The temperature gradient plate consists of a high precision chromium measuring plate, with equispaced temperature sensors beneath the surface.

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1 Temperature Gradient Plate MFFT 10 / MFFT 20 ISO 2115 ASTM D 2354 The new designed temperature gradient plate for measuring the Minimum Film Forming Temperature, MFFT The minimum film forming temperature (MFFT) is the minimum temperature at which synthetic latex, emulsions, polymers or adhesives will coalesce when laid on a substrate as a thin film. The ideal way to determine MFFT is to simultaneously dry the emulsion under test over a range of temperatures to see which is the lowest at which film-forming has occurred. This is best achieved in practice by using the Coesfeld MFFT gradient plate. Three steps of the film-forming 1. Evaporation of water 2. Packing and deformation of particles 3. Diffusion of water out of film and coalescence of particles. A film of the latex under test is cast along the stage and left to dry. A visual inspection of the dry film is then made to determine the position along the length of the film where it changes from the coalesced to the non-coalesced state. A noncoalesced film shows whitening and/or cracking. The lowest temperature at which the film is coalesced is reported as the MFFT. The Coesfeld MFFT has been developed to give the user a comfortable possibility to measure the MFFT according the practice described in the ASTM D 2354 and ISO The temperature gradient plate consists of a high precision chromium measuring plate, with equispaced temperature sensors beneath the surface. For measuring the temperature, the MFFT 20 is equipped with 20 Pt-100 temperature sensors. (MFFT 10: 10 Pt-100 sensors). The microprocessor controller guaranteed an optimum temperature control. The temperature set points for the MFFT 20 can vary in a wide range from 30 to +250 C with a maximum possible gradient on the surface of 100. (MFFT 10: -5 to +80 C with a maximum gradient of 20 ). Purge gas is dried with an integrated membrane dryer and flows over the platen. A constant flow acc. to the standards can be set with a built in flow meter. The flat hinged perspex cover provides thermal and atmospheric insulation whilst allowing constant visual inspection of an experiment. Option Cooling devices with different ranges of capacity adapted to the customer requirements are available. Different kinds of film casters completed the components of the temperature gradient plate.

2 art.-no.: type: Temperature Gradient Plate MFFT 20 minimum film forming temperature MFFT acc. to current standards: description: necessary accessories: DIN ISO 2115 DIN ASTM D 2354 ASTM D 1465 ISO 2115 ISO/DIS 4622 chromium-plated measuring plate: measuring length: 500 mm measuring width: 180 mm temperature display: C temperature gradient: max. 100 K (depends on the external cryostat) electronic temperature controller with digital temperature display and temperature preselection as well as excess temperature protection 20 built-in temperature sensors accuracy: 0,1 C display of nominal value and actual value of the temperature of the hot and cold side scroll function to request the temperature measuring stations manual selection of the single temperature measuring stations integrated membrane drying unit with digital flowmeter hood made of PMMA, for temperatures up to +80 C option: hood made of stainless steel with cover made of safety glass for temperatures up to +250 C The necessary cooling unit for operating does not belong to the scope of delivery of the MFFT 20. It must be ordered separately. The working temperature range and the maximum temperature gradient depend on the effective cooling power of the connected cryostat. We recommend the standard cryostat type RP845 Working temperature range and temperature gradient MFFT 20 with connected cryostat RP845 Cryostats for other working temperature ranges and gradients upon request

3 technical data: dimensions (L x W x H): (with closed cover) 800 x 350 x 320 mm weight: 50 kg power supply: 230 V, 50 Hz, 1,5 kw MFFT 20 with digital flow meter Film caster for 6 parallel tests

4 Membrane dryer for compressed air or nitrogen Digital flow meter 0 10 l/min Temperature controller

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