Start with a meter, not a brochure

Energy claims for packaging machinery are easy to make and hard to compare. The useful approach is a clamp meter and a week of readings. On a typical cup line the split we see is roughly: extrusion 55 to 65 percent of total consumption, cup forming 25 to 35 percent, and compressed air and auxiliaries the remainder. Within the former, the heaters take most of the load and the drive system the second largest share. Shantou Longsheng Industry Co., Ltd. supports customers through this kind of audit during commissioning and after the first year.

The three biggest savings on the former

• Idle heating — heaters held at production temperature during breaks may account for 8 to 12 percent of daily use; a proper standby mode with a warm-up ramp pays back in one season
• Hydraulic versus servo drive — a full-servo FS-8556 avoids the continuous pump load of a hydraulic machine, which matters most on short cycles and frequent idling
• Air leakage — vacuum and eject air leaks are invisible and constant; a weekend leak survey typically finds 15 to 25 percent of air consumption

On the extrusion side

The extruder barrel heaters and the screw drive dominate. What helps: correct barrel temperature profile so the screw does not have to work against over-cooled zones; insulation jackets on the barrel; and running the crystalliser and dryer at the load actually needed instead of at maximum. On the LSI line with drying and crystallising system, the dryer is often left at full setpoint through the night, which is pure waste.

Measure these five points

1. Main incoming power at the line panel, logged hourly
2. Extruder screw drive power
3. Former heater bank power
4. Compressed air flow to the line
5. Chiller or cooling water temperature, since cooling demand follows the setpoint

Turning readings into money

Once you know the split, savings are arithmetic: a 10 percent cut on a 120 kW line running 6,000 hours is roughly 72,000 kWh a year. That is usually more than the price of the instrumentation needed to find it.

About Shantou Longsheng

Founded 1998 in Shantou, Guangdong Province, China. 30,000 m², "Longsheng" trademark, 25 granted patents (1 invention, 24 utility models), high-tech enterprise. Sheet extruders, multi-station thermoformers, vacuum forming machines, cup making machines, precision molds.

https://www.stlongsheng.com