News Decal

28 Apr 2021

Vinyl humidity? We explain the problems and reveal the solutions

Vinyl humidity is a constant “headache” for professionals in large format digital printing. If this is your case, you are certainly familiar with the waving and curling of the material, which compromises quality and generates waste of consumables, time and money.

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In this article we explain how the humidity problem affects the different phases of Sign Graphics' jobs, what impact it has on your company's results and reveal solutions.

Are you interested? Then, continue reading.

1. Waving in printing:
a race against time and waste

The waving generated by humidity transforms the prints into a real race against time and contributes to the waste of vinyl and inks, as well as to the accelerated wear of the equipment.

Printing preparation

The clock starts counting when the roll is removed from the packaging and placed in the machine, starting the process of preparing the image for printing through the RIP (Raster Image Processor). The waving appears on the vinyl in this waiting period and, when the equipment starts to print, the print heads will scratch the material.

The negative consequences multiply in the short and long term. Immediately, you will have direct breaks of material, inks and products to clean the print heads. Later, the wear of the print heads will cause the need to replace them.

With regard to the amount of material wasted, if it is disconcerting to think about what happens in a single job, imagine how much you throw away at the end of a month and, consequently, the impact that this has on your company's annual accounts.

Temperature differences

The temperature differences during the heating period of the equipment also affect the dimensional stability of the vinyl. The results will be far from what was intended with the strong possibility of altered colors, spots, lines and more open or closed points appearing in different parts of the job.

It is in latex printing technology that this problem generated by vinyl humidity is most evident, since it involves temperatures between 100 and 120oC. The same happens, although on a smaller scale, in solvent printing technology, with temperatures varying between 40 and 50oC.

UV printing technology, despite the low temperatures, does not escape this problem, but it is the one that less disappoints the professionals' expectations.

Time between jobs

Another moment when waving appears on vinyl is when the roll is in the equipment between prints. About an hour is enough for the part of the material that is exposed from the printing area to the first roll turn to have to be thrown away.

The same happens in cases where the same roll is used for different jobs. We know that it is not possible to monetize a roll in its entirety, however, one thing is certain, humidity indirectly affects the investment.

Rush to store

When it seemed that the limitations had been overcome, the race against time and waste continues with the rush caused by, at the end of printing, the necessity to immediately place the roll in the original packaging and store it in a place without humidity.

2. Waving and curling in finishes:
when simple things get complicated

If you think it was time to catch your breath when you get to the finishing stage, don't. Humidity remains a problem and complicates what appeared to be simple in crucial stages, such as lamination and cutting.

Solvent evaporation

However, before reaching these stages and using solvent printing technology, you are also faced with the negative effects of humidity.

As you know, it is sometimes necessary to let the solvent evaporate for, at least, 48 hours in a ventilated environment after printing, and it is in this period when the vinyl curling appears.

Lamination

If the jobs involve lamination, the curling created by humidity makes difficult something that seemed to be a quick process, which is the placement of vinyl in the laminator.

Once this difficulty is overcome, it is the waving what influences the good results as it can lead to the appearance of spots, creases and bubbles.

Material cut

When it is necessary to cut the vinyl, its placement on the equipment also becomes more complicated if it is curled. The problems double when the waving joins the curling during the reading of the cutting registers, forcing unnecessary procedures, such as holding the vinyl until the machine can read the marks.

The cutting pressure is also disturbed, oscillating between points where it is not enough to cut the vinyl and others where the cut reaches the liner.

3. Curling in the application:
multiplied demand and patience

Ok, you have managed to overcome the challenges in the printing and finishing phases. The vinyl application phase has arrived and the humidity starts to “attack” again, making it time-consuming and demanding.

Despite experience (or dexterity), you will soon realize that, in some cases, it will take more than one person to guarantee a well done job.

Creases and tears

The first obstacle is to take the rolled vinyl off and position it. Even the most experienced professionals exasperate with the creases and tears that, often, appear.

In the application of the following panels, the difficulty makes paper tape the “best friend” to ensure the accuracy of the correctness of the image between them.

Local temperatures

Another constant concern is the differences in the relative humidity rate of the places where vinyl is applied, yet one warning, curling does not appear only when we talk about different countries or regions.

You may have been able to overcome the challenges of humidity during printing, finishing and application and, after some time, your customers complain about the vinyl curling caused by temperature changes, during the day and at night, in the same place.

Do not exasperate, do not wait any longer … there is a solution

Now that you know how the humidity of the vinyl hinders the different phases of the Sign Graphics' jobs, do not exasperate, do not wait any longer and find out the solution to this problem.

In fact, not "the solution". But different solutions that, currently, allow defying the extra bills provoked by the time and waste caused by the waving and curling of the vinyl.

It was with this goal in mind that decal developed the new vinyl anti-humidity collection range, which includes monomeric, polymeric and PVC Free products. Diversified options to ensure that each job (and your company's job) stands out for its profitability, speed and quality.