April 17, 2024

Screen printing is a printing technique where a mesh is used to transfer ink

onto a substrate, except in areas made impermeable to the ink by a blocking stencil. A blade or squeegee is moved across the screen to fill the open mesh apertures with ink, and a reverse stroke then causes the screen to touch the substrate momentarily, enough for the image to be transferred.

History of Screen Printing

The basic screen printing technique has been around for a very long time and can be traced back to hand printing with flatbed screens in China during the Han Dynasty around 110–220 AD. This technique was further developed in Japan around the 17th century where stencils made from wood or lacquered paper called ” Karen-e” were used. The modern screen printing process was further developed in the United States during the early 20th century. It became one of the major industrial printing processes of the 20th century, penetrating many industries including but not limited to textiles, automotive, medical, corporate image and marketing.

Screen Printing Process

The screen printing process generally involves the following basic steps:

– Design and Image Preparation: Designs are created digitally or by hand and are photographed or scanned and converted into a printing screen compatible format.

– Screen Making: The digital image is used to expose an emulsion coated screen to make the stencil. Exposed emulsion hardens and unexposed areas are washed away to create the stencil.

– Ink Mixing and Filling: The ink is mixed and viscosity adjusted as per the substrate and placed on the ink side of the screen.

– Positioning and Printing: The substrate/item to be printed is properly positioned under the screen. The squeegee blade pushes the ink through the open areas of the stencil onto the substrate below.

– Drying and Curing: On some substrates wet ink is then dried using flash drying units or conveyor dryers. On heat-resistant substrates, ink may be cured using flash curing or conveyor oven processes.

– Inspection and Finishing: The printed items are inspected and any reworks are performed. Finishing operations like packaging, labeling etc. may be carried out.

Areas of Application

Some key industries and areas where screen printing sees widespread application include:

– Textile Printing: It is one of the major industrial applications of screen printing where designs and logos are printed onto fabrics, garments, home furnishings etc. in the apparel and textile industry.

– Signage and Graphics: Large format screen printing is extensively used to print graphics, signage and visual communication materials outdoor and indoor.

– Product Decorating: Various consumer and industrial products are decorated using screen printing to add customizable designs, information and branding. This includes items like electronic devices, wall décor, ceramic tiles, packaging etc.

– Technical Textiles: Technical textiles for applications like windshield sunshades, digital printing, membranes are screen printed.

– Printed Electronics: Screen printing is emerging as a key technique for printed electronics applications like OLED displays, photovoltaic cells, sensors and more.

– Others: Screen printing also finds use in applications like carpet and floor graphics printing, vehicle wraps, membrane switches, medical dressings and more.

Advantages of Industrial Screen Printing

Some key advantages of screen printing in an industrial production environment include:

– High Production Speeds: Screen printing is one of the fastest industrial printing processes allowing for high volume production runs.

– Economical for Mass Production: With high asset utilization, screen printing becomes very cost effective for medium to large production volumes.

– Versatile Printing Capability: A single screen print operation can print on almost any substrate like flexible/rigid surfaces in multiple colors.

– Durability: Screen printed images are highly durable and resistant to weathering, abrasion, chemicals and heat when compared to other processes.

– Repeatability: Screen printed jobs have excellent consistency and repeatability essential for industrial production.

– Suitable for Dense/Intricate Graphics: Screen printing can reproduce fine detailed graphics, patterns, logos and high density text.

– Short Cleaning Times: Screen printing equipment has quick changeover and cleaning times essential for industrial efficiency.

– Minimal Material Wastage: Screen printing transfers most of the ink deposited on screen leading to minimal ink, substrate and consumable wastage.

Industrial Screen Printing Equipment and Technology

Automated screen printing machines are capable of taking screens mounted with stencils through precise registration and squeegee functions. Typical modern machines feature:

– Robotic Screen Changers: Automated handling of multiple screens with quick change ability.

– Automatic Squeegee Control: Programmable squeegee pressure, speed and stroke functions.

– Precise Registration: Optical, mechanical and magnetic registration systems for multi-color accuracy.

– Integrated Inking Systems: Rotor screen, roller and pump inking suitable for various ink types.

– Drying/Curing Systems: Infrared, hot air, UV/EB curing units for instant or conveyor drying.

– Central Ink Mixing: Computer controlled ink mixing for consistent colors over long runs.

– Top/Double-Sided Printing: Capable of printing on top, bottom or double sides in one pass.

– In-Line QC and Finishing: Quality control, slitting, shearing, packaging functions integrated on line.

To summarize, industrial screen printing has established itself as an efficient mass production printing process. It capabilities allow for consistent, durable and economical decoration and marking of a wide variety of substrate materials. New developments in automation, engineering and ink technologies continue to expand its applications further.

*Note:
1. Source: Coherent Market Insights, Public sources, Desk research
2. We have leveraged AI tools to mine information and compile it