MILTON — Ever been mildly amazed at how easily and cleanly the perforated top seal on a plastic pouch of cough drops tears away? There's a science to that.
Ever marvel at how difficult it can be to snap a piece of adhesive masking tape by hand? Again, that's science at work.
It comes from a source that's closer than you might imagine.
The packaging for some of the more common consumer items—plastic baby-wipe containers, pre-packaged pizza crust wrappers, microwaveable food bags and re-sealable pouches of chocolate, cat food and chicken jerky—begins its life cycle as plastic film produced at NEX Performance Films in Milton.
The plastics production plant at 1264 E. High St. is one of four plants owned by Charter NEX Films that designs and produces specialty plastic films—sheets of flat plastic in bulk rolls for use in dozens of applications in packaging for consumer products.
It all starts with bubbles of plastic that rise high into the air inside the five-story Milton plant.
In a recent tour of NEX, Plant Manager Paul Szablowski gave The Gazette an in-depth walkthrough of the process. It's incredibly technical how plastic for a product such as yogurt container lids is made, but Szablowski broke it down.
"What we do here is WIP," Szablowski said, using a plastics industry acronym for "work in process"—a bulk, raw product for use in later production. "No printing or labeling here. It's the bulk rolls of material plastic that go into all kinds of products."
Each plastic film product at NEX is made from a blend of plastic pellets a little smaller than Tic Tac breath mints. The pellets, each type made from a different blend of resins, are stored outside in a series of silos at the plant and pumped into the silos from train cars at the plant's rail site.
For an order of, say, plastic film to produce lids for Pringles potato chip canisters, NEX will calculate the density, strength and consistency needed for the product. Then workers pump pellets from the silo into the plant floor through a series of tubes that curve around the plant like a giant, futuristic-looking church pipe organ.
From there, the pellets are shot into computerized blenders that can blend nearly two-dozen different types of pellets to match the product's "recipe." From there, the pellets go into hoppers that fill plastic extruders—machines that melt and extrude the pellets as plastic film.
This is where the giant plastic bubble thing comes into play.
The extruders push out the plastic film that's still in a near-melted state. It becomes a long cylinder—a 3-foot to 6-foot-wide bubble of thin plastic film—that rises through a series of guides, all the way up to the fifth floor of the plant.
As it rises, the bubble cools and runs through a series of computerized autogaugers—electric eyes that test the plastic for density and consistency.
"The consistency is very important. One tiny miscalculation in the blend, and you've got a roll of scrap. It can cost hundreds of dollars," Szablowski said.
When the bubble reaches the top, the guides narrow gradually until the bubble's two sides meet.
There it is split with a cutter into two pieces of film.
The two pieces of film then are then pulled through rollers back down to the plant floor, where they're wound into bulk rolls, boxed up, trucked to the plant's storeroom and shipped out.
Szablowski wouldn't give the volume of the plant's daily output, but he said the floor's 45 workers do 12-hour shifts and ship out about four to six truckloads of plastic film a day.
An expanding corporate bubble
In December 2012, NEX, which has other plants in Turner Falls, Mass., and Rhinelander, merged with a competitor, Charter Films—a plastics company with a plant in Superior.
Szablowski said the merger means one major thing for Milton's NEX plant: new extrusion equipment in two of the plant's "bubble bays." That will increase the speed and capacity of production at the plant, he said.
"We're really excited that the newly formed company partnership has faith in the Milton plant to increase production capacity here," Szablowki said.
The Milton plant has been in operation since 1995, and the bulk of its workers are from Milton and Janesville. Szablowski said the upgrades are an indication that the company is looking to its Milton plant as a long-term fit for production.
So the next time you're amazed at how fresh that month-old container of Pringles potato chips has stayed, don't just thank preservatives.
Think about the plastic, seal-tight lid. It started as a big, floating bubble in Milton.