Home > Technology > Compounding

Suppliers enhancing capabilities of compounding lines and components

Issue: April 2017

Suppliers of compounding extruders and related components have been busy working on innovations that offer versatility and maximize throughput, all the while improving speed to market. They’re also striving to make components easy to assemble and disassemble for cleaning — an important feature as compounders run more formulations.

During the K show, Farrel Pomini received a very favorable response to its CPeX combined extruder/compounder/continuous mixer that is geared toward product development trials, officials said.

“The CPeX was developed to help compounders successfully test and develop the most challenging formulations in a lab environment,” said Paul Lloyd, business unit director at Farrel Pomini. “The marketplace is increasingly competitive. Usually, raw materials are purchased from large global suppliers almost on a fixed commodity pricing basis and sold into a highly competitive global marketplace sensitive to price and delivery conditions. All producers face these common market conditions.”

Farrel’s CPeX is focused on lab-scale development trials and speeding time to market, but also reducing development costs. The machine made its debut at the K show and will be introduced to the Asian market at Chinaplas in May.

Here are other companies that have recently introduced innovations to the market.

BUSS

Buss AG, Pratteln, Switzerland, has upgraded its MX 105 kneader compounding line for the production of halogen-free flame-retardant (HFFR) cable compounds. Its MX series is geared for making highly filled and cross-linkable HFFR compounds, such as flame retardants, masterbatches, cross-linked PE, semiconductive materials and cable compounds. The series was introduced at the end of 2007, said Mike Irish, VP and sales manager with Buss Inc. USA.

“The industry is continually looking for compounding equipment that is versatile, cost-effective, energy-efficient, easy and quick to clean, with a small footprint,” he said.

To that end, Buss introduced the redesigned MX 105 during the K show. It can handle throughputs of up to 3,300 pounds per hour, and Buss has made the machine quieter and more energy-efficient. This was accomplished through mechanical simplifications, including a new reduction/stroke gearbox with an optimized timing belt and electrical drives. Additional features for the drive include an integrated lubricating station and optional noise-absorption hood for the drive gear.

The company said that major modifications have been made to the discharge extruder, including the reduction of its diameter. It now is 160mm instead of 200mm and includes a fully retractable pelletizer, resulting in significant space savings. The discharge screw is electrically heated and air-cooled. That is safer and simpler compared to the oil-fired heating system previously used. The pelletizer also has an upgraded aluminum three-blade knife arm.

On the model 105-22 F, the screw diameter is 105mm and the barrel has a L:D of 22-to-1. The 105 is the mid-range model of the series and is also available with barrels that have L:D ratios of 15-to-1, Irish said. The machine can be fitted with two or three feed hoppers. The “F” in the model name designates the flanged extruder, Irish said, which has a flange that attaches directly to the kneader.

If a melt or gear pump is used, Buss indicates that in the model name with a “P.” To process semiconductor compounds or carbon black masterbatches, the discharge extruder can be replaced by a melt pump, according to the company.

The machine’s throughput is up to 2,200 pounds per hour with a maximum screw speed of 750 rpm.

CPM CENTURY EXTRUSION

CPM Century Extrusion now is marketing and selling screw technologies from its recent acquisition of Extricom GmbH, a Lauffen, Germany, company founded by Josef Blach, a twin-screw extruder innovator. CPM now has sales, manufacturing and assembly services and development/trial labs in the Americas, Europe and Asia, said Bob Urtel, president of CPM. (See related Short Run on Page 83 of this issue).

Officials said that they have seen increased demand for higher concentrations of fillers, improved dispersion and the use of natural fibers, which has driven development of new mixing technologies. Customers want the ability to process these materials using high-torque, high-speed twin-screw compounding extruders.

Extricom’s technologies include the Barrier Screw, which is designed for dispersive mixing through elongational flow across the barrier, which is integrated in the mixing element design. The interchanging flow channels in the two screw flights of Extricom’s Segment Screws allow for distributive mixing. The company also offers T-profile elements, components that allow users to change the screw’s channel depths to meet the mixing requirements of particular materials.

The T-profiles use different channel depths, from one screw shaft to an adjacent element on the other shaft, which results in different screw/barrel clearances to achieve uniform shear for improved dispersion with less energy input, according to the company. These typically are used in the dispersive mixing section, for example, in downstream mixing following the addition of filler after the side feeder.

CPM now also is promoting Extricom’s RingExtruder RE, which Extricom has marketed as the latest step in the evolution of the twin-screw extruder because of its tightly intermeshing screws. Twelve screw shafts are arranged symmetrically in a circle and rotate in the same direction, but each on its own axis. The outer barrel and the stationary core enclose the screws with a narrow gap, the company said. Blach developed the RingExtruder.

COPERION

Coperion is using a new material for die plates in its UG underwater pelletizers. In conjunction with DEW Deutsche Edelstahlwerke GmbH, Witten, Germany, Coperion has developed NikroDur, which is a new wear- and corrosion-resistant metal matrix composite produced by powder metallurgy. It has improved hardness and wear-resistance, and lower thermal conductivity. Coperion said that advantages include longer die plate life, reduced downtime, higher corrosion-resistance, energy savings and improved pellet quality.

Coperion’s new UG 750W underwater pelletizer, which has a die plate made from the new material, is designed for producing polyolefins and is capable of achieving throughputs of 60 to 70 tons an hour. It has an extended cutting surface adapted from the UG 1000, and borrows its blade shaft bearing, pelletizer hood and drivetrain from the UG 750. In this model, Coperion increased the number of holes by roughly 27 percent, to about 5,700.

ENTEK

Entek Extruder is offering a new size in its QC³ line of twin-screw, co-rotating extruders. The QC³ 33mm has been designed for the production of small lots, according to the company.

This size is in direct response to customer demand, President Kirk Hanawalt said. Its 27mm machine in this line is for lab environments; the 43mm that it introduced at NPE2015 is for small to medium-sized lots of compounds.

“We were getting a lot of requests for something in between,” Hanawalt said, “a machine specifically designed for small lots, but with more output than the lab machine.”

The QC³ designation stands for quick change, quick clean and quality control, the ruling triumvirate in compounding operations. The 33mm has new mechanical features, including self-aligning and keyed screw-gearbox couplings to allow for fast and foolproof installation of screws. A lock-and-key feature on splined shafts prevents screw timing errors. Gauges are conveniently located for quick monitoring of lube- and cooling-system running conditions. The quick-change strand die and a robust barrel shroud are easy to remove. A tip wrench gives operators the ability to remove tips with screws in the extruder.

An optional air tool and an air connection can be mounted on the machine. The machine has tool holders for keeping tools organized, visible and nearby. The controls package features software that keeps the machine running unless the operating conditions exceed clearly defined, customer-specified limits or if the safety of the operator is in jeopardy.

The extruder comes standard with Entek’s vacuum stuffer/side feeder combination unit that it introduced last year, the company said.

LEISTRITZ

Leistritz Extrusionstechnik GmbH, Nuremberg, Germany, showcased several innovations during the K show, but officials emphasized that the days of simply designing and building a twin-screw extruder are gone.

“We are thinking now in systems,” said Sven Wolf, managing director of Leistritz Extrusionstechnik.

Recent innovations represent superlatives. The ZSE 260 MAXX is the largest twin-screw the company has brought to market, officials said during presentations, and its ZSE 12 HP-PH is the smallest. The 260 is a co-rotating model with a variable-speed drive designed for large-scale compounding but with the flexibility to adjust to fluctuating production requirements. At the Leistritz booth, attendees could see one of the extruder’s barrels on display; the company used virtual reality to showcase the compounder.

According to compounding experts, more users are seeking processing flexibility in their equipment, and the 260 was built for that purpose. The machine has a drive power of nearly 9,500 kilowatts and a screw torque of almost 112,500 newton meters (Nm), which can yield a throughput of 35 tons an hour, depending on the application. That variable-speed drive means energy input can be controlled very efficiently for producing compounds with different melt-flow index values. The system can be equipped with cartridges for heating, or an oil/steam heating-and-cooling system.

As Leistritz’s smallest twin-screw, the 12 HP-PH is geared for the pharmaceutical industry and is ideal for testing plastic compounds. It has a throughput of 50 to 1,000 grams an hour. In designing the machine, Leistritz paid special attention to making handling, cleaning, assembly and disassembly easy. The machine is mobile and features horizontally split barrels; this allows users to view the process, and the screws can either be segmented or compact.

Heating and cooling are critical issues; temperature probes monitor eight separate heating and cooling zones. The heating and cooling system is easy to assemble or disassemble because it has a simple clamping system. The drive has a torque of 20 Nm. The machine is controlled by a PLC interface that monitors functions like torque setting and heating and cooling.

Leistritz’s ZSE 35 iMaxx co-rotating twin-screw extruder follows the ZSE 27 iMaxx. The 35 is designed for the masterbatch industry. As the industry moves toward more frequent product changes, that also means more cleaning, officials said, which can drive up costs. The entire processing unit and the drive are protected against contamination or contact by stainless steel. The machine is equipped with one central water connection. For energy-efficiency, Leistritz has used a synchronous drive; customers can install torque-measuring devices, Wolf said, which can give them insight into energy input, especially when it comes to working with new formulations.

Officials also touted its flexibility. The standard frame length, for example, is designed for barrel lengths with L:D ratios ranging from 24-to-1 to a maximum of 48-to-1. “With a change of formulation, the processing unit can be extended or shortened with no problems,” Wolf said. Add-on modules such as side feeders can be mounted on the left or right of the processing unit.

Angie DeRosa, managing editor

aderosa@plasticsmachinerymagazine.com

For more information

Buss Inc. USA
Carol Stream, Ill., 630-933-9100, www.busscorp.com

Coperion Corp.
Sewell, N.J., 201-327-6300, www.coperion.com

CPM Century Extrusion Group
Traverse City, Mich., 231-947-6400, www.centuryextrusion.com

Entek Extruders
Lebanon, Ore., 541-259-1068, www.entek.com

Farrel Corp.
Ansonia, Conn., 203-736-5500, www.farrel-pomini.com

Leistritz Extrusion
Somerville, N.J., 908-685-2333, www.leistritz.com