Polyester/Cotton Blended Fabric Dyeing:
In the case of polyester/cotton blended fabric, double dyeing is done. For this reason, this dyeing process is called the double part dyeing process. In this dyeing process; the polyester part is dyed first then the cotton part is dyed. Flow Chart of Polyester/Cotton Blended Fabric Dyeing is as follows.
Sequence of dyeing Polyester/Cotton fabric:
Select bleach fabric (5gm)
↓
Carbonizing of cotton part
↓
Fabric weight measure with carbonized part
↓
Recipe making
↓
Select dyes
↓
Dyeing of polyester part
↓
Matching dyed PES part with standard
(If Yes)
↓
Dyeing of cotton part
↓
Hot wash
↓
Neutralization
↓
Soaping
↓
Cold wash
↓
Drying
↓
Total sample match with standard sample
(If yes)
↓
Bulk production
Blending cotton/polyester fibers is common practice in the textile industry. In comparison with 100% cotton, cotton/ polyester blends have higher breaking and abrasion strength, crease-resistance, are more comfortable to wear and display better easy-care properties. However, the P/C blends possess some challenges to dyer as polyester shows a hydrophobic character while cotton shows a hydrophilic character making it inevitable to dye them with chemically different classes of dyes.
Commercially polyester/cotton blended fabrics are dyed by two-bath or one-bath two-step dyeing method employing suitable dyes and chemicals for each fiber. Two bath dyeing methods are relatively long and complicated. The one-bath two-step dyeing procedure is shorter as compared to the two-bath method, but the drawbacks are lower dyeability and poor reproducibility. Many research works have been carried out to dye polyester/cotton blends in one-bath dyeing method using conventional dispersed dyes and newly developed reactive dyes which can be dyed at acidic or neutral conditions around 100– 130°C and are added simultaneously to the same bath.
Generally, this process is done to get the light and a medium shade of P/C blended fabric in a shorter possible time than any other process as like a two-bath process. The present work involves one-bath one-step dyeing and two bath process of P/C blend fabric using the same amount of dyes and comparison is done between two methods.
Author of this Article Rana Sohel Executive Engineer Sunman Textile Mills Ltd. Chittagong Cell: +8801912-420118 Email: [email protected]