The difference between Siat and Sandwich printing? Let us explain
What is the difference between Siat and Sandwich printing? This is a question which could only be asked by those who approach the world of personalized adhesive tape for the first time and who, at the same time, want to be sure they are making the right printing mode choice.
It is important to state this before giving an answer: understanding the difference between personalized adhesive tape with Siat and Sandwich printing means investigating a rather technical aspect of the customization process of these products, an aspect which many companies who buy adhesive tape with personalized logos are not aware of at all.
But it should also be noted that printing in one way or the other leads to differences in the quality of printing, strength of the printed image, cost of adhesive tape, and so on.
It is, therefore, worth investing for a few minutes of your time to better understand if it you require printing with a Siat or a Sandwich machine to customize your own rolls of adhesive tape!
A review on the structure of adhesive tape
To understand the difference between Siat and Sandwich printing, it is best to know in a rather advanced way the structure of a normal adhesive tape: looking at this product as a single element, as is the case for fabric tape, is wrong from the start.
It is therefore worth remembering that a normal double-sided adhesive tape – made with PPL, PVC, paper, and so on – consists of 4 different layers. At the top is the release layer, which is very thin, and, just below, is the support layer, which is precisely what defines the “type” of tape.
Supports, as you might now, can be made with plastics, cellulose, and so on. Immediately below is the adhesive part, which is divided into the primer layer and the actual adhesive layer, which can be made with natural rubber, acrylic rubber, hot melt adhesive, and so on. The primer has the function of keeping the adhesive attached to the support.
Now that we have reviewed the composition of industrial double-sided adhesive, it is possible to explain the difference between Siat and Sandwich printing of customized double-sided adhesive tape!
Customized adhesive tape with Siat printing
Let’s start by noting how the term Siat refers to a particular type of printing machines for adhesive tape, and therefore being linked to absolutely specific use.
Inside these machines, the tape’s spool – which will become your custom strong double-sided adhesive tape – Ii loaded on a special pin.
Once this is done, it is possible to start the printing process, with the industrial double-sided adhesive tape being subjected to printing by means of special rubber stamps, which draw out the colour placed in specific trays by the machine operator.
The resulting print is, as you might understand, quite similar to what you could do manually on regular adhesive tape: it is a print on the back of the tape, on the outside of the support and the release layer.
At first glance, you might think that this is the only way to print tapes, and therefore the only possible process to customize adhesive tape. However, this technique has its disadvantages, which lead to the development and, very often, the adoption of another type of printing process.
Custom Adhesive Tape with Sandwich Printing
To understand the customization operation for adhesive tape by means of Sandwich printing, our earlier review of the structure of the adhesive tape is now evidently fundamental.
In these machines, which are more advanced and more complex, printing is not, in fact, carried out on the back of the tape, and therefore on its outside layer, but rather on the inside, lower part; that is, the one which will come into contact with primer and adhesive layer.
Printing is then carried out on the plastic or PVC sheet, on the side which will receive the glue afterwards, right before the final roll is put together. But why was this slightly more complex printing technique developed?
Pros and cons of Siat and Sandwich printing
The first and fundamental reason for the creation Sandwich printing is that adhesive tape printed with Siat machines offer a print that, if subjected to rubbing or prolonged contact, could deteriorate or detach, as it is placed on the outer layer of the tape; on the contrary, Sandwich printing, as it protects the ink between two layers, does not present such issues.
It must be said that this second printing method allows more defined, better-quality results.
On the other hand, preparing Sandwich machines takes longer, and is therefore more expensive: it follows that Sandwich printing is generally used only for the customization of large quantities of adhesive tape, so as to spread the cost of preparation on the total number of rolls.
One last advantage of Sandwich printing is that it is possible to use four-colour printing!
