Taking the guesswork and apprehension out of cold peel transfer application!
We believe that most garment decorators would agree that the percentage of garments spoiled when using cold peel transfers is much higher than with hot splits. If you are one of those, read on. If you are satisfied with the results from your present method, don’t waste your time.
Whether you like it or not, you must invest enough time to acquire at least a basic understanding of what is happening when you apply a heat transfer to a garment.
Here is the way it is supposed to work.
Place the garment on the FLAT, lower platen which is equipped with a resilient pad. Smooth it out with your hands to ensure there are no wrinkles in the bottom layer.
Position the transfer. Place a slip sheet over the transfer to break the vacuum created when the machine opens. If the opening vacuum causes the transfer to follow the upper platen even a few one-thousandths of an inch, the ink will hot split ruining the garment.
Close the machine bringing the FLAT, heated platen into pressurized contact with the transfer.
Now, some interesting stuff starts to happen.
Heat is conducted from the platen through the slip sheet and the transfer sheet into the ink deposit causing the ink to remelt. Then the pressure from the upper platen forces the ink into the fabric. While all this happens fairly quickly, none of these processes are instantaneous.
If the platen is not hot enough, the process is slowed. If the platen is too hot, the process is accelerated. Likewise, light pressure slows the process and heavy pressure speeds it up.
Take a minute to visualize the process as if it were in slow motion and greatly magnified.
The molten ink starts to penetrate the weave of the fabric. As it reaches platen temperature it flows faster and faster. Ideally we would stop the process by removing the pressure when there is sufficient penetration to ensure adhesion and enough deposit on top for the opacity which necessitated a cold peel in the first place.
The reason for the emphasis on flat and wrinkles should now be apparent. Wrinkles, seams and/or warped platens cause areas of greater and lesser pressure. Penetration will be deeper in areas of high pressure and shallower in low pressure areas to the point of total lack of adhesion if the platens are badly warped or the pressure setting is too low. (Continue on reverse side of page.)
When opening the machine, the first ¼” of platen separation is the only critical time. This must be done slowly enough so that the vacuum created by platen separation does not lift the transfer paper while the ink is molten.
Now if you yank the shirt off the machine while the ink is still molten and carefully lay it on the table to cool, you’ve probably ruined it.
Here’s why!
The shirt is elastic; the transfer paper is not. It is very nearly impossible to remove a garment from a heat transfer machine without causing some relative movement between the rigid paper and the elastic garment-thus hot splitting the still molten ink. While this usually affects only the edges of a transfer or small, unsupported text, the result is still less than perfect and unacceptable in some cases.
Here’s what you already have heard!
Most transfer and equipment manufacturers recommend that the transfer be cooled and peeled on the machine. Various methods have been suggested and tried.
These methods are better than pulling the garment off the machine while it is hot, but the results are still uncertain and all are s-l-o-w.
Our secret weapon – The “Chiller”!
At First Edition Screenprinting, we print and apply thousands of transfers. Over the years we have developed methods to improve our batting average.
We solved the cold peel transfer problem with a simple device we call the “Chiller”. Our production rate with cold peels is now very near that of hot splits and the scrap from hot splitting of cold peels has been eliminated.
The “Chiller” is a flat aluminum plate 14 inches square with a handle mounted on top. It weighs approximately 5 pounds. We apply it to the transfer for 3 seconds cooling the transfer enough to be peeled immediately after.
Another little note: Be careful when removing the garment from the machine, because the image is still warm and will stick to itself.
To Recap:
You must have control of the 3 variables – Time, Temperature, and Pressure – to successfully deal with cold peel transfers.
If you cannot control these variables, you are going to lose.
I’ve told you what a “Chiller” is and how to use it, so go forth and dread cold peels no more.