BS 14022:2010 pdf download – Structural adhesives — Determination of the pot life (working life) of multicomponent adhesives 6.2Method 1: Determination by means of a change in apparent viscosity (rotatingviscometer or oscillating rheometer) 6.2.1 Principle A multi-component adhesive is mixed and its pot life established by measuring the time taken for its viscosityto change by a specified amount. This method is not suitable for the determination of pot lives that are shorter than 5 min in duration. 6.2.2Apparatus 6.2.2.1alance, capable of weighing up to (500± 0.2)g. 6.2.2.2 Beaker, squat form,capacity 400 ml, made of an unreactive material with adhesive,whose wallthickness does not exceed 1 mm. 6.2.2.3 Spatula made of a non-reactive material with adhesive and with an angular , not circular end. 6.2.2.4 Viscometer,any suitable means of measuring the viscosity of the adhesive (rotating viscometer oroscillating rheometer) may be selected.See EN 120922001，Method 1, for the viscosity measurement withrotating viscometer. 6.2.2.5Stopwatch,accurate to 土 1 s. 6.2.2.6 Test enclosure, capable of being maintained at the test temperature and if necessary at a relativehumidity of (50 ± 5)%. 6.2.3 Procedure Both components of the product shall be maintained separately at (23 ± 2)*℃. The single components shallbe weighed into the beaker (see 6.2.2.2) according to the mixing ratio specific for the product,with thepreferred mass of the batch of the products being (200 主 20) g. Start the stopwatch (see 6.2.2.5) and mix the batch with an angular , not circular end of a spatula (see 6.2.2.3)for (60 ±10) s. Take care that also the areas within the angle between side and bottom of the beaker are wellmixed. lt is also allowed to determine a pot life of a batch which was produced with the help of a static or dynamicmixer, which has to be defined specifically. lmmediately after mixing measure the viscosity with a viscometer (see 6.2.2.4) of the freshly preparedadhesive. Record the first data after having finished mixing as the starting viscosity point. Continue the measurement inintervals dependent on the pot life expected. NOTE The number of measurements as will as the extent of shear at mixing of the components and themeasurement itself can have an infuence on viscosity and pot life.Therefore,it is recommended to fix the intervals ofmeasurements as well as mixing, shear speed and rotational speed specific to the adhesive, The pot life of the adhesive is the difference between time at the end of mixing and the time when...
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