In principle, every doubling process is a transverse doubling because the feeds are united side by side. In this context, however, the expression is used to refer to a quite specific type of blending, i.e. transverse doubling.
If two drawframes operate as passages I and II, respectively, and each has two deliveries, then all cans from delivery 1 of the first passage can be passed only to delivery I of the second passage, and the cans of delivery 2 can be handled in the same way.
This gives a straight-line throughflow. However, half the cans of the first passage could also be crossed over, i.e. in the transverse direction (Fig. 40) for feed to the second passage. Transverse doubling can improve both maintenance of long-term evenness and blending. Unfortunately, owing to the elimination of machine passages and the continual increase in production speeds, transverse doubling is becoming steadily more infrequent in practice. Previously, an important transverse doubling point was, for example, lap blending between the scutcher and the card.
In this buffer zone, the laps were laid out in one (vertical) direction and removed in the other (horizontal).