Screen Printing on Acrylic: The Ultimate Guide

What is Screen Printing on Acrylic?

Screen printing is the process of transferring ink onto the acrylic substrate through a mesh, using a squeegee/roller to fill the open apertures.

Due to its simplicity, it is common in many acrylic fabrication applications.

Besides, it does not create any problems when there is no tension.

Implying, it can survive a single wiping.

Sometimes, screen printing on acrylic with a hard coating is a bit difficult.

Still, with you can achieve this, by making some adjustments to the screen printing acrylic procedure.

To succeed in this, you can either treat the plates with corona or control the ink hardening much carefully.

Acrylic sheet

It is much easier and safer to work with acrylic than glass.

This is because it is cheap and also offers transparency and smooth surface just like glass.

Advantages of Screen Printing on Acrylic

Some of the main advantages of acrylic screen printing include the following:

Screen printing on acrylic

• Provides screen printers many opportunities like point of purchase graphics, flat faced and thermoformed signage.
• Cost effective since you don’t need any equipment to start your work. The acrylic itself is also affordable compared to polycarbonate sheet.
• When mistakes are made in the course of printing, it can easily be erased as compared to other screen printing substrate materials.
• It is durable when printed either directly or on paper and faces mount behind the acrylic method. This is because it provides UV protection between 70-99% depending on the acrylic type used.
• Acrylic does not fade, tear, stain, wrinkle or peel off. Also, it can last long for close to 10 years without yellowing.
• It protects against moisture if printing is done directly on acrylic.
• Acrylic is resistant to shattering, light in weight, and has glass-like qualities like clarity, brightness, transparency, and translucence.
• Screen printing on acrylic is unique, especially when compared with other printouts from other substrates. This is because it provides sleek, modern and vibrant looks which are terrific in contemporary decors.
• Gives a refractive light that is almost 3-D like and gives greater color vibrancy.
• Saves time since it is printed directly unlike paper graphics which takes a much longer time. It can easily be recycled when there is need.
• It is open to creativity as it can be tinted or colored, mirrored or made opaque depending on how you want it.
• Many coatings can be applied to a sheet for performance to enhance resistance, anti-fogging, glare reduction and solar reflexivity.

The outcome of its products have an immaculate look and has no label edges.

Disadvantages of Screen Printing on Acrylic

Also, you should know that screen printing on acrylic has the following main disadvantages:

Acrylic sheet with anti-fog coating

• The print outs on acrylic can easily be scratched off during transportation. So you have to be very careful on the way they are handled during transit, loading and offloading.
• Generally, acrylic is hard, and it is always difficult for ink to penetrate it. This can sometimes result due to variation in acrylic batches.

Sometimes, failure on ink to bite into acrylic is caused by the residue from masking film for protecting the acrylic sheet.

• It can only use UV thermoforming ink which can adhere to many types of acrylic sheets. This ink is considered ideal for acrylic because it makes it flexible to undergo secondary operations like cutting, bending and thermoforming.

However, when this ink is used, it requires careful monitoring of ink performance during production, and this is tedious.

It is very risky to use general purpose ink because the failure of adhesion is high.

Acrylic Screen Printing Tools and Equipment

When you visit a screen printing floor, it is crowded with machinery, other tools and material waiting to be used.

The equipment is in three categories.

These include:

Screen printing kit

· Pre-press Equipment

Before the final product is printed out, there are some things that have to be done.

For digital screen printing for acrylic, the artwork has to be prepared.

You also have to get the screen ready.

Therefore, pre-press equipment includes:

• Computer with installed design software for creating graphics.
• Printer and a film for making a stencil on the screen. The graphics created will be printed onto a clear film. This printer must lay down an opaque black ink which should block UV light during screen exposure.
• You will also need screens for a screen printing shop.
• For manual printing, you need transparency of image to be printed. This is the tool that contains the image to be printed on acrylic sheet.

The image should be in black.

It is placed upside down on the screen because it’s the back side of the screen that is flat.

• A glass frame: This is used to flatten the transparency on top of the screen. It, therefore, helps to hold it in place during the screen printing process.
• 150-watt bulb: This provides the light that exposes the screen-in about 2 ft away from the screen for around 13-14 minutes.

The light helps to dry up the uncovered areas of the screen.

Once the timing is up, this light is turned off.

· Actual Screen Printing Tools and Equipment

For the actual screen printing work, you will need the following key accessories:

• Printing press: It is always recommended that you start screen printing with a six-color press. This allows you to do any printing job.

We also have an 8-color printing press, and so on.

 Manual screen printing press

• Ink: This is also useful. For acrylic screen printing, you will require UV thermoforming ink. This ink is ideal for acrylic screen printing because it penetrates its surface very well.
• Some plastic containers and ink scoops will also be relevant for ink mixing.

In some cases, you may use scales and mixers to aid in mixing the ink appropriately.

• Squeegee: This is used to pull ink across the screen and lay down the print. There are varieties of these to choose from.
• Masking tape: This is used to tape acrylic on to the flat surface to hold it in place during the screen printing process.

· Post-press Equipment

Well post printing is an important process in acrylic screen printing.

You need the right tool and equipment to accomplish this process.

Here, the tools and equipment required include:

• Conveyer dryer: It heats the ink to a curing temperature so that the print can last longer.
• Heat sensors: Apart from this, you may also need some heat sensors like a heat gun or heat tape. This will check if the ink has the required temperature at the time it is coming out of the drier.
• Small fan: This may be needed in manual printing. It is used to speed up the drying process of the screen printed acrylic; else drying would take a relatively long time like 3 hours.
• Handheld pressure washer: This is used to clean the screen just immediately after printing the image. With water inside it, pressure is applied. All the screen parts that have not been exposed to light will wash away.

All the exposed areas will remain unwashed since with exposure to this light, they have dried and hardened up.

This equipment is therefore very significant in manual screen printing for acrylic.

• Packaging accessories: After this, you may need some bags and boxes for keeping the finished acrylic products.

Step-by-step Process in Screen Printing on Acrylic

The process involves several sequential stages.

It requires that some sections of the screen are blocked to come up with the desired image.

The materials needed are silkscreen, masking tape, printing ink, roller/ squeegee, acrylic sheet, and transparency.

i. Preparing for printing

First of all, you have to prepare your screen and decide on the image you want to print.

If you are drawing the image, ensure you leave a margin around the drawing.

If you desire a multi-color print, create individual screens for each color you intend to use and on separate transparencies.

Ensure the surface of the acrylic substrate is clean and flat.

ii. Mount and tape the acrylic on a flat surface like a table to prevent it from moving about during the printing process.

iii. Place the screen over the top of the acrylic and tape it to reinforce its stability during printing.

iv. Using a roll of masking tape, tape each corner of the screen to raise it slightly above the table. You may also use small pieces of cads at each corner.

v. Draw registration marks on the acrylic to ensure ink is applied on to the right areas only.

vi. On a horizontal straight line, apply a layer of ink over the image top. Using a roller or squeegee, slowly spread it over the design at 45° angle. Be careful not to push too much ink through the screen since this can lead to color bleeding to the image.

vii. Scrap all the excess ink using a plastic spatula or spoon and return then into the ink pot.

viii. Remove the screen slowly from the acrylic top to prevent the ink from smearing on to the image. Now leave the acrylic to dry for many hours without moving it. You can use a hair dryer to speed up the drying process.

ix. Remove the tapes and wash the screen with cold water spray and sponge on both sides. Using a hand towel, carefully dry the screen printed acrylic.

Once it is dry, your acrylic screen print is ready and ready for use.

Techniques Used in Screen Printing on Acrylic

There are two main techniques that can be used in screen printing on acrylic: digital and manual.

These techniques are specifically relevant depending on the outcome desired by the printer.

In this topic, we shall go through these techniques, and their advantages and disadvantages.

1) Digital Screen Printing on Acrylic

This is the use of an automatic to screen print on acrylic.

Before printing, a protective release liner must be peeled off from acrylic.

This ensures the achievement of a clean print on the substrate material.

With digital print, full sheets of acrylic of up to 5 x 10 inches in size can be printed.

The machine prints directly on acrylic and, after that, can be custom-cut into the desired shapes and sizes.

The digital machine can laminate and mount the screen printed acrylic.

Also, large banner materials can be printed through digital screen printing for acrylic.

The picture below illustrates a digital machine that can print large formats.

Digital screen printing

Benefits of Digital Screen Printing on Acrylic

Some of the main benefits of digital screen printing on acrylic include:

i. Screen printing is improved since the machine has both faster dryers and ink cured with UV light. It offers a faster and efficient process and therefore can deliver quickly.

It, therefore, eliminates a lot of waiting that is experienced while dealing with manual screen printing on an acrylic substrate.

ii. It produces images with precision to details. This is because even little details are not lost in the final product during the printing process. Remember, this is not possible with manual screen printing on an acrylic substrate.

That is why digital printing is preferred for sharp photographic prints or other more complex artwork or images.

iii. Can produce images in bulk at a time thus saving time and resources. This is because digital screen printing involves a few steps as compared to the manual one. It can, therefore, handle small, medium and big orders.

iv. The printer only needs an image and acrylic. This process, therefore, costs less than manual.

v. This type of print is flexible and allows for variability without hiking the cost and time for production. For example, you can print the same design with numerous captions. This is just a matter of manipulations done on Photoshop on the computer.

vi. It is environmentally friendly because it does not require many materials. Therefore, there is no worry for waste disposal and other chemicals that may be harmful to the environment.

Disadvantages of Digital Screen Printing on Acrylic

As you plan to adopt digital screen printing on acrylic, always remember that it has the following key disadvantages:

i. With this technology, a digital file is translated into color output. This may result in a transfer of unintended color dilution or saturation. Thereby losing purity and the actual color of the image.

The risk of this is even higher if many printers are used to mix the colors so that they can get shades.

• Purchasing of the machine is difficult and expensive, unlike manual where the tools are not very expensive.
• Also, the operator of the machine has to undergo thorough technical training on machine operation. They must be trained on how to handle the machine, clean it and sometimes even handle minor repairs. This is expensive and time-consuming.

2) Manual Screen Printing on Acrylic

If you cannot afford the digital printing option, you can go for a manual careen printing on acrylic sheet.

Here is a summary of what happens here:

i. Clamp your acrylic sheet firmly on the surface you are working on to avoid shifting during the printing process.

ii. Place the laser print at the center of acrylic sheet with the print side facing down.

iii. Tape down the print onto the sheet and the surface using masking tape.

iv. Using a blender pen, rub the back of the print or photocopy. Apply pressure using this pen methodologically bearing in mind to cover the whole image area.

This pen has a xylene chemical that releases toner from print/ photocopy and aids in transferring it to the acrylic sheet.

v. Using a heavy wooden or metal spoon, rub the back of the paper and the entire image thoroughly.

With firm pressure, the image will be affixed onto the acrylic. This application process is called serigraphy and is done for each color of the image if many colors are desired.

vi. Peel off a corner of the paper to examine the quality of the print that has been transferred. If the image is too light, repeat the blending pen pushing steps to achieve the desired outcome.

The diagram below shows manual screen printing for acrylic.

Manual screen printing

Advantages of Manual Screen Printing on Acrylic

• It is less expensive, especially when you have a bulk order. This is because once the screens have been made, they can be re-used for screen printing over and over again.
• Manual screen printing for acrylic gives the true and exact color you would desire for your finished products. This is achieved because a thicker ink layer is applied on acrylic during screen printing resulting in bolder colors.
• Designs of different shapes and sizes can be manually screen printed. It does not matter which shape. For example, a logo on a pen, a motif on a lampshade can be produced.
• Manually, the object can be maneuvered to ensure good quality is printed.

Disadvantages of Manual Screen Printing on Acrylic

• It consumes a lot of time. For this reason, the producers cannot handle big orders within a short time like in digital screen printing for acrylic.
• It lacks the precision that digital printing offers. This is because some essential details may get lost during screen stenciling process.
• This process requires color separation especially when you want multiple colors. This is relatively an expensive process.

Acrylic Screen Printing Machines

There are a number of machines like Galaxy-Jet X al UV flatbed printer, ZXD print digital acrylic drinking glass printing machine.

There is also the acrylic board printing machine, among others.

These machines cost from around 2,500 USD, up to even more than 30,000 USD depending on the quality and capacity.

Main Features of the Machines

Acrylic screen printing machines can produce large prints of about 60*90 CM compatible with acrylic printing material.

They have an adjustable print tooling that supports UV printing on an acrylic cylindrical shape.

Some have 8-color ink cartridge design, other 6-color with CMYK+LC+LM two spot colors.

This feature aids the vivid movement of color, making a natural and realistic color effect.

Besides, the ink cartridge has a liquid sensor which gives an automatic alarm when there is no ink.

Also, this machine has an automatic print head wipe.

This prevents print head clogging when the machine is not running.

It has laser engraved margin rule that is marked X and Y axis on the printing table.

This makes printing position easy and helps in improving the printing effect.

The picture below shows an example of an acrylic screen printing machine.

Acrylic screen printing machine

Common Problems in Acrylic Screen Printing

Below are some of the identified challenges that you are likely to face when printing on acrylic.

 Screen printing acrylic – Photo courtesy: Plastic Formers

· Bleeding of colors

This happens when the pigment is loose.

During printing, at every registration, the printing paste will bleed to the surrounding areas of the image on acrylic.

This spoils the printed image.

The remedy here is that you should ensure that the paint is thick to the extent that it will stick to the acrylic.

Also, at every registration, make sure you clean the under part of the screen.

· Unequal gaps left between repeats

Sometimes, repeats of the design do not join.

Therefore, you have to make sure you calculate the registration of the screen.

You also have to check the repeats just before printing begins.

· Irregular screen placement

This happens when you don’t check the repeats.

Therefore, you have to check the repeats before you place the screen to register the print.

· Formation of color patches

This occurs when the color is not evenly distributed on acrylic.

The remedy here is to use enough ink and to pull the squeegee properly over the image.

· Acrylic sheet sticks to the screen

This is common and causes difficulty when being pulled off.

Do not press the screen so hard on the acrylic sheet. Just mask tape it on the edges and pass the squeegee slowly over the screen.

Applications of Screen Printing on Acrylic

Screen printing on acrylic has been applied widely on items that are made from acrylic materials.

The applications are very appealing and have been commonly accepted in the current market.

· Printing Awards

It has been used to print acrylic awards like Professor J Anderson memorial award, 2014 fielder of the year Jack Thomas Award among others.

Below is a picture of some of these screen print acrylic awards

Printing awards

· Printing Images

It is applied in printing stunning, colorful images with a raised texture of 3-D on round items with cylindrical printing.

For example in beer and wine bottles, cups, candles, awards, tubes, cans, and glasses.

· Industrial Labeling

Apart from these, the application is also seen in industrial labeling, dial faces, and serial plate printing.

Here direct inkjet printers are used.

You can print full-color, photo-quality images, logos and text directly on acrylic.

The image below is an example of an industrial logo for PSI.

Industrial labeling

Cutting-edge direct jet UV LED inkjet printers provides high-quality print outs, and detailed text on cell phone cases and tablet covers.

This is done on board to allow easy printing of eye-popping, raised texture cell phone and tablet cases.

They are amazing and most customers like them thus giving the producers a competitive edge.

Printing Consumer Accessories

The image below is an illustration of phone and tablet case print applications.

Printing consumer accessories

Printing Logos

It is also used to produce good quality images like logos on phones and tablets cases like the ones shown below.

Printing logo

Printing Signage

It is used to print both interior and exterior signage, name badges, photo IDs and luggage tags.

Printing signage

Conclusion

Screen printing on acrylic is useful and very relevant for printing labels, logos, and texts.

This has also been applied in printing drinking glasses, ID cards, candles and organization signboards.

Thanks to technology, this process has been digitalized, meeting the demands of the fast-growing population around the world.

However, the manual technique is still used widely to produce desired images with pure and true colors.