Flow-Marks in Latex Balloons

Manufacturer: We are manufacturing latex balloons and countering the issue of "water marks" on inflated balloons. The balloon when inflated shows a lot of running down marks. These are the same marks which we observed after coagulant dip.

We had checked the cloud point of wetting agent and had controlled the temperature of coagulant accordingly. But still could not troubleshoot the right Issue. Please suggest a suitable remedy. Your kind advice is highly appreciated. 

John Woon (Senior Latex Consultant): 1) Ideally, the coagulant on the former should "set" immediately, without excessive flow, as soon as the former is withdrawn from the coagulant tank.

2) To achieve this, one should ensure that both the former temperature and coagulant temperatures are high enough so as to accelerate the evaporation of the coagulant. You might want to increase the former temperature. You should also consider switching to another wetting agent having a higher cloud point so that you could also increase the coagulant temperature further.

3) To ascertain whether evaporation is a causative factor, I suggest you blend the water used in the coagulant with alcohol (e.g. isopropyl alcohol). This should improve the evaporation. However, please beware of the health and fire hazards of alcohol.

4) Another possible route is to increase the viscosity of the coagulant mix by increasing the amount of the detack powder or better still, by adding a thickener.

5) This flow mark could also be due to the cumulative build-up of the detack powder on the formers. Therefore all formers must be properly cleaned before dipping.

6) Sometimes, the uneven coating of latex on the formers (not necessarily the flow mark) could be due to poor wetting of the coagulant or dirty formers.