The impregnation section is the zone where the caustic comes into intimate contact with the fabric; the caustic is filtered and sprayed with a number of distributors on the top of each roller, after which the lye is constantly recirculated through the pump of the preparation vat. Each distributor ensures a uniform coverage of the area widthwise, and each impregnation compartment is constantly flooded. The entire impregnation is driven by motors connected to inverters. The tension on the fabric is controlled by specially designed pneumatic compensators.The bottom rollers are chemically plated with Nickel, and grooved. A proper squeezing of the fabric on the bottom grooved rollers is achieved by the upper soft rubber coated rollers, which press the fabric by their own weight.

The position of the reaction section allows sufficient dwell time between the cellulose and the lye in order to have a complete process, while the fabric is still in the plastic state. The complete mercerizing reaction will taken place, according to the process temperature, after 25-30 sec in hot mercerizing and after 40-50 sec in cold mercerizing.

This section is vital for the final dimensional stability of the fabric and for attaining a proper washing and neutralizing in the washing section, for the sake of the minimum water consumption.

The weak lye coming from the washing section is taken to the end of the stabilizing section; from there, the lye flows countercurrent the main fabric direction, while being continuously recirculated and sprayed on the fabric, section by section, in order to improve the contact time. Recirculation in each counter current section is guaranteed by a number of pumps. Each section in the stabilization has its own temperature control. The control of the residual caustic on the fabric is achieved by measuring the lye equilibrium concentration at the beginning of the stabilization section.

The specially designed fluted rollers or drums in both washing boxes (ACTIVA or ESSETEX) allow a high water turbulence under liquor and a higher washing efficiency, if compared to the traditional washing boxes with plain rollers. In ESSETEX, the fluted drum is also the perfect system to provide an in-depth penetration of the water spray through the fabric.

The pH control is achieved in the last washing box, it is specially designed for having two separate
and independently regulated compartment. One compartment is equipped with a recirculation pump and a pH probe connected to the PLC for automatic neutralization via metered injection of acid.

After the stabilization, the modularly assembled washing range ACTIVA o ESSETEX take care of the final washing and neutralizing. The washing is required to achieve the desired neutralization of the fabric, with the least acid and washing water consumption. Choice between ACTIVA or ESSETEX ranges mainly depends on the type of fabric, whether woven or knitted.

Individual drive system of rollers and drums, and load cell tension control, are the guarantee for a crease free operation, and a perfect tension control any time required, even at the lowest values required by the knitted fabric.

Separate and independent thermoregulations are provided in each washing box, to adapt the temperature profile to the required processing for the specific dyestuff. The water flow rate is optimised by means of PLC managed flow meters, to cope with different fabric weights and range speeds (the washing liquor flows in the opposite direction of the fabric, therefore minimizing the water consumption in the overall process).

Mezzera experience, accrued with the day – by – day activity in many dye houses, has led to the
implementation of state-of-the-art mercerizing process; Mezzera provide his customers a basic mercerizing scheme, that may be adapted from time to time to the customer’s specific requirements with the addition different options (cold, hot, chainless, chain, combi).