Plastic bags have many different ways that you can use to print a design on them; it all depends on the press run size.
If you want to carry out long runs, you will surely need a procedure that will be more affordable. This boils down to joining two sets of sheets on top of each other with the pressure from the press.
What is Flexography and How Does it Work?
Another way of designing plastic bags is by using flexography. This is the method whereby your designed image is impressed on rubber printing plates which allow the ink to pass through to the item being printed on.
This process is not done manually rather passed through the heat press machine while stamped with an adhesive tape. When the machine rollers are rotated, the plates will go through the web press and allow the heat platens to imprint the graphic onto the plastic bags.
Then there is the method of printing designs on a plastic bag which we are concerned about in this article being the Screen Printing process.
This procedure is carried out manually and requires that the plastic bags be printed one at a time.
Screen printing involves using a mesh to transfer ink to an item. The apertures of the mesh are thoroughly filled with ink as the squeegee is moved across the screen.
This method is the easiest, fastest and inexpensive way of creating exemplary plastic bags. It is a sure way to fulfill your customer’s dreams at home and overseas.
You can use this process to print designs on plastic bags for boutiques, malls or super markets that want their own branded design on the plastic bags.
Screen Printing can even be done on recycled plastic bags and still bring out an effective result. Although Screen printing is one the less complicated methods of printing design onto an item, it really needs mastering when the objects of your screen printing are plastic bags.
Plastic bags are usually printed before they are formed into bags. This is more so for the plastic bags used for food stuff.
Screen printing is usually done manually which could be stressful most times due to the fact that the material tends to stick on the Screen.
That is the reason this article is all about guiding and instructing you on how you can successfully carry out your screen printing on plastic bags.
What Do You Need to Screen Print on a Plastic Bag?
- Plastic bags that is well-stretched out without leaving any wrinkle
- A stenciled Screen
- A photo emulsion that has been mixed with the sensitizer
- A black ink for the screen printing
- A plastic knife
- A stick made of popsicle
- A squeegee
- A light piece of cardboard paper
- Plastic Canvas
- A framed screen
- A hand glove made from latex
- A dark room
- 250 watts bulb
Step-By-Step Guide to Screen Printing On Plastic Bags
If you are using the heat press machine, these steps should be appropriate;
- There is a flat surface that is built to be wide called the platen, keep the bags one after the other on it to maintain the stability of the bags while they are being worked on
- Bring down the metal Screen on each of the bags and pull a squeegee with ink across its screen.
If you are following the manual process, these steps should be appropriate:
1. You should, first of all, build your own frame and the affix it to a screen. Make sure that your framed screen is built with high-quality materials for a long lasting and effective output. Then prepare the graphic design on a heat transfer vinyl that you want to print on the plastic bag. If the designs are made in simple lines, it will be much more effective.
2. Carefully study the complexity of your designs so that you can remove any problem. Cut the graphic design on a stencil and ready to be used and soak it with Emulsion mixed with a sensitizer.
3. Gather the necessary items that are needed for the process. Place the pieces of light cardboard papers into each plastic bag that you are going to print. This will help to block the ink from seeping through to the other side of the bag.
4. Position the already prepared stencil at the appropriate place that you want the design to appear. You can make use of a colored tape or a rubber frame to stabilize it.
5. You can then pour the pink onto the squeegee with the rubber knife or the Popsicle stick. Use your squeegee to move the ink from up to down and from right to the left on the stencil.
6. Make sure that the movement crosses over the image several times to ensure that the ink has been imprinted. Do not be forceful; rather apply gentle pressure on the stencil.
7. Raise the corners of the stencil to make sure that the ink printed on the right side and did not pass through to the other side of the bag. Go through the whole process again several times if the image was not printed to make sure that it prints.
8. After inspecting the bag to make sure that the image is appropriately printed, gently remove the whole stencil, keep it upon the canvas and wash it with cold water.
Keep dry for about one hour. You can even speed up the drying process by a blow-dryer to dry some minutes. After the blow drying, check the image to make sure that it has dried properly.
Tips For a Successful Screen Printing on a Plastic Bag
1. Print only one color and Make sure to print black on white or vice versa.
2. When you are cutting out the stencil, ensure that only the white rings are cut out leaving the red rings to be covered by the stencil.
4. The design must be cut with a solid paper or an alternative transparent paper.
5. If you are making use of the transparent paper, always use the black ink.