FOAM | TECHNOLOGY
specially engineered to maximise the physical properties of CO2 as a foaming agent for stable, predictable outcomes in foam injection moulding,” said Linde. UK technology start-up firm Bockatech has developed EcoCore foam moulding, which it says can be carried out on standard injection moulding machines with minimal extra investment. It is targeting insulated food packaging applications, where moulding of smooth-walled foam containers using EcoCore technology can match cycle times for standard single wall injection moulded containers, the company says. Bockatech is also promoting the green credentials of EcoCore: the first commer- cial product made with the technology is Corretto, a PP cup for on-the-go use, such as in coffee shops, which can be reused many times and is then recyclable in established PP packaging waste streams. In September 2018,
Borealis announced it was partnering Bockatech in the development of EcoCore using two of its PP materials suited to the foaming process. Andreas Leitner, Borealis Head of New Business Develop- ment, said: “As strong advocates for the circular economy within our industry, we at Borealis are eager to partner with pioneering firms like Bockat- ech to develop polyolefins-based solutions that are reusable and recyclable.” Peter Clarke, Co-Founder of Bockatech, said
Borealis is the exclusive materials development partner for EcoCore. Injection moulders are not restricted to using the Borealis materials for EcoCore, however, they have outperformed all other materials tested. But moulders must take a technology licence from Bockatech which applies to a particular product group in a particular territory. Clarke has developed other patented packag- ing moulding technologies, including Coralfoam core-back expansion moulding. With EcoCore, the mould is also opened to allow expansion after injection, but it is a more controlled foaming process than Coralfoam where fast expansion leads to an open cell structure. “EcoCore is a controlled expansion, with very, very fine cell structure,” Clarke said to Injection World. The benefit of the fine, closed cell structure is improved thermal insulation in the cup.
www.injectionworld.com
Achieving the fine cell structure comes from a
combination of the blowing agent and the materi- als. The Borealis PP grade BH381MO is used in EcoCore containers for its high stiffness and high impact strength, and a percentage of Daploy WB140HMS is added, as this high melt strength PP material improves the cell structure. Clarke said the cup’s exterior is designed with a waveform, creating thick and thin sections around the cup. The surface expands during foaming in a controlled way that determines how thick the wall section is (typically 2-3mm). The skin does retain a remnant of the original waveform, said Clarke, but it has a very good surface that enables good printing quality. Bockatech has also created a new waveform designed specifically for IML containers. As well as cups,
EcoCore can be used for other packaging that needs thermal insulation, such as noodle pots,
freezer tubs for ice cream
and microwavable trays. The company sees good potential in a variety of other applications too, such as industrial packaging and medical sharp-safe containers, said Clarke.
Injection moulders do not need much additional equipment to run the EcoCore process. Clarke said a mould heater is required to control the surface tempera- ture in the cavity. Chemical blowing agents are widely available in masterbatch form which can be added in a standard blender. AMI’s Polymer Foam conference in November showed that R&D organisations are active in foam injection moulding. Neue Materialien Bayreuth in Germany offers a number of foam-related services to injection moulders: material and process develop- ment for the production of injection moulded integral foams; foam structure analysis and mechanical characterisation; matching of foam injection moulds; and optimisation of foam injection moulding processes with regard to surface quality and lightweight construction potential through special process technologies. Volker Altstädt, CEO of NMB, said at the confer- ence: “If you are interested to compare the foamability of your materials on different machines independently, we can do that.” NMB is involved in a comparative analysis
Left: Corretto is a reuseable on-the-go coffee cup, foam injection moulded in PP using Bockatech’s EcoCore technology
Above: Bockatech has created a new waveform designed
specifically for IML containers made with the EcoCore foam technology
March 2019 | INJECTION WORLD 33
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64
