Cryogenic machining, as dry and clean process is closely connected with sustainable development. The idea of sustainable development is quite well defined and implemented in some fields (architecture, agriculture, etc.), but there is a huge lack of those principles implemented into the manufacturing systems and technologies, which are the dominant sectors of the EU economy. The economic importance of sustaining a strong manufacturing base in the EU is evident from the fact that it provides jobs for around 34 million people and produces an added value exceeding 1.500 billion €. Manufacturing waste equals around 40 per cent of the EU total. More than 90% of those wastes are from production processes (EUROSTAT). Therefore, the manufacturing industry is striving to achieve sustainability also through changes and innovations in production technologies. These changes also allow implementation of the cryogenic machining as a replacement to existing conventional machining with oil emulsion. This is also a fundamental objective of this project.

Medical, pharmaceutical and military industrial innovations, from companies: A) SIBO G - packaging development and production and B) AREX - production of tools, devices and services, are results of Slovenian knowledge and represent revolutionary innovations in each field. Both companies are one of the leading companies in their field and are dealing with following common topics: i) development of smaller products made of plastic, metal or a combination of both, according to customer’s specifications, ii) prototype manufacture of our own tools, testing and modifying prototypes, iii) making tools for serial manufacture, iv) serial manufacture with modern CNC machines. Both companies have their own development and serial production. Therefore, their main focus, besides development of new products, is directed to the setup of production technologies and start-up of the mass production. Thus, the main objective is to find and develop, for their key products, more optimal/efficient production technology for improving productivity, quality, environmental and worker safety. The solution to upgrade existing technologies, in both cases, is expected through the implementation of cryogenic technology based on liquefied carbon dioxide LCO2 into a strategic Slovenian industry. In one case goes for implementation of the technology in the individual tool-making products with high added value, with an emphasis on clean processing technologies. In the other case, it goes for the implementation of high performance technology in the mass production of products, also with high added value.

The originality of this project shows the possibilities for application development and transfer of technology into a serial production, as well as the achievement of: (1) increased productivity, (2) the purity of production and processes, (3) cheaper and more competitive production and (4) without troublesome drilling and milling with higher cutting speeds. Thus, the develop implementation of cryogenic machining into regular production represented an original score for Slovenian situation. Upon success of this project, it is expected to carry out the first Slovenian industrial applications LCO₂ cryogenic technology to process high precision and efficient drilling and milling. The ultimate objective of the proposed project is the implementation of sustainability principles into the production processes through the implementation of cryogenic LCO₂ technology at both companies production, SIBO and AREX.

As for originality and objectives of this project, we can thus conclude the following:

• > implementation of the cryogenic LCO₂ machining which represent sustainable development and thus successful replacement of current conventional machining with oil based emulsions and so:
  • - reduce the ecological footprint of machining processes,
  • - increase productivity by increasing cutting speeds, as a result of reduced tool wear and longer tool life,
  • - reduce costs in regular production, due to the extension of tool life, dry and clean process, and thus without the need for additional machine, workpiece and working environment cleaning and unnecessary recycling emulsions,
• > after successful transition into a serial production, an additional objective of the process is to make it flexible for use in a wide range of machining centres, which would allow the application to a wider range of SME industry in future and also for processing less demanding products, while ensuring increased productivity.

Objectives outlined above will be achieved through the implementation of cryogenic technology based on liquefied carbon dioxide LCO2 into the production of both companies. This will be achieved by upgrading existing machinery and adaptation with relevant systems for LCO₂ cryogenic medium delivery. It is necessary to create an appropriate specification for equipping and upgrading existing CNC machines, which allow supply of cryogenic medium through the main spindle into the cutting zone. The equipment will be partially elaborated on the FS and other work at strategic partners as specialists in the field (rotary unit, etc.). Appropriate equipment will be installed on the CNC machines, tested and applied in the production of both companies. It will be necessary to carry out optimization and adjustment of previously used cutting parameters to the cryogenic machining mode. It will also be necessary to carry out the economical and environmental analysis and to monitor the impact of applied technology at the machines, the working environment and workers.

Therefore, it is proposed the following work program, which is divided into various work packages (WP):

• > WP1: Mechanical specifications for equipping/upgrading an existing machine technology for LCO₂ cryogenic milling and drilling
• > WP2: Manufacture and supply of the equipment for upgrading machinery for LCO₂ cryogenic milling and drilling
• > WP3: Upgrading machines, commissioning and testing the operation of the LCO₂ cryogenic milling and drilling
• > WP4: Optimization and cutting parameters adjustment for LCO₂ cryogenic milling and drilling for achieving most efficient production
• > WP5: Economical and environmental analysis
• > WP6: Monitoring the impact on the machines, working environment, workers

Work packages are for easier management and project planning divided into three phases:

• > Phase 1: start of the project - preparation: preparation and purchase of equipment for cryogenic LCO₂ milling and drilling (WP1 and WP2)
• > Phase 2: the basic installation and optimization of the cryogenic LCO₂ technology in the production of both companies (WP3, WP4)
• > Phase 3: final analysis - monitoring of economical, environmental and other benefits of implemented cryogenic technology (WP4 and WP5)