GB962188A - Improvements in or relating to pressboard panels - Google Patents

Abstract

<FORM:0962188/C3/1> Chipboard comprising two inner layers of coarse shavings and two outer layers of fine shavings is produced by passing a supporting plate across separate streams of coarse and fine shavings coated with a bonding agent to form successive layers of fine and coarse shavings and then reversing the direction of travel to form successive layers of coarse and fine shavings, the layers then being pressed together in a hot press. As shown in Fig. 1, shavings are conveyed from a storage container 1 to an inclined rotary drying drum 3 wherein the shavings are sprayed with a bonding agent from an injection nozzle 20. After passing through a second storage container 8, coarse shavings are passed to a feeder 10 while fine shavings are passed to a feeder 22. The shavings may be separated into two streams on leaving drum 3. Alternatively, a drum for each of two separate streams may be employed. Plates 26, 27 and 28 are successively coated with the four layers and fed into a hot press 29. As shown in Fig. 3, a single feeder 37 which divides a mixture of coarse and fine shavings into two streams is employed. The weight of shavings to be mixed with a given weight of glue may be measured on an inclined pan (Fig. 5, not shown), since the proportion of shavings required is proportional to the coarseness of the shavings. Pressing may be stopped if more than a certain amount of steam is evolved (Fig. 6, not shown).