CHICAGO — Merritt Extruder of Hamden, Conn., has entered the shape extrusion market.
``For the first time, we can tell a customer to send us a shape and we'll send you equipment to make it,'' Sandy Guthrie, president of Merritt Davis Corp., said in an interview at Plastics USA, held Oct. 6-8 in Chicago.
Merritt Extruder is a division of Merritt Davis. The firm's exhibit featured an extrusion line capable of producing quarter-inch hollow, round and square shapes of high-impact polystyrene. The machine was developed for a first-time Merritt customer.
``It will take 10 days for us to train the customer's employees and set up the equipment,'' and the customer will use the line to make toys, he said.
The Vanguard series is a complete system, from single-screw extruder through cutter.
`This is a cost-conscious system,'' Guthrie said. ``It has a life span of 20-25 years.''
Depending on the die and other needed equipment, the lines costs $150,000-$250,000.
The line is designed to operate continuously at rates up to 240 pounds per hour. The 21/2-inch extruder, with a 24:1 length-to-diameter ratio, features a double-reduction gear reducer with all hardened and ground gearing and a high-capacity thrust bearing. Extruders can range from three-fourths of an inch to 12 inches.
In addition, the line offers Merritt's new six-bolt design for heaters, which helps the heaters last longer, he said.
The line, which can be as long as 44 feet, has two dies for round and square shapes. The dies provide consistent material-flow characteristics at all speeds. The spiderless design includes an integral heating system to ensure constant heat throughout the die. A spray ring helps cool material and helps the plastic keep its shape.
A 10-foot vacuum tank with two separate compartments and controls is included. The precision component has adjustable valves and a 3-horsepower vacuum pump. A separate, closed-loop water-circulation system is available.
Instead of having the vacuum and cooling tanks on wheels, they are bolted to the ground. The trough can move horizontally as much as 18 inches.
The heavy-duty, dual-belt puller has a long-wearing set of seamless rubber belts and an easy-open system for simple product insertion. The belt also has an encoder feedback loop to the main motor control, which keeps the belt from pulling too fast, making the walls of the tube too thin.
The fly knife cutter is driven by an 80-inch-per-pound brushless servo motor and is capable of 500 cuts per minute manually and 1,500 cuts per minute with a single blade on an automatic setting. The cutter moves with the material as it is extruded, providing clean cuts instead of diagonal cuts, Guthrie said.
In addition, a winder can be added to the end of the line. The same setup is used for extruding pipe and gaskets. The line speed depends on the material, Guthrie added. Styrenes cool faster than some other materials.
Stephen Peterson, vice president of sales for Merritt Extruder, called the new machine ``a very affordable extruder and system.''
Merritt also recently shipped a large reclaim extruder. The 10-inch, 32:1 length-to-diameter ratio was designed to process as much as 10,000 pounds per hour of low, linear low or high density polyethylene. The extruder has twin oversized, closed-loop systems and twin 600-horsepower motors.
``We can supply an entire system for those who need that service, for rates from a few hundred pounds per hour up to 10,000 pounds per hour,'' Peterson said.
Also, Merritt recently shipped a new 6-inch extruder with a vented, 39:1 length-to-diameter ratio. It can produce more than 3,000 pounds per hour.
The line features a new, extra-high-capacity, closed-loop cooling system. The heaters have cast-in cooling coils that are piped for easy maintenance and efficient cooling. The two-stage Merrexx High Performance Feed Screw used in the process provides melt-temperature control, melt homogeneity and pressure stabilization while maintaining high material-output rates.
The machine complies with the European Commission's safety and liability regulations.
Merritt designs and builds extruders and systems for the profile, compounding, reclaim, pipe, sheet, wire and cable, cast and blown films, tubing, fiber, fiber-optic, blow molding and rubber industries.