2.1. Determination of solid resin content
1 +- 0.1 g of resin are weighed in a little metal dish
with a diameter of approx. 5 cm, and dried in a drying
cabinet for 2 hours at 120°C. After cooling in desiccator, the dish is weighed again.
final weight (g) x 100
value given: ---------------------- = % solid resin
initial weight (g)
Double measurement is necessary
2.2. Determination of viscosity
As a measuring device, a Ford cup with a 4 mm diameter efflux nozzle at 20 °C is used. About 150 ml of test solution is necessary for testing. The cup will be filled fully till the solution overflows. The edge of the cup has to wipe off then by means of s glass road.
Value given: Efflux time in seconds
2.3. Determination of cold turbidity point
12 +- 0.001 g of the sample are weight in a 300 ml Erlenmayer flask and it must be with distilled water diluted till a milky white turbidity is reached. The final endpoint is reaches, when a cross, pencilled with a black marker onto a white paper is not visible any more through the test solution. Water and sample must be tempered to exact 20°C.
Value given: % consumption of distilled water in proportion to the weight of sample.
Double measurement is reqired
2.4. Determination of turbidity time for melamine resin and gel time for
urea resin.
2.4.1. Turbidity time of melamine resin
- Melamine resin from supplier: 100ml resin plus 0.50 ml Catalyst
FMH 510 will be well mixed.
- Melamine resin from the IFA mixing station:
100 ml from the ready mixed resin must be taken. Note the recipe Nr.
5 ml from one of the above sample will be filled
into a dry test tube. The test tube shall be immersed
in continuously boiling water, whereby it should be
ascertained that the water level is a few centimetres
above the resin solution. A glass rod shall be used for
stirring slightly in the test tube during the whole
time. The curing time of melamine resin is determined
by the time for immersion of the resin solution into
the boiling water until the melamine resin turns to
milky white.
Specified value:
- for melamine resin from supplier see position 1.1.
- for resin from IFA station see position 6.
2.4.2. Gel time of Urea resin
- Urea resin from supplier: 100 ml resin plus 0.9 ml Urea resin
catalyst will be mixed well. Carry out the Gel time test within
less than 5 minutes after mixing with catalyst in order to reach correct results.
- Urea resin from the IFA mixing station:
100 ml from the ready mixed resin must be taken. Note the recipe Nr.
The test shall be carried out as in item 2.4.1 described
The gel time of urea resin shall be determined by the time for immersion of the resin solution into the boiling water until the urea resin becomes gel respectively solid.
Specified Gel time:
- for Urea resin from supplier see position 1.2
- for resin from IFA station see position 6.
2.5. Determination of pH Value, diluted and not diluted
The pH-value of all the test solutions will be measured with
a combined glass electrode at a temperature of 20°C.
About 150 ml of sample is necessary for determination.
During measuring samples must be stirred or shaked continuously.
Before determination adjust pH meter with puffer standards of 4.00 / 7.00 and 10.00.
Value given: units of pH
2.6. Determination of Density
Determination with Densometer:
About 20 ml of the sample has to be tempered to 20°C
The measuring capillary of the Densometer will be rinsed with about 2 ml Aceton solution. After that, the capillary will be air dried by means of a 20 ml one way injection.
For measuring, a 2 ml one way injection will be used for air bubble free filling of the measuring capillary with the sample. As soon the indicated temperature on the densometer stays at 20 °C, the density value will be taken as soon density stays constant for approx. 20 seconds.
Value given: Density in g/cm3
A double determination is required
For cleaning rins capillary with distilled water, than with Aceton, again with dist. Water and finally with Ethyl alcohol by means of a 20 ml one way injection.