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Equipment makers tout specialized machinery

Issue: February 2018

Since compression molding was invented more than 160 years ago, it’s become recognized as an efficient, low-waste process that offers a significant amount of flexibility with a low initial investment.

While many types of equipment manufacturers offer standard models that are readily available off the shelf, buyers of compression molding machinery often are looking for customized models. When buyers have an unusual application, or are dealing with multiple types of materials, the manufacturer often works with them to design a custom press from the ground up.

Sometimes it costs a little more or takes a little longer, but many processors consider those small prices to pay to get a machine that’s perfectly suited to their needs.
Below are the latest offerings from two compression molding equipment manufacturers that specialize in creating custom machines.

Surface Generation

For many companies, change is an incremental process, but there are others that make huge leaps. When Surface Generation delivered its most recent press to a customer — a compression molding machine with 200 channels, which are individually heated and cooled pixels — it represented a major step forward.

U.K. Government Minister Sir Alan Duncan MP, left, and Surface Generation’s Ben Halford discuss a PtFS mold base at the company’s facility in Rutland, U.K.

“We’d never before created a system with this number of channels,” said Ben Halford, founder and CEO of Surface Generation. “I think the biggest we’d done was 128 channels for commercial use, and maybe 150 for research and development.”

The press takes advantage of Surface Generation’s Production to Functional Specification (PtFS) technology, which was developed to provide precise temperature control when working with advanced composite materials like carbon fiber.

The buyer of the 200-channel machine — Quatro Composites of Poway, Calif. — needed the bigger size because it wanted to improve the way it manufactured a very large part for an aerospace company, made from a carbon fiber and thermoplastic composite with a melting point of 750 degrees Fahrenheit.

Quatro wanted to be able to make the part as a monolith — a single piece, like a statue carved from a single block of stone — rather than from several smaller pieces.

The advantages are many:
• A monolith is inherently stronger than a part made of separate pieces.
• It eliminates a hand layup process.
• It provides a “massively better” buy-to-fly ratio, a measurement that reflects the percentage of a given material that makes it into the final part.
“In the prior process, the buy-to-fly ratio was maybe 65 percent or 70 percent,” Halford said.  “With this new process, it’s probably closer to 90 or 95 percent.”

Beyond its exceptional size, Surface Generation’s 200-channel compression molding machine debuts several new technologies. The first is the sixth version of its SG Heater software platform that provides exceptional control over temperatures throughout the molding process.

“Ultimately, that’s what we sell to our customers: multizone thermal control,” Halford explained, using the concept of a checkerboard as an analogy for how the process works.

“Each of the squares on the board is individually heated and cooled on demand, fully independent of its neighbor. We can group two adjacent pixels together and say, ‘You must not have a temperature variation between the two of you more than 5 degrees,’ and that becomes one zone. Then we can group all of the other 62 pixels as another zone and say, ‘You can’t vary more than 10 degrees, and the variation between the two zones can’t be more than 20 degrees.’”

Think of it this way: A thermostat might hold a room at a steady temperature, but it really isn’t a uniform temperature; it’s colder by the doors and windows, for example.

“Our ability to put heat in and take it out instantaneously, we discovered, results in about a 75-percent reduction in pressure required to process something,” Halford said. “Everyone has hot and cold spots on their molds. With other systems, when they want to address that cold spot ‘by the window,’ they need to add heat everywhere in the room, not just the few small areas where it’s cold. With multizone temperature control, we can put the exact amount of heat needed, in the exact place it’s required.”

Users are not limited to an eight-by-eight grid of pixels, which are available in 2-, 3- and 4-inch versions. They can add another row if it becomes necessary, and can even change the shape and configuration of the pixels to produce a different product.

Another innovation is that the new machine heats and cools using the same fluid medium, which, in this case, is air.

“That allows us to not be biased towards heating or cooling,” Halford said. “In any molding process, what goes up must come down in temperature terms, so most people focus on the hot first and then put the cooling system — literally and physically — behind it. But we don’t have that dividing line.

“Picture a hair dryer. We can vary the amount of air going through it, and we can vary the amount of power, so we can be heating and/or cooling fairly instantaneously.

“So now think of your checkerboard as being more like a disco floor from ‘Saturday Night Fever,’ where the pixels are pulsing, adding or removing energy, and constantly adjusting to what’s going on,” Halford said. “We call it ‘active thermal management.’”

French Oil Mill Machinery

French Oil Mill Machinery has introduced a new brand of hydraulic presses for compression molding in addition to its traditional line of custom presses. The new brand, TMP Asian, offers seven models in its Econo-Tech RC compression molding presses, which have clamping forces ranging from 200 tons to 600 tons and platen sizes ranging from 21.7 inches to 35.4 inches. The two largest machines, the 500- and 600-ton presses, were added to the lineup in August. All models in the line are capable of high-speed production using double mold plates.

French Oil Mill’s Econo-Tech RC hydraulic compression molding machine, shown in an RTMO configuration.

“The breadth of the line and the press construction ensures a variety of options for many customer requirements,” said Tayte French-Lutz, the company’s director of marketing. “Customers choose their appropriate press construction options based on the level of automation they want in their process, which is typically determined by the type of part the customer needs to mold. The higher levels of automation enhance material loading and part unloading.”

French Oil experts guide customers through the various sizes of presses and options. One of the newest options available is an advanced PLC for processing accuracy and recipe storage.

“We differentiate ourselves in the market with TMP Asian by supplying presses that feature a widely accepted PLC that allows for sequence changes,” French-Lutz said. “The PLCs are programmable and allow storage of multiple pressing ‘recipes’ that allow the operators to easily mold each cycle with the same temperature and pressure parameters, yielding more consistent parts.”

One of the biggest selling points of the Econo-Tech RC series is the number of options and configurations available. Buyers can choose one of four mold-opening (MO) configurations, in which the heated platen moves:
• UDMO — up and down only;
• NTMO — up and down, plus bottom mold slides in and out on a rail;
• RTMO — up and down, bottom mold slides in and out, and can be opened 90 degrees on the rail; and
• FTMO — up and down, in and out, and offers front top mold open for molds with two, three or four layers.

For even greater accuracy and more precise positioning, users can operate the press at slower speeds, and they also can adjust the speed at which a mold opens. A variety of sensors is available to prevent damage by ensuring molds are perfectly positioned during operation.

Michael T. McCue, copy editor

mmccue@plasticsmachinerymagazine.com

For more information

French Oil Mill Machinery Co.,
Piqua, Ohio, 937-773-3420, www.frenchoil.com

Surface Generation America,
Richardson, Texas, 972-699-9976, www.surface-generation.com