The NPE2009 international plastics showcase was held June 22-26 in Chicago’s McCormick Place. While attendance was down from NPE2006, the preliminary total of visitor registrations numbered 44,000. Sustainability and energy efficiency was a prominent topic in the booths of exhibitors. Manufacturers of compressed air and injection molding equipment had many developments with Sustainability to show the visitors to NPE2009.
As we experienced in the booth for Compressed Air Best Practices Magazine, the visitors were professionals from large multi-factory companies who make plastic products (naturally). They came from firms who deploy plastic extrusion and injection molding lines (using 100 psi systems) to create their plastic products. The visitors also came from companies deploying stretch blow molding processes at 30-40 bar. We welcomed a record number of new subscribers from firms like Silgan Plastics Corporation, Ball Corporation, and Graham Packaging (to name a few).
“Lightweighting” Plastic Bottles
The plastics industry, when it comes to injection molding and blow molding, is changing quickly. Sustainability concerns, raised by consumers, are one of the main reasons why. Consumers are concerned about the volume of plastics used in plastic products and the solid waste that this generates. As a result, many food companies are “lightweighting” their product packaging. Some of the ramifications of light-weighting for compressed air systems are:
- ½ litre bottles are now being blown at 20 bar (vs. 40 bar) due to the reduced plastic content. This is now the norm for water bottles.
- Carbonated soft drinks and juices in containers of less than 1 litre are using 30 bar air. CSD’s in 2 litre-and above containers are using compressed air in the 35 bar range.
|"As part of Sidel's larger options and upgrades initiatives to their global base of 27,000 machines, air recovery can reuse up to 40% of the compressed air expelled during bottle blow molding."|
Sidel Air Recovery Systems
We spoke with managers at Sidel Inc., one of the world’s largest manufacturers of machinery used in bottling systems. As part of their Sustainability strategy, Sidel has introduced an “Air Recovery” system to help blow molders reduce their energy costs associated with compressed air. As part of Sidel’s larger “Options & Upgrades” initiatives on their global base of 27,000 machines, Air Recovery can reuse up to 40 percent of the compressed air expelled during bottle blow molding. This can result in a 15 percent overall drop in air consumption.
The Sidel Air Recovery system consists of an additional pneumatic circuit that recycles part of the exhaust air and then reinjects the air into the machine’s low-pressure blow molding circuit and into the plant’s air supply network. The recovered air can be used to:
- produce preblow air
- produce service air for the blow wheel (stretching and nozzle cylinders)
- supply the plant’s compressed air network
The surplus recovery air is accessible at the foot of the machine and can be used for other plant air purposes. The Air Recovery system can be retrofitted onto existing machines and is being well received by Sidel’s customers.
We learned that in Sidel’s traditional Heat Resistant (HR) machine, that up to 60 percent of the exhaust air can be collected and reinjected into the machine’s low-pressure circuit. The upgrade involves a specific low-pressure panel where the recovery option is recorded into the process recipes and the installation of one recovery valve on each blowing station, activated by the PLC during the cooling phase.
Krones Air Recyling Package
Krones Inc., is a world lead in the manufacture of fully integrated packaging and bottling line systems. We spoke with a manager in their booth about their Air Wizard air recycling packages. Krones offers the Air Wizard 2 as a standard feature on their Contiform S blow molders. The Air Wizard 2 is also (similar to Sidel) a system where the exhaust air is recaptured by a return valve with negative pressure. The air is recaptured at pressures between 118-176 psi.
Some of the highlights of the Air Wizard packages referenced to a Contiform S16 with 25,600 containers an hour and 6,000 working hours a year include:
• Produces the following compressed- air savings: the reduction in the dead space involves downsizing the volume at the valve block and the blow nozzles, which for 0.5 litre bottles reduces the consumption of compressed air from its previous 1,360 m³/h to a mere 1,017 m³/h.
• Reducing the final blow-moulding pressure results in compressed-air consumption for a 2.0 litre bottle of a mere 1,812 m³/h instead of the previous 2,455 m³/h.
• Recycling the final-blow-moulding air means that part of it can be used during the pressure- relief phase for pre-blowing and stretching. For a 2.5 litre bottle this cuts the blow-moulding air consumption from its previous 2,455 m³/h to a mere 2,198 m³/h.
• The previous consumption of stretching air, amounting to 174 m³/h, can be reduced to zero.
Krones also introduced it’s new NitroHotfill process – which it claims is the most cost-efficient option for PET hotfill applications. Process control is based on the newly developed “Relax-Cooling” (RC) concept, where the installation of a nitrogen injection dosing feature just before the capper creates a positive pressure of 1.5 to 2 bar inside the bottle. The positive bottle pressure compensates for the shrinkage in product volume downstream of the recooler, thus preventing any bottle deformation due to underpressure.
This means the panel design hitherto required to compensate for the vacuum pressure with hot-filled products can be dispensed with. The process can be utilised for the bottle production process in the Contiform H, which also enables aluminium moulds to be used, and reduces the machine’s air consumption dramatically.
The Relax-Cooling (RC) technology also enables the Contiform H’s flushing air consumption to be substantially reduced. This is the result of a small flow rate and a shorter flushing time.
Compressed Air Equipment at NPE2009
Hitachi America introduced their new third-party verified ISO 8573.1 Class Zero certification for their DSP Series oil-free rotary screw air compressors. The Class Zero verification tests were performed by Mitsubishi Chemical Analytech. The company also announced and expansion of their rotary screw product line to 300 horsepower with new 132 kW, 145 kW, 160 kW, 200 kW, and 240 kW models.
Atlas Copco featured their Class Zero capabilities prominently in their booth and offered customers free “walk-through surveys” – which drew a lot of interest. Renner Kompressoren, from Germany, announced their new partnership with Shrader to represent their air compressor product line in the U.S. They have just launched their 5-50 hp rotary screw, belt-drive, with available VFD, product line. Cameron had a booth where they displayed their oil-free, centrifugal compressors and also introduced their new MAESTRO suite of programmable centrifugal compressor controls.
AF Compressors introduced their new range of 7 - 16 bar, oil-free, piston air compressors. These air compressors are designed for the innovative “air recycling/recovery” systems they are working on with the different blow molding equipment manufacturers. Gardner Denver Bellis & Morcom displayed their PET Compressors designed for bottle blowing. GD Elmo Rietschle also displayed their vacuum and pressure solutions for the plastics industry.
Kaeser Compressors had a large booth displaying many products including their Sigma Frequency Control (100 to 450 hp) air compressors featuring variable frequency/speed drive technology. Kaeser also diplayed their Sigma Air Manager designed to monitor and sequence up to 16 air compressors.
Vaisala had a booth where they displayed their DRYCAP® hand-held dewpoint meter. The unit is portable and designed to measure dewpoints ranging from -76 F to +140 F. Dekker Vacuum Technologies also displayed their newly launched P3 Commander, their newest advancement of control and monitoring of vacuum systems.
My apologies go out to the companies not mentioned due to lack of space in this article. Milacron is leading a very strong Sustainability initiative with their injection molding machines. Conair is introducing very energy efficient plastic-resin dryers. The chiller manufacturers, like Berg and Frigel, are driving down cooling system energy costs…..and so on.
I personally think the NPE shows are among the best industrial shows in the world, when one looks at the quality and volume of visitors – and the quality of the exhibits. Impressive to me was the degree of focus the packaging and bottling line manufacturers have on improving the energy efficiency of their equipment and processes. I am very much looking forward to NPE2012.
For more information, contact Rod Smith, Compressed Air Best Practices, email: firstname.lastname@example.org