Molder’s Mantra: Go Lean, Stay Green

If anyone doubts that “shoot-and-ship” molding is a thing of the past, they might want to visit Plastic Molding Technology (PMT), Inc. at its 60,000 ft² plant in El Paso, Tex. The molder is constantly challenging itself, exploring new markets, and investing in new technology. Have you ever heard of a molder with a drone?

The company (pmtinc.com), owned by CEO Charles A. Sholtis, has been around for more than 40 years, molding more than 150 million parts/yr for the automotive, appliance, electrical, and consumer-products industries. PMT runs a wide range of engineering thermoplastics and produces parts in more than 50 colors. The molder runs 58 presses ranging from 45 to 390 tons. About half of them are all-electrics from Toshiba and Roboshots from Milacron. PMT’s goal is to eventually transition its entire fleet of presses to all-electrics.

Its most recent purchase of three Toshiba all-electric, 55-ton machines began making parts last November. They replaced eight machines more than 15 years old, and represent a continued investment in PMT’s sustainability initiatives put in place over the past three years, Sholtis states. The presses improve cycle time by 20%, he adds, so parts are made faster using less energy. The company augments its molding operation with a wide range of value-added services.

Last year, PMT’s commitment to sustainability was recognized nationally by the Manufacturing Leadership Council, which named the molder Manufacturer of the Year and presented PMT with two Manufacturing Leadership Awards for its commitment to sustainability and operational improvements. The molder’s strategy for improving its manufacturing sustainability includes developing proprietary technology, identifying energy savings, and making operational improvements.

Where the former is concerned, PMT has developed a proprietary control system called Shopwatch that monitors machine run-time in real time. Shopwatch shuts off pump motors left unattended or in standby mode, saving energy by cutting waste. PMT also developed another novel control system that regulates the energy use of its granulators.

That system significantly reduces grinder idling time without compromising functionality, dropping grinder energy consumption by 95% and saving 891,395 kWh/yr.

Through its partnership with the El Paso Electric Co., PMT conducted an audit that revealed numerous opportunities for energy efficiency, Sholtis recalls. Energy-saving improvements include the new all-electric presses, saving approximately 398,000 kWh a year; energy-efficient T5/T8 fluorescent lighting, saving over 96,000 kWh; and a variable-speed air compressor, reducing compressed-air discharge by 20 psi and saving 185,167 kWh a year. “Our sustainability initiative has resulted in a savings of 1.8 million kWh of energy per year — and we’re continuing to look for ways to improve,” Sholtis states.

In the area of lean manufacturing, PMT runs robots on virtually all of its presses, having added six three-axis robots last year.  It is among the few molders that has invested in Baxter, the “collaborative” production robot from Rethink Robotics, Boston (see Nov. ’13 Close Up).

Sholtis says PMT’s goal is to increase its business in medical by 15% over the next two years. “We are allocating a clean area in our plant where we will do medical molding and assembly of products like prep kits used in operating and emergency rooms,” he notes.

In September, PMT also invested in a Stratasys Fused Deposition Modeling desktop 3D printer, which can produce fixtures for its own quality control and assembly work, as well customer prototypes in under 24 hr. Longer term, Sholtis projects using 3D printing for additive manufacturing of production parts. “Molding and additive manufacturing are complementary technologies,” he states. “The molder of the future will have both technologies side by side.”

About that drone… It’s equipped with a high-resolution camera and Sholtis envisions it someday possibly delivering spare parts to operators. For now, it will be part of PMT’s upcoming “customer innovation center,” where the molder will display  its “creative thinking” to clients.