Hiscien Engineering’s team is the first engineering team in China that has started the study on the PA6 polymerization technology. The design work for the first plant was started in the year 1996 and the plant was successfully put into production in 1998. 
Up to the year of 2020, Hiscien Engineering has accomplished more than 40 PA6 polymerization projects. Also, Hiscien Engineering has exported and successfully commissioned 3 PA6 polymerization plants to Turkey and India, marking the first of this kind of business activities of Chinese engineering companies.  
Through the accumulation of experiences and innovation of technology for more than 20 years, Hiscien Engineering has developed its mature technology with the main features of, 
1. customerized solutions for the reuse of recovered caprolactam according to customer’s actual scheme of product and the actual configuration of production lines, to keep the high quality of product chips and in the mean time minimizing the raw material consumption;
2. optimization of the process design, equipment design and the control system design to guarantee the stable and economic operating of the plant. 

·Products and Applications

➢Textile chips for high speed POY and FDY spinning

➢Conventional chips (for the spinning of micro-fibre, PET/PA conjugated yarn, BCF, staple fibre, fishing net yarn etc.)  

➢Chips for IDY spinning

➢Chips for engineering plastics

➢Chips for film use

·High Lights of the Technology

➢1) Raw material preparation system

——Proportional mixing for the materials from different suppliers is possible in order to keep the stable specification of the raw materials under the condition of sourcing raw materials from different suppliers.

➢2) Polymerization system

——The “direct re-use of recovered CPL” process is adopted

——The process of “3 stage polymerization” or “2 stage polymerization with cracking system for the recovered CPL” are to be adopted according to the actual product scheme and the configuration of production lines with different projects, giving the most optimal solution for the re-use of recovered CPL

——The process conditions with each of the reactors being flexibly controllable, the RV range can be wide.

——Low raw material consumption. The loss of raw material with above process shall be less than 1 kg per ton of dry chips

——The above mentioned 3 stage polymerization process having well solved the problem of fluctuating temperature, pressure and level in pre-polymerizer which is common with the conventional 2 stage polymerization process, which has given the plant a condition to stabilize the quality of product.    

——By taking proper measures with the equipment manufacturing and the process design, the problem of “scaling” which is common with the pre-polymerizer when producing semi-dull or dull chips has well been eradicated.

➢3) Additive preparation system

——Fulfilling the requirement of the additive preparation and adding of different recipe that are needed for different products

——The function of the system is complete and the automation level is high. 

➢4) Extraction system

——Several unique design are adopted, guaranteeing the extraction effect and in the meantime minimizing the bath ratio. 

➢5) Drying system

——Stable moisture content of the chips.

——Optimized design to minimize the pressure loss and to save energy consumption.

——SSP function can be designed with the system if needed

➢6) Chips conveying system

——Automatic pneumatic conveying system designed as per the actual condition of the project, having the advantages of low pressure fluctuation, stable running, low maintenance, low N2 consumption and low energy consumption.

——By way of reasonable design, the system is equipped with the function of dust-removing. Low powder content with the packaged chips is achieve.

➢7) Recovery system

——multi-stage evaporation system powered mainly by steam or MVR system powered mainly by electricity, according to the actual situation of energy costs. 

➢8) Other measures for energy saving

——Making the reasonable use of steam and steam condensate to uplift the efficiency of energy

——Close loop with the process water circulation, waste water effluent is minimized.

·Typical Products 

➢PA6 Chips for High Speed Textile Spinning 

      RV of 2.4~2.6, Bright (BR) / Semi-dull (SD) / Full-dull (FD) chips, used for textile POY and FDY spinning.

➢PA6 Chips （Bright）for Conventional Spinning

      RV 2.6~2.9, used for micro-fibre, PET/PA conjugated yarn, BCF, staple fibre, fishing net yarn spinning.

➢PA6 IDY Grade Chips

      RV 3.3-3.45, used for industrial yarn spinning.

➢PA6 Film Grade Chips

      RV 2.7~3.4, usd for different grades of nylon films.

➢PA6 Engineering Plastic Chips

      RV 2.0-3.4, used for different grades of engineering plastics.