The two component (2K) micro injection moulding machine was purchased from Dr. Boy GmbH & CO.KG of Germany. The machine consists of:
The mould fabrication begins as blocks of chromium steel, namely 1.2312 steel, a high durability metal that can withstand repeated high injection pressure of plastic and clamping forces. A milling process was then used for machining the mould plates and other mould components. After a vacuum hardening heat treatment was applied to the core and cavity plate inserts, the EDM was adopted for the fabrication of core insert and cavities features. Initially, the CAD models for each electrode were developed. The electrodes have features opposite to those required by the mould cavity features. The machining of the electrodes was done using a 5-axes Computer numerically Controlled (CNC) machine. Two electrodes were produced for each core and cavity feature i.e. an electrode for roughening and the other electrode for finishing. A number of common mould components were purchased off the shelf. These comprise the rack and pinion mechanism to operate the index plate, guide pins, shoulder bolts, hydraulic cylinders (one for the operation of the index plate mechanism and the other for the operation of the ejectors), proximity sensors and quick release fittings for the cooling channels. Once all the mould components were manufactured or bought, the assembly process commenced. This is the most challenging phase of the mould fabrication since it must be ensured that all components fit precisely together. The assembly process was done in two phases. First, the fixed side of the mould was assembled i.e. the cavity plate and the feed plate assembly. The second phase focused on the construction of the core plate assembly. Mould design and fabrication was carried out in collaboration with Tek-Moulds Precision Engineering Ltd. The technical expertise from the other industrial partners and from the research team at UOM was very useful to optimise the mould design such that defects on the micro parts could be eliminated.
A number of meetings were organized in order to familiarize university technical to issues related to the installation of machine services such as gantry systems, water chilling system to control the temperature of the machine hydraulics and to operation of injection moulding machines. Members of the technical staff of the Department of Industrial and Manufacturing Engineering (DIME) paid visits at one of the industrial partners, Techniplast Ltd., in order to receive brief informal training on mechanical and electrical aspects of injection moulding tools and machine.
A formal training session was provided to the DIME technical staff by the machine supplier representatives in Malta. This covered basics of injection moulding, process parameters and an overview of the machine main functions.
In addition, members of the DIME academic and technical staff, at UOM were given training on the 2K micro injection moulding machine, by highly skilled technical staff at Playmobil Malta Ltd. The micro injection mould tool was used as a case study to set up the exact timeframes of the different steps of the injection moulding cycle (e.g. the sequence of injecting the material of the optical component followed by the injection of the housing material). This exercise was also useful in order to test the core pull dual function of the machine.
Meeting
Various internal and consortium meetings have been organised during the two stages of the project in order to ensure that tasks and deliverables are timely executed and submitted. The outline of these consortium meetings typically consisted of an introductory message followed by a series of discussions regarding issues that required to be tackled.
Dr Farrugia presented a paper entitled ‘Design of an endoscopic micro optical part for fabrication with micro shot injection moulding’ at the ASME 2014 International Design Engineering Technical Conferences & Computers and Information in Engineering Conference (IDETC/CIE 2014), August 17-20, 2014, Buffalo, USA, co-authored by Ing. L Said, Dr A. Rochman and Ing. P Vella.
A half-day seminar on multi-material micro injection moulding was held on the Thursday 22 October 2015 at MCST premises in Kalkara. The seminar was addressed by a number of speakers, who treated various aspects related to high-value added manufacturing, micro fabrication and the EX-MMIM project in general
Dr Pullicino Orlando, Executive Chairman of MCST formally opened the seminar. This was followed by an address by the Parliamentary Secretariat for Research, Innovation, Youth and Sport, Hon. Chris Agius. Hon. Chris Cardona, Minister for the Economy, Investment and Small Business, delivered a speech on high-value added manufacturing in Malta. Dr Ing. Philip Farrugia, Project Principal Investigator and Senior Lecturer at DIME, gave an overview of the EX-MMIM project. The key project experts, Dr Ing Vella and Dr Rochman, lecturers at DIME, spoke respectively about micro and nano manufacturing processes and micro injection moulding. Mr Chris Camilleri, Research Support Officer presented the research results generated in this project. Mr Kevin Busuttil, managing director of Tek-Moulds Precision Eng. ltd spoke about the lessons learnt by industry as a result of participating in funded research projects. Ing. Andreas Striegel, researcher at the Karlsruhe Institute of Technology in Germany, delivered a presentation on applied research in micro and nano replication. After the presentations two working groups discussed the benefits of amplifying micro manufacturing in Malta and the challenged faced by industry concerning micro injection moulding. Prof. Jonathan Borg, Professor at DIME moderated the discussion. The seminar was well attended by people from academia and industry.
Dissemination of project results locally including articles in the Malta Chamber of Professional Engineers and the Times of Malta.
A service on the seminar has been aired by the newsroom of ONE and TVM on the day of the seminar. An article on the event was published on tvm.com.mt and on-line newspapers including the Times of Malta and the Malta Independent. In addition, following the seminar, a number of actions were taken to promote its outcomes, including the issue of a press release by MCST, a snippet on the NEWSPOINT section of the University of Malta website and posting in the Facebook page of the Industrial & Manufacturing Engineering.
