From CDL Technology, the leader in plastic production technology, comes a new line of extrusion equipment for the processing of plastics, rubber and other materials. The modular design of CDL twin-screw extruders allows unlimited flexibility in screw configuration and process design. Due to the flexible design, CDL twin screw extruders are extremely versatile. These quality-built machines feature compact design with a tuck under or rear drive motor that provides ease of operation and maintenance. CDL offers one of the widest selections of twin screw extruders in the industry. CDL twin screw extruders are available in 30 mm, 40 mm, 50 mm, 60 mm, 70 mm, 80 mm, 90 mm, 120 mm, 160 mm and 240 mm diameters. An assortment of standard and custom-designed screw and barrel sections are available for various applications.
Small diameter CDL extruders are ideal for material testing, new product development and quality control purposes; while the larger equipment is used for pelletizing, co-extrusion, compounding, wire coating, and blown film, pipe and sheet extrusion.
CDL extruders are rugged, efficient and may be customized to meet specific requirements…
The most important components in all CDL Extruders are the barrel and screw assemblies. The quality and finish are carefully matched to the complex interaction of barrel, screw and raw material. CDL barrels are hardened alloy steel or contain bimetallic cast liners to add wear and chemical resistance. The barrel end sections are equipped with a rupture disc port to protect against excessive pressure buildup. These features ensure consistent quality of the final product as well as extend the service life of the equipment.
CDL barrels and screws can be assembled in any combination to provide plasticizing raw material feeding, ventilation, or gas extraction. The co-rotating intermeshing screws are arranged in parallel and are self-cleaning. Screw geometry can be adapted to individual applications.
The barrels are segmented into sections. The standard material is Nitrided Steel, but a wide variety of other materials are available such as bimetallic liners for highly corrosive or highly abrasive materials. Barrel segments available are designed for conveying/mixing (no holes), top feed, glass fiber feed, side feed, liquid/gas injection, pressure monitoring, venting, or other custom ports. Each barrel segment is standard with cast aluminum or bronze heaters with air or liquid cooling.
Barrel ventingThe CDL system provides that screw channels in the venting area are only partially filled with material. This permits efficient single-stage or multi-stage venting. A vacuum system with separator is installed on the extruder frame, and, like all serviced elements, it is easily accessible.
Vent Barrel SectionsFor vacuum and atmospheric venting to remove moisture, solvents, and other volatile substances.
Feed Barrel SectionsEnable multiple feeding of dry ingredients and injection of liquid materials.
Combination Barrel SectionsIntroduce materials downstream of the main feed point with the use of a CDL side feeder. The combination barrel top port may also be used for venting.
A variety of materials, metal treatments and special wear resistant liners are available to provide wear and corrosion resistance for specific applications.
Metering/FeedingAll extruders can be equipped with feed hoppers or metering equipment as desired. By using a volumetric or gravimetric metering system, an individual spectrum of formulation can be provided. Gravimetric metering permits continuous weighing and feeding of raw materials and consistent, accurate production.
Control SystemsCDL control panels incorporate the latest in solid-state technology, DC ammeters, digital speed indicators, heat zone meters, pressure gauges, melt thermocouples, strip chart recorders, and other custom instrumentation as required.
The standard CDL control and monitoring unit is readily accessible and easy to operate. This ensures that the machine and process can be reliably operated and monitored simultaneously.
Temperature controlAll CDL machines are equipped with a temperature control system. Barrels are divided into heating and cooling zones according to the process technology of the individual barrel or screw section and their respective functions. This guarantees a precise temperature profile over the entire length of the barrel. Heating is derived from resistance heating elements, cooling from the use of air or fluid. The temperature of each barrel zone is controlled separately.
Auto tuning PID temperature controls are standard for each zone, which display set point, present value and digital amp meter and heater open alarm.
Drive unitThe drive units comprise high-performance, low-noise gear reducers with integrated torque distribution that is connected to the AC or DC drive motor by means of a clutch. AC inverter drives are standard as they offer excellent torque over the speed range. DC drives with or without tach feedback are also available.
Torque Distribution CaseThe thrust bearings are lubricated by filtered oil with pump and cooling system, pressure switch and drive shutdown alarm in case of low oil pressure.
ScrewsStandard or special design conveying elements are available in nitrided through-hardened, corrosion or wear resistant alloys and are thoroughly inspected and tested to assure the highest quality. High volume feed elements provide improved material intake for materials with poor feeding characteristics.
Kneading Blocks and Dispersive Mixing ElementsCDL extruder mixing and kneading elements are designed in a variety of lengths, pitches and pitch directions. Kneading blocks are constructed using several disks of equal or varying widths spaced at equal distances from each other. The result is precise shear, melt and energy control. In addition, this mixing process provides homogeneous melt and controlled dispersion-distribution of additives.
The order in which kneading and mixing components are arranged can be freely selected depending on product formulation. The positive engagement of the screw segments on the screw shaft enables individual segments to be easily replaced and thus ideally adapted to continuous high output.
Screw finishes include…