What kind of dye are you using?

I am using Nylon dyes as local dyers told me that with nylon dyes its easy to get result at 100 C and with disperse dyes it require very high temp.

While you can get good results with disperse dye (polyester dye) on nylon, you should not use acid dye (nylon dye) on polyester, or so the dye experts tell me. (I am assuming that your local dyers are referring to acid dye when they say nylon dye, as acid dye is very commonly used on nylon, though disperse dye can be used on it as well.)

Disperse dye can be used at 100 degrees C., if you use a carrier chemical. See the list of links to instructions, halfway down the page at http://www.pburch.net/dyeing/dispersedye.shtml . Pro Chemical & Dye recommends the use of a chemical that they call Dye Carrier NSC. I am not sure of the best European source for this material. Zijdelings sells disperse dye, but I cannot find the carrier on their web site, nor in the Rainbow Silks catalog. Kemtex probably carries it. Prices in the UK tend to be higher on dyes, so it might turn out to be best to order directly from ProChemical, even though it is in the US, if you cannot find a local source. See my "Sources for supplies" page at http://www.pburch.net/dyeing/dyesources.shtml for a list of European sources. These are all small-quantity retailers, for individual users; there are many companies which sell only huge quantities suitable for industrial use.

The carrier is required for vat-dyeing with disperse dye, but there is another alternative. Have you tried painting the disperse dye onto paper and then transferring it with a hot iron? You can get wonderful results this way, without the carrier NSC. See the information at http://www.pburch.net/dyeing/dispersedye.shtml . Those companies which carry disperse dye, but not the carrier, sell it for this sort of use.