IMM's Plant Tour: Where exotic plastics meet heavy metal

We never seek the low-hanging fruits," says Mel Goldenberg, president of a privately held technology-based custom molder in Clifton, NJ called Polymer Technologies Inc. (PTI). "The business is just not there for the low-tech stuff anymore. We seek the high-tech end of the business. They say the economy is slowing down, but I haven't seen it. We are expanding our capacity and hiring more people." 

To those who know him, colleagues and competitors alike, Goldenberg is a true Renaissance man, an entrepreneur gifted with an unstoppable "I can do it—let's go after it" spirit, and skilled in a wide variety of manufacturing technologies. One of his many admirers even says he's got the Midas touch: "There's not a marketplace out there that Mel touches that he fails to improve." 

Goldenberg has been involved in plastics molding since the 1960s, serving markets ranging from toys, to the military, to medical. He was one of the first molders in the country to successfully dry and mold an exotic new material called polycarbonate when it first arrived. He's been just as successful molding synthetics that are equally exotic these days, like PEKEKK and implantable PLA. 

When he was about to start his own company, Goldenberg joked to his wife that he would name it Buckshot. His punch line? He wanted to make a buck a shot. Today PTI molds parts selling for hundreds of bucks a shot. 

One is a 1700g aerospace valve flow body with an 8.8-cm ID. Some of the largest commercial MIM parts ever produced, these parts are molded by PTI out of a nickel-based Inconel super alloy. Low-hanging fruits? Sure—golden apples. Let's tour. 

We're a Soup-to-Nuts Supplier 
That's how our tour guide, Neal J. Goldenberg, vp of marketing and son of Mel, likes to summarize the full array of services PTI offers to help its domestic and international customers get to market on time. It is agile enough to manufacture complex parts in high volumes and in short runs. 

In addition to part and mold design, FEA, and mold flow analysis, basic R&D is fundamental to PTI's business plan. For example, it develops its own molding materials when jobs warrant them. 

The company can help customers select the proper material for their applications. PTI is often recommended to customers with problem parts by material suppliers. In fact, material suppliers themselves seek PTI's field-proven expertise. It has served as a Beta site for the development of a number of advanced plastics and metal molding materials. 

"My father was one of the first to come on board with the PowderFlo feedstock," Neal Goldenberg says. "About nine years ago he had been doing some work on molding refractory metals with a friend who is in the MIM business. That whetted his appetite. He had developed his own organic binder but it limited the part sizes. He wanted to mold large metal parts." 

About three years ago a supplier of ceramic PIM feedstocks stopped by. It was AlliedSignal Inc. (Morristown, NJ), later to be absorbed into Honeywell. Then-AlliedSignal's PowderFlo feedstocks use a water-based agar binder designed to speed debinding, thereby making the molding of large MIM parts economically feasible. Honeywell wanted to put PIM feedstocks containing metal powders on the market. To supplement its lab work, it sought the legendary real-world experience available just 20 minutes away, door-to-door, at PTI. 

Honeywell dropped out of the PIM feedstock business earlier this year. More than a half-dozen people who made up its PowderFlo brain-trust now work in nearby Clifton. This includes Jerry C. LaSalle, MIM operations director at PTI. LaSalle was with AlliedSignal/Honeywell for 16 years and was actively involved in the creation of PowderFlo. 

"When I left Honeywell, I didn't even look anywhere else for work," explains LaSalle. He landed at a company where 35 percent of its business is now being cooked up by its soup-to-nuts production of fully qualified metal parts—golden apples weighing up to 4 lb. 

Hip Overmolding 
PTI treats all of its raw materials as just that—raw materials. Its exotic plastics and its PIM feedstocks are staged in the same area, molded in the same room, and tracked through to shipping by a single material control system. 

Everything coming in and going out of PTI is certified. Tests on incoming materials are used only when absolutely necessary. As you might expect from the markets it serves, the quality room at PTI is state of the art. "When you are producing parts like surgical implants and working for aerospace, you can't use anything less," says Neal Goldenberg. 

The environmentally controlled molding shop has a 28-ft-high ceiling and 16 product family workcells on the floor. The first that catches your eye is one with a late-model vertical Engel overmolding implantable plastic onto titanium-cobalt hip replacements. 

Like all of PTI's molding machines, the Engel is computer controlled and closed loop. It is also customized to PTI's proprietary specs so that it can be used for molding either plastic or metal parts. 

Workcells and Furnaces 
PTI favors equipment made in North America. Most of its loaders are purchased from Conair, its granulators are provided by Cumberland, and its water treatment system is a Thermal Care product. The company has more than 100 active molds, producing some very interesting parts. 

For example, one cell is molding 200-round ammunition containers for the 5.56-mm rounds used in the lightweight M249 SAW (Squad Automatic Weapon). PTI helped modify the visual and tactile feel of the cases to better distinguish those carrying blanks from those loaded with live ammo. Talk about error-proofing! 

PPS containers for housing and dispersing radar-reflective materials are molded in a cell nearby. These go out of the press and right into a lathe in the cell, resulting in manufacturing cost savings PTI passes along to its customers. Cold and hot environment thermal cycling chambers in another area are used to condition the properties of some of its exotic plastic parts prior to mechanical testing. 

Speaking of hot conditioning, PTI's sintering room houses a custom-built AVS batch furnace with a 10-cu-ft, high-purity molybdenum hot zone. "With the binder systems in our feedstocks, we can put large MIM parts into the furnace when they are still green. There is virtually zero debinding," says LaSalle. "When it comes to MIM part sizes, we are not yet operating at the wall, not by any stretch of the imagination." 

For higher-volume jobs, PTI has a 300 Series pusher from CM Furnaces. It features high-precision controls that use advanced feedback and control capabilities that were developed for PTI under a government-sponsored NIST (National Institute of Standards and Technology) grant program. Purchase of similar pusher and batch furnaces is being considered. A twin-screw compounding extruder for feedstock manufacturing also is on the way, as is an entirely new PTI plant. 

Wanted: Strategic Allies
"We have a strong background in the corporate cultures of our customers that helps open doors. This is very important when dealing with aerospace and the military," says LaSalle. 

Donald M. Olson, engineering manager and information systems coordinator, tells us that this is especially true when projects involve R&D work, like PTI's development of a proprietary alloy of different plastics that is degradable in fresh and salt water, UV light, and compost. It could be used for making chaff—counter-measures ejected from an aircraft to reflect a radar threat—and for making it green. 

Olson says PTI currently is molding a 316-L stainless steel backing plate of its own design that is the first aircraft-certified MIM part ever produced. MIM is the primary process called for in the certification. 

PTI also works in close communication with its suppliers. Using financing from another government grant under NIST, it recently challenged molding machine OEMs to build an ideal MIM press—one capable of molding feedstocks with higher solids loadings to reduce shrinkage. 

"But we have no intentions of getting out of molding plastics," Neal Goldenberg says. "Plastic is still 65 percent of our business and molding is our core competency. We're not really getting into new markets with MIM so much as we are bringing a new product base into our existing markets. It's a natural progression."