Plastics and moulds
Application of the Electroforming in the rapid manufacturing of thermoplastic injection molds (Rapid Tooling)
M. monsoon Verona, M.D. Marrero German, p. Hernández Castellano, a. Benítez Vega
Department of mechanical engineering. University of Las Palmas de Gran Canaria.Campus of Tafira Baja. Las Palmas de Gran Canaria. 34 928458618. mmonzon@cicei.ulpgc.es
01/12/2002 1. Introduction
Comprehensive development in the last years of the technology of rapid prototyping (RP) and as a result of the rapid mould (RT) have made it possible to greatly shorten the time ranging from the conception of a new idea of product, in the early stages of design, until the final manufacture in series and sale of the same. The RT is a very diverse and varied set of techniques that will allow us to obtain short series and even mean plastic parts that can be considered as prototypes or even final pieces. Within the RT have different procedures allowing to obtain molds with inserts total or partially metal. One of the following object of this work is that of obtaining insert metal mould by Electroforming. According to the B8 Committee of the ASTM "electroforming is the production or reproduction of pieces by electrodeposition on a mandrel or model which is then separated".
The analyzed process basically is to get a shell of nickel electroformada on the basis of a model manufactured by rapid prototyping, once separated from the model for later, make an insert combining the shell with a resin filling epoxy and conductive metal burden of heat or other elements of thermal diffusion.
For the electroformado of the shell is sumergerán in the electrolytic bath an anode of nickel as well as a cathode consisting of the model of RP previously waterproofed and covered with conductive paint
2 Experimental
For the study and analysis it has a team of rapid prototyping technique FDM; a machine design and manufacturing for electroformado consisting of: bucket with 100 liters of sulfamato of nickel, electrical resistance, mechanical agitation, pump recirculation, filter, sensor of temperature and PH, Rectifier current, table of electric and regulatory control of temperature. Teams of dimensional control, analysis metallography, testing of mechanical resistance and scanning electronic microscope in the study and analysis of the resulting shells will also be used.
3. Results and discussion
In this first phase of the study the appropriate elements of process as well as the parameters involved are defined: concentration of sulfamato of nickel, temperature, PH, electroformado time, current, thickness-tiermpo of process relationship density. On the resulting shells mechanical features, structure, surface, as well as the degree of deformation quality due, for example, to an excess of internal tensions will be monitored.
4 Conclusions
Is intended to validate the process of electroformado insert metal in certain applications, for example, requiring a level of reproducibility and precision high as well as the obtaining of a mould with high capacity of production, in relation to other methods of RTeven for average series due to the high resistance of the shell of nickel.