Printing Screen Preparation
Screen printing is a printing technique that uses a woven mesh to support an ink-blocking stencil to receive a desired image. Screen printing is an old age process and involves creating a screen and uses it as a stencil to apply layers of ink on the printing surface. A different screen is needed for each color that is used in the design, one at a time, combined to achieve the final look. For this, various types of printing screens are need. Here the printing screen preparation flow chart is given below.
Process Sequence of Printing Screen Preparation
Mesh fabric tight with frame
Applied chemical autosol and potassium dichromate on the mesh & dried 8 min in air.
Placed design paper under the mesh.
Light passes through the design paper & mesh fabric for 3-4 min.
Remove the colored TXR from the design area by water spraying.
Step-by-step screen printing process
Screen printing can be carried out in a number of different ways. But the basic technique remains the same. These are:
- Design creation: First and foremost, the design to be printed onto the fabric is printed out onto a transparent acetate film. That will be used to create the stencil or screen.
- Preparing the screen: The method gets its name from the use of a screen to print the design. There’s no ‘one size fits all’ approach here. And choosing the right mesh screen involves assessing the complexity of the design to be printed, and the material which is to be printed on.
- Exposing the emulsion: The transparent acetate film which holds the design is then carefully placed onto the emulsion-coated mesh screen. This is placed under a very bright light, which causes the light-reactive emulsion to harden and develop. This is an important step in creating the design imprint, as any areas of the screen which are covered by the design will remain in liquid form.
- Creation of the stencil: The screen must be exposed under the light for a set amount of time. Before the emulsion has hardened on any areas that are not covered by the design. In order to leave a clear imprint of the design on the screen, any emulsion which has remained in liquid form will be carefully rinsed away.
- Preparation for print: The silk to be printed on is laid down flat on the printing press, and the screen is carefully placed on top in the desired position, ready to print.
- Printing: This is when the printed design finally starts to come to life! The screen is lowered down onto the printing board, above the piece of silk. A thick layer of ink in the desired color is applied to the top of the screen and a squeegee is used to drag the ink across the whole length of the screen, covering the full stencil.
- Quality check & finishing: Finally, the ink is cured by passing the silk through a special dryer to reveal a smooth, colorfast finish design. The final product will be checked and thoroughly washed to remove all traces of emulsion residue and ensure it’s ready for use.
Author of this Article: Rana Sohel Executive Engineer Sunman Textile Mills Ltd. Chittagong Cell: +8801912-420118 Email: [email protected]