The agitator should be of highly effectively in agitation and heating.Any agitator that is capable of preventing the

formation of lumps,and transfer heat evenly can be used for dissolving PVA.Two-blade paddle type propellers

are usually used,with agitation speed of 80-100 rpm.The propeller blade should be carefully designed with

care,especially for dissolving high viscosity and high solid content BP type PVA.Propeller blade of up to 65-75%

of the inside diameter of the vessel,with the propeller shaft perpendicular to the bottom,and a speed of 80-

100 rpm seems to give the favorable results.