ACS Advanced Control System

Gravimetric weighing and blending of one to seven components per extruder with extruder and/or line speed control . The basis for this world-wide accepted technology starts by suspending a hopper on a load cell with a filling slide gate above the weighing hopper. The computer opens the slide gate and allows the filling of the hopper until a high limit is reached. The gate is closed and the loss-in-weight cycle begins. The actual weight of the hopper and resin is continuously measured and the computer subtracts the new reading from the last reading. After making numerous measurements the computer calculates the average throughput of the extruder every minute. Concurrently the speed of the line is measured with an encoder which allows the average weight per length to be calculated. By adjusting the screw rpm or the line speed (depends on application) the system controls the process to maintain the target value entered by the operator. In addition to mono lines all co-extrusion lines are controlled where each extruder is maintain to a percentage of the overall thickness or weight. Even during line speed changes the correct layer ratios and overall thickness is maintained at all times. On the throat blending is also available to a maximum of seven components per extruder. Rates from 0.3 - 1650 lb/hr per additive and main materials to 4000 lb/hr per extruder. Optional features include communication to other devices, product, roll and shift reports, screen printouts and for blown film applications width measurement/control and profile measurement /control. Information is displayed on a high resolution 17" color monitor. All continuous extrusion applications can be controlled on average to 0.5% of target value or better. All features can be added at a later date.

ADVANTAGES

• Independent from the bulk density of the material
• Shorter start-up, typically 2-3 minutes to be at target
• Simple operation
• Retrofit of all existing lines or for new installations
• Fast return on investment
• Considerable reduction of scrap produced
• Increased production time due to faster start-up
• Increase in yield by typically 4-5% of resin usage
• Report storage for quality control requirements (ISO9000)

UPGRADE FEATURES

• Width measurement and control of the layflat
• Gravimetric Extrusion Control, mono and co-extrusion lines
• Automatic profile control, three sizes of segmented air ring available, single,dual and triple lip
• Communication to other devices
• Data collection and full process reports
• Control applications with melt pumps, liquid additive pumps, constant lb/hr

EXTRUSION APPLICATIONS

• Pipe
• Profile
• Cast
• Sheet
• Blown film
• Netting
• Wire & cable

Plast-Control, Inc., 29 Green Street. Tel: 978-462-0306; Fax: 978-462-1425.