Effective process optimisation for LDPE production

Transformadora de Etileno A.I.E. (TDE) has three plants for the production of LDPE in Spain, with an annual capacity of approximately 160,000 t/year.

In order to detect and optimise dynamic production fluctuations at an early stage, two OP5 measuring systems from Optical Control Systems (OCS) are in use in two of three production lines. Various deviations in production have an impact on viscosity and can therefore be monitored by online viscosity measurement using the OP5s. The continuous measurement of the Melt Index (MI) of polymer samples also enables a final classification of the batch material.

Due to the continuous measurement, real-time results can be visualised in under 10 minutes via the touch panel with a data trend in 24/7 operation. This leads to considerable time savings compared to a manual ISO 1133 measurement. The permanent data logging makes it possible to intervene significantly in the production process and save costs.

The OP5 MFR measurement is a method carried out by means of exact control of the melt flow in combination with a high-precision and self- developed melt pressure measurement. This method achieves a typical reproducibility of +/- 1 % in comparison to the manual ISO 1133 measurement with +/- 5-10 % deviation.

TDE Quality Co-ordinator David Cerra González said: “Quality control has always been important to us. But we were not really aware at the beginning that we could also ensure a considerable process optimisation by means of the OP5 … The continuous quality control with the use of the OP5 allows us to optimise the production process at any time and at the same time to finally classify our batch material. The advantages such as the fully automated measurement, the considerable time savings through the reduction of transition times and the high reproducibility through the OCS equipment, in comparison to the manual ISO1133 measurement, contribute to an effective process optimisation and reduction.”