P is a powder Urea Formaldehyde resin, which is used in the manufacture of MDF, Particleboard and other cellulosic products. A mechanical stirrer may be needed for this purpose.
Important parameters are platen temperature, moisture content of the mat, pressing cycle etc.
The reactivity of the glue can be adjusted over a wide range by varying the composition and amount of hardener system. The reactivity of the glue is expressed in terms of gelation time at 100 o C. A commonly used method for determining the reactivity is to measure gel time of resin at 100 o C with addition of Ammonium Salt such as Ammonium Chloride or Ammonium Sulphate. Gel time at 100 o C 55 seconds For outer layers of three-layer particleboard, the amount of hardener may be reduced or its addition totally avoided. This is needed to reduce the thickness swelling of the finished board. The quantity of resin to be used is expressed as weight of solid resin calculated on dry chips or fiber.