Solutions polymerization
LEWA pumps offer the following advantages for polyethylene production:
- Hermetically tight
- Pressures over 300 bar
- High flow rates
- Drives with electrical stroke adjustment
- Motors for frequency converter operation
- Wide reproducible adjustment range
- Extremely precise flow rates
- Sturdiness and reliability
- Explosion proof
Areas of application in polymerization
LEWA supplies metering pumps and systems for ethylene polymerization which are used in processes including the following:
- Radical production in high pressure reactors, e.g., autoclave reactors, tube reactors (LDPE)
- Catalytic production in low pressure reactors (MDPE, HDPE, LLDPE)
Application examples are:
- Packaging materials, e.g., shrink wrap, wrapping film, film for “bag-in-box” applications, food packaging film, laminated papers
- Highly stressable containers for industrial use
Background for ethylene polymerization
Process description
Polyethylene consists of hydrogen and carbon. The properties of polyethylene can be changed through copolymerization. It is very resistant to acids, alkaline solutions and other chemicals. Its range of application is limited because it softens at temperatures above 80 °C. Polyethylene is a thermoplastic produced from the polymerization of ethylene. It belongs to the polyolefins and is produced based on ethylene gas.
LDPE (soft polyethylene) results from the high-pressure process and HDPE (hard polyethylene) from the low-pressure process. In both production methods, it appears first as a viscous fluid.
Source: Wikipedia, February 2012
