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Side Tanks & Remote Color Kitchen Used in Dyeing & Bleaching Processes

Dyeing and bleaching processes require the addition of various ingredients (dyes and chemicals) at pre-determined points throughout the process.  Except for fully automated systems, ingredients must be prepared manually by an operator within an open mixing tank for later transfer to the machine on which the process is being run.  Ingredients may be used separately or in combination and may require dissolving, dilution, agitation, or heating, depending on each plant's process.

The purpose of this SAFETY ALERT is to advise of certain hazards associated with the manual preparation of dye and chemical hazards associated with the manual preparation of dye and chemical ingredients in open mixing tanks.  It's purpose is also to provide general recommendations for the safe operation of mixing tanks used with dyeing and bleaching machinery.  Safety Warning Labels are available on request from the company.


1.  Certain heat reactive chemicals are known to produce a violent exothermic reaction when mixed with water above the recommended mixing temperature or when heated.  Sodium hydroxide (caustic soda) and sodium hydrosulfite (hydro) are two common examples.  The reaction may be greater where excessive amounts of such chemicals are used or the chemical is added more quickly than the time necessary for the chemical to dissolve.  In order to minimize the hazard to operators, procedures for mixing heat reactive chemicals must specify the tank preparation temperature and require operator verification of temperature immediately prior to adding the chemical to the tank.  Tanks containing heat reactive chemicals should not be heated after the chemical is in the tank.

2.  The combination of certain chemical ingredients may produce a violent reaction accompanied by the release of fumes, gas, heat and the possibility of tank boil-over.  The reaction may be greater when chemicals are in concentrated form and not sufficiently diluted or are combined too quickly.  When confined within a closed add line, intermixing of incompatible chemicals can result in catastrophic failure of add system piping due to pressure build-up.  Procedures should be structured in order to minimize the risk of such reactions and operators warned of this danger and how to avoid this danger.  Tank liquid level controls and flush systems must be maintained in good working condition to insure that tanks and lines are thoroughly cleared and rinsed before beginning the next tank preparation.

3.  Mixing tanks equipped with manually operated steam spargers or heating coils may be subject to over-heating and boil-over if left unattended while heating.  Operators must remain near the tank in order to monitor the tank's temperature while the tank is being heated.  Proper tank temperature must be verified immediately prior to adding any ingredients to the tank.

Should you have any questions regarding this SAFETY ALERT please contact Gaston County Dyeing Machine Company Customer Service Department.  For a nominal charge, we can do a full safety inspection of your machine(s) as well as providing parts and technical service for recommended updates and any other needed repairs.  You can reach our offices at the following telephone and FAX numbers:

Telephone:  (704) 822-5000
FAX: (704) 822-0753

Written inquiries may be addressed to the attention of your Account Manager at the following address:

Gaston County Dyeing Machine Company, Inc.
P.O. Box 308
Stanley, NC 28164

Gaston County Dyeing Machine Company offers various levels of automation for use on mixing tanks ranging from the simplest manual tanks to state-of-the-art automated dissolving and dispensing systems.  Should you wish to consider upgrading your present system, please contact Gaston County Customer Service or your Account Manager.



1.  Warnings regarding boil-over and process hazards must be prominently displayed on or about the mix tanks.  Adhesive backed warning labels are available through the Gaston County Dyeing Machine Company Parts Department by calling 704-822-5000.  Part numbers and wording are shown below:

FREE UPON REQUEST - Adhesive label (8.3" X 2.7") 
Part number 4121608

FREE UPON REQUEST - Adhesive label (8.3" X 2.7")
Part number 9118508

FREE UPON REQUEST - Adhesive label (8.3" X 2.7")
Part number 9118857

NOTE:  Due to the harsh environment associated with dyeing and bleaching equipment, warning plates and labels may deteriorate over time and require periodic replacement.  For proper application instructions, refer to "Application Procedures for Pressure Sensitive Adhesive Backed Labels & Plates."

2.  Each plant must develop written procedures, instructions, and training for the safe preparation of mix tanks based on ingredients being used and tank automation provided.  Consult your chemical supplier and current Material Safety Data Sheets (MSDS) for safe handling and mixing instructions.  Procedures should be periodically reviewed and updated as new chemical products and processes are introduced.  Use of these procedures by operators must be strictly enforced.

3.  Each plant must provide operators with suitable protective equipment and training in the use of this equipment based on the chemicals and ingredients being used. Required equipment may include such items as face shield, body apron, boots, gloves, breathing apparatus, etc.  Refer to current MSD Sheets for specific recommendations.  Use of this equipment by operators must be strictly enforced.

4.  Each plant must provide thermometers (hand held or tank mounted) and training to enable operators to monitor tank temperature while heating and throughout the mixing process.  Operators must verify that tank temperature is within established procedure limits before ingredients are added to the tank.  Use of this equipment must be strictly enforced.

5.  Mix tank systems should undergo regularly scheduled preventive maintenance at least quarterly - more often when experience dictates or problems are suspected.  Customer provided temperature indicators and thermometers used by operators to verify tank temperature must be checked for accuracy.  Tank level sensing systems and temperature controls (where equipped) must be calibrated and tested.  Tank filling, delivery and rinsing systems must also be checked for proper operation.

6.  Tank mixers are optional on Gaston County mixing tanks.  Depending on your process and the ingredients used, you may require a mixer to insure that all solid materials are completely dissolved and to prevent possible clogging of tanks and add systems.  Mixers can be purchased through Gaston County's parts department.  NOTE:  Steam spargers should not be used for mixing ingredients!

7.  Insert this SAFETY ALERT in your Gaston County Operating and Maintenance Manual for quick reference.


Copyright 2014 by Gaston County Dyeing Machine Company.  All rights reserved. 

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