The process of selecting a method when it comes to screen printing on plastic can be more complex than simply picking out an artwork and printing your materials.
Every part of the process needs to be carefully tested before moving onto the next step to avoid adhesion issues down the road. You would not want your companies logo or brand name slowly chipping off of your product from general use or from rolling around in a purse.
This article will help to guide you through some things to consider when researching a supplier. You can contact us for a quote if you are interested for more information on your specific needs.
What types of plastic can be screen printed?
There are many different variations of plastic substrates that can be screen printed. Each substrate contains its own unique properties and chemical formulas that can provide different surface textures to adhere to. This information is vital to screen printing on plastic as it is used to determine the right ink for your substrate.
Polypropylene
Polypropylene (PP) is a tough, rigid and crystalline thermoplastic. The linear hydrocarbon resin is the lightest polymer among among all commodity plastics. The plastic surface is low density and high heat resistant.
Polyethylene
Polyethylene (PE) is one of the most thermoplastic materials. Polyethylene plastics are lightweight and durable. It is available in different structures such as HDPE, LDPE, and LLDPE.
PET
Polyethylene Terephthalate (PET) belongs to the family of polyesters. It is recyclable and shows resistance to impact, moistures, alcohol, and solvents.
ABS
Acrylonitrile Butadiene Styrene (ABS) is an impact resistant engineering thermoplastic. Psychical properties include high rigidity, resistance to impact, abrasion, and strain.
Polycarbonate
Polycarbonate (PC) is a high strength transparent thermoplastic that makes it resistant to impact and fracture. This substrate is lightweight and a good substitute for glass. It is known for its eco friendly processing and recyclability.
Styrene
Styrene is an affordable and lightweight expandable plastic substance.
Acrylic
A transparent plastic material with outstanding strength and weighs much less than glass.
What screen printing method is best for my plastic materials?
When silk screen printing on plastic, it is important to select a machine process that matches the shape of the part to screen a clearly printed image. Our range of equipment has the ability to handle many different screen printing applications.
Flat screen printing
Flat substrates remain in a stable position during the printing process. This is typically achieved by placing the part on a fixture or specialized tooling.
This is the most common method for screen printing on caps or lids.
Cylindrical screen printing
Cylindrical or round substrates will need to rotate during the printing process. This can be achieved by driving the part with the squeegee, gear driven, or specialized tooling.
This is the method when printing plastic bottles, vials, and jars.
Unique shape screen printing
Some plastic products require creativity and specialized tooling to screen print clear results. Certain factors of the plastic substrate will determine what method is best for screen printing.
The shape of the plastic and the desired artwork will be used in choosing a method that best fits your product.
Check out some of our past production runs for a further breakdown of our screen printing capabilities.
How to properly cure plastic screen printing ink?
When screen printing on plastic substrates, your material and ink series will be used to determine the best curing method. Different series of plastic printing inks may result in different methods of curing the ink.
Conventional
Curing the ink by baking parts in an conventional oven. Parts exit the screen printing machine and are placed onto a conveyor belt. The parts then enter the oven for 3-4 minutes until the desired adhesion is reached.
UV Light
Curing the ink by running the parts under a bright UV light. Upon exiting from the screening station, the part then passes under a UV light station that's constantly rotating. After a few seconds the ink will be dry and the plastic containers ready to pack.
Air dry
This method involves special air dry inks designed to fully cure over time. This method is more difficult when dealing with quantities larger than a few parts because of the warehouse space needed to stack parts until complete.
Pretreatment
Certain plastic materials require a pretreatment process to properly adhere to the surface during the silk screen printing process. The pretreatment process is designed to change the chemical properties of the plastic surface before printing. This allows the ink to "bite in" with the capability to pass thorough testing and adhesion requirements.
Most popular molding processes for screen printing on plastic
Although screen printing can be done on a wide range of plastic materials, some of the most popular methods for producing the plastic substrate to screen print are the following.
Injection molding
A manufacturing process for producing parts by injecting molten plastic into a mold, forming the desired piece.
Injection blow molding
This process requires a plastic preform to be injection molded. The (male) preform then travels on a rod to the blow mold station where air pressure is used to blow the plastic material into the shape of the (female) preform.
Compression molding
A process that involves the preheated substrate to be placed in an open, heated mold cavity. The mold is then closed with force that uses pressure and heat to mold the substrate into the desired shape.
There are other molding processes, but when it comes to the cosmetic industry, these tend to be the most commonly used for screen printing.
Types of plastic products we screen print
Jars
Tubes
Bottles
Caps
Production Decorating has the ability to screen print on a wide range of plastic products, with the cosmetic industry being our specialty.
Screen printing on plastic is an art that is mastered over time. With over 50 years of experience in our field, we have the knowledge and experience to accomplish your screen printing goals.