The new ASPI 150.3 model on display at K 2016 includes dramatic innovations, which always keeps the production of blow moulded items under control, even via remote devices.
Among the world leaders of blow moulding machinery manufacturers, ST Soffiaggio Tecnica ( www.st-blowmoulding.com ) has earned a recognized position of excellence in parison suction technology. The ASPI series of machines has been the market benchmark for the past ten years, to such an extent that today the name “ASPI” is synonymous with “parison suction” technology.
The parison suction process is a technique of efficiently manufacturing convoluted 3D ducts: no seam lines, enhanced wall thickness uniformity and minimum energy consumption. This technique has proven to be extremely efficient for the production of ducts for the air induction systems of turbocharged engines for cars and trucks .
As a world leader in this technology, ST Soffiaggio Tecnica has been continuously improving the performances of its ASPI machines and developing new features to achieve better quality of the blow moulded parts, more efficient production and easier machine operation and maintenance.
Other specific features introduced for the first time on this ASPI 150.3 model – such as the Parison Diameter Monitoring and the Production Data Report accessible from remote devices via ST App – make the new ST Soffiaggio Tecnica machines ready for Industry 4.0.
The new ASPI 150.3 at the K 2016
At K 2016 ST Soffiaggio Tecnica is exhibiting the new ASPI 150.3 machine – the third release of the best-selling model of parison suction machines.
Compared with the previous version ASPI 150.2, the new model offers larger platens (900mm wide – 1100mm high) to accommodate moulds up to 1650mm long. The machine is equipped with a new HMI based on a 21,5” full HD multi-touch screen that integrates all machine functions in a new job-oriented and context-sensitive navigation concept. The operators can log-in simply and quickly through a personal RFID card instead of inputting alphanumeric codes.
The job-oriented navigation concept works on configurable profiles (production/tool-setting/maintenance/quality control) for mistake-proof access to the functions of interest for each profile.
A revolutionary parison marking: “D-Print” (patent pending)
During the suction process the parison tends to twist in the mould cavity, depending on the cavity shape and on some process parameters. This type of parison rotation (which is not visible, because the parison is fed into the cavity when the mould is already closed) can jeopardize the specific radial variations of the parison thickness that are intentionally generated during extrusion to compensate for the different stretch ratios during the blowing process – unless it can be accurately predicted and taken into account in the radial profiling of the parison. In order to measure the twisting behaviour of the parison in a specific mould and adjust the radial profile accordingly, it has been a common practice to spray white paint on one side of the parison during extrusion to create a white line: the position of this white line on the blow moulded item identifies the rotation that has occurred in each section of the parison.
This marking technique involves some significant drawbacks:
- Inaccurate identification of the marked position because of the poor definition of the marks and the low spraying speed;
- Rejection of marked parts because of the unacceptable aesthetic appearance; this technique can be used only for tuning the process – not in standard production;
- Cleaning is required before each activation of the marking device, due to dried paint on the spraying nozzle.
The new dot printing technique “D-Print” eliminates all drawbacks and opens new opportunities for the use of parison marking in production:
- Sharp definition of the marking dots , results in a very accurate identification of the marked position;
- Small dimension of a single dot, allows the use of ”D-Print” to generate quality check points during standard production;
- Self-cleaning nozzle , because of the ink formulation and the high-pressure circuit.
Extending the limits of parison marking: new possibilities with “W-Print”
The new “W-Print” takes advantage of the sharp definition of the marking dots and offers the possibility of printing characters and text directly on the parison during extrusion. This function opens a wide array of new possibilities to tune the process (marking the point number instead of just a dot), in the quality control (marking the type of inspection to be performed at that point), and in production traceability (marking the date and time of manufacture).
A ghost ink is also available, if the marked characters must be visible only to intended operators when illuminated by a UV lamp.
In-line Parison Diameter Monitoring (patent pending)
The “swell factor” measures the tendency of the parison diameter to exceed the head tool diameter due of a variety of factors: plastic resin type, head tool profile, push-out speed, and others. It is a very important parameter in any extrusion blow moulding process, and it may become critical in the parison suction process.
Measuring the parison diameter at every cycle and monitoring the swell factor is now possible on the new ASPI 150.3 machine. Once the process has been accurately optimized for a certain mould, the parison diameter can be recorded in the recipe and used by the SPC (Statistical Process Control) as a parameter for the evaluation of the process stability and production repeatability . If the diameter, measured at every cycle, exceeds the lower or the upper set limit in the tolerance range for the QC (Quality Control), a warning message or an alarm can be generated.
Maximum power usage under control
It is a common experience in blow moulding factories that the maximum power usage is reached on Monday mornings, when all machines have to be heated up to working temperature. In some cases, such a simultaneous request of power can exceed the threshold agreed in the contract with the electric energy provider, resulting in huge penalties for the blow moulding company.
The Smart Heating Control implemented in the new ASPI 150.3 machine prevents such occurrences by limiting the maximum power used by each machine, and by optimizing the heating sequence of each zone.
Actual measurements have proven that the Smart Heating Control also reduces the total energy used to heat up the machine.
Monitoring production data from remote devices via the ST App
All ST machines located in a Customer’s factory can be networked, and the production data made accessible to the production supervisor’s computer. The same function can be extended to other factories and made available on smartphones or tablets via the ST App.
“Match point” with ST Soffiaggio Tecnica.
The tradition of creativity introduced by ST Soffiaggio Tecnica at the K 2010 with the walking stick and confirmed three years later at the K 2013 with the shoehorn has not been abandoned at K 2016: the tennis rackets produced as demonstration items at the ST booth have been carried around by thousands of visitors and have caught the imagination of the entire K audience, being the most sought after “gadget” of K 2016.