Why is screen printing a suitable technique for making opaque transfers?

The most commonly used garment for prints since 1925 is the T-shirt. In 1956 was developed the screen printing ink that has since become a standard for the decoration of this garment: the “Plastisol”. One of the innovative features of Plastisol was that it could be thermo fused above 160° - 170°C so it could allow the transfer of the graphic from a sheet of paper to a fabric through a hot press.

The screen printing is a technology based on the permeation of the ink through a fabric. By varying the characteristics of this fabric, you can easily change the amount of ink deposit.

We quote as a reference of high thickness in the comparison schema on the right a 60 micron deposit that can be obtained in screen printing but this data is not correct.

For some time now technologies have been available for making high thickness direct/indirect film screens (called MS-thick film) that can allow prints with ink deposit of 150-200-300-400-700 up to max 1000 micron = 1mm.

Screen printing inks for the production of opaque transfers

Here below a sum up of the features of the various inks for transfer

Inks for Plastisol screen printing

Advantages:

Easy to print
High opacity
High stretchiness
Affordable transfer materials

Disadvantages:

“Plastic” hand
Not ironable
High transfer temperatures
Sensitive to migration

Solvent inks for screen printing

Advantages:

Easy to print
Higher stability of the support
High definition
Lower transfer temperature

Disadvantages:

Hard hand
Less opacity
Less stretchiness

Water based inks for screen printing

Advantages:

Textile hand
High opacity
Ironable
Excellent stretchiness

Disadvantages:

More expensive transfer materials
Not easy to print

The key elements for opaque quality transfers

The difference between a transfer and a quality transfer is determined by the following factors

Screen printing technique

High deposit of the various ink layers
Register precision

Inks

Must be especially developed with specific features for transfer applications
Reliable technical support for a correct use of the inks

Transfer sheet

Final aspect
Precision and definition of the print (based on the specific features of the material, please check our page on this subject

Polymerization oven

Guarantee of right and constant drying to prevent transfer problems
Increased washing fastness
Better precision and definition of the final result

Hot press

Increased washing fastness
Evenness of results

The cooperation between Grafco and GrafcoAST, distributors and technical support in Italy of the screen printing machines of INO, has led to the building of a show room of over 500 square meters in Treviso where the customers, together with Grafco’s technicians, can test the Grafco products for transfer on the screen printing automatic and semiautomatic INO machines.