Shrinkage tester apparatus designed to determine the leather shrinkage temperature. A strip of leather is slowly heated in water a sudden shrinkage occurs at a temperature that is characteristic of the tannage. shrinkage temperature is above 100°C and has to be determined in water under pressure. This is the special feature of the apparatus which measures shrinkage temperatures up to 115°C. apparatus should consist of a vertical sight glass, connected by tubes to a smaller boiler which can be heated by a Bunsen burner, so providing a convection circuit of heated water. A strip of leather and a thermometer are suspended in the sight glass, the upper end of the leather is fixed and the position of the lower end is indicated by an adjustable marker outside the tube to help judge when shrinkage occurs. A safety valve is fitted to the apparatus which limits the pressure to that corresponding to a temperature of 120°C. A Perspex guard is provided around the sight tube as a safety precaution.

General requirement:

Vessel, minimum volume 500ml and minimum working volume depth 110mm, the vessel may be pressurized to operate at temperatures in excess of 120ºC. Fixed test piece holder, for example, a pin or clip,30mm±5mm above the base of the plate. Movable test pieces holder, for example, a hook or clip. One end is attached to the top of the test pieces. The other end is attached to a thread that passes over a pulley and terminates in a mass 3g heavier than the moveable holder. Pointer, with means of monitoring its movement. In the instrument shown, the relative dimension of the pulley and pointer shall be such that any movement of the movable holder is magnified by a factor of at least 5. Temperature measuring device, graduated to 1oc and shown to be accurate to ±0.5ºC with the sensors placed close to the center of the test pieces and working range suitable for the sample under test. Sample size: (50+2) (3+/-0.2) mm, Beaker: 1000ml, depth 140mm, Test board 50mm X 125mm, mirror, The dial resolution: 0.3%, Dimension (42 X 27 X 86) cm, Weight: 10kg. Standards: SATM, ISO, DIN, SATRA. Accessories: 2 pcs Bunsen burner, 2 pcs Thermometer, 1pcs Distiller: Conforming to the requirements of grade 3, 1 pcs Heater: Capable of heating the vessel heating filled to its working depth within distilled or deionizer water at a rate of 2oC± 0.2 0.2oC/min, 20pcs Stirrer: Capable of sufficient agitating the water in the vessel such that the temperature at the top and bottom of the test pieces do not differ by more than 1OC, 20 pcs Glass test tube: with internal diameter 10mm±2mm and minimum height 100mm, 1 pcs Cutting die for determination of leather shrinkage temperature.