It probably won’t surprise you that energy is second only to materials in terms of high costs in the plastics industry at present. Energy costs are rising – and this is a trend that’s likely to continue over time.
The good news, however, is that around 30% of energy use is ‘discretionary’. In other words, the cost is incurred because firms do not recognise - or attempt to take opportunities - in improving energy standards.
This obviously represents a very significant opportunity to cut back on your energy spend. The tools at your disposal in this regard are quite extensive. You can use energy efficient components such as variable speed drives and energy efficient motors, for example, to conserve and save as much as possible.
The greatest potential to save energy and money in plastics manufacturing, however, is through improved efficiencies in energy intensive end-use processes such as compressed air, vacuum, pump and fan equipment – along with process heating applications
. Of the energy used for non-process needs, lighting and HVAC provide the most substantial savings opportunities.
Better optimised controls are another key driver of energy efficiency. Examples include ensuring that motors are only on when needed - and that heat is recovered from extrusion processes. By monitoring, controlling and tracking the energy each unit uses, producers can analyse total energy consumed and its related cost - allowing for greater control over their energy processes.
By the way of example, extruder heat energy savings of up to 60% are achievable by providing the barrels and heater-bands with insulating sleeves. This super-simple solution can result in energy savings of up to 100,000 kWh per year for a typical 5-layer line.
And when you add that to other easily achieved savings – such as use of energy-efficient lighting, with a 50% saving over traditional lighting – it’s easy to see how much of that 30% discretionary spending on energy can be reined in. And that’s before you look at savings in VSDs (potential saving of 20 to 50%); compressed air savings (potential saving of 40%); or process heating (potential saving of 60%).
The message is simple. By concentrating on your discretionary energy spend, you can do much to drive down your energy costs, creating a leaner and more profitable plastic manufacturing
business. And who could say no to that?