Coperion equipment: ZSK, STS and CTE PLUS extruders, K-Tron feeders

ZSK twin screw extruders: how the machine is built

ZSK machines are co-rotating twin screw extruders for plastics, recycling, chemicals, food and pharmaceutical products. The process section is modular: melting, mixing, devolatilizing and pressure build-up zones are assembled from individual barrels for the task.

The screws are self-wiping, and a configuration scales from laboratory to production size.

• Modular process section: individual barrels, self-wiping screws
• Every barrel tempered separately: electric heating, water cooling
• Nitrided steel as standard, wear protected versions available
• Constant diameter ratio across a series secures scale-up

ZSK Mc18, Mv14, MEGAcompounder and MEGAlab

The ZSK range is split by duty. Mc18 serves high torque work: engineering plastics, glass-filled compounds, filling and devolatilization. Mv14 is for a large free volume and materials with low bulk density. MEGAcompounder homogenizes polyolefins downstream of the reactor, MEGAlab develops recipes.

• ZSK 18 MEGAlab: batches from 200 g, up to 40 kg/h
• Kombiplast: single screw discharge for sensitive products
• ZSK FilCo: filtration and compounding of recyclate in one step
• ZSK Food and ZSK Pharma designs

STS Mc11 and Mc PLUS: 11.3 and 13.6 Nm/cm³ specific torque

STS compounders cover engineering plastics, masterbatch, cable compounds, recycling and battery materials. The series is split by specific torque: Mc11 at 11.3 Nm/cm³ and Mc PLUS at 13.6 Nm/cm³. The laboratory STS 25 Mc11 proves a recipe, and the two-stage design serves sensitive plastics.

• STS Mc11 — 11.3 Nm/cm³, STS Mc PLUS — 13.6 Nm/cm³
• Engineered in Germany, assembled in Nanjing to CE directives
• Pressure build-up up to 30 bar, side feeder with swivel arm
• Modular section, individually tempered barrels

CTE PLUS: the Coperion Nanjing series

CTE PLUS covers twin screw compounding for small and medium plants. The new gearboxes were engineered in Stuttgart and carry 7.2 Nm/cm³ of specific torque; they are interchangeable with the previous CTE generation.

The range runs from CTE 20 PLUS to CTE 165 PLUS: up to 14,300 Nm per shaft and 5,000 kg/h.

• Gearbox specific torque 7.2 Nm/cm³, exchangeable with the previous generation
• Range CTE 20 PLUS … CTE 165 PLUS: up to 14,300 Nm per shaft, 5,000 kg/h
• Factory Acceptance Test in Nanjing before every system ships
• Controls: relay, IPC, PLC or PCC; TÜV CE option

Coperion K-Tron feeders: gravimetric and volumetric

Coperion K-Tron builds gravimetric and volumetric feeders with pneumatic conveying and material handling systems. Gravimetric dosing rests on SFT load cells, volumetric dosing on screw and vibratory units. Feeder type, screw and controls follow the material and the accuracy required.

• SFT load cell: 8,000,000:1 resolution in 20 ms, RS-485 signal
• Single and twin screw, micro, BSP, vibratory, liquid feeders
• AccuRate, SWB and FB130 weigh belts, K-SFM flow meter, K4G blender
• KCM control and SmartConnex network for a feeder group

K-Tron feeder components: wear and replacement

In a feeder the screw, sleeve and insert wear first, then the turbine, shaft and drive; on a weigh belt the belt, the rollers and the load cell. We identify the component from the feeder type, screw diameter and material: abrasive powders need a reinforced design, food lines a hygienic finish.

• Wearing parts: screw, sleeve, insert, turbine, shaft, drive
• Weigh belts: belt, rollers, SFT load cell
• K3 design for pharmaceutical lines
• Quick Change QC fast-changeover feeder

ZSK barrels, screw elements and wear

The main wear items of an extruder are the cylinder liners, screw elements and shafts, throttle bushings, seals and dies. Nitrided steel is standard; filled compounds call for high-alloy versions. These components set the length of a planned line stop.

• Wear parts: liners, screw elements, shafts, bushings, seals, dies
• Material: nitrided steel or high-alloy wear protected version
• Patented quick-release screw shaft coupling for ZSK 26 Mc18
• Gearbox replacement and barrel service as a separate line

Feeding and devolatilization: ZS-B, ZS-EG and FET

Auxiliary equipment raises throughput where material intake and devolatilization limit the line. Feed Enhancement Technology fits the feeding zone with a gas permeable wall and applies vacuum from outside.

The ZS-B side feeder handles powders, additives and chopped glass fibre, ZS-EG removes volatiles through a larger cross section.

• ZS-B MEGAfeed feeds materials with bulk density from 20 kg/m³
• ZS-EG: throughput increase up to 30%
• Quick-release clamps on feed hopper and degassing dome
• Pluggable cartridge heaters up to ZSK 92 Mc18, IP67 plugs

Pelletizing: UG, WRG, EGR and ZGF

Pelletizers are divided by product. The underwater UG covers almost all thermoplastics, above all polyolefins at high throughput. The water ring WRG runs up to 15 t/h, filled products included.

The eccentric EGR serves temperature and shear sensitive plastics, the centric ZGF food and pharmaceutical products.

• UG — underwater, throughput up to 100 t/h
• WRG — water ring, up to 15 t/h including filled products
• EGR — eccentric, ZGF — centric design
• Strand pelletizing with water bath and air knife

Pneumatic conveying, loading and valves

Pneumatic conveying moves bulk solids through a pipe on a flow of air or another gas. Typical materials are powders, pellets, granules and irregular particles below 20 mm, most with a bulk density between 0.1 and 1 kg/dm³.

In dilute phase particles are airborne at 4 to 40 m/s; dense phase is slower and gentler.

• Dilute phase gas velocity 4–40 m/s, particles below 20 mm
• Bulk density of most materials 0.1–1 kg/dm³
• Built as a pressure or a vacuum system
• Components: loaders, receivers, filters, blowers, valves

Rotary and diverter valves

Rotary valves feed and discharge material in pneumatic conveying systems and act as airlocks below receivers, filters and cyclones, holding system pressure while material keeps flowing.

The design follows the material, the drop-through or blow-through arrangement, and pressure, hygiene and wear requirements.

• Flange sizes from 80 mm up to 1000 mm
• Standard up to 3.5 bar, reinforced to 6 bar, special above 20 bar
• Rotor speeds from 1 to 70 rpm
• Sanitary, ATEX flameproof and wear protected designs

Spare parts and unit service: 48,000 items

The spare parts store holds more than 48,000 items, original components and parts from other suppliers among them. Stock items support 24-hour express delivery, key components are held as emergency stock, and alternative types are supplied for discontinued parts.

Gearbox replacement and barrel service cut downtime.

• More than 48,000 items, other suppliers included
• 24-hour express delivery for stock items
• Emergency stock of key components
• Alternative types for discontinued parts

Industries, materials and digital services

The equipment serves plastics processing and recycling, chemicals, battery materials, food, pet food and pharmaceuticals. The material decides which screw, insert, seal and wear protection a unit needs.

Lines come with controls up to open Industry 4.0 systems, the C-BEYOND platform and VibeTrack monitoring.

• 5,000 employees, 50 locations, 140 years of experience
• Divisions Performance Materials and Food, Health & Nutrition
• More than 15,000 compounding machines and extruders installed
• 20,000 feeders and pneumatic conveying systems, 10,000 bulk handling systems