Measure moisture content in plastic pellets
The moisture content of plastic pellets has to be controlled as it's an important aspect for the production of high-quality plastic parts. The right moisture content of polymer resins ensures trouble-free compounding and injection molding, smooth surfaces and ideal mechanical properties of the injection-molded parts. Controlling the moisture content in plastic resins is crucial for the manufacturing of high-quality products. An accurate and easy alternative to the official Karl Fischer Titration method is the HX204 moisture balance.
What are alternative methods to the Karl Fischer Titration?
- Karl Fischer Titration is the ASTM standard test method to determine the residual moisture content in plastics (see ASTM D6869; Standard Test Method for Coulometric and Volumetric Determination of Moisture in Plastics). However, Karl Fisher Titration isn't well suited for using 24/7 on the factory floor by factory personnel.
- As an alternative to Karl Fischer titration for routine testing, ASTM has established the 'Standard Test Method for Determination of Moisture in Plastics by Loss in Weight', ASTM D6980. This method describes the use of moisture analyzers.
- Using a halogen moisture analyzer is an ASTM-recognized test method to determine the residual moisture content in plastics.
Do I need to use an instrument with 0.1 mg resolution?
- Plastic pellets contains approx. 100x less moisture than food samples. To determine such small amounts of water content in a robust and accurate manner, using a moisture balance with high resolution of 0.1 mg is mandatory.
- Within the METTLER TOLEDO range of instruments, only the HX204 moisture analyser offers this high resolution.