This study was conducted to investigate thermokinetic behavior of powdered phenol-formaldehyde (PPF) resins used for the production of wood-based panel products. Both fusion diameter and stroke cure time of the PPF resins were measured to characterize flow properties and reactivity of PPF resins. In addition, differential scanning calorimetry (DSC) was also used to obtain apparent glass transition temperature (T-g) and activation energy (E-a) of the PPF resins. The results showed that the stroke cure time of PPF resins was positively related with fusion diameter of the PPF resins. The T-g of PPF resins depended on the heating rate with a linear relationship established between heating rate and the T-g. The E-a of PPF resins depended on types of PPF resin and spray-drying temperatures. (c) 2005 Elsevier B.V. All rights reserved.