This processing can take place in continuous or discontinuous phases, each work cycle deals with a certain
number of pieces sewn head-to-tail together and spread wide.
The carbonization phases are:
A. Acidification
Impregnation of the patches
in the bathroom (see figure A, point
1) composed of sulfuric acid
diluted in water to 30/50 gr
liter (3°/5° Be, Baumè degrees) and hydroextraction with the squeezing cylinders (fig. A, 2).
B. Pre-drying – Charring
The pieces must be continuously inserted into the machine which consists of two or more chambers (fig. A, 3),
the first, drying, has a temperature increasing from 50° to 90° C.
the second, called carbonization (fig. A, 4), can reach 100/110° C in relation to:
heaviness of the fabric, speed of passage, quantity of plant parts to be charred.
The carbonization process therefore occurs in two subsequent moments, in the first of which the patch
it dries and the sulfuric acid concentrates; in the second moment, at a higher temperature, the acid acts
on the vegetal parts by charring them.
At the end of the process the fabric is folded (fig. A, 5).