Moisture Balance Ideal for QC in Molding Plastics

Moisture Balance Ideal for QC in Molding Plastics

Operators of extrusion molding, injection molding, thermoforming and related equipment must pay particular attention to resin moisture content because too much or too little moisture will impact the quality of molded products.  Correct moisture content depends on the resins being used and is specified by plastic resin manufacturers.    

Resin manufacturers may ship product at the correct moisture content but equipment operators should take steps to ensure ambient conditions at the plant do not raise or lower the content prior to processing.  Two important steps in quality control are proper resin storage and using commercial drying ovens.  Periodic checks with a benchtop moisture analyzer programmed for plastic resins provide assurances that moisture content is on target, or otherwise call for pre-processing adjustments.

The Benchtop DSC 71P Lab Moisture Analyzer for Quality Control

Operating on the LOD (loss of weight on drying) process it handles samples to 71 grams and delivers a moisture content accuracy of 0.01% with a 10 g sample.  Drying temperatures can be set in 1⁰C increments over a range of 30⁰ to 200⁰C.

Fast, accurate calculation of moisture content to readout (resolution) of 0.0001 g or 0.001% moisture content is accomplished with the benchtop DSC 71P halogen moisture analyzer available from Tovatech.  Mastering the DSC 71P is easy compared to the chemical-based Karl Fisher method and is much more environmentally friendly.


A special feature of the moisture balance is its real time graphic display of the moisture loss rate using the WinCT program and a PC.  Moreover, injection molding QC personnel can program up to 20 sets of test parameters for quick call-up when different resins and procedures are employed in the plant.

Programmable features include drying time, shut off criteria at the end of the analysis, and drying profiles.* 

Once the moisture analyzer is programmed it is easy to operate. 

Simply call up the program, tare and load the sample pan with evenly spread resin, close the lid and press the start key.  When moisture testing is complete data are sent to the PC and/or optional printer to maintain GLP, GMP, and ISO protocols.

A Complete Resin Moisture Analysis Package

In addition to the features mentioned above, the DSC 71P is equipped with a secondary radiation assist filter to augment the halogen heater and shorten measurement time, 30 g of sodium tartrate dihydrate for accuracy checks, an easily read vacuum fluorescent display panel, and a 5-year warranty.  The unit comes with a detailed operating manual.

Contact the moisture analysis professionals at Tovatech for additional information on the DSC 71P moisture balance or for answers to other weighing and measuring questions. 

About Rachel Kohn

So how did an MIT Ph.D. end up selling refrigerators? When I figured out that a lot more scientists buy lab refrigerators than innovative leading-edge instruments. I hope that my many years of lab experience will help you find the right equipment for your work. Before co-founding Tovatech I worked in business development and project management at Smiths Detection, Photon-X, Cardinal Health, and Hoechst Celanese. And before that I spent 12 years as an R&D chemist at Hoechst Celanese and Aventis working on advanced drug delivery systems, polymer films and membranes, optical disks, and polysaccharides. Some day, eventually, I’ll make enough money to develop an innovative technology that will change the world. Read More