Dyeing of Meta-aramid FibresBack
1 Aramid fibres at a glance
Aramid is the generic name assigned to aromatic polyamide fibres.
Aramid is divided into Meta – aramid, creamish aramid fibres, dyeable, and Para-aramid, yellowish aramid fibre, not dyeable.
Aramid fibres are highly resistant to chemical agents, extra stable at high temperatures, and very good in terms of tenacity; they are mainly used in military and civil protection applications, safety sports gear, safety ropes, etc.
2 The dyeing method
Aramid fibres can be dyed in a Discontinuous process, and the requirements for high color yield and good fastness are challenging:
- High-temperature dyeing machines
- Application pH between 3 and 4
- The use of a carrier
- Cationic dyestuff
The most used carriers in the dyeing industry are Benzyl alcohol and Phenoxypropanol, two very harmful substances with a negative impact on sludges in effluent treatment plants.
They are also poor-performing chemicals: a high quantity of product is needed to achieve acceptable dyeing yields, resulting in deeply impacting the wastewaters.
3 Cindye VAS, the green solution
We developed a non-harmful & high yield chemical structure suitable for all types of aramid fibres: Cindye VAS.
With less chemical carrier, the dark shades achieved with benzyl alcohol and PPH are outshined, the dyestuff performance Increases, and crocking and washing fastnesses are drastically improved, thanks to the uniform dye penetration vs. ring dyeing effect.
Cindye VAS doesn’t affect breaking strength, maintaining the required strict standard of safety.
4 The environmental profile
Cindy Vas has an outstanding environmental profile.
The savings related to production (time, energy, and steam) are on a 15% average, and the ETP plant impact is drastically reduced as Cindye Vas is
- 10 times less water-soluble than Benzyl Alcohol and 4 times less water-soluble than PPH
- 90% biodegradable
- Non-toxic to microorganism
Find out more on Cindye VAS full document