Apparatus and process for performing optical readings on packaged textile material subjected to dyeing

Abstract

Apparatus for performing optical readings on yarn spools subjected to dyeing in a dyeing tank or machine (1) in which a spool (6) provided with a pierced axial shaft (6A) is placed with the said shaft on the outlet of a feedpipe (IM) of a circuit that feeds a dyeing bath in the same tank or machine (1), so that the dyeing bath enters the dyeing tank or machine (1) passing by the feedpipe (IM) through the shaft (6A) and is subsequently collected through collecting conduit (IR) of the same feeding circuit. The apparatus comprises optical detection means connected with electronic processing means and the said optical detection means comprise a detector (9) with an optical window (92) located inside the dyeing tank or machine (1), a base of the spool (6) being cyclically put in contact with said optical window (92), periodically, the said spool being moved towards the optical window (92) by means of an actuator (7) which, cyclically, moves the said shaft (6A) the said base of the spool (6) towards a part (2) of the dyeing tank or machine (1) where the said optical window (92) is located.

Description

technical field [0001] The present invention relates to an apparatus and method for optical reading on packaging fabric material which is subject to dyeing. Background technique [0002] More particularly, the apparatus and method of the present invention enable the control of consumption (that is, absorption) of individual colorants or colorants present in the dyebath. [0003] Optical systems and methods based on transmission spectrophotometry are well known in the art. The concentration of a single colorant present in the bath solution (ie the dyebath) will be measured by the system by passing a beam of known properties through it. A portion of the light is absorbed by substances present in the fluid, while the remainder is sent to a spectrophotometer, which detects its quantity and nature. These constitute information for determining the residual amounts of individual colorants present in the bath solution according to the well-known Beer-Lambert law. [0004] It is a...

AI Technical Summary

Problems solved by technology

[0005] When using known optical systems for in-line transmission reading, it is practically difficult to determine with sufficient accuracy the concentration of individual colorants present in the dyebath, especially concerning very small concentrations as well as concerning concentrations exceeding a given value when the determination

Indeed, known optical systems have proven ineffective in controlling bath solutions containing colorants whose concentration values ​​are outside the given range

In other words, optical control systems currently available on the market are largely impractical for use when the concentrations involved are values ​​that are not within the given range (that is, when the bath solution is too dilute or too concentrated)

[0006] A further drawback caused by the use of known optical systems is the apparent inaccuracy of the results obtained by readings carried out on baths containing different kinds of colorants (i.e. different chemical classes), and the inability to distinguish essentially two colors of the same type. Different colors (two reds, two yellows or two blues present in the same bath solution)

[0007] Other inconveniences arise from changes of state, i.e. changes in the color of individual colorants when the pH, salinity or temperature of the solution changes, as usually occurs in dyeing cycles: in fact, in this case, the transmission Optical controls do not ensure correct and uniform readings as color changes may occur and bath solutions may become sluggish

[0008] Also, when the transmission of light through the liquid changes, it is very difficult to control dispersions and opalescent baths as part of the light is deflected by dispersed particles within the liquid.

This leads to miscalculations, i.e., spectrophotometer estimates may be wrong

Images