Green Plants, Processes and Products: Recycling the Nation's Scrap
Comfortably situated in Washington’s gorgeous, agriculturally rich Yakima valley, Rainier Plastics has been successfully reprocessing plastic scrap for more than 40 years, with today’s rate at a 24/7 pace.
While maintaining a strong regional presence, Rainier is also able to reach customers throughout North America by taking advantage of the efficient transportation network that serves the Yakima area’s highly productive agricultural industries.
According to general manager Kathy Williamson, a Rainier Plastics veteran with 25 years of experience, Rainier’s success comes from a classic blend of technical know how, diligent customer service and investment in the best technology Rainier can find.
Rainier bales, shreds, grinds, pelletizes and blends raw materials for the plastics industry, reprocessing, for example, more than 25 million pounds of polyethylene in a typical year. The company has high capacity silo storage and offers load blending capabilities up to 50,000 pound quantities.
Reprocessing for the Flexible Packaging IndustryWhile Rainier buys, sells and brokers most types of plastic materials, the company is especially adept at contract reprocessing polyethylene and polypropylene, efficiently picking up scrap from customers and returning the same material as high quality, custom processed pellets produced to precisely match each customer’s requirements.
The scrap comes from extrusion processors and flexible packaging producers and arrives in solid materials, plastic parts and film, in cartons, in bales and on rolls. The solid material is ground or shredded before it is passed on to a pelletizer, made by Erema. Film, often custom configured, multi layered, loaded with additives and heavily inked, usually goes directly into the Erema system, either via the integrated conveyor or roll feed systems.
Williamson says the consistent, round, solid pellets produced on the Erema systems and their ability to handle ink and additives opened more markets for us. Building the contract service for each customer is a hands-on process of becoming a business partner, visiting a customer’s plant and spending as much time there as is needed to understand the customer’s business and what performance they desire in reprocessed materials.
Rainier Plastic’s recently installed Erema plastics reprocessing system is a highly advanced model. The new 1514 TVEplus is capable of a production rate of 1,800 lbs per hour production. It joins a TVEplus installed at Rainier in 2005, and an earlier of TVE purchased in 2004.
Maintaining the MachinesAlonzo Cornella, maintenance manager, says the Erema system effectively processes material fed directly into the cutter/compactor, via either roll feed or conveyor. Most film material goes into the system without preprocessing, without compromising quality.
In the basic Erema recycling system, scrap material is fed into a large vertical cutter/compactor unit that uses friction to compress, size reduce and pre-warm the plastic material. A unique advantage of the large cutter/compactor is the ability to dynamically blend scrap materials while they are in the chamber. Scrap, inconsistent in its material make up and amounts, is blended to produce a steady, predictable melt. The preheated, densified material is then fed directly to the extruder screw. Compression and melting occur gradually, at a precisely controlled temperature, adding minimal heat history to the reclaim.
The TVEplus is a good match for because it is specifically designed to reclaim the increasingly more heavily inked and additive laden plastics packaging common today. When compared to less advanced systems, tests of the TVEplus, with heavily printed packaging film, show an increase of approximately three times the efficiency at removing gases derived from ink, binding agents and other additives. In less efficient systems, traces of these items are more likely to survive, causing bubbles, blisters and film tears, which can cause finished products to be unusable.
In ’s Erema systems any additional, incidental contaminating material is handled by Erema’s unique RTF automatic back flushing screen changers. is especially bullish on the RTFs. “The back flushing capability is really important to us,” he says. “Automatic back flushing keeps production moving and saves a lot of labor.”
Saving Production DowntimeAnother savings comes from a significant reduction of material and down time in screen replacements. When a change of screens is necessary production continues.
RTF screen changers, available in a wide range of sizes, readily integrate with Erema reprocessing systems. Since multiple screens are employed, back flushing can be accomplished with a minimal interruption of melt flow pressure. In the four screen models employed by ’s systems, while one screen is being black flushed, the others remain on line, thus allowing production to continue without interruption and without operator action.
, who is responsible for keeping production moving, says the scrap recycling machines are easy to operate, require low maintenance and minimal labor. “One operator for each machine is all it takes, whether roll or conveyor fed,” he says. “In addition to efficiency, we all also appreciate how quietly the lines run.”
As for installation and startup, says it was a cinch. “Up and running in three weeks with very little time needed to get the temperature profiles right,” he says.
Williamson adds, “We know what it takes to thrive in our challenging corner of the whole plastics reclaim picture and Erema is part of the solution. They delivered the perfect system for us. It allows precise temperature controls, imparts minimal heat history and delivers top quality pellets. Most of our contract scrap goes into an Erema and goes back to customers in precisely the form they require.”