Italian companies are beating the crisis, and they are beating it with great determination on foreign markets, focusing on quality and innovative technology. An undertaking that is not a done deal, according to the Friuli based Pezzutti (Fiume Veneto, near Pordenone, Italy). Historically a family-owned business, in 2010 the company was acquired by Ezio Chies, Emanuele Bassetto, and another four silent shareholders, who reshuffled the organisation, staff and facilities, developing growth which over the past five years has trended at an average of 12 per cent each year. «We took on the market challenge and glimpsed the great growth opportunities which could come from collaboration with some customers», director and Sales and Marketing Manager for the company, Ezio Chies, told Plastix. An example is the recent launch of a line for PET injection moulding (RPET), which required an investment of 5 million euro and the development and creation of a complex dedicated process. «Nobody loves difficulties. But undertaking this path means clarifying our vocation – and capacity – to resolve problems that customers who, like us, want to get in on difficult challenges», Chies pointed out.
Is this what prompted you to focus on RPET?
Our production processes have always been structured around attention for natural resources, energy saving, and careful use of raw materials. Energy consumption at our plants is constantly monitored and optimized, in part because the reduction in environmental impact is a must for some key customers, who understand the importance for the final consumer and, therefore, have inserted “green” product lines into their range. The idea of making goods from recycled PET came from one of our customers.
Generally, RPET is not processed by injection moulding…
It is true, processing of the material is more often associated with other technologies. The process that we have developed entails the direct injection of RPET flakes, to which the masterbatch is added directly in the line. From an environmental point of view, this translates into great energy saving associated with a second polymer extrusion. An advantage which, however, has enormous repercussions on the difficulties of processing, because problems resolved in the regrading stage of the recycled material inevitably have to be addressed during moulding. In practice, we are managing the alchemy of compounding.
What treatments do RPET flakes undergo?
A metal detector is installed along the central line for transporting the flakes which detects the presence of metal particles (aluminium, steel or other metals) – even of minimal weight – and removes them from the system. The material then goes to the drying system, fitted with two special Genesys GP35 dehumidifiers by Piovan, which reduces relative humidity to about 100 ppm. The treatment is also optimized for the elimination of other impurities that are still present: these are residues from label adhesives and sleeves, plasticizers and other additives, but also inevitable traces of organic substances from the differentiated waste containers. In the dryers at high temperature, pollutants, by this point gassed, are removed by controlled flows of hot air for filtration and condensed. The flakes, on the other hand, are taken to the presses after the treatment.
What adjustments have you adopted for in line compounding?
Metering the flakes and the masterbatch is managed accurately by a special configuration Lybra feeder by Piovan. Through propriety weight loss control, the system measures the quantity of material transported from the feed screw to the unit mixer. The blend is then continuously transferred by gravity to the central block of the Lybra to the plasticizing screw on the moulding machine. Adequate dispersal of the masterbatch in the flakes is ensured by a plasticizing cylinder and a screw with a custom designed profile.
And for the injection moulding?
Given the variability in RPET flake composition, moulding processing conditions must continually be adapted: this is possible thanks to the KraussMaffei APC system, which constantly measures variations in material viscosity and regulates the point of changeover fill so the filling system is always accurate, thereby guaranteeing the production of items with stable weight and quality.
In our experience, it has emerged that this material particularly stresses the mould surface, injection channels and hot chambers. Therefore, in addition to using special steel, we have experimented with different protection treatments, configuring the cavities and cooling circuits to reach zero degrees centigrade. Every mould has been developed and constructed with attention paid to every minimum detail, from our internal team of technicians and equipment department.
From what you are saying, it can be deduced that development of the process has required a great commitment of time and resources…
Yes, it has taken many months. We invested 5 million euro to set up a fully equipped production department, made up of four injection presses in the MX Blue Power series by KraussMaffei (two with clamping force of 1,000 tons, one of 2,000 and one of 550), the moulds and transportation system and flake conditioning. Considering the importance of the project, which has received excellent feedback from the final customer, we expect an expansion: within a few months, another two large-tonnage machines will begin operation, while another ten or so existing presses are scheduled to be reconfigured to process RPET.
In addition to inserting new units for special projects, what other criteria do you follow for your production machines?
Normally we assess replacement of an injection press after a decade of use. A machine deemed to be able to still function is however upgraded by the installation of high performance robots, pumps and latest generation inverters, updated software, new screws or plasticizing screws.
At your three sites, 120 injection presses are in operation. What is your policy to limit energy consumption?
For three years already, we have used energy exclusively from renewable sources. In 2015, 5 per cent of our need was met by out photovoltaic plant, which generated more than a million kilowatt hours, while the rest of our power comes from hydroelectric plants. For cooling systems, we use more than a million cubic metres of groundwater (natural local hydro geological phenomenon whereby water emerges from underground to provide ample availability, NDR), which is returned to the environment unaltered and without ever coming into contact with polluting substances.
Returning to RPET, do you think that demand for recycled plastic products will rise in the future?
Yes. Environmental sustainability is an increasingly pervasive approach, and not just because it is identified as a powerful marketing instrument. An ever increasing number of companies and consumers believe in preservation of resources.
You have opted to focus on recycled plastic. What do you think, instead, of biopolymers?
I am convinced that in the future, we will see an increase in application in food packaging, a segment where we are highly active. More than anything, in the food sector, biomaterials are a new frontier from a philosophical and health standpoint. The association between biological foodstuffs and green containers, therefore, is not out of place: what we are still missing before we can implement this is large-scale technology to deliver efficiency and productivity at levels similar to those already in place for processing traditional plastic.