Brief History:

The current helicopter view of Interpower’s product line shows a manufacturing landscape vastly different than the view from 1993. In ’93, still called Panel Components Corporation, the company moved from Santa Rosa, California, to Oskaloosa, Iowa. That year, the company manufactured its first Accessory Power Strip (APS) in Iowa. Three years later, the company manufactured its first run of North American power cords in June of 1996. In 2004, the company officially changed its name to the Interpower Corporation.

Today, 31 years after making its first NEMA power cord, Interpower’s product line has expanded exponentially. The company holds numerous worldwide agency approvals bolstered by its injection molding offerings such as North American and international power cord sets, hospital-grade cord sets, and inlet and outlets. Its line of IEC 60320 cords and components is comprehensive as well: jumper cords, plug connectors, connectors, and inlets and outlets. Its accessory power line features Accessory Power Strips and Power Distribution Units which distribute power up to 12 AC devices using a single country-specific plug at the wall.

The 1-Week Unique

While “setting the industry standard” sounds like a carmaker’s catchphrase, it’s quite apt when referring to Interpower’s industry-unique 1-week manufacturing lead-times on power cords, cord sets, and components. In 2008, Interpower launched its 1-week lead-times, allowing customers to consistently place orders when needed to stay on schedule. The company also offers same-day shipping on in-stock cords and components. What are key factors in maintaining a 1-week lead-time?

Molding Capabilities

Interpower’s Quick-Change Molding Process in tandem with an adept and adaptable workforce is key in maintaining 1-week manufacturing lead-times. Changing up to 40 100-lb molding dies a week is rare in the industry, yet country-specific customization is an Interpower hallmark. Using customized spring-loaded die plates, rapid-disconnect water lines, and a customized cart with rollers to smoothly move dies to and from the molding machine, new work orders of country-specific cord sets keep humming along.

Whether manufacturing North American, European, Asian or Australian cords, all cords and components must bear the mark of the approval agency as well as other marks (amperages and voltages, line, neutral, and ground designations, date of manufacture, and maker’s mark). Those marks are engraved on thick steel inserts, which are placed into the mold.

The marks are transferred onto plugs, outlets, and other components by a similar relief method used in intaglio. Instead of ink and copper, the injection molding version uses steel and hot resin (upwards of 350°F) along with high resin temperatures and pressure to produce the mark. The PVC plugs are often left in the molds to cool for 45 seconds.

“Other molders may have to unbolt the entire mold, which is a far more labor-intensive and time-consuming process. Our quick-change mold process plays a major role in offering our unique 1-week lead-times. By changing molds and colors on the fly, we can keep diversifying our product line,” said Interpower Vice President of Manufacturing and Logistics, Mike Boyle.

As for the cords, approvals and maker’s marks are specially printed on the outer jacket by an automated printer near the end of the extrusion line. Soon afterward, the jacketed cord is ready to be reeled, wrapped, and shipped.

A Short List of Molding Compounds

Thermoplastic

Thermoplastic can be softened through heating and hardened through cooling. It can be molded when heated and can retain its shape after cooling. Thermoplastic is the opposite of thermoset.

Thermoplastic Elastomer

Thermoplastic Elastomer or TPE is a material that has characteristics of rubber as well as thermoplastic.

Thermoset

Thermoset uses a heating process—curing—and once the plastic is cured, it can't be altered from its original state.

PVC

PVC is a common thermoplastic material for cable and conductor jackets and some molded plugs.

Rubber

Rubber is also a common material for cable. It is a thermoset-type material. While it may be more costly than thermoplastic cable, rubber is extremely durable. Rubber is an excellent choice for outdoor applications.