The right polymerization method to get the best result.

Those who want to obtain the best result, usually choose the most promising method that they are familiar with. Our specialists can tell you exactly which polymerization method is most suitable for your application. The selection of the polymerization method and the design of the plant also take into account commercial considerations, and the further processing and production depth desired by each individual customer.

EPC uses the method appropriate to the particular chemical properties to convert (polymerise) low-molecular compounds (monomers) into high-molecular compounds (polymers) by radical, ionic or Ziegler-Natta polymerization [PE, PP, PS, PVC, PAN), polycondensation (PET, PBT, PC, PA), or polyaddition.

Solution, precipitation, emulsion, suspension or bead, or melt polymerization is used depending on which method is most suitable for the application and the modification of the desired polymers.

Polyethylene terephthalate (PET) is probably the most important polyester. It is obtained by an esterification reaction between ethylene glycol (MEG) and terephthalic acid (PTA) to produce the low viscosity monomer in the first stage. The esterified material is then transformed into a high molecular polymer in a polycondensation reaction.

The PET polymer is a transparent, lightweight, strong, safe, shatterproof and recyclable material. PET in its natural state is colourless and semi-crystalline. Depending on the processing method, the PET can be semi-rigid to rigid, and it is also especially light in weight. PET makes an excellent gas and moisture barrier.

PET resin is also very sustainable as it is recyclable. It is by far the world's most recycled plastic. PET can be recycled many times – and used in food applications, personal care products, carpets, clothing and many other products.

As well as developing and constructing PET plants, EPC also offers a number of tried and tested technologies it has developed in-house, that restore PET plants to profitability. EPC PETvantage® is a patented, customer-orientated revamping and de-bottlenecking process that meets your need to maximize plant profitability with minimal retrofitting costs and the shortest plant stoppages. EPC engineers have succeeded in converting a textile fibre plant to food-quality PET bottle grade chips, and at the same time they increased the capacity from 440 to  more than 1,000 tons per day. It was, and still is, the world's largest PET plant revamp – "Made by EPC".

The PET-G belongs to the family of PET and is commonly defined as glycol modified polyester. It is produced by partial replacement of the ethylene glycol (MEG) with CHDM (1-4 Cyclohexane-dimethanol) during the PTA esterification reaction. The usage of CHDM as a co-monomer enhances specific properties of the polymer, and compared to PET, the PET-G polymer offers the following advantages:

  • Inability to develop crystalline haze. This leads to high transparency (glass like clarity), making it suitable for packaging of high clarity requirements, e.g. packaging for medical devices.
  • Outstanding thermoforming properties, This allows extreme draw definition, thus modern, thin-wall containers/products with demanding shapes can be produced
  • No yellowing in molding due to high thermal stability
  • Superior chemical resistance - Thus making PET-G suitable for a wide-range of application e.g. containers, electronics, food and medical packaging.

We offer a wide range of industrial solutions for producing quality PET-G polymers:

  • Turnkey delivery of a PET-G Production Facility
  • Conversion of PET Production Facility to produce PET-G
  • Revamping of existing PET Production Facility to produce both PET and PET-G
  • Turnkey delivery of CHDM Hydrogenation Plant for the production of quality CHDM co-monomers (Linked to EPC’s CHDM Hydrogenation Technology)

Like polyethylene terephthalate, polybutylene terephthalate is a derivate of terephthalic acid. The two compounds possess practically identical properties. On account of its more favourable cooling and process behaviour, PBT is particularly suitable for injection moulding processes. It is used for housings of electrical equipment, in motor vehicle components, such as plug-in connectors, and in many other applications.

EPC insidePBT is an in-house software development that gives plant operators substantial advantages in PBT production.

The patented reactor design has hydraulically driven shafts and prevents leaks in the vacuum range. A high level of plant safety is ensured because the hydraulic units do not have to be mounted directly on the shaft. It also has redundancy to avoid outages. The transesterification system is designed for easier and stable process control. The result is high profitability, because reduced downtimes increase availability, and the plant delivers consistently high product qualities.

A substantial quantity of THF is produced as a by-product of the PTA-based process. It can be sold at an attractive price after treatment to improve its quality and purity in the integrated recovery plant. This also shortens the amortization time and increases the profitability of the entire plant.

For commercial reasons, the DMT-based process is hardly ever used, because the by-products cannot be processed at an economic price.

Ingenious process control enables the BDO consumption to be minimized, which drastically reduces not only raw material and energy costs but also the pollution caused by emissions.

On account of its high heat deflection temperature, polyethylene naphthalate (PEN) is a preferred constituent of highly stressed vehicle tyres, such as those used in Formula 1. It is also an alternative packaging plastic for all foods that have to be packed when hot. Due to their higher glass transition temperature, PEN containers can be washed at up to 85°C , whereas 60°C is the maximum temperature for washing PET. Other fields of application for PEN include medical devices, films and threads, as well as loudspeaker diaphragms.

The properties of PEN place high demands on the spinning process and its pull-off forces.

The EPC Group offers not only the process technology, engineering services and the equipment for constructing PEN plants, but also modular concepts for smaller capacity plants to meet all the requirements  of our customers.


EPC Exclusives

Cyclohexanedimethanol (CHDM) is a high value co-monomer used in the production of various polymers e.g. PETG, PCT, PCTG and PCTA to enhance the strength, clarity, and solvent resistance of polymers. CHDM is produced via a two-step catalytic hydrogenation of DMT. DMT is firstly hydrogenated into the intermediate DMDC and then further into CHDM.

EPC Group has vast experience in the polymers and fibers industry and offers complete engineering packages in delivering world-class polymer/fiber manufacturing plants. For the production of high-quality PETG, PCT, PCTG and PCTA, EPC Group offers its modern CHDM Hydrogenation Technology for the production of top-grade CHDM.

EPC’s highly efficient and flexible continuous hydrogenation process guarantees a feasible production of top quality CHDM. Furthermore, having your own state-of-the-art CHDM production line will ensure a continuous supply of high-grade CHDM as raw material for the manufacturing of high value polyesters resin for the fast growing technical applications in electronics, food and medical packaging, construction components and consumer goods.

EPC insidePET® is an operating software developed by EPC for the fully automatic operation and quality control of plants using the innovative EPC polyester process. EPC insidePET® evens out fluctuations in the quality of the raw materials. The consistency of the final products produced by existing plants is significantly improved by the comprehensive, intelligent process control. We offer EPC insidePET® either as a stand-alone solution or in combination with the process optimisation and higher capacity gained with our tried and tested EPC PETvantage® technology.

Commercial and qualitative advantages of EPC insidePET®:

  • Waste and "out of spec" products reduced by more than 80%
  • Freer choice in the purchase of raw materials, unaffected by fluctuations in raw material quality
  • Continuous plant operation and control increase capacity
  • More stable product quality

Over the course of its typical 40 to 50 year lifecycle, an industrial plant is repeatedly modified, modernised and optimised. EPC PETvantage® is a patented, customer-orientated revamping (upgrading) and de-bottlenecking process that meets your need to maximise plant profitability with minimum retrofitting costs and downtimes.

EPC PETvantage® is the most cost-effective alternative to investing in a new plant. Depending on the plant configuration, a return on the investment is usually achieved in less than 2 years. In most cases, the main reactors do not need to be replaced. Operational safety, product qualities and production capacities are increased by a multiple, depending on the basic design of the plant and the space available on site.

EPC PETvantage® generates very high profits, mainly through quality assurance and the consequent greater competitiveness:

  • Plants converted to use alternative raw materials or produce new types of polymers
  • Conversion from textile to bottle PET
  • Flexibility – thanks to polymer modification for the production of specialities
  • Versatility through direct spinning to produce fibre and filament yarn specialities
  • Lower consumption, for example, of blue toner

EPC VARIPLANT® is a flexible plant concept for polymer manufacture. Amongst other things, we use this concept to plan and develop polycarbonate plants. With this continuous process technology, the EPC Group offers you a future-proof plant design backed up by efficient project execution that saves time and money. This all comes from one source, starting from the reactor system and progressing through a process-optimised rectification and modern vacuum system to efficient process control.

EPC VARIPLANT® gives you the following competitive advantages:

  • Highly flexible production
  • Consistent product quality of the highest standard
  • Gains from economies of scale
  • Compact plant design
  • A high degree of automation and ultra-modern process control
  • Technology for efficient consumption of energy and operating materials
  • An environmentally friendly design that meets the requirements of EU standards

Masterbatch, also known as colour granulate, is a granular plastic additive. The content of dyes or additives in the granulates is higher than in the final application. Masterbatches are added to change the properties of the raw polymer to make it suitable for its later intended use. They increase process safety, and are very easy to process in comparison to pastes, powders and liquid additives.

In the refining process, the desired additives are added to the raw polymer material in a mixer, and intermingled in the extruder. The melt is then allowed to solidify again in a cooling trough, after which it is cut up in the granulator. With the masterbatch process, EPC enables its customers to change the products their plants produce quickly and keep cleaning costs low. Energy-efficient extruder systems are long lasting, and economical because the waste heat from the extruders is fed back into the entire plant for re-use.

As the polymerisation reaction does not achieve 100% caprolactam conversion, the polyamide 6 product still has a residual monomer content. After polymerisation, this residual monomer is extracted from the polymer, and fed back into the process. The product is fed out of the cooler into the post-condensation device, which works in a nitrogen atmosphere in the absence of oxygen.

The process patented by EPC enables the material to be optimally substituted by means of nitrogen evolution in combination with a higher pressure. This significantly reduces the extract content in the granulate, while at the same time enriching the extract water to about 18%, and achieving a considerably more consistent retention time. This minimizes fluctuations in the extraction concentration.

The extraction process developed by EPC can also be used in existing plants without requiring any large investments or lengthy modernisation times. A special device distributes nitrogen into up to 16 extraction zones in the column. Granulate flows from top to bottom through a packed bed in the device.

The nitrogen and extract water are fed upwards in a counter-flow. The extraction rate depends on the number of trays, which is determined on a case by case basis. The device consists of trays arranged one above the other. Nitrogen is distributed homogeneously through these trays.

Advantages of the solution patented by EPC:

  • Formation of many extraction zones in one extractor (12 to 16 zones)
  • High utilisation rate of the extract volume (up to 98%)
  • The extraction effect improved by maintaining a highly consistent retention time for the granulate in the extractor combined with the high homogeneity of the water in the zones create the conditions for keeping the extract content of the granulate within tight tolerances
  • A specific, differentiated diffusion drop within the zones enables the highest extract water concentrations to be obtained at the outflow (> 18%) while simultaneously reducing the residual extract content in the granulate (< 0.25%).
  • Existing extractors retrofitted with short shutdown times and low investment costs
  • Higher granulate capacity and product quality, low mechanical requirements
  • Short return on investment time with substantial energy savings in the lactam recovery, maximum energy efficiency
  • Minimised vapour consumption for recovery, smaller vaporiser plants for new investments
  • Reduction of plant size, volume and height, smaller space requirement with higher capacities
  • Reduced specific granulate production costs

 

 

Compounding is a special synthetic refining process. The admixture of additives optimises the properties of the polymer. Different quantities of granulate can be produced by varying the formulation, raw materials and the operating mode of the extruder. The additives – such as glass fibres, flameproofing agents, UV stabilisers, impact strength modifiers, carbon fibres, mineral fillers and dye pigments – are added to improve the properties of the granulates and make them suitable for their intended purpose.

Many polyacrylonitrile production plants use the suspension polymerisation process. Numerous earlier plants have had to be shut down after just a few weeks for thorough cleaning on account of contamination and deposits building up in the apparatus, which always involves lost production. Previous reactors have usually had to be replaced after just a few years because of high material abrasion.

EPC has developed a reactor material based on a special aluminium alloy that is inert under the reaction conditions (no material abrasion), and consequently has no effect on the reaction medium (no uncontrolled reaction behaviour). The material is used in the manufacture of the reactor and in the up and downstream stages involved in the polymerisation reaction. Plant components made of this material do not have to be replaced during the projected lifetime of the plant.

Avoiding deposits building up lengthens production cycles. Less frequent cleaning increases the production capacity and reduces the use of cleansers. The material has strength properties similar to those of steel, and can be worked with conventional machining and forming processes (rolling, bending, grinding, polishing, welding).

The process developed by EPC covers many factors that have a great effect on the profitability of a plant. Handling phosgene is technologically demanding, and highly dangerous for people and the environment. EPC is therefore focusing on a phosgene-free process. The phosgene-free EPC technology for producing polycarbonate considerably reduces the impact on nature and the environment. The by-products of the production of raw materials can be almost completely recycled. For example, the waste water is not contaminated, and can be fed directly into the normal waste water treatment (sewage plants). Furthermore, operational malfunctions do not usually lead to emissions with detrimental effects on the environment.

EPC has developed a modular spinning system that offers you a highly efficient and flexible, complete solution for your filament production. EPC variYARN® is ideal for quick, trouble-free product changes. With EPC variYARN®, you can fulfil your customers' requests at all times with individual PET, PA or PBT filament yarns for each spinning position, such as POY or FDY speciality yarns (NC, HC or micro), and with the most diverse colour nuances or degrees of matting.

The technology

  • Individual spinning positions with gravimetric masterbatch dosing for changing the formulation quickly
  • Individual extruder and additive dosing capable of modular expansion
  • Upgradable for liquid dye dosing technology
  • Upgradable for polypropylene spinning (PP)
  • Shortest product retention times for optimal properties
  • Individual spinning point parameterisation

EPC variPILOT® gives you the flexibility to test new formulations and optimise additive consumption. The quick simulation of new process parameters saves time, while any defective batches have no effect on the quality of your main production. Another advantage is the low consumption of raw and operating materials.

Choosing EPC variPILOT® is a good decision. We examine the site, and specify the future location of your pilot plant before we configure it. We plan and construct your specific test plant in accordance with the conditions, the product parameters and your requirements. We deliver your variPILOT plant pre-assembled, so it can be quickly and easily installed and commissioned.

  •  All the necessary ancillary plants and even a laboratory are available
  • Basic, detailed and turnkey engineering – all from one source
  • Flexibility to meet every degree of complexity of your customers' requests
  • High productivity with maximum variability of your production program
  • Longer campaigns with economical batch sizes (waste and intermediate products are minimised)
  • More economical than other comparable large extruder plants
  • Highly variable number of Variyarn® modules per spinning line, for example 2, 4, 6, 8, 10 or 20 spinning modules