary amount is used to produce a thin layer over the entire internal surface of the mold.

[061] Next, in substep “e.2”, the silicone mold is closed, at least two guide pins (14) are inserted and positioned appropriately for molding.

[062] Thus, the males or models that produce the resin mold cavities are first molded in silicone using the silicone mold already produced.

[063] For this purpose, in substep “e.3” the liquid silicone rubber with catalyst is prepared in the proportion that ranges from 10.0: 0.9 to 10.0: 1.1, preferably 10.0: 1 , 0. Subsequently, this mixture is poured into the inlet channel (24) of the split mold prepared in step “d” to produce the model set (26) in silicone and to

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17/27 generate the resin injection mold cavity.

[064] After curing or solidifying the silicone of the model set (26) (substep e.4), which varies from 12 to 24 hours, preferably 24 hours, the mold (34) is opened and the guide pins are removed ( 14) and the silicone part is removed from the inside (substep “e.5”).

[065] Thus, in substep e.6 a cleaning is performed inside the mold (15 and 16), and it will be ready to be used as the generator of the resin injection cavity.

[066] Thus, in step f, resin molds are produced. To this end, this stage comprises the substeps of:

f.1) Prepare the molding casing with the caulking compound;

f.2) Fit the silicone parts to the first half of the silicone mold;

f.3) Coat the walls of the molding casing with release agent;

f.4) Pour liquid resin with catalyst into the molding casing, over the whole silicone part and the first half of the silicone mold;

f.5) Wait for the resin to cure or solidify;

f.6) Separate all the component parts of this molding;

f.7) Fit the silicone part to the other half of the silicone mold.

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f.8) Position the silicone part and the other half of the silicone mold on the molding base;

f.9) Surround the assembly with a molding casing;

f.10) Cover the walls of the molding casing with release agent;

f.11) Pour liquid resin with catalyst into the molding casing, over the whole silicone part and the other half of the silicone mold;

f.12) Wait for the resin to cure or solidify; and

f.13) Separate all component parts of this impression.

[067] To obtain the first half of the resin mold, the same accessories used in the production of the silicone mold carried out in step e are used.

[068] It is worth mentioning that the referred resin is selected from the group consisting of thermoset polymers. Alternatively, thermoplastic and / or thermoset polymers are used; or elastomeric polymers or rubbers.

[069] For this, in substep f.1, the first half (15) of the silicone mold, with at least two guide pins (14), is mounted in the molding casing formed by the angles (12), on the base ( 13) molding, using caulking compound or any product indicated to seal cracks and holes that prevent liquid penetration, in the case of liquid resin.

[070] Additionally, in substep f.2, the silicone parts obtained in the step and in the first

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19/27 half of the silicone mold (15). Then, in substep f.3, the molding casing walls are coated with release agent, in which vaseline is preferably used in the amount necessary to produce a thin layer over the entire internal surface of the mold.

[071] The liquid polymeric resin with catalyst in the proportion ranging from 1.0: 0.9 to 1.0: 1.1, preferably 1.0: 1.0 is then poured into the molding shell, over the first half (15) of the silicone mold and on the silicone piece set (silicone cores (26)) until its halves, to form the first half (17) of the resin mold.

[072] Next, in substep f.5, the resin is expected to cure or solidify over a period of time ranging from 5 to 10 minutes, preferably 3 minutes. After this period, in substep f.6 the first half (17) of the resin mold is removed from the molding shell to await the making of its second half.

[073] Thus, in order to obtain the second half of the resin mold, in substep f.7, the silicone piece is fitted in the other half of the silicone mold, and the silicone piece set (silicone cores (26 )) and the other half of the silicone mold (16) on the molding base (13) (substep f.8). Subsequently, said set is surrounded with the molding casing (substep f.9).

[074] Before the liquid resin is poured, in substep f.10, the walls of the molding molding liner are coated, preferably petroleum jelly.

[075] Liquid resin with catalyst in

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20/27 ratio ranging from 1.0: 0.9 to 1.0: 1.1, preferably 1.0: 1.0, is then poured into the molding casing over the silicone part assembly (silicone cores) (26)) and in the other half of the silicone mold (16) to form the second half (18) of the resin mold (substep f.11).

[076] After curing the resin in a period of time ranging from 5 to 10 minutes, preferably 3 minutes (substep f.12), the second half (18) of the resin mold is removed from the component parts of this molding.

[077] In this way, the two parts of the obtained resin molds (17 and 18) are coupled and guided by the guide pins (14) which are lodged in the holes (30) of the two halves (17 and 18) to form the mold split resin (32).

[078] It is worth noting that step f is performed in a number of steps depending on the partition of the mold. For example, if the template is split, 13 substeps (f.1 to f.13); tripartite, 20 stages (f.1 to f.13 + f.7 to f.13); quadripartite, 27 stages (f.1 to f.13 + f.1 to f.13).

[079] Therefore, after carrying out the process of the present invention, the bipartite resin mold (32) obtained will be ready for use. For this purpose, the silicone cores (22, 23) of the pieces to be reproduced in lost wax are assembled next to the wax cluster (33). Thus, once the injected wax has solidified, the bunch with the lost wax pieces is removed from the mold to start the process of microfusion in lost wax.

[080] To obtain a total and complete visualization of how the process of the present invention is carried out,

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Examples of embodiments are presented below.

Examples of the Invention:

[081] For a better understanding of the proposed process, a model (35) of an articulated eight ring prosthesis was used, as shown in patent application PI1100101-1, exemplifying all the stages of making the mold for injection of lost wax from of silicone molds, as proposed by the present invention.

- Preparation for Production (Molding) of Molds:

[082] The making of molds to manufacture resin molds (32) from silicone rubber molds (34) started with the definition of a part or model (35) to be reproduced one or several times in lost wax , according to the objectives of the production and application of the eight metallic ring replicas to be obtained through the micro casting process.

[083] The following focus is dedicated to the preparation of the two parts of the model (35), that is, the proximal ring (1) and the distal ring (2) to be replicated in lost wax, and the positioning of these parts a be replicated, coupled to their respective channel taps (7) and hole taps (9, 10), as shown in Fig. 4A to Fig. 4C and Fig. 5A to Fig. 5C, on the molding base (13) on the silicone buttons (11), and the assembly of the housing

molding angles (12) around all the set described, as shown in Fig. 5A to Fig. 5C. [084] The casing in molding what produces the conformation peripheral mold silicone is produced

by metallic (12) or polymeric or similar angles in the desired perimeter shape for the mold

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22/27 silicone; they have adequate dimensions so that the replica to be reproduced is at its center with a tolerable distance from the walls, base and top edge of the molding casing from 5.0mm to 10.0mm (Fig. 5A to Fig. 5C).

[085] Once the model set (36) is formed by parts 1 (proximal ring), 2 (distal ring), 7 (proximal ring), 8 (air outlet pins), 9 (ring bore male) proximal), and 10 (distal ring bore male), all coupled, the set is then properly fixed on the base (13), in the center of the molding shell formed by metallic, polymeric or similar angles (12), equidistant from their side walls; the molding shell is then fixed with the caulk, as shown in figures Fig.5A to Fig. 5C. Then, the guide pins (14) of the silicone mold are glued to the base (13), in strategic positions for the perfect separation of the silicone mold in two halves after curing (Fig.5A to Fig. 5C); two guide pins (14) are needed to facilitate the correct assembly for making the mold, thus preventing the replicas (35) of the ring orthosis eight to be reproduced from being deformed; the guide pins (14) are positioned between the walls of the angle molding casing (12) and the model set (36); this way, after the cured silicone acquires the solid state, the guide pins are fixed and positioned on the side of the mold.

- Production (Molding) of Silicone Molds:

[086] Liquid silicone, composed of rubber

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23/27 of silicone and the catalyst, in its liquid form, is poured (poured) into the angle molding wrapper (12), involving the lower half of the model set forming the first half (15) of the silicone mold, in the molding housing, as shown in figures Fig. 6A to Fig. 6C; the poured silicone fills all the accidents on the surfaces of half of the model set (36) and up to half of the molding shell; the liquid silicone of this half (15) of the silicone mold penetrates into simple and deep holes, grooves and chamfers of the model set (36).

[087] After the silicone curing of the first half (15) of the silicone mold, a new amount of liquid silicone, composed of the silicone rubber and the catalyst, in its liquid form, is poured (spilled) into the molding shell angle brackets (12), involving the other (upper) half of the model set (36), formed by the male halves (7) of channels, proximal rings (1), proximal males (9), distal rings (2), males distal (10) and air outlet pins (8), all coupled, and guide pins (14), to form the second half (16), the upper one, of the silicone mold, in the molding shell, as illustrated in the figures Fig. 7A to Fig.

7C.

[088] After the silicone curing of the second half (16) of the silicone mold, the angles (12) of the molding shell are removed and the silicone mold formed by the two halves (15, 16) is detached from the base (13 ) molding; the model set (36) is removed from the silicone mold; the silicone mold with its molding cavity

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24/27 consisting of the two halves, the upper (25) and lower (24), as shown in the figure Fig. 7D, is ready for molding silicone replicas and also, if it is necessary to produce several molds of silicone with the technique described here.

- Production (Molding) of Silicone Replicas:

[089] The production of resin molds for injection of lost wax from silicone molds is made possible through the initial molding of male replicas or models of the parts to be obtained also in silicone, to be used in the production of cavities of the resin molds sought. This method of producing cores or models in silicone using the silicone molds themselves is possible with the use of commercial release agents suitable for this practice.

[090] In this proposal, to produce a resin mold for injection of lost wax from silicone molds, the males or models that produce the resin mold cavities are first molded in silicone using the silicone mold already produced. This can be done by injecting the mixture of silicone rubber and catalyst, in its liquid form, inside the cavity (24) of the bipartite silicone mold, as shown in figures Fig. 7D and Fig. 7E, to produce the model set (26) in silicone, shown in figures Fig. 7E to Fig. 7H, to generate the injection mold cavity in resin.

[091] After curing the silicone of the model set (26), it is removed from the silicone mold (34), Fig. 7D and Fig. 7E, and is ready to be used as the generator of the

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25/27 resin injection cavity of this proposal.

[092] Similarly, the males (9, 10) of the proximal (1) and distal (2) rings, figures Fig. 4A to 4C, can reproduce the males (22, 23) in silicone of these rings, figures Fig. 11A to Fig. 11D, by this same technique of molding silicone parts using silicone molds.

- Production (Molding) of Resin Molds:

[093] The production of resin molds for injection of lost wax from silicone molds is carried out in a number of stages depending on the partition of the mold. If the mold is split, two steps; tripartite, three stages; quadripartite, four stages. In this proposal, the production technique (molding) of resin molds will show, as an example, the molding of a bipartite mold and its two stages of production.

[094] To obtain the first half of the resin mold, the same accessories used in the production (molding) of the silicone mold are used. For this, the first half (15) of the silicone mold is mounted in the molding shell formed by the angles (12), on the molding base (13). The polymeric resin is then poured (poured) on the first half (15) of the silicone mold and on the silicone core (26) to form the first half (17) of the resin mold. The polymeric resin fills the silicone core (26) and the molding shell formed by the angles (12) up to its halves, as shown in figures Fig. 8A to Fig. 8C. After curing the resin, the first half (17) of the resin mold is removed from the molding shell to await the making of its second half.

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26/27 [095] To obtain the second half of the resin mold, the same accessories used in the production (molding) of the resin mold described above are used, with the exception of the first half (15) of the silicone mold. For this, the second half (16) of the silicone mold is mounted in the molding shell formed by the angles (12), on the molding base (13). The polymeric resin is then poured (poured) on the second half (16) of the silicone mold and on the uncovered part of the silicone core (26) to form the second half (18) of the resin mold. The polymeric resin fills the remainder of the silicone core (26) and the molding shell formed by the angles (12) up to its edge, as shown in figures Fig. 9A to Fig. 9C. After curing the resin, the second half (18) of the resin mold is removed from the molding casing to be coupled and guided by the guide pins (14) which are lodged in the holes (30) of the two halves (17, 18) , with its first half (17) to form the split resin mold (32), as shown in figures Fig. 10A to 10D.

- Production (Molding) of Lost Wax Replicas:

[096] With the split resin mold (32) ready for use after going through the steps already described and coupled with its guide pins (14), in the half cavities (19, 20) inside the two halves (17, 18), respectively, from the resin mold, the silicone cores (22, 23) of the proximal (1) and distal (2) rings are mounted to be reproduced in lost wax next to the wax cluster (33), as shown in figures 11A to 11F. Once the injected wax has solidified, the bunch with the wax pieces

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The lost 27/27 is removed from the mold to start the microfusion process in lost wax.

[097] Therefore, the present process of obtaining a mold in non-metallic material greatly replaces, in all technical aspects, the metallic molds currently used in the lost wax injection process.

[098] Thus, the main advantage of using the present process of obtaining wax injection molds from silicone molds is to allow the production of high quality rigid polymeric molds to be used in the production of wax replicas of parts complex or simple, providing ease of mold production, material savings, repeatability of use and durability of the mold.

[099] Those skilled in the art will value the knowledge presented here and will be able to reproduce the invention in the modalities presented and in other variants, covered by the scope of the attached claims.

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1/10

Claims (11)

1. Process for producing wax injection molds, characterized by the fact that it is based on silicone molds for making polymeric or polyurethane molds or rigid resinoids; and understand the steps of: a) Define a piece or model (35) to be reproduced; b) Prepare the model set (36) in the center of the molding shell; c) Prepare the molding casing; d) Carry out the production of the silicone mold in at least two parts (bipartite); e) Carry out the production of silicone replicas; and f) Carry out the production of resin molds. 2. Process, according to claim 1, characterized by the fact that, in step a, said part or model (35) is any parts or models obtained by rapid prototyping, multi-axis CNC machining or another process intended for the manufacture of components of precision selected from groups consisting of machine elements; medical and dental devices; orthoses in general; surgical implants and prostheses; which it is possible to obtain the geometric shape and functionality of the pieces to give rise to the polymeric molds, or polyurethanes, or rigid resin. 3. Process, according to claim 1, characterized by the fact that, in step b, said model set (36) consists of the coupling of the parts of the chosen piece to the groove cores (7) that consist of branches (3,4) , 5,6), conical and / or cylindrical, in material Petition 870170004797, of 01/24/2017, p. 36/67 2/10 polymeric, metallic or similar, which form the tree or cluster, and tap holes (9, 10) on the silicone buttons (11), which are fixed on a mounting base (13) in the center of the housing molding, in which the coupling of the parts of the part will depend on the geometry of the part and the functionality of each of its surfaces. 4. Process, according to claim 3, characterized by the fact that said molding casing is formed by angles (12) selected from the groups consisting of metallic, polymeric or similar, in the desired perimeter shape for the silicone mold, in that they have equidistant dimensions so that the replica to be reproduced is in its center with a distance that varies from 5.0mm to 10.0mm from the walls, base and top edge of the molding shell. 5. Process, according to claim 1, characterized by the fact that, in step “c”, the said molding envelope of angles (12) is mounted around the entire model set (36) described in step “b” , which is fixed with any product indicated to seal cracks and holes that prevent the penetration of liquid, preferably the caulk. 6. Process, according to claim 2, characterized by the fact that, still in step “c”, at least two guide pins (14) of the silicone mold are attached to the base (13) between the walls of the molding shell angle brackets (12) and the model set (36), in which said guide pins (14) are necessary to facilitate the correct assembly for making the mold. 7. Process according to claim 1, Petition 870170004797, of 01/24/2017, p. 37/67 3/10 characterized by the fact that, in step d, said silicone mold is formed by at least two parts (bipartite); or alternatively, be tripartite, quadripartite, or more. 8. Process, according to claim 7, characterized by the fact that step d comprises the substeps of: d.1) Pour the liquid silicone into the molding casing to half the total volume available; d.2) Wait for the first half of silicone to cure or solidify; d.3) Coating the resulting silicone surface with release agent; d.4) Fill totally with silicone in state liquid a other half remaining in the casing of molding; d.5) Wait the cure or solidification gives Monday half of silicone; and d.6) Remove the wrapper molding and O set model (36). 9. Process, according to claim 8, characterized by the fact that, in substep d.1, the liquid silicone is poured inside the molding casing of angles (12), involving the lower half of the model set (36), penetrating simple, deep holes, grooves and chamfers of set model ( 36), forming The first half (15) of mold of silicone , in the enclosure in molding. 10. Process, in wake up with the claim 9, characterized by fact that referred liquid silicone consist in a mix of eraser silicone and Petition 870170004797, of 01/24/2017, p. 38/67 4/10 catalyst in the ratio ranging from 10.0: 0.9 to 10.0: 1.1, preferably 10.0: 1.0. 11. Process, according to claim 8, characterized by the fact that, in substep d.2 ", the curing of the silicone in the first half (15) of the silicone mold takes a period of time ranging from 12 to 24 hours , preferably 24 hours. 12. Process, according to claim 8, characterized by the fact that, in substep d.3 ”, the amount of release agent is the minimum possible to fully cover the surface to be coated. 13. Process, according to claim 8, characterized by the fact that, in substep d.4 ”, a new amount of liquid silicone in its liquid form, is poured into the molding casing of angles (12), involving the the other (upper) half of the model assembly (36) to form the second, upper (16) half of the silicone mold in the molding shell. 14. Process, according to claim 8, characterized by the fact that, in substep d.5 ", the curing of the silicone in the second half (16) of the silicone mold takes a period of time ranging from 12 to 24 hours , preferably 24 hours. 15. Process, according to claim 8, characterized by the fact that, after curing, in subsection d.6 ”the angles (12) of the molding shell are removed and the silicone mold formed by the two halves (15, 16 ) be detached from the impression base (13), in which the model set (36) is removed from the silicone mold. 16. Process according to claim 1, Petition 870170004797, of 01/24/2017, p. 39/67 5/10 characterized by the fact that, after the preparation of the silicone mold, the production of silicone replicas is carried out in the stage, which comprises the substeps of: e.1) Prepare the mold by coating it with release agent on the surface of the cavities of each half of the silicone mold; e.2) Close the silicone mold, insert guide pins (14) and position this mold appropriately for molding; e.3) Prepare the catalyst rubber and pour it into the channel prepared in the previous step; liquid silicone with inlet mold e.4) Wait for the silicone to cure or solidify; e.5) Open or remove the mold part by removing the silicone pins from inside; and guides 14) and e.6) Clean the inside of the mold. 17. Process, according to claim 16, characterized by the fact that, in substep e.1, the silicone mold obtained in step d is prepared by coating it with release agent on the surface of the cavities of each half of the silicone mold in a amount needed to produce a thin layer over the entire internal surface of the mold, wherein said release agent is preferably petroleum jelly. 18. Process, according to claim 16, characterized by the fact that, in substep e.2, insert at least two guide pins (14). Petition 870170004797, of 01/24/2017, p. 40/67 6/10 19. Process, according to claim 16, characterized by the fact that, in substep e.3, liquid silicone rubber with catalyst is prepared in the proportion ranging from 10.0: 0.9 to 10.0: 1, 1, preferably 10.0: 1.0, where later, this mixture is poured into the inlet channel (24) of the split mold prepared in step d to produce the silicone model set (26) and generate the injection cavity of the resin mold. 20. Process, according to claim 16, characterized by the fact that, in substep e.4, the curing or solidification of the silicone of the model set (26) varies from 12 to 24 hours, preferably 24 hours. 21. Process, according to claim 1, characterized by the fact that, in step f, resin molds are produced, and comprise the substeps of: f.1) Prepare the molding casing with the caulking compound; f.2) Fit the silicone parts to the first half of the silicone mold; f.3) Coat the walls of the molding casing with release agent; f.4) Pour liquid resin with catalyst into the molding casing, over the whole silicone part and the first half of the silicone mold; f.5) Wait for the resin to cure or solidify; f.6) Separate all component parts of this Petition 870170004797, of 01/24/2017, p. 41/67 7/10 molding; f.7) Fit the silicone part to the other half of the silicone mold. f.8) Position the silicone part set and other half of the mold silicone on base molding; f.9) Surround the set with one wrapper in molding; f.10) Coating release agent at walls of molding casing; f.11) Pour liquid resin with catalyst into the molding casing, over the whole silicone part and the other half of the silicone mold; f.12) Wait for the resin to cure or solidify; and f.13) Separate all component parts of this impression. 22. Process, according to claim 21, characterized by the fact that the first half of the resin mold is obtained with the same accessories used in the production of the silicone mold performed in step “e”, in which said resin is selected from the group consisting of thermoset polymers; and alternatively, thermoplastic and / or thermoset polymers are used; or elastomeric polymers or rubbers. 23. Process, according to claim 21, characterized by the fact that, in substep “f.1”, the first half (15) of the silicone mold, with at least two pins Petition 870170004797, of 01/24/2017, p. 42/67 8/10 guides (14), be mounted in the molding casing formed by the angles (12), on the molding base (13), using caulking putty or any product indicated to seal cracks and holes that prevent liquid penetration. 24. Process, according to claim 21, characterized by the fact that, in substep f.2, the silicone parts obtained in the step and are fitted in the first half of the silicone mold (15). 25. Process, according to claim 21, characterized by the fact that, in substep f.3, the walls of the molding shell are coated with release agent, in which petroleum jelly is preferably used in the amount necessary to produce a thin layer over the entire the inner surface of the mold. 26. Process according to claim 21, characterized in that, in substep f.4, the liquid polymeric resin with catalyst is poured into the molding shell, over the first half (15) of the silicone mold and over the set piece of silicone (silicone cores (26)) to its halves, to form the first half (17) of the resin mold, in which the liquid polymeric resin with catalyst is in the proportion that varies from 1.0: 0.9 to 1.0: 1.1, preferably 1.0: 1.0. 27. Process, according to claim 21, characterized by the fact that, in substep f.5, the curing or solidification of the resin takes a period of time ranging from 5 to 10 minutes, preferably 3 minutes; where after that period, in substep f.6, the first half (17) of the resin mold is removed from the molding shell Petition 870170004797, of 01/24/2017, p. 43/67 9/10 to wait for the second half to be made. 28. Process, according to claim 21, characterized by the fact that, in substep f.7, the second half of the resin mold is obtained by fitting the silicone piece into the other half of the silicone mold, and by means of positioning of the silicone part set (silicone cores (26)) and the other half of the silicone mold (16) on the molding base (13) (substep f.8), in which the referred set is subsequently surrounded with the molding casing (substep f.9). 29. Process according to claim 21, characterized by the fact that, before the liquid resin is poured, in substep f.10, the walls of the molding shell are coated with release agent, preferably petroleum jelly. 30. Process, according to claim 21, characterized by the fact that, in substep f.11, the liquid resin with catalyst is poured into the molding casing, over the silicone part assembly (silicone cores (26)) and in the the other half of the silicone mold (16) to form the second half (18) of the resin mold, where the liquid resin with catalyst is in the proportion ranging from 1.0: 0.9 to 1.0: 1.1 , preferably 1.0: 1.0. 31. Process according to claim 21, characterized by the fact that, in substep f.12, the resin is cured over a period of time ranging from 5 to 10 minutes, preferably 3 minutes. 32. Process according to claim 21, characterized by the fact that, in substep f.13, the two parts of the resin molds obtained (17 and 18) are coupled Petition 870170004797, of 01/24/2017, p. 44/67 10/10 and guided by the guide pins (14) that are lodged in the holes (30) of the two halves (17 and 18) to form the mold split resin (32). 33. Process, in a deal with any an of claims 21 to 32, featured by the fact that at substeps of step f be carried out depending gives partition mold, in which if the mold is bipartite, 13 substeps (f.1 to f.13) ι; tripartite, 20 steps (f.1  The f.13 + f.7 to f .13); quadripartite, 27 steps (f.1  The f.13 + f.1 to f .13), or more. 34. Use of molds silicone obtained according process defined in any of the claims 1 to 15, characterized by the fact that the silicone molds with their molding cavity constituted by the two halves, the upper (25) and lower (24), are for the molding of silicone replicas and for the production of various polymeric or polyurethane or resin molds rigid. 35. Use of polymeric or polyurethane molds or rigid resinoids obtained according to the process defined in any one of claims 1 to 33, characterized by the fact that they are for the injection of lost wax, in which the silicone cores (22, 23) are first assembled. pieces to be reproduced in lost wax next to the bunch of wax in the referred molds. Petition 870170004797, of 01/24/2017, p. 45/67 1/18