EC-Twist - MEP Instruments

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Melt Rheology EC-Twist’s range of measuring possibilities is not limited to solid samples. With cone-plate, TruGap TM or parallel-plate measuring systems with automatic gap control, polymers can also be measured as melts. Constant TruGap TM monitoring and control enables the use of cone-plate measuring systems to determine Mastercurves (Time-Temperature Superposition TTS) and measure temperature ramps – so when measuring polymer melts, you benefit from a constant shear rate in the measuring gap. Gap errors due to thermal expansion are no longer an issue. Shear rheology of melts A flow curve over a wide range of shear rates can also be generated from a Mastercurve using the Cox-Merz transformation. Regression models such as Carreau- Yasuda allow the calculation of important material parameters such as the relaxation time and power law index. The polymer's zero-shear viscosity is directly proportional to the molar mass. Transient time effects Stress relaxation tests provide information on time-dependent relaxation behavior after a defined deflection; creep tests on the other hand enable “longterm flow” measurements of melts, bars, films and fibers under a constant stress load. Time-Temperature Superposition The Time-Temperature Superposition enables the determination of Mastercurves at a given reference temperature. In this way, the frequency response and relaxation behavior can be determined over a range of more than 10 decades. Extensional viscosity Extensional rheology is an excellent method for morphologically investigating elastomers or polymers. By measuring extensional viscosity under a preset constant strain rate, a distinction between linear and branched polymers is easily made. Further testing options In addition to the applications presented here, various further tests are available. EC-Twist’s application software offers diverse presets such as strain and amplitude, torsion, extension, compression (normal force), temperature and many more which can be combined in real time, enabling the exact simulation of application conditions. Flow curve converted from frequency sweep using Cox-Merz Mastercurve (Time-Temperature Superposition) Extensional viscosity of branched and linear polymer melts vs. time
Specifications Unit EC-Twist 302 EC-Twist 502 Bearing - Air Air EC motor (brushless DC) with high-resolution optical encoder - Permanent torque (60 min), no signal drift - EC mode (controlled shear rate and shear stress) Maximum torque mNm 200 230 Minimum torque, rotation nNm 10 10 Minimum torque, oscillation nNm 2 2 Torque resolution nNm 0.1 0.1 Angular deflection, set value µrad 0.1 to ∞ 0.1 to ∞ Angular deflection, resolution nrad 10 10 Step rate, time constant ms 5 5 Step strain, time constant ms 10 10 Step time (rate, strain), 99 % of set value (all samples) ms 30 30 Minimum angular velocity (1 rad/s 10 -9 10 -9 Maximum angular velocity rad/s 314 314 Minimum angular frequency (2 rad/s 10 -7 (3 10 -7 (3 Maximum angular frequency rad/s 628 628 Normal force range N 0.005 to 50 0.005 to 50 Normal force resolution mN 0.5 0.5 Dimensions mm 678 x 444 x 586 753 x 444 x 586 Weight kg 42 47 Toolmaster TM , measuring system - Toolmaster TM , measuring cell - QuickConnect for measuring systems, screwless - Electronic trimlock for the measuring system - Digital Eye, Software video option and camera - Virtually gradient-free (horizontal, vertical) temperature control - CoolPeltier TM , Peltier system with built-in cooling option requiring no additional accessories for counter-cooling °C -5 to 200 -5 to 200 Peltier-based convection oven, does not require LN 2 for cooling °C -20 to 180 -20 to 180 Actively Peltier-controlled hood, Peltier technology °C -40 to 200 -40 to 200 Concentric-cylinder Peltier temperature control °C -30 to 200 -30 to 200 Convection Temperature Devices (CTD) °C -150 to 1000 -150 to 1000 Automatic gap control/setting, AGC/AGS - TruGap TM for in-place measurement and control of the gap - T-Ready TM - Direct strain, amplitude controller - Direct stress, amplitude controller - TruRate TM - TruStrain TM - Normal force and velocity profiles, tack, squeeze - Raw data (LAOS, waveform, ...) - 1) Depending on measuring point duration and sampling time, practically any value is achieved 2) Set frequencies below 10 -4 rad/s are of no practical relevance due to the measuring point duration > 1 day 3) Theoretical value (duration per cycle = 2 years) Legend: optional
Page 1 and 2: EC-Twist Dynamic Mechanical Analyze
Page 4 and 5: Ready to Meet Your Requirements Con
Page 6 and 7: DMTA in Torsion and Extension Relax
Page 10: Photos: Croce & Wir Anton Paar ® G

EC-Twist - MEP Instruments

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