High Performance Compounding

Application Example High Performance Compounding

Introduction Typical Production Masterbatch Engineering Plastics The production of plastic con- With high performance com- Compounding and pelletizing sists of many important process Output pounding technology, the time- of engineering plastics (i.e. steps, which are needed to gen- Twin screw compounders are consuming step of fine grind- filling, reinforcing, alloying, erate a homogeneous applica- equipped with different screw ing of pellets and premixing colouring and degassing of PA, tion specific plastic compound diameters from 25 up to 150 in batch quantities can be PP, PET, ABS, PUR, PC or POM) from a number of different raw mm in various steps depend- eliminated. Pigments are fed are the specialty of high perfor- materials. ing on the manufacturer of the directly into the melt by means mance compounders. compounder. The typical line of gravimetric feeders. Pig- rates range from 50kg/h up to Process ment concentrations up to 70 6’000 kg/h. The compounding process is a percent are possible. Compared continuous process. The main with the old premix feeding steps in the compounding pro- End-Products method, the new process allows cess are: Automotive, Building & Con- formulations with reduced wax content or no wax at all. This > conveying struction, Appliances & House- wares, Electronics, Furniture, means that high performance > plasticizing/melting Health & Hygiene, Leisure & compounding technology not > mixing Sport, Packaging, Pipes, Tex- only benefits productivity and quality but also contributes to > homogenizing tiles, etc. reduced raw material costs. > blending > dispersing Fillers Typical layout for filling, > devolatizing Polymer A, polymer Chopped B and additives glass fibers > reacting as a premix reinforcing, alloying > heating/cooling and colouring > visc-breaking Loss-in- weight > Loss-in- screw feeder cooking weight > belt feeder Loss-in- pressurizing weight vibratory feeder Main Ingredients Twin screw side feeder The main ingredients which Devolatizing must be continuously and very High Performance accurately fed are base poly- Compounder Strand die head Air knife Pelletizer mers such as PP and PE. Water bath Typical Additives > Stabilizers, lubricants, plas To bagging tifiers, colour pigments, fillers, station flame retardant, cross linking agents, foam agents, etc. Polymer Additives Pigment > Glass or carbon fibers for Masterbatch production using reinfor-cement, base polymer pellets for alloying to new new split feed technology compounds > Recycled material > The additives can be in the form of powders or masterbatch pellets. Loss-in-weight screw feeders Twin screw Key Requirements side feeder One of the key requirements in High Perfor- Devolatizing mance Strand high speed compounding is to Compounder die head ensure a continuous, uniform Air knife Pelletizer Water bath infeed with very tight short- term accuracy and repeatability.

To bagging station

1 Higher Accuracy with Advanced Feeding Technology

Feeding Process Typical Scope of For sticky additives, such as Environmental Irganox, Tinuvin, or CaCO3, The main polymer and additive Supply etc. Coperion K-Tron P-Series Conditions masterbatch are fed very accu- The main polymers are normally receivers are the ideal solution. Plastic compounding systems rately with a single screw feeder, pellets or powders fed with a are typically classified as IP55/ e.g. K4G, into the main inlet of single screw feeder type K4G or NEMA 12. In some processes the compounder. Control System K2-ML-S60/S100. Alternatively N blanketing is required. This The loss-in-weight feeders dose 2 Refill is conducted via a Co- a K-ML-KV2/3 vibratory feeder means that the LWF’s are the ingredients in a preset ratio, perion K-Tron vacuum loader can be used. equipped with a well-prov- set in the operator interface or system from an octabin station en pressure compensation > The typical feed range for downloaded from the host com- and large storage silos. system at the inlets and outlets. screw feeders is 0.2 - 15’000 puter via K-Vision Line control- A K2-ML-T35 feeds the stabi- 3 dm /h ler to the locally mounted KCM. Depending on the process, gas lizer in the form of powder into explosion protection may be re- > The typical feed range for All the process relevant param- the main extruder inlet. quired, i.e. Zone 1, Temperature vibratory feeders is 2 - 5’000 eters for each feeder are stored The chopped fiberglass is fed 3 class T3 for Europe and Zone 1, dm /h in the appropriate recipe. via K-ML-KV2F into the side Division 2 for USA. In this case > The additives are feed by feeder of the second inlet of The on-machine KCM combines standards Coperion K-Tron XP Loss-in-weight screw feed- the extruder. The ratio control the function of motor drive and executions must be applied. ers such as K2-ML-T20/T35 is handled via the K-Vision feeder control in a compact at rates of 0.2 – 200 kg/h, operator interface which in package. depending on the recipe. turn controls the feeders via In this example the K-Vision pro- KCM (Coperion K-Tron Control vides a single user interface for Module), mounted locally at Refill up to 16 feeders. The integrated each feeder. For free flowing products Co- K-Link feature allows for com- All the recipe handling and line perion K-Tron vacuum loaders munication with the host DCS monitoring is done via the fac- or receivers can be used to system via Modbus (Modicon) tory DCS-System. keep the feeders well sup- RTU, Allen Bradley DF1 or Sie- plied. Thanks to the patented mens (3964R). Alternatively, a dual cyclone technology, most Coperion K-Tron Smart Com- materials can be fed without mander could be used for up to needing a filter. 30 feeders and 8 lines.

Host communication Typical Process Layout Control network

Fiberglass Powder additive

K-Vision Main polymer Masterbatch Host computer Operator Interface DCS / PLC Bag Octobin dump discharg- station ing station Coperion K-Tron receivers

Loss-in- weight vibratory K4G feeder screw feeders Loss-in- weight screw feeder

Degasing Side feeder Main inlet

Pelletizing Drying High Performace Coating Compounder

Conveying to storage

2 Advantages of In order to even be able to Proven Performance with Coperion K-Tron Smart speak of adhering to recipes Technology Smart Weighing with changing operating data, one condition must be fulfilled: Technology kg/h the mass flow must adapt to new setpoint The goal of a compounding the setpoint as quickly as pos- plant is economical production! sible. This is only possible with Among other things, this means advanced gravimetric control Feeder 1 as little waste as possible and and the high sampling rate and minimum reconfiguration time. resolution offered by Coperion The Coperion K-Tron feeding K-Tron’s Smart Force Trans- system makes this possible. ducer weighing technology. Feeder 2 new setpoint achieved An important factor is the ad- herence to the recipe during t ramping up of the extruder and t1 t2 t3 naturally also during large set- Conventional feeder control t1+ t2 point changes. The short-term ModernK-Tron SmartConnex feeder control t1 accuracy of a high performance extruder is a key factor for qual- Massflow during setpoint change ity of the end product. This image shows the requirements of an extruder manufacturer with regard to the desired behaviour during a setpoint change in the line. It is nice to show that this challenge could be met in the test lab well beyond any expectations. Instead of overriding the new values first and then working them in, the desired value could be obtained almost directly. This is extremely advantageous for high speed extruder feeding.

Feeding test with free flowing material

1.8 Modern K-Tron SmartConnex Control System

) 1.6 1.547 Conventional Control System ( % 1.4 1.2 m ple s

s a 1 c . 0.93 0.925 S e

0.8 5 , 0.6 m a g

S i 0.4 0.506 2 0.2 0.343 0 0 100 200 300 400 500 600 700 800 900 1000 1100 Feed rate (kg/h)

Feeding test with poor flowing material

Modern K-Tron SmartConnex Control System 2.5 Conventional Control System ) % (

s 2 1.999 e l

p 1.921 m

a 1.727 s 1.5 . c e S 1.139 5

, 1 1.186

a 1.135 m g i S

2 0.5

0 0 500 1000 1500 2000 2500 3000 3500 4000 4500 Feed rate (kg/h)

The graphs above show a comparison of feeding accuracy, which was obtained with different gravimetric control systems. To ob- tain these results, the following conditions must be given: a high sampling rate (here 112/sec.), efficient digital filtering and a fast control algorithm. In other words: the sampling rate must be higher than the controlled elements can react. Coperion K-Tron feeding station with refill system

3 Smart Solutions

Advantages of Typical Applications Coperion K-Tron There are a number of well known users of high perfor- Modular Feeders mance compounding lines in > practically no wear parts the following industries/pro- > smooth surfaces avoid con- cesses: tamination > Technopolymers compound- > weighing technology with ing integrated digital filter for > Engineering plastics dynamic weighing even in > Thermoplastic difficult environments > Masterbatch Producers > feeder does not cause weight > fluctuations Special areas in BOPP-Film lines References > Adhesives and Sealants Several thousand customers worldwide are successfully us- Testing Facilities ing Coperion K-Tron Modular Coperion K-Tron has well- Feeders in their compounding equipped testing facilties to processes. Our Sales depart- test high rates of PE powder ment will be glad to provide you and additives. We can handle with a reference list. up to 20 t/hr of PE powder for We will be glad to provide accuracy testing. Long term contact information or to help testing is also available since arrange visits to reference sites. material can be recirculated.

Future Potential Services The plastic compounding mar- Additional services are also ket is steady growing approxi- available, such as: mately 3% annually. The auto > industry is replacing more and System Engineering more steel parts with highly reli- > Installation Start-up able plastic parts. New plastic > Operator and Maintenance Coperion K-Tron feeders with refill system on a compounder composites will be developed Training which will lead to the building of new compounding lines. Retrofitting and debottleneck- ing of existing compounding lines also offers the opportunity for process improvement.

Manufacturing plants: Coperion K-Tron Pitman, Inc. Coperion K-Tron Salina, Inc. Coperion K-Tron (Switzerland) LLC 590 Woodbury-Glassboro Rd 606 North Front St. Lenzhardweg 43/45 Sewell, NJ 08080, USA Salina, KS 67401, USA CH-5702 Niederlenz Tel +1 856 589 0500 Tel +1 785 825 1611 Tel +41 62 885 71 71 Fax +1 856 589 8113 Fax +1 785 825 8759 Fax +41 62 885 71 80 www.coperion.com E-mail: [email protected] E-mail: [email protected] E-mail: [email protected]