MXPA95003671A - Method for the manufacture of pieces to mold plasti - Google Patents

Abstract

A method for the manufacture of dies for the molding of plastics in which a layer of metal is formed on the surface of a mandrel at a rapid rate of deposition and with few modifications. The surface of the mandrel is heated to the deposition temperature of the carbonyl metal and by introducing steam of the carbonyl metal onto the surface of the mandrel a metal layer is formed. The deposition temperature of the metal from the carbonyl metal vapor is notoriously faster than the temperatures of the electric laminate. Compared with the electric laminate with the same Ni, it is 10 times faster and productivity is considerably higher. Also, the deposition of the metal from the vapor of the carbonyl metal is done uniformly regardless of whether the shape of the mandrel is irregular. Moreover, the separation is easy when the surface of the mandrel composed of an Al or Al alloy forms a heat-resistant layer and when the heat-resistant resin layer is burned after the metal layer of carbonyl metal is formed.

Description

METHOD FOR THE MANUFACTURE OF PIECES FOR MOLDING PLASTICS BACKGROUND OF THE INVENTION This invention relates to a method for the manufacture of dies (dies) for molding plastics by the use of a metallic mandrel (master model).

The methods of manufacturing dies for molding prior plastics for complicated irregular shapes utilize plastic injection or foaming. These methods allow for the conductivity of a metallic layer made by an electrolytic deposition on the surface of a matrix made of synthetic resins. A thick layer of copper, nickel or silver metal was formed on this conductive layer by means of an electrolytic deposition and, the metallic skin was peeled or disassembled from the mandrel through an electric discharge.

Problems Solved by the Invention In the above methods for the manufacture of dies for molding plastics from an electrical emptying, an electrolytic deposition layer formed by an electric laminate took place for the electric lamination layer to grow. Because of this, a long period of time was needed to obtain a molding die of the desired thickness. For example, the forming velocity for a nickel electric laminate layer from an electric laminate is 0.001 inches per hour.

Furthermore, it was easy for the electric current to be directed to the tip because the properties of the electric laminate make it difficult for the electric current to flow in the concave part, so that the electric deposition layer becomes uneven and thick in the convex part. Because of that, an additional time is needed to make modifications to the plastic molding die once the electric deposition layer has been completed.

Also, in methods of manufacturing dies for molding prior plastics from the electric casting it was impossible to swell an electric deposition layer at a desired location. Moreover, when a direct reinforcing metal is cast for the electric deposition layer, it is easy to peel off the electrical deposition layer of the reinforcing metal layer.

SUMMARY OF THE INVENTION This invention proposes a method for the manufacture of dies for molding plastics to solve the aforementioned problems in methods of manufacturing dies for molding plastics from an electric emptying, to complete the manufacture of dies for molding of plastics. plastic in a short time and reduce the work of modifications to the die for molding plastics after finished. It is also the purpose of this invention to provide a method of manufacturing dies for molding plastics wherein a seal can be swelled at a desired and specific location and in which the electrical deposition and the reinforcing metal do not peel.

In the manufacturing method of this invention for dies for plastics molding a mandrel is coupled to a surface is a sealed deposition chamber and, the surface of the mandrel is heated to the deposition temperature of the carbonyl metal. The metal layer is formed on the surface of the mandrel by introducing the carbonyl metal into the deposition chamber. The metal carbonyl can be any of Ni, Co, Ta or W carbonyl.

In the manufacturing method of this invention for plastic molding dies a heat-resistant resin layer is formed on the surface of the mandrel consisting of an Al or Al alloy. A heat lamp can also be placed inside the alloy of Al or Al in this heating method. In the manufacturing method of this invention for dies for the molding of plastics, a heat resistant layer is used for the mandrel and the heat can also be increased with a fixed electrical cable in the heat resistant resin layer.

Moreover, in claim 13 of the method of manufacture of this invention for dies for molding plasticsVentilation means are employed to provide vapors of the carbonyl metal directly to a specific part of the mandrel. Then, the mandrel is adhered to the surface of the sealed deposition chamber and, the surface of the mandrel is heated to the deposition temperature of the carbonyl metal. After the metal layer is formed on the surface of the mandrel by introducing the carbonyl metal into the deposition chamber, a layer of vaporized metal is interposed as an inner cooling reinforcing metal.

In the manufacturing method of this invention for plastic molding dies, the surface of the mandrel is heated to the deposition temperature of the carbonyl metal and, the vapor of the carbonyl metal degrades the surface of the mandrel upon introducing the vapor of a carbonyl metal on the surface of the mandrel where a metallic layer is formed. The deposition temperature of the metal from the carbonyl metal vapor is noticeably faster than the temperatures of the electric laminate. For example, Ni carbonyl takes one hour by 0.01 inches but compared to electric laminate, this invention is 10 times faster and productivity is significantly higher. Also, deposition from the carbonyl metal vapor occurs on a regular basis regardless of whether the shape of the mandrel is irregular so that there is no need to make further modifications after the plastic molding die is complete.

The material of the mandrel is resistant to heat at the deposition temperature of the carbonyl metal so it does not matter if the material can be easily separated as metal or synthetic resin. For example, as stated in claim 3, when the surface of the mandrel composed of an Al or Al alloy forms a heat resistant layer and the heat resistant layer is burned after the carbonyl metal layer is formed, then the separation can be easily carried out. Also, the Al or the Al alloy comprising the metal wick of the mandrel can be reused.

The heat of the oil directly heating the back of the mandrel can be blown or the back of the mandrel can be illuminated by a heat lamp, on the Al alloy or the Al comprising the metal wick of the mandrel. Hot oil circulates inside a fixed heating tube inside the Al or Al alloy and the surface of the mandrel is heated on a regular basis so that a uniform metal layer is formed. Further, when the mandrel is composed of a layer of heat-resistant resin, then the same effect can be obtained by introducing an electrical cable into the heat-resistant resin layer.

In the manufacturing method of this invention for dies for the molding of plastics, the desired thickness of a specific part of the thickness of the metal layer can be formed from the vapor of the carbonyl metal provided by a blowing medium directly to a part specific to the mandrel. Also, after the vaporized metal layer is formed on the back of the metal layer so that the reinforcing metal and the deposition metal layer are held together and do not peel.

Claims 1 to 5 of the invention describe that the heat resistance temperature of the heat resistant resin layer is below 150 degrees Celsius. Even if an epoxy resin (a functional group of more than 3 epoxy resins) with a temperature of heat resistance lower than 150 degrees Celsius is replaced by an epoxy resin (a functional group of more than 2 epoxy resins) with a temperature of Heat resistance of 150 to 250 degrees Celsius for the heat resistant temperature layer, there is a metal wick to heat as well as a reinforcement composed of Al or an Al alloy so that even when the heat resistant resin layer is heated at the decomposition temperature of nickel carbonyl (148 - 191 degrees Celsius), due to the complex combination of the metal wick used to heat there is no deformation and after metal deposition, it is not easy to peel.

The invention in claim 10 describes that the agitator is placed outside the deposition chamber and a stirrer is placed inside the deposition chamber at a specific location. The invention in claim 13 recites that the venting means is in the form of a steam branch pipe for sending the carbonyl vapor from a vapor management pipe.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a diagram that delineates the apparatus used in the useful example; Figure 2 is a cross-sectional diagram of the deposition chamber used by the mandrel in the useful example; Figure 3 is a cross-sectional diagram of the deposition chamber in the useful example of claim 12; Figure 4 is a cross-sectional diagram of the deposition chamber in the useful example of claim 13.

DETAILED DESCRIPTION OF THE PRESENT INVENTION Example 1 The benefits of this invention will become clearer from the description of the useful examples of the invention. Figure 1 shows a simple diagram of the process in a useful example. The nickel powder is fed and the CO is supplied to the reaction tower 10 and reacted to obtain the nickel carbonyl vapor. The nickel carbonyl vapor is introduced into a condenser 12 and cooled to 38 degrees Celsius to make a nickel carbonyl liquid and then this fluid is sent to a storage tank for storage.

The nickel carbonyl fluid is removed from the storage tank 14 and sent to the vaporization chamber 16. The nickel carbonyl vapor and the carrier gas CO 18 are sent to the deposition chamber 20. The mandrel 22 is placed in the center at the bottom of the deposition chamber and an adiabatic platform (or insulating board) 24 seals the space between the inner walls of the mandrel 22 and the deposition chamber 20. A vaporized nickel carbonyl temperature of more than 38 degrees Celsius is maintained within of the deposition chamber 20 and the temperature inside the deposition chamber is cooled to the temperature at which the nickel carbonyl vapor decomposes; 148 degrees Celsius.

The mandrel 22 is constructed of a metal wick of an Al 28 alloy covered with a heat resistant resin layer 26 and a heating tube 32 provided within the metal wick 28 and the oil heated by the heater 34 circulated by the pump 36 through the heating tube 32 and, the heat resistant resin layer 26 on the surface of the mandrel 22 heated between 148 and 191 degrees Celsius, the temperature at which the nickel carbonyl decomposes.

The unreacted nickel carbonyl is in the exhaust of the deposition chamber 20 so that the gas is released after the nickel carbonyl is recovered from the exhaust gas condenser 38. The recovered nickel carbonyl is returned to the storage tank 14.

Below is a description of a useful example of the plastic molding die used in the apparatus of the useful example composed of the construction mentioned above. The nickel powder is fed and the CO is supplied to the reaction tower 10 and reacted to obtain the nickel carbonyl vapor. Then, the nickel carbonyl vapor is introduced into the condenser 12 and cooled to 38 degrees Celsius to make the nickel carbonyl liquid that is sent to a storage tank 14 for storage.

The mandrel 22 is placed in the center of the bottom of the deposition chamber 20 and an adiabatic platform 24 seals the space between the inner walls of the mandrel 22 and the deposition chamber 20. A vaporized temperature for the nickel carbonyl of more than 38 degrees Celsius is kept inside the deposition chamber 20 and, the temperature in the deposition chamber is cooled until it is not higher than 148 degrees Celsius, the temperature at which the nickel carbonyl decomposes.

The mandrel 22 is composed of a metal wick of an Al 28 alloy covered by a layer of heat resistant resin of 10 mm thickness. A 10 mm copper heater tube 32 is provided inside the metal wick 28. The oil heated by the heater 34 circulates via the pump 36 through the heater tube 32 and the heat resistant resin layer 26 on the surface of the mandrel 22 is heated between 148 and 191 degrees Celsius, the temperature at which the nickel carbonyl decomposes.

It then takes 16 hours for the nickel carbonyl vapor and the carrier gas CO 18 to be sent to the deposition chamber 20 and for a 4 mm nickel layer 40 to be deposited on the surface of the mandrel 22. The unreacted nickel carbonyl contained within the exhaust pipe of the deposition chamber 20 is released after the nickel carbonyl is recovered from the exhaust gas condenser 38.

The nickel layer 40 deposited on the surface of the mandrel 22 is removed from the deposition chamber 20 and the heat resistant resin layer 26 is heated to a combustible temperature and the nickel layer 40 can be easily peeled from the mandrel 22 and, because the peeled nickel layer 40 was deposited regularly on the surface of the mandrel 22 the plastic molding die can be used almost unchanged. When the metal wick of Al is made inside the same plastic die, the die can be reused.

EXAMPLE 2 Next, FIG. 2 shows the mandrel 22 made of a heat resistant resin layer using an electric cable 42 inserted inside the mandrel resulting from the heat resistant resin layer and, as in the previous example, the mandrel 22 is placed in the center of the bottom of the deposition chamber 20 and the space between the mandrel 22 and the deposition chamber 20 is sealed with an adiabatic platform or insulating board 24. The interior of the deposition chamber 20 is maintained at a nickel carbonyl temperature above 38 degrees Celsius and simultaneously the temperature of the internal walls of the deposition chamber 20 is cooled so that the temperature does not exceed 148 degrees Celsius, the temperature at which the nickel carbonyl It decomposes.

A current flows through an electrical cable 42 and heats the surface of the heat resistant resin layer 26 over the mandrel 22 between 148 and 191 degrees Celsius, the temperature at which nickel carbonyl decomposes and, the nickel liquid carbonyl from the storage tank 14 is sent to the vaporization chamber 16 and the vaporized nickel carbonyl with the carrier gas 18 are sent to the deposition chamber 20 for a period of 12 hours and a 3 mm layer of nickel is deposited on the mandrel surface 22.

The mandrel 22 with the nickel layer 40 deposited on its surface is removed from the deposition chamber 20 and as the heat increases at a temperature the heat resistant resin layer 26 is burned, the nickel layer 40 can be peeled off easily from the mandrel 22 and, since the peeled nickel layer 40 was deposited regularly on the surface of the mandrel 22, the plastic molding die can be used almost unchanged.

Example 3 On the surface of the metal wick of the Al 28 alloy used in the useful Example 1 there are two epoxy resins used as a functional group with a heat resistance temperature of 150 degrees Celsius to form a heat resistant resin layer 10 mm thick 26. This mandrel 22 is placed in the center of the bottom of the deposition chamber 20 and, the space between the internal walls of the mandrel 22 and the deposition chamber 20 is sealed with an adiabatic platform 24. Next , the oil heated by the heater 34 circulates by the pump 36 through a 10 mm copper tube placed inside the metal wick 28 and, the heat resistant resin layer 26 on the surface of the mandrel 22 is heated to 148. - 191 degrees Celsius, the temperature at which nickel carbonyl decomposes but the heat resistant resin layer does not deform despite the increase in temperature.

Then, following the same method illustrated in the useful Example 1, a layer of nickel of 4 mm 40 is deposited on the surface of the mandrel 22. Compared to the surface of the metal wick of the alloy of Al 28 used in the useful Example 1, in this example there are three epoxy resins used as a functional group with a heat resistance temperature of 250 degrees Celsius to form a layer of heat-resistant resin 26 with a thickness of 10 mm and a layer of 4 mm of nickel 40 is deposited on the surface of the mandrel 22 by the same method illustrated in Useful Example 1.

The mandrel 22 on the surface of which the nickel layer 40 was deposited in this or in the reference example, is removed from the deposition chamber 20 and heated to the temperature at which the heat resistant resin layer 26 is burned and , the nickel layer 40 is peeled from the mandrel 22. However, in the reference example the heat resistant resin layer 26 hardens at 300 degrees Celsius and a temperature higher than 300 degrees Celsius is necessary for a total separation. However, the benefit of this invention is that the heat resistant resin layer in this example can be easily separated at 300 degrees Celsius.

Figure 3 illustrates the mandrel 22 with a concave portion 44 positioned in the center of the lower part of the deposition chamber 20, and a ventilation blade 46 positioned on the shaft so that the air can blow towards the concave portion 44 of the mandrel 22 and, the motor 50 made of a magnetic material fixed to the tip of the shaft 48. The agitator 52 is installed outside the wall of the deposition chamber separating it from the motor 50. The magnetic rotor 56 is installed on the axis of the transmission 54 of the agitator 52 in the relative direction of the wall between it and the transmission motor 50 and, when the magnetic motor 56 rotates, the transmission motor 50 rotates resulting in the rotation of the agitator and the ventilation blade 46 The apparatus used in this useful example makes it difficult for the carbonyl vapors to circulate so that the concave portion 44 of the mandrel 22 can obtain a quantity of carbonyl vapor, and the thickness of the nickel layer in the concave portion 44 can be controlled by controlling the number of rotations of the agitator.

Example S Figure 4 shows a mandrel 22 with two concave portions 44 placed in the center of the bottom of the deposition chamber 20. Two steam branching tubes 62 branch off from the steam distributor branch 60 installed in the roof of the deposition chamber to provide carbonyl vapor and, the tips of each steam branching tube open to point towards the concave portions 44.

In this useful example, the vaporized nickel carbonyl is sent with a carrier gas C018 via the steam feeder tube 60 to the deposition chamber 20 and the nickel carbonyl vapors are fed to the concave portions on the mandrel 22 where it is difficult for the nickel carbonyl vapors circulate, by means of two steam feeder tubes 62 from the steam feeder tube 60. Because of this, it is difficult for the carbonyl vapors and the concave portion 44 of the mandrel 22 to obtain a sufficient supply of carbonyl vapor.

BENEFITS OF THIS INVENTION The benefits of this invention for a method of manufacturing dies for plastics molding as described above are: the surface of the mandrel is heated to the deposition temperature of the carbonyl metal and, the vapor of the carbonyl metal degrades the surface of the mandrel when introducing a carbonyl metal vapor, and a metallic layer is formed on the surface of the mandrel. The deposition temperature of the metal from the carbonyl metal vapor is notoriously faster than the temperatures of the electric plating. For example, Ni carbonyl takes one hour by 0.01 inches, but compared to electro plated Ni, it is 10 times faster and productivity is notoriously higher. Also, the deposition of the metal from the carbonyl metal vapor is done uniformly regardless of whether the shape of the mandrel is irregular so there is no need to make additional modifications after the die is complete.

The separation can also be easily achieved when the surface of the mandrel composed of an Al or Al alloy forms a heat resistant layer and if the heat resistant resin layer is burned after the metal layer of the carbonyl metal is formed. Likewise, the Al or Al alloy that turns on the metal wick of the mandrel can be reused.

DESCRIPTION OF THE ARTICLES NUMBERED 10 Reaction tower. 12 Condenser 14 Storage tank 16 Vaporization chamber 18 Conveyor gas 20 Deposition chamber 22 Mandrel 24 Adiabatic platform 26 Heat-resistant resin layer

Claims (13)

28 Metal wick 32 Heating tube 34 Heater 36 Pump 38 Exhaust gas condenser 40 Nickel layer 42 Electric cable 44 Concave part 46 Ventilation sheet 48 Shaft 50 Drive motor 52 Stirrer 54 Drive shaft 56 Magnetic rotor 60 Feed tube Steam 62 Bifurcated exhaust pipe While I have shown currently favored specimens of the present invention, it will be apparent to those skilled in the art that the invention can be exemplified in other ways within the scope of the following claims. CLAIMS:

1. A method for the manufacture of dies for the molding of plastics comprising fixing a mandrel to the surface in a sealed deposition chamber, heating the surface of the mandrel to the deposition temperature of the carbonyl metal and forming a Metallic layer on the surface of the mandrel by introducing the carbonyl metal inside the deposition chamber.

2. - A method for the manufacture of dies for the molding of plastics as in claim 1 wherein the metal carbonyl is taken from a group comprising Ni, Co, Ta or W.

3. - A method for the manufacture of dies for the molding of plastics as in claim 2 comprising the formation of a layer of heat-resistant resins composed of an alloy of Al or Al on the surface of the mandrel.

4. - A method for the manufacture of dies for the molding of plastics as stated in claim 3 and comprising circulating oil inside the heating tube in the rear part of the alloy d Al or Al as means for heating the mandrel.

5. - A method for the manufacture of dies for the molding of plastics as set forth in claim 3 and comprising placing a heat lamp on the back of the Al or Al alloy as a means for heating the mandrel.

6. - A method for manufacturing dies for the molding of plastics as set forth in claim 1 wherein the mandrel is composed of a layer of heat-resistant resin.

7. - A method for the manufacture of dies for the molding of plastics as set forth in claim 2 wherein the mandrel is composed of a layer of heat-resistant resin.

8. - A method for manufacturing dies for the molding of plastics as set forth in claim 6 wherein the mandrel is composed of a fixed electrical cable within the heat resistant resin layer.

9. A method for the manufacture of dies for the molding of plastics described in the claim employing a ventilation means that provides a carbonyl metal vapor directed to a specific location in the mandrel.

10. - A method for the manufacture of dies for the molding of plastics comprising fixing a mandrel to the surface in a deposition chamber and heating the surface of the mandrel to the deposition temperature of the carbonyl metal, and forming a metal layer on the surface of the mandrel by introducing the carbonyl metal into the deposition chamber and, after the vaporized metal layer is formed on the surface of the metallic layer, the vaporized metal layer is interposed as a cooling reinforcing metal internal.

11. - A method for manufacturing dies for the molding of plastics as claimed in claim 3 at a heat resistance temperature of a heat-resistant resin layer of less than 150 degrees Celsius.

12. - A method for the manufacture of dies for the molding of plastics as set forth in claim 10 wherein the ventilation means comprises a stirrer placed outside the deposition chamber and a circulating air by means of an agitator placed in a specific place within of the deposition chamber.

13. - A method for the manufacture of dies for the molding of plastics as set forth in claim 7 which comprises the use of a ventilation means in the form of a steam feeder tube for sending carbonyl steam from a steam feeder tube.ABSTRACT OF THE INVENTION A method for the manufacture of dies for the molding of plastics in which a layer of metal is formed on the surface of a mandrel at a rapid rate of deposition and with few modifications. The surface of the mandrel is heated to the deposition temperature of the carbonyl metal and by introducing steam of the carbonyl metal onto the surface of the mandrel a metal layer is formed. The deposition temperature of the metal from the carbonyl metal vapor is notoriously faster than the temperatures of the electric laminate. Compared with the electric laminate with the same Ni, it is 10 times faster and the productivity is considerably higher. Also, the deposition of the metal from the vapor of the carbonyl metal is done uniformly regardless of whether the shape of the mandrel is irregular. Moreover, the separation is easy when the surface of the mandrel composed of an Al or Al alloy forms a heat resistant layer and when the heat resistant resin layer is burned after the metal layer of carbonyl metal is formed. In Testimony of which signs this declaration and claims in Mexico, D.F. on the 25th day of the month of August of one thousand nine hundred and ninety-five. | P.P. FET ENGINEERING, INC.