| Automation | Closed-loop thickness control | Automatic die-bolt or die-gap adjustment with continuous thickness feedback; specify the control tolerance in the purchase contract. | Reduces manual adjustment, material waste, and thickness variation across the sheet width. | Run a production trial and compare measured thickness at multiple points across the sheet. |
| Recipe and process-data management | HMI recipe storage for temperature zones, screw speed, roll speed, gap settings, and alarm history; require user access levels. | Improves repeatability when changing products, operators, or production shifts. | Check whether recipes can be backed up, restored, exported, and protected from unauthorized changes. |
| Automatic haul-off, cutting, and stacking | Synchronized speed control between the extruder, calender, haul-off, edge trim, cutter, and stacker. | Prevents sheet stretching, length errors, edge damage, and unnecessary operator intervention. | Observe a complete cycle at the intended sheet width, thickness, and line speed. |
| Remote monitoring and data logging | Record production rate, temperatures, motor load, alarms, downtime, and energy data with export capability. | Supports preventive maintenance, root-cause analysis, and energy-performance tracking. | Request a sample daily report and confirm data ownership, storage, and network-security requirements. |
| Safety | Guarding and interlocked access doors | Fixed guards and interlocked doors around the extruder, drive components, calender, haul-off, cutter, and other hazardous moving parts. | Prevents access to nip points, rotating parts, hot surfaces, and cutting zones during operation. | Perform a documented risk assessment using ISO 12100 principles and test every interlock. |
| Emergency-stop system | Clearly visible emergency-stop devices positioned at operator stations and accessible service areas; reset must not restart the machine. | Provides rapid shutdown during entanglement, crushing, cutting, or other emergency conditions. | Check function, reset behavior, accessibility, and documentation against ISO 13850 requirements. |
| Safety-related control functions | Safety circuits designed to the required performance level based on the machine risk assessment; dual-channel architecture may be required for selected functions. | Reduces the probability that a single control failure will defeat a safety function. | Request the safety circuit design, validation documents, and performance-level calculation under ISO 13849-1. |
| Electrical and thermal protection | Overcurrent protection, motor overload protection, heater over-temperature alarms, thermal insulation, and lockable main isolation. | Limits electrical, fire, burn, and unexpected-start hazards. | Review the electrical drawings and test isolation, alarms, protective devices, and hot-surface guarding. |
| Maintenance | Access to wear parts and cleaning points | Tool-accessible die, screen changer, filters, heaters, thermocouples, roll surfaces, knives, and lubrication points. | Shorter cleaning and changeover time improves availability and reduces maintenance exposure. | Time a supervised cleaning and changeover using the intended material and tooling. |
| Preventive-maintenance documentation | Maintenance schedule based on operating hours, cycles, temperature, lubrication condition, filter pressure, and component wear. | Condition-based information is more reliable than using one fixed interval for every application. | Request service intervals, checklists, fault codes, spare-parts lists, and recommended inspection limits. |
| Critical-spare availability | Identify spare heaters, thermocouples, fuses, sensors, knives, seals, filters, belts, and control components before commissioning. | Reduces downtime caused by low-cost but production-critical components. | Verify part numbers, interchangeability, lead times, storage conditions, and local technical support. |
| Changeover and troubleshooting time | Measure actual time for material change, screen replacement, die cleaning, thickness adjustment, and restart stabilization. | A shorter, repeatable changeover improves utilization and lowers startup scrap. | Use a factory acceptance test with agreed time limits and acceptable startup waste. |
| Energy Use | Specific energy consumption | Measure electricity in kWh per kilogram of saleable PP sheet, including the extruder, heaters, cooling, haul-off, cutting, and auxiliary equipment. | Specific energy is more useful than installed motor power when comparing machines with different capacities. | Use calibrated power meters during a stable production run and record output, scrap, product thickness, and line speed. |
| Drive and heater efficiency | Prefer high-efficiency motor-drive systems, insulated heated zones, accurate temperature control, and automatic heater power modulation. | Reduces conversion losses and heat loss during continuous operation. | Compare measured load profiles rather than comparing motor nameplate ratings alone. |
| Cooling-water demand | Record cooling-water flow, inlet temperature, outlet temperature, pump power, and whether a recirculating chiller or cooling tower is used. | Cooling can be a significant auxiliary load and affects sheet quality and dimensional stability. | Measure water flow and temperature difference at the intended production rate. |
| Standby and warm-up energy | Check automatic standby mode, zone-by-zone heating, scheduled startup, and restart settings. | Avoids unnecessary energy use during breaks, changeovers, and non-production periods. | Compare energy consumption during warm-up, production, standby, and shutdown states. |