When it comes to the time-management of your heat press, estimates about the number of seconds required for dye sublimation or fixation are only a rough indication of what is needed.
This information is useful for the initial set up of the machine, but – ultimately – colour development and fastness-levels are the only outcomes that will tell you how much time in the press is enough to ensure a high-quality print. The most important factors to consider are
- the application of the printed textile,
- the colour-shades being printed, and
- the quality of the heat source.
The diameter of the heating drum defines the speed I can run at, right?
There is some truth to this: generally speaking, the larger the drum, the more surface contact, meaning more speed at any given time. So far, so good. However, if you look at the various heat-press designs, you may notice that some machines use a significantly larger portion of the drum; the wrap-around angle is bigger. A bigger drum with less contact surface will not provide you with the output you initially anticipated. What’s more, two different machines with the same diameter and wrap-around angle may still result in a different colour-yield or fixation level, due to the difference in heat consistency.
How do I get a more precise measurement?
When comparing the contact time, you’ll want to actually count the seconds during which the exact process temperature is reached. With unstable heat sources, such as IR systems, not oil based or partially filled drums, the time of the correct process temperature should not be taken into account fully. If the temperature gets too low, this will slow down the process, or stop it altogether, resulting in a different colour development to the one desired. For all of these reasons, you cannot use the same settings of one brand of heat-press for another. On a high-quality press, all these parameters will work in favour of maintaining the shortest possible contact time.
So, a more expensive machine will end up being the cheapest in the long-term if you calculate the cost per square metre or yard of material. At the end of the day, time is money – especially when it comes to dye sublimation or disperse dye fixation!