What is Cationic Polyester?
Cationic Polyester refers to cationic dyed (dyeable) polyester. The abbreviations for cationic polyester are PBT and CDP.
PBT is a specialty or modified polyester, which is produced by charging macromolecules with the cationic dyeable group. As a result, CDP can be dyed with cationic dyes at 110℃. Conventional polyester can only be dyed at 130℃.
Why need CDP?
Polyester fiber is a hydrophobic synthetic fiber. It lacks functional groups that can be used to combine with direct, acid, and basic dyes. Although the ester group can form hydrogen bonds with disperse dyes, the polyester molecular chain structure is tight, and the dye molecules are not easy to enter the inside of the fiber. As a result, it is difficult to dye regular polyester fibers, and their color and luster are very monotonous.
Due to high crystallinity, there is only a small gap beside the polyester fiber. When the temperature is low, molecular thermal motion causes their positions to change only slightly. Under wet conditions, polyester fiber does not increase the gap due to violent swelling as cotton fiber does, so dye molecules have difficulty penetrating the fiber. Dyeing of polyester fibers is usually done only with disperse dyes and requires high temperatures and pressure, or a carrier.
From the above, we can see that regular polyester (polyethylene terephthalate) has the disadvantages of low moisture absorption, poor dyeing performance, a tendency to accumulate static, and a tendency to fuzz. Cationic polyester is designed to overcome these defects.
How to produce CDP?
Nowadays, the commonly used method is to add dimethyl isophthalate and polarity-based SO3Na to the polyester chips. The filament spinning from this way looks similar to the common one. However, thanks to ion modification, this method not only greatly improves the fiber’s color absorption performance but also reduces its crystallinity. As a result, the dye molecules are easily able to penetrate the fiber. Then the dyeing property, color absorption, and hygroscopicity are remarkably improved.
We are experts on cationic dyeable polyester chips. For more information, please contact us.
Why is higher -COOH as end groups are desirable in Cationic chips over the normal Polyester chips ?
Dear Mr. Rajesh Jalan. Thanks for your comments. Generally speaking, the -COOH (End Group) content in the Cationic chip is lower than that in the normal PET chip. Lower End Group in Cationic Chips is good for the uniform dying. But if you need a higher End group in Cationic Chip, we can customize it for you.
How to identify CDP with solvent
Could you provide more information about your question? Like, identify CDP from Which yarn? We have sent an email to your email address. For the further discussion, please check your email box. Thanks in advance!
what are changes required during polyester chips manufacturing to get higher draw force as well as elongation during melt spinning for filament production . Means some polyester chips getting high draw force and high elongation .So what are chemical or properties of chips required to change to get the same during melt spinning ?
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Thanks a lot for your comment on our website.
As far as we know, the easiest way to improve the two factors lies in the spinning processing method.
But if you need some changes in polyester chips, we can add some flexibility monomer or chain.
Hope this information could help you.
And we have already sent you one email regarding this question. Reply to us, if you need more help.
Hi
very informative content ..
I am keen to know more about the cationic polyester and the mills doing such fabrics in piece dyed and prints in India and China
Thanks for your comment and very glad to hear this article is informative for you.
We will send you emails to discuss more details with you.
hi there,
could you let us know which one is having better color fastness?
Cationic Polyester has the better color fastness.
can cationic poly be converted to recycled poly and vice versa?]
Thanks for your question.
We do not think it can.
Hi, Could you explain a bit further your last answer. Why can’t you recycle CDP ? ( both chemically and mechanical recycling )
In a mixed cotton-polyester fabric, is it possible to dye in a single bath with reactive dye by pad batch process if the polyester yarn is cationic?
Why some cdp diffucult draw texture? Jumping out of heater
Dear Mr.Hamsun,
Glad to receive your inquiry.
We can have a further discussion about it through email.
Best Regards!
Hubei Decon
can we dye Cat ionic polyester with disperse dyes ?
Dear Asif,
Thanks for your comments.
We do not think Cationic polyester can be dyed by disperse dyes.
I am very impressed with your post because this post is very beneficial for me and provide new knowledge to me. Solvent Dyes Manufacturers in India
Thanks for your comments! Best wishes for all of us.
Is it possible to make mélange effect by cationic polyester ?
Yes, Sir.
Cationic Polyester can make Melange effect.
Is there a reason to use DMI instead of DMT?
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Which chemical dissolve catonic dyeable polyester for blend test
We are facing one challenge in Knitted Socks where Polyester Logo Yarn getting TINTED by Reactive Dyes. Yarn is imported from China and having variation within LOT. What can be the reason and is there any quick LAB TESTING METHOD to catch such cones which can get TINTED during Exahust Dyeing PRocess with Reactive Dyes ?
What is better to use in CDP polymer in Continuous polymer.erisation plant using PTA as feed stock?
A direct esterified salt like SIPA pr use SIPM, estrrofy and then use?