Radiant heater band system helps molders reduce spiraling energy costs

Increasingly, plastics processors are finding that energy is one of their biggest challenges, ranging from cost to availability. While many states are moving toward more energy from renewable sources, which can present its own problems, California in particular has had difficulty providing adequate, consistent and reliable electricity in its push for greater dependence on renewables over the past several years. 

One equipment upgrade that is gaining acceptance by injection molders throughout the United States—and especially in California—is the TCS system from Rex Materials Group (RMG; Howell, MI). The TCS system is an energy efficient replacement for traditional heater bands on barrels. “In California, energy conservation is very important, considering the exorbitant rate that molders are charged,” said Bruce Blau, an energy consultant in Southern California who works with RMG.

Over the past 20 years, injection molding machines have become more energy efficient with improved technology, such as fixed-volume hydraulic units and servo hybrid or all electric machines. “The one component that has not changed is the heater band,” said Blau.

The TCS system is a custom radiant band heater system that offers an alternative to traditional inefficient heater bands. The TCS system combines high-efficiency radiant heat transfer and heat containment, and directs that energy into the melt, rather than into the factory, Blau explains.

“Several major injection molding machine OEMs recognize the superiority of the TCS system and are offering TCS on new machines as an upgrade over ISP mica or ceramic bands,” Blau added. “Milacron offers TCS both on new machines and as systems for retrofit, through their aftermarket sales network.”

TCS energy-saving systems can be quickly and easily installed. The old heater bands are removed and replaced with custom sections of the TCS system that cover the entire length of each zone. There are no gaps in order to reduce heat loss and improve operating temperature consistency.

Another benefit of heat containment is a substantially more comfortable, and safer, work environment, which boosts employee morale and retention. Heater barrels equipped with mica or ceramic bands typically produce between 300° and 400° F temperatures in the plant. With the TCS system, exterior temperature is reduced to around 100° F. Extraneous heat on the plant floor is a major concern in the summer, where temperatures can become extremely uncomfortable for employees.

Barrels fitted with the TCS system also reduce the air-conditioning load in controlled environments such as cleanrooms. In fact, notes Blau, TCS is part of the corporate continuous improvement initiative at two multinational medical molders to reduce both energy consumption and the load on cleanroom air conditioning units. “The energy savings are key, but in some cases the longer-term goal is to install additional machines in existing cleanrooms, without upgrading the AC units,” he added.

TCS insulated radiant heating bands from RMG offer several additional benefits, including:

Tom Hutchinson, President of Medway Plastics, a custom injection molder in Long Beach, CA, commented on his company’s use of the TCS system: “The heaters are all working well; some have been in service for more than six years without a failure. The wiring is different than the standard setup, but not rocket science.”

Medway’s Operations Manager, George McDaniel, added: “I love the heaters. They are much more efficient. You can put your hand on them.”

Blau is currently working with the utilities in California to secure incentives for the retrofit of more than 100 injection molding machines from inefficient heater bands to the TCS system. “Molders readily recognize that replacing old mica and ceramic bands with new TCS energy-efficient radiant heater bands is the easiest and most cost-effective way to reduce injection molding machine energy consumption,” said Blau. “Payback is normally under one year. Southern California Edison has recognized the energy savings of the TCS and has reserved incentives on three large heater bank retrofit projects.”

Of the total energy consumed by injection molding machines, it is estimated that barrel heating constitutes 15 to 40%, with injection molding facilities requiring 0.9 to 1.6 kWh/kg to process plastics. “The actual value depends on many factors including processing efficiency,” said Blau, “but the real message is that no energy plan is complete without a strong focus on machine energy and barrel heating.”