Instron: New Melt Flow Tester for Automated Test Series with up to 5 Selectable Weights

Instron's CEAST MMF Multiweight 7028 is a new Single and Multi Weight Melt Flow Tester for high-precision MFR and MVR determination in quality control and incoming goods inspection, in plastic production and compounding facilities, in the plastic processing industry and R&D centres. Designed as an enhancement of the CEAST MMF 7027, the new top-of-the-range system is conceived for conducting automatic test series with up to five preinstalled weights, which can be selected in increasing or decreasing, and now also in arbitrary sequence. The system performs measurements that fully comply with ISO 1133 A and B, ASTM D 1238 procedures A, B C and the multi-weight procedure D. Piston displacement measurement with a resolution of 0.02 mm (optionally 0.05 mm) and a precise and stable temperature profile in the barrel (50 °C to 400 °C, optionally 500 °C, at ± 0.1 °C) provides for high repeatability of the tests. The system therefore anticipates the stricter requirements of the ISO/DIS 1133, T.2 standard currently under preparation.

The entire test sequence, including compacting of the material undergoing test, loading with a specified force and final purging of the barrel, takes place entirely without operator intervention. To this end, the MMF 7028 instrument is equipped with a fully automatic system for loading the weights onto the piston. These can be chosen from the integrated set of eight weights, graduated from 0.325 kg to 21.6 kg in line with internationals standards, for single- and multiple-weight measurements. The wide spread of weights makes the system suitable for testing virtually all plastics, from fast flowing masterbatches or short-chain polymers to highly viscous rubbery or filled compounds.

The innovative mechanical concept of the new Instron CEAST MMF 7028 includes a heating chamber which tilts towards the user for easy cleaning of the instrument. Optionally, a powerful, fully integrated semi-automatic cleaning system for quick, easy, and effective barrel cleaning can be added to the instrument. A piston with magnetic insert facilitates testing of high-fluidity polymers. To prevent material escaping from the die during the pre-heating phase, a swivel device is available. Automatic extrudate cutting devices, a die swell measuring device, or a digital weighing system can also be integrated into the system. For chemically aggressive materials such as PVC or fluoropolymers a corrosion resistant combination of barrel, piston and die is available.

The proprietary VISUALMELT Software includes pre-programmed test sequences for standard measurements (to ISO 1133 and ASTM D 1238) and additionally enables a variety of parameters and settings such as the temperature profile during pre-heating, or the order of individual test sequences, to be individually configured for adaptation to different national standards or other testing tasks. The software processes acquired measurement values, outputs results as numerical data or as a graph and organises the measurement values in the integral data base. The system´s large touch screen display facilitates programming of test sequences und calling up of test results.