Producing the basis for PET with Siemens
2Pages

{{requestButtons}}

Catalog excerpts

Producing the basis for PET with Siemens - 1

Producing the basis for PET with Siemens siemens.com/instrumentation The many faces of plastic They come as apparel, home furnishings or comforters – while their industrial equivalents are used to reinforce tires and conveyor belts: polyester has become an inherent part of our daily lives, especially in the form of polyethylene terephthalate (PET). What makes polyester so popular is its manifold characteristics: it is a light, low-maintenance material, it is soft and keeps you warm, it is firm yet flexible. While these varied characteristics result in diverse benefits for the consumer, they can pose just as diverse challenges to PET producers. Reducing material waste in flexible PET production A chemical plant in Indonesia specializing in producing PET was looking for a solution to reduce the waste resulting from product variance. The factory produces 25,000 tons of polyester annually, which is then provided to other manufacturers to produce a vast range of end products. This vast range requires different PET grades, which are achieved by slight variations in the synthesis procedures. In order to investigate possible options to upgrade their primary processing, understanding the complete process is vital. In the case of PET production, this process starts with mixing three key ingredients – PTA and IPA powder along with glycol liquid – in specific ratios to make a paste. These source materials are stored in stainless steel bins with a volume of 75m3. Rotary feeders move the material from these bins to a batching vessel along with glycol to make the polyester paste. The batching vessel is agitated to ensure that the mixture is always consistent. Monitoring tank levels, precisely controlling the dosing, the efficient use of raw materials and ensuring a consistent mix are the key parameters when it comes to improving the primary processing. When Siemens designed a new system for the chemical plant from the bottom up, the Siemens S7-1200 PLC controller was the first product that was installed to set up a compact and flexible automation solution, which keeps track of the key parameters and the process efficiency. Don’t get mixed up during mixing Each raw material bin is mounted on Siwarex WL280 ring torsion load cells to achieve optimum weighing accuracy. These load cells are connected to two Siwarex WP251 weighing modules, which are specifically designed for batching applications. The advantages of this solution are that the WL280 load cells feature a C3 class rating for accuracy as well as an IP68 rating for protection against dust and direct high-pressure cleaning – ideal for handling powder materials such as PTA. In connection with the Siwarex WP251, a customer-specific application was engineered with a resolution of up to +/- 4 million

Open the catalog to page 1
Producing the basis for PET with Siemens - 2

The SITRANS FC430 monitors the glycol flow. The glycol as the liquid component in this process is monitored by a Sitrans FC430 coriolis mass flowmeter provi-ding a 4-20 mA output, which varies based on the flow rate of the material. This signal is fed into an analog S7-1200 input module. A Sipart PS2 positioner controls the valves to regulate the flow rate. In such flexible processes as this one, the operator individually sets the setpoint for total production. At the field level, this flexibility is achieved using Sinamics variable frequency drives, which independently adjust the flow rate...

Open the catalog to page 2

All Siemens Process Instrumentation catalogs and technical brochures

  1. MAG 5000/6000

    12 Pages

  2. SIPART PS100

    4 Pages

  3. SITRANS

    12 Pages

Archived catalogs