The US Department of Labor reports that the energy management sector has more than doubled in the last two years, with 75% of all jobs in an industrial setting. While energy managers prove a valuable asset to large corporations, many plastics manufacturers with a slimmer budget are tasking current employees with energy related projects.
So how does a non-energy-expert implement energy saving projects? As with any project, the first task lies in evaluating the current situation, researching potential options for improvements, and calculating the potential results of each option.
What are your true energy costs?
With home energy costs, lighting and temperature control usually come to mind as the biggest portion of energy costs. This isn’t the case in plastics manufacturing, according to a recent study focusing on the balance of energy usage in an average plastic plant. Energy consumption for lighting, temperature control and ventilation equate to just over a third of the energy that machines use in most plastics facilities.
While specific energy consumption of machinery varies slightly from plant to plant, there is virtually no difference between the amount of energy consumed in injection and extrusion molding.
A critical first step in any successful energy management plan for a plastics facility is ensuring that machines, which account for 60% of all energy consumption, operate as efficiently as possible.
Energy-saving Measures for Extrusion and Injection Molding
To reduce energy use in extrusion processes, consult with production managers and plant engineers to optimize equipment performance. In many cases optimization of the extruder speed can significantly lower energy usage without impacting end results.
Another low-cost method for saving energy in the extrusion process lies in minimizing the use of compressed air. When cooling easy to reach areas of equipment substituting fans for compressed air can lower energy expenses.
When reviewing energy costs in injection molding equipment, focus first on the objects your machines produce. Verify that the equipment parameters are optimal for the object being produced and not an earlier production run. When possible, use molds to maximum capacity and avoid using larger molds built for multiple objects to manufacture a single product.
A simple method of energy reduction in both extrusion and injection molding is to implement procedures to switch off energy consumers when production stops. For example, turning off heating and cooling elements when they are not needed limits wasted stand-by power consumption.
In both types of processes, heating machines and cooling ambient air temperature in facilities consumes substantial amounts of energy. Equipment insulation systems allow for efficient process heating and lessen energy usage required to cool a facility. A Department of Energy study of plastics manufacturing plants listed machine insulation as one of the top eight plant improvements with the greatest energy savings and highest overall paybacks.
Calculating the return-on-investment of potential energy management projects serves as a key decision making tool for energy management projects.
For example, manufacturers who install UniTherm’s Insulation blankets usually see anywhere between 35-60% reduction in energy costs at the machine. These insulation blankets pay for themselves within one year, whereas lighting projects might take six to seven years to generate positive cash flow.
When researching potential energy projects, consult with plant engineers, energy product vendors and even your electric provider to determine the potential paybacks for improvements. Once you determine what improvements offer the greatest amount of energy savings with the lowest cost to implement, prioritizing energy management becomes a much more straightforward task.
What steps are you taking to reduce energy in your facility?