DIN EN 3094:2018 pdf free.Aerospace series -Sealants -Test method – determination of the application time.
4 Principle of the test method
The application time is determined by two different methods, depending on the viscosity of the sealant.
4.1 Method A (viscosity) For sealants with a viscosity lower than 75 Pa.s, the viscosity is measured with a BROOKFIELD viscometer or equivalent at the end of the specified application time according to Iso 2555.
4.2 Method B (extrusion) For sealants with a viscosity higher than 75 Pa.s, the mass extruded through a nozzle under specified conditions is measured at the end of the stated application time.
5 Method A (viscosity)
5.1 Conditioning The base compound and the curing system shall be stabilized at (23 ± 2) °C in closed containers for at least 8 h before testing.
5.2 Procedure The base compound shall be mixed with the proper amount of the curing system and filled into a can. The can shall be kept at (23 ± 2) °C and tightly covered until the testing of the viscosity. At the end of the specified application time, measured from the beginning of the mixing period, the viscosity of the sealant shall be determined according to Iso 2555 using spindle, rotation speed and stirring procedures as defined in the material specification.
5.3 Calculation and expression of results The reading taken on the viscometer shall be converted into a viscosity value using the procedure stated for the viscometer, spindle and speed.
6.1.4 Air supply with a pressure of (620 ± 35) kPa
6.1.5 Balance with an accuracy of 0,1 g.
6.2 Conditioning The base compound and the curing system shall be stabilized at (23 ± 2) °C in closed containers for at least 8 h before testing.
6.3 Procedure At least 250 g of the base compound shall be mixed with the proper amount of the curing system. The mixed sealant shall promptly be filled into a cartridge (see 7.1.2) with a nozzle (see 7.1.3) and placed in a gun. The gun and sealant shall be maintained at (23 ± 2) °C throughout the test. The gun shall be attached to a constant air supply of (620 ± 35) kPa. Initially 50 mm to 80 mm of sealant shall be extruded to clear trapped air. At the end of the specified application time, measured from the beginning of the mixing period, the sealant shall be extruded into a suitable receptacle for (60 ± 2) s and the amount of extruded sealant determined by weighing.
6.4 Calculation and expression of results The amount of extruded sealant shall be expressed in g.min-1.DIN EN 3094 pdf download.