EPC variPLANT is a flexible plant concept for polymer production. 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-optimized 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

Over the course of its typical 40 to 50 year lifecycle, an industrial plant is repeatedly modified, modernized and optimized. EPC PETvantage® is a patented, customer-orientated revamping (upgrading) and de-bottlenecking process that meets your need to maximize 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 fiber and filament yarn specialities
• Lower consumption, for example, of blue toner

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 optimization 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

Masterbatch, also known as color 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 polymerization reaction does not achieve 100% caprolactam conversion, the polyamide 6 product still has a residual monomer content. After polymerization, 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.

Theprocess 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 modernization 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 utilization 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
• Minimized 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 optimizes 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.