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SCHOPPER RIEGLER BEATING & FREENESS TESTER

Supp l i ed by : Supp l i ed by : P R O D U C T T E S T I N G A P P A R A T U S P R O D U C T T E S T I N G A P P A R A T U S 27 Beaconsfield Road, Sittingborne, Kent. ME10 3BD. U.K.

Tel/Fax +44 (0) 1795 553234Email:billjones@tesco.netWeb: www.producttestingapparatus.com

These notes are intended as a brief introduction to the subject and are not a definitiveprocedure. Operators should always follow the procedures prescribed in the relevant national,international or industry standard methods.

DefinitionThe Schopper Riegler apparatus was the first drainability tester to be designed and the application isvirtually identical with that of the Canadian Freeness Tester. Although, in principle, suitable for testingall kinds of pulp in aqueous suspension, the test only provides acceptable results if a sufficiently densematt of fibre of the correct weight is deposited on the wire screen. Due caution should therefore beexercised when pulps contain high percentages of debris or fines and when SR values are outside therange 10 to 90 SR. The Schopper Riegler number scale is the scale on which a discharge of 1000 mlcorresponds to a SR number of zero and zero discharge to a SR number of 100

In practice therefore, it is suitable for use with all pulps in common usage in the manufacture of paperand board products. The instrument conforms to the International and all relevant National Standardsincluding ISO 5267/1.ApparatusSchopper Riegler Freeness Tester See models HM1SR1, HM1P95587 (Instruments - PulpEvaluation Section).Measuring cylinders.

SpecificationThe instrument is basically similar in principle to the Canadian Freeness Tester, consisting of drainagechamber and rate measuring chamber. The drainage chamber is constructed of corrosion resistantmaterial with the base consisting of a phosphor bronze wire screen. This is sealed with an internal cone,which, when released, rises through the dilute pulp sample, mixing the stock in the process.

The rate measuring funnel is similar in design to that of the Canadian Freeness Tester having acalibrated orifice to govern flow and sidearm for the discharge of excess water.

The SR value is the inverse of the volume of water collected divided by 10.

All critical dimensions and calibration are according to ISO 5267, BS 6035 and SCAN C19 to which theinstrument supplied by Product Testing Apparatus conforms in every respect.

Apparatus CharacteristicsThe instrument is again designed for ease of operation and is easily taken apart for ease ofmaintenance. This only requires the wire screen and orifice to be cleaned regularly to remove any

adhering material and replacement of the rubber seal when worn.The apparatus should be used in an environment, which is free from vibrations. It needs to be mountedin a true level position.The digital version provides a more rapid and precise method of measurement.

The disintegrated pulp sample should be at a concentration of approximately 0,22 % by diluting asrequired with distilled or de-ionised water.The concentration of the stock should be determined by oven dry method. Further dilution of the pulp isthen required to achieve 0,2 % 0,002 %. Air bubbles must not be allowed to form in the pulp and thetemperature of the pulp needs to be controlled at 20,0 C 0,5 CPulp taken from the mill system should be tested within 30 minutes after which time the pulp at theabove mentioned concentration should be subjected to 6000 revolutions in a pulp disintegrator.

7/28/2019 Schooper - Srft Meth

2/2

SCHOPPER RIEGLER BEATING & FREENESS TESTER

Supp l i ed by : Supp l i ed by : P R O D U C T T E S T I N G A P P A R A T U S P R O D U C T T E S T I N G A P P A R A T U S 27 Beaconsfield Road, Sittingborne, Kent. ME10 3BD. U.K.

Tel/Fax +44 (0) 1795 553234Email:billjones@tesco.netWeb: www.producttestingapparatus.com

Comparison with other InstrumentsPlease see under Canadian Freeness Tester. The digital version, however, does provide extra facilities.

MethodMake sure the apparatus is clean especially the drainage chamber and the funnel. The apparatusshould be rinsed with water at the prescribed temperature 20,0 0,5 CPosition the measuring cylinder beneath the side orifice and close the sealing cone. A collection vesselshould also be placed beneath the bottom orifice.Take 1000ml of the well stirred pulp in a clean cylinder. Make sure it is well mixed by covering the mouthof the cylinder with the palm of one hand and tipping the contents back and forth a couple of times. Tryto avoid causing bubbles in the pulp.Pour the pulp into the drainage chamber quickly but steadily so as to avoid the pulp swirling. After fiveseconds release the sealing cone to lift and allow the pulp to drain through the apparatus.When all of the pulp has drained form the apparatus, the Schopper Riegler number can be read off thegraduated measuring cylinder beneath the side orifice to the nearest unit. Repeat the determination asecond time and with the same sample which should duplicate the result with 4%

These notes are intended as a brief introduction to the subject and are not a definitiveprocedure. Operators should always follow the procedures prescribed in the relevant national,international or industry standard methods