Minimum Temperature Film Forming Bar
MFFT BAR
MEETS ASTM D 2354-91 and ISO 2115
Self-contained bench top instrument for the determination of the minimum film-forming temperatures of synthetic latex, emulsions, polymers and adhesives. Electronically controlled heating and cooling with integral air processor.
The "Minimum film-forming temperature" has been described as: "the minimum temperature at which water-borne synthetic latex or emulsion will coalesce when laid on a substrate as a thin film". "When this process occurs, in the absence of pigmentation or other opacifying material, a clear, transparent film is formed. At temperatures lower than the minimum, a white, powdery, cracked film will result."
The MFFT is usually closely related to the glass transition temperature Tg but not synonymous with it. While the Tg may be determined by predicted calculation, the MFFT is best determined by the use of the MFFT Bar. The basic principles of which are described in ASTM D 2354.
The initial development was carried out in I.C.I. laboratories and is presently produced by RHOPOINT, LTD.
Specifications:
Platen: |
Copper, dull nickel plated. (Other options available) |
Platen Dimensions: |
483mm x 235mm (19" x 9.25") |
Parallel Tracks: |
Using 1" cube applicator max 10 tracks |
Weight: |
8kg. (85lbs) |
Dimensions: |
550 w x 350 h x 610 d mm (21.65"w x 13.77"h x 24"d) |
Temperature Sensing: |
10 points on center line at width intervals 37mm (1.45°) |
Accuracy: |
±.2°C |
Display: |
Point temperature & temperature differential between adjacent points. |
Indication: |
Lamps: instruments ON, heating, cooling. |
Alarms: |
Audible & visual for water flow failure. |
Services Required:
Mains: |
Please specify 220-240 volts AC or 110-120 volts AC |
Air: |
4 liters/min-1 @ 100 psig. |
Water: |
Normal mains supply (<20°C/68°F) |
Water Drain: |
Gravity |
Hinged transparant cover plate raised,
allows clear access for track laying & cleaning.
Complete Instrument Comprises:
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MFFT Instrument
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Mains Cable
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Air Connector
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Water Connectors
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Roving Temperature Sensor
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Cube applicator 75U x 1" cube
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Guide Bar
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Quantity-Desiccant
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Quantity-Indicator Crystals
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5 Hypodermic Type Dispensers
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Spare Fuses
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Instruction Book
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The MFFT bar is a complete system
and the purchase of additional accessories is not required. |
Special Options:
Unit for Nitrogen supply only, no air processor fitted. Unplated copper platen (Prices on Request).
The use of this instrument may involve hazardous materials and operational procedures. It is the responsibility of the user of this instrument to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
Method:
A dull nickel-plated copper platen is cooled at one end electronically and warmed at the other end, while air or nitrogen is caused to flow over the surface as a uniform blanket. The air flow is from the cold end to the hot end.
To achieve the required uniformity, the air or gas is delivered via a very carefully designed sintered metal distribution block. The design is such that the freezing does not take place at the inlet. For use air, a drying system is incorporated into the housing together with a flow controller. The air dryer contains indicator crystals which are clearly visible in their transparent container. The complete air conditioning system is accessible at the side of the instrument.
Water at normal mains pressure removes the excess heat from the coolers. Quick release couplings are provided. Water is normally drawn from a laboratory tap and the outlet is run to drain by gravity. Alarms, both audible and visible, protect the cooling water supply. Temperature sensors are mounted at intervals under the surface of the platen, these are used to control the temperature of the platen in accordance with the chosen program. They are also used to indicate platen temperatures down the length of the bar, or they can be switched to indicate differential temperature at sweat intervals and so provide an instant indication of temperature gradient. A roving probe temperature sensor is also provide to facilitate temperature measurement at every point on the platen, it also serves to check the static sensors. A hinged viewing cover over the platen provides thermal insulation while allowing visual inspection of the determination as it progresses.
Operation:
n practice, the instrument is switched on and the program chosen. Air and water having been connected, an equilibrium condition is noted after about 20 minutes (the time may be less dependent on the program chosen). At equilibrium, the heating cooling lamps illuminate at very low frequency. Several tracks are laid down in quick succession using an applicator, normally a 75 micron (3 mil) one inch cube applicator. The tracks may be laid down left to right or right to left, but the most common form is a U horizontal, with the track starting and finishing at the right, warm end. Two tracks are normally laid down last as a control using an emulsion of known MFFT.
![](file:///C:\Users\toshiba1\AppData\Local\Temp\msohtml1\01\clip_image005.jpg)
A clearly defined limit of coalescence will show in about 90 minutes and the MFFT temperature can then be read using the cursor scale. Pigmented emulsions may be tested but the determination is more difficult to see. Most operators, however, find that they can readily ascertain the MFFT point. This can be proven by using a wooden spatula or, more commonly, a fingernail to check the point at which the soft, uncoalesced coating commences.
MFFT Determination, one continuous track displays the evenness of the heating, cooling and air flow. A photographic record of the performance of every instrument is made before dispatch
Programs:
Standard Model MFFT -60 (Degrees C) |
Cool End (Left): |
-5 |
0 |
+5 |
+15 |
+23 |
+33 |
Warm End (Right): |
+13 |
+18 |
+23 |
+33 |
+50 |
+60 |
Extended Range Model MFFT -90 (additional programs) |
Cool End (Left): |
+43 |
+53 |
+63 |
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Warm End (Right): |
+70 |
+80 |
+90 |
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front panel of instrument
![](http://www.gardco.com/images/mois_air_tmp/mfft/mfft_drawing_2.jpg) |
ALARM AND ON MODULE |
INDICAITON MODULE |
CONTROL MODULE |
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Mains switch on/off
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Heating lamp indicator
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Cooling lamp indicator
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Coolant failure lamp
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Pressure gage
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Pressure regulator
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Air flow controller
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Temperature Display
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Probe Socket
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Temp. Mode Switch
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Temp. Mode Selector
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Heating LED
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Cooling LED
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Program Selector
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THE ROVING PROBE
available items |
Item Number |
Item |
TE- MFFT-60 |
Standard Model MFFT apparatus complete as described for operation for 110V, 60Hz AC, Warm End range of +60 (220V also available) |
TE-MFFT-90 |
Extended Range Model MFFT apparatus complete as described for operation for 110V, 60Hz AC, Warm End range of +90 (220V also available) |