Mobile filling machine uses servo-pneumatic technology to maximise production flexibility.
Accurate velocity and position control capabilities make the technology ideal for product dispensing applications. In this case, the filling machine accommodates an exceptionally wide range of product parameters and deposition rates, making it suitable for diverse applications in the food processing, and manufacturing industries.
After acquiring the Optima line of depositors and filling systems at couple of years ago--which it re-branded 'Optifill'--Unitech has expanded its product offering significantly, and now manufactures a wide range of single- and multi-lane depositors, hopper systems and tanks, depositing nozzles and decorating heads.
A key feature of all Optifill products is that they are specifically designed for operator friendliness, which necessarily involves automating as ranch of the process as practicable, and for minimum component count to help keep manufacturing and maintenance costs as low as possible. The latest addition to the range is a mobile depositor, intended to maximise production flexibility by combining highly versatile dispense capabilities with built-in self-cleaning facilities. Housed in a compact, small footprint package, the depositor is intended as a general purpose filling solution, and is available in high and low, level configurations to simplify integration with conveying systems and other processing equipment.
According to Dennis Wood, Group Design Manager for Unitech, "Festo servo-pneumatic drives were an obvious choice for our new Optifill self-clean depositor. The technology is now sufficiently mature to be used with confidence, and costs significantly less than electrical drives and serves. It is also much easier to physically accommodate, making it ideal for small footprint volumetric dispensing applications such as this. And because we already have extensive experience of pneumatic drives, the transition to closed-loop control techniques didn't pose too much of a design challenge," The piston in the product dispense cylinder of the Optifill self-clean depositor is driven by a standard 80mm diameter Festo DNC cylinder, fitted with a custom displacement encoder to provide position feedback to a Festo SPC200 smart positioning controller. The pneumatic leeds for this cylinder are routed via directional proportional valves controlled by the SPC200, which executes previously-stored motion control sequences in response to commands from the system's host DLC: communications between the PLC and the SPC200 are handled via an industry-standard Fieldbus network. At the end of a filling cycle, the piston in the main product dispenser is automatically returned to its start position, ready for the next production batch. A key feature of the Optifill self-clean depositor is that, aside from removal of the hopper and dispense nozzle, it does not need dismantling for cleaning, which facilitates fast and easy product changeover.
All machine control functions, such as dispense rates and volumes, are controlled via an HMI linked to the PLC. The HMI menu structures are easy to understand, enabling even relatively unskilled people to operate the system, and the PLC can also be networked to a third party controller for customers who wish to download fill settings such as speed, weight, etc, from a minute system. The ability to accurately control the position and speed of the DNC cylinder driving the dispense piston enables the Optifill self-clean depositor to accommodate fill volumes from us low as 6cc to as much us 660cc, making it suitable for an exceptionally wide range of products.
The machine is versatile in the food processing sector, where it can be used for dispensing a wide variety of products, including batters, sauces and mashed potato. Deposition rates depend upon product type and volume, but as a typical example, the machine is capable of depositing 500g portions of mashed potato tit a rate of 30 per minute: for smaller volumes or more fluid products, the deposition rate can be as high as 40 portions per minute.
The PLC software features a built-in fail-safe procedure to prevent operation if a cleaning cycle has not been carried out since the machine was last used, to help customers maintain full HACCP (Hazard Analysis Critical Control Point) compliance. The machine's built-in self clean capabilities make this a very simple procedure. Unitech has developed a unique combined rotary sleeve valve and product cylinder--driven via a rack and pinion system by a DNC cylinder--which reduces the number of wash cycles to a minimum. The valve block, rotary valve, product cylinder and piston can all be cleaned in-situ, using a three-stage cycle comprising a cold water flush, sanitiser wash-through and final hot water rinse. Depending upon the type of product, a complete wash cycle typically takes just 10 to 15 minutes. The system automatically maintains date- and time-stamped records of cleaning cycles, together with other pertinent data such as throughput, for customers who wish to maintain till audit trail for quality control purposes.
Contact Festo Lid Way oil tel: 01252 775000 or www.festo.com
Contact Unitech Filling Systems on tel: 01543 675800 or visit www.unitech.uk.com
|Printer friendly Cite/link Email Feedback|
|Title Annotation:||Unitech Filling Systems corp.|
|Publication:||Food Trade Review|
|Date:||Jun 1, 2005|
|Previous Article:||New Siemens measurement probes for the process industries.|
|Next Article:||Atex-approved detector is non-invasive and reusable.|