HomeHome / Blog / Milacron

Aug 15, 2023


MADISON HEIGHTS, MICH. — Milacron LLC is back in PET preforms, with the new M-PET injection molding machine. The M-PET debuted at NPE 2015, but it was overshadowed in Milacron's booth by another press

MADISON HEIGHTS, MICH. — Milacron LLC is back in PET preforms, with the new M-PET injection molding machine.

The M-PET debuted at NPE 2015, but it was overshadowed in Milacron's booth by another press which was molding the Klear Can, designed to replace metal food cans. NPE marked the first time the Klear Cans have been molded at a trade fair, and people lined up to check it out.

The M-PET side of the exhibit was more low-key — but is an important step for Milacron, according to Rich Sieradzki, vice president and general manager of PET systems.

It's a well-known story in Milacron circles, that Milacron was a pioneer in PET packaging, but got out of that sector.

“Around 1975, they were the original inventors of the injection molding machine and blow molder for PET,” Siedradzki said. “They collaborated with another company at that time on tooling. And they pretty much led the industry up until the late 1980s.”

Robert Schad's Husky Injection Molding Systems Ltd. was coming on strong, as his Canadian company focused on high-speed injection presses for packaging. Milacron, a broad-line machinery maker, took an early position in all-electric molding machines, promoting the technology in North America. The Cincinnati-based company knew a lot about electric motors through its business in machine tools, a sector that was one of the first to adopt electric technology.

“Well, we're back!” Sieradzki said.

The M-PET also signals how Milacron will work with its Mold-Masters unit, to design hot runner systems for the preform equipment, and Kortec, which specializes in coinjection molding.

Sieradzki explained Milacron's PET preform strategy and technology in separate interviews at NPE 2015 in Orlando, and in Madison Heights, the headquarters of the company's DME business.

Milacron is pitching M-PET as a flexible system that can run any preform molds, and be set up to run a variety of preforms — monolayer or coinjection for a barrier layer — using expertise from Kortec. The M-PET has a transfer station for cooling of the preforms, and can be fitted out with additional stations to do in-line neck-finish crystallization, for hot-fill products, and other processes.

Milacron sold its NPE show press to Bomatic Inc., a custom blow molder in California and a partner in the development of the M-PET.

Bomatic President Kjeld Hestehave said he likes the ability to use anybody's molds in the press. “We're a custom molder and we have everything from a small preform of 14 grams up to 100 grams,” he said.

Hestehave said he is impressed with the balanced hot runner system. Bomatic plans to run 48-cavity preform molds in its M-PET. “To make a good preform you've got to get the plastic to run the same length on every one of them,” he said.

Sieradzki said machinery manufacturers like to work with processors to develop new equipment. “Customers like Bomatic are in front of the market more than we are. When they see an application they attempt to determine whether or not they can do that in-house. Or they have to hire an OEM to develop a machine apparatus to do what they want it to do,” he said.

Hestehave said Bomatic contacted Milacron about getting a preform press. He explained that, in the early 1980s, Bomatic bought a PET preform injection press from Milacron. Fast forward to 2013.

“We contacted our Cincinnati guy and he came out and we told them what we were looking for, and he told me that Milacron was not in that business anymore,” he recalled.

Hestehave, of course, knew about Husky, the PET preform leader. Netstal and other press brands also build preform machines.

“We looked at them all and we were trying to narrow down which one we wanted to go with. Service is very big for us,” he said.

They went with Milacron. Bomatic officials appreciated the fact that Milacron had a technical center nearby in Irvine, Calif. (Bomatic is moving its headquarters plant from Ontario, Calif., to Temecula, in an expansion move.)

Hestehave also likes the fact that Milacron owns Mold-Masters.

“They've got a good group of people. They're all together so there's only one person to call if I have problems,” he said.

The M-PET is Bomatic's third preform molding press.

Geared toward custom molding

Sieradzki said M-PET uses conformal technology for both mold cooling and hot runners. The Mold-Masters cooling system uses less energy and water, and boosts cycle times by 5 to 10 percent, the company claims. “We take a multi-piece approach, and are able to increase the surface area of cooling up to 50 times more,” he said.

Mold-Masters' iFlow hot runner technology uses two machined pieces of steel with cooling channels following the shape of the mold, then uses furnace brazing to bring them together. “So what you get, essentially, is a very streamlined, hot runner melt channel, that has very good balance characteristics and very good thermal uniformity and excellent performance,” Sieradzki said.

The technology gives M-PET a larger molding window and a faster fill rate, which cuts cycle time, he said.

Milacron engineers designed the press to be modular.

“Our approach here is not to duplicate. We take a different approach by putting in the transfer stations,” Sieradzki said. “We're more interested in providing other value services in manufacturing preforms.”

A robot takes preforms out of the mold and moves them to one or more transfer stations for cooling, inspection, gate cutting, or special in-line finishing operations like neck-finish crystallization.

Normally, Sieradzki said, preforms for hot-fill beverages like juices and teas are stored off-line, then returned back to a crystallization station. That method gives production flexibility, but the preforms can retain moisture. “To be able to do it in-line is beneficial to achieve a higher degree of crystallization,” he said. “We want to make sure we deliver more of a finished product before it blows.”

The M-PET uses a parts handling system called mCool Plus. The “plus” stands for “being able to take tertiary operations like neck-finish crystallization, and other preform treatments like that, and do it all within one molding cell,” he said.

“Normally that stuff is done off-line, and we're integrating it into that system.”

Do you have an opinion about this story? Do you have some thoughts you'd like to share with our readers? Plastics News would love to hear from you. Email your letter to Editor at [email protected]

Please enter a valid email address.

Please enter your email address.

Please verify captcha.

Please select at least one newsletter to subscribe.

Find more newsletters at can unsubscribe at any time through links in these emails. For more information, see our Privacy Policy.

View the discussion thread.

Geared toward custom moldingFind more newsletters at