Dark fabric stacked in neat rolls, the cores visible
Run a fluorine-free flame retardant finish on polyester and the FR requirement does pass, yet the water repellency on the surface collapses with it, the bath throws sediment when the two are run together, and the finished fabric carries defects, so a whole dye lot is thrown away.
Chemi Tech makes water repellent finishing agents for outdoor fabrics, nonwovens and industrial textiles, in the water repellent agent KMF-603 series. Which grade is added depends on the fibre composition, the fabric construction, and whether the test protocol the customer supplies looks at spray rating or at repellency continuity after rain. On polyester and nylon fabrics, KMF-603 is built in the direction of continuous repellency with handle kept in balance; where the perfluorinated item also has to be held down, the fluorine-free KMWF-03 is the simpler route and is used widely on export orders. Send over the greige specification and the test standard, and we will settle it against that protocol for you, with no round of groping in the dark on your side first.
Advantages of Chemi Tech Water Repellent Agents
Film formation across the fibre surface is continuous with this grade of the Chemi Tech water repellent agent KMF-603 series; it does not rely on a layer floating on top, so it is not easily lost after washing. Its compatibility with the common flame retardants and resins is good as well, so a one-bath run does not fight, and the bath throws no sediment. The handle is soft, too: the finished fabric does not go stiff or harsh, and downstream laminating does not need its parameters changed. Wash resistance keeps pace as well, with the spray rating after twenty washes still falling inside the thresholds customers commonly set. On top of that, it contains no perfluorinated compounds, so the test protocol is cleared in one pass.
A note from Chemi Tech: the behaviour above comes from a typical polyester fabric finishing condition. Change the fibre composition or the fabric construction and the results move. Confirm on a small sample before scaling up.
Industry Pain Points and Solutions
The most grinding part of water repellent finishing is that repellency, flame retardancy and handle are forever pulling against one another.
Testing repellency without testing the one-bath run is the most common place to slip. The sample's repellency looks good the day it is made, then sediment appears once it runs with the flame retardant, and the fabric defects are only found downstream. Chemi Tech runs a round of one-bath validation with the finishing agent and each of the common flame retardants, so the process window is marked out first.
What follows is the wash resistance gate. The score looks good on the day of sampling, then repellency falls away after a few washes and complaints break out at the garment plant. Chemi Tech's approach is to lay out the spray rating and rain data before and after washing together, rather than producing a report that only looks good on the day.
One more point is where the handle gives out first. Push the finishing agent dosage up and the repellency rises, but the fabric goes stiff and harsh and the laminating step will not bond. Chemi Tech's approach is to put the handle score and the repellency score into one comparison table and find the boundary at both ends together.
Sampling and testing are taken over by us, and repellency, one-bath flame retardancy, wash resistance and handle are all done in one pass against the customer's test protocol, with the process sheet passed straight to the workshop.
Typical Conditions and Verification
Customer: an industrial textiles manufacturer in Jiangsu, applying it to the combined flame retardant and water repellent finishing of polyester fabric.
This mill makes protective fabric for European customers and runs a fluorine-free system for the flame retardant finish, but the repellency item would not pass, the one-bath use threw sediment in the bath, and fabric defects led to two lots being reworked. The solution offered by Chemi Tech water repellent agents was: against the fibre composition and the test standard the customer supplied, KMF-603 was selected from the KMF-603 series, the finishing process was recalibrated together with the curing conditions, and a small sample was sent first to the customer's laboratory for confirmation. After the change the flame retardancy and repellency items both passed in one run, the one-bath liquor threw no sediment, and repellency before washing and after twenty washes both stayed inside the customer's threshold. The rework station this mill used to staff has been converted into a sampling bench.
Frequently Asked Questions
With a fluorine-free system for the flame retardant finish, must the water repellent agent also be switched to fluorine-free?
On export orders it is required to be fluorine-free in most cases, but how far that has to be taken depends on the customer's test protocol; plenty of orders can pass on a fluorinated system, and what matters is whether the one-bath compatibility with the flame retardant can hold up. The KMWF-03 Chemi Tech supplies to fabric mills has been tested against the fluorine-free direction, and which grade is used is settled by us after looking at the data. Give the fibre composition, the flame retardant system and the customer's test standard to the Chemi Tech technical department, and sampling and process parameters come back together; tight delivery schedules are scheduled first by us.