Page 39 - Sustainability report 2018 Ratti Group

2018 SUSTAINABILITY REPORT | RATTI GROUP
The phases of dyeing and printing
SCOURING
This operation is carried out continuously on a device whose purpose is to remove sericin and oils from the raw fabric.
At the end of the process the fabric is dried, smoothed and wrapped
on a beam.
DYEING
Usually items are dyed mainly as a base for printing and only minimally for the production of plain-weave fabric.
The fabrics are dried and smoothed and subsequently checked (colour sample and defects).
PLATING
Fabrics destined for inkjet printing are impregnated with a substrate that is chemically compatible
with the fabric, so that the ink can set.
PREPARING COLOURS
The production order being worked on is sent to the Colour Kitchen for the preparation of dyes.
The system is supplied by silos containing the necessary products: dyes in powder form, thickeners and auxiliary fluids. The system mixes pure colours with the thickener, producing the colour tone required by the production specification.
DYEING LAB
ennoblement processes. Following this process
a further check is performed before the product is sent for shipment, to ensure that the product complies with the specifications of the customer or those of the hemming professional who will produce the final garment.
Dyeing and printing: creativity becomes a pattern
The Dyeing and Printing department carries out
a critical dual role: on the one hand it is the place where, through dyeing and printing on the raw fabric, the designer’s artistic expression becomes a concrete design, on the other hand it is also one of the production phases that is particularly delicate from an eco-sustainability point of view, given the use of chemical products required.
These chemicals, apart from dyeing and printing, may be involved in phases such as washing, where excess colour is removed, or finishing, where the fabric is treated to improve its properties.
A quality check is carried out in the finishing phase and, if necessary, specific retouching techniques may be applied.
The fabric arrives already prepared for printing
or as raw fabric. In the latter case it first undergoes preparation processes, before moving on to the actual printing phase which, according to the fabric and design specifications, may be carried out using a variety of technologies.
Traditional table printing
The technology of traditional table printing
is characterised by “wet on dry” printing.
The fabric to be printed is rolled out on a table on which there is a printing carriage which contains the print screen. This consists of a metal frame with a material (mesh) which is serigraphed and permeable in the areas through which the colour passes, which is applied automatically to the screen using a blade. The original design is divided according to the number of colours, and each colour corresponds to a print screen.
Traditional printing technology may be in “application” (a white or clear fabric swatch and the print covers the colour of the fabric swatch) or in “corrosion” (fabric watch in a single colour, colours containing a whitener and the print replaces the background colour).
Inkjet printing
TYPES OF TRADITIONAL PRINTING
TABLE
flat or rotary, used mainly for production limited-quantity batches.
HAND-MACHINE
the same principle as for table printing
but with more printing locations in action at the same time.
Used for large-quantity batches.
ROTARY
CONTINUOUS PRINTING
where the print screen is replaced by
a cylinder with the same characteristics.
Inkjet printing is the most recent technology. It uses the same technique as that used by inkjet printers. The design is reproduced not by means of screens but by using electronic formats produced on CADs. The print pastes are replaced by liquid inks whose principal characteristic is their high degree of purity, which guarantees their transmission through the micro-jets on the print heads.
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WARPING
This involves the unwinding of the yarn threads, which are then rewound very close to each other on a loom, in order to comply with the number of threads required by the production specification (warp).
WEAVING
This is the process by which the fabric is constructed, through the weaving of warp (vertical) with weft (horizontal). The loom predominantly used is the “jacquard”. This allows, by moving a single yarn, various designs and types of weaving to be executed on the fabric.