A new "Closely Packed Equal Sphere" (CPES) infiltration model has been developed by us. It differs from the classical capillary infiltration model mainly in the value of the critical contact angle of spontaneous infiltration (50,7degrees, instead of 90degrees), and as a consequence, it also differs in the functional relationship between the threshold pressure and the contact angle. Our new equation becomes identical with the Carman equation for perfectly wettability. Our experimental results are in good agreement with these theoretical results.