Ink cups for pad printing machines
There are many types of Ink cups for pad printing machines. These come in a variety of types and styles. Initially, pad printing equipment utilized inkwell doctor blade systems. With time, sealed or closed cup systems have replaced doctor blades. In the USA sealed ink cups pad printing machines have gained popularity. While in other parts of the world, doctor blade systems are still in use. While both types of inking systems have a great deal of merit, as a new equipment you need to understand the pros and cons of both systems. Check out our wide variety of pad printing ceramic rings! Let us look at the different types of doctoring systems in detail.
Doctor Blade System
Doctor blade system consists of an ink well, a doctor blade, and a flood bar. The doctor blade system is also known as open inkwell system. Open ink well systems are older methods of pad printing ink supply. This method uses an ink trough to hold ink. The ink trough is located behind the printing plate. A flood bar pushes printing ink over the plate. Then a sharp blade (doctor blade) removes the ink from the plate surface, leaving ink on the etched artwork. The ink filled in the artwork is then picked up by the printing pad. Check out (Pad) printing machine – ResearchGate
Closed Cup System
The closed system consists of an inverted cup with a pad printing ceramic rings made of Cubic zirconia (CZ) or carbide. The purposes of the ink is to remove excess ink from the cliché (plate). The ink cups moves back and forth. As the cup system moves over the plate, it floods and doctors (wipes) the ink from the cliché. The ink cups system requires less maintenance. Additionally, this doctoring system limits the pad printing ink exposure to the air. There by limiting solvent evaporation and ink viscosity changes. Because there is less solvent evaporation, then there is less odor. The cup system is environmentally friendly.
Why a Doctor blade system
The doctor blade ideal is very popular in a situation with:
- long images,
- several color changes,
- short print run (less than 500-1000 pieces).
This system requires experienced pad printing machine operators. To use this system the operator must understand the nuances of the pad printing process. The doctor blade system is still used in plastic molding and golf ball. This pad printing machine inking system is also widely used by promotional products. Especially in long images and shot runs. Some of the inks ideal to use with this system are silicone inks and glass printing inks.
Advantages of doctor blade system
Doctor blade systems are ideal for printing long images. The doctor blade can print long images, an impossibility with a cup system until recently. We will discuss the invention of Transverse doctoring system shortly.
Transverse doctoring system
Transverse doctoring system is a modified seal ink cup designed to print very long images. The pad printer machine ink cup moves repeatedly over the long cliché/ plate. Please note that the artwork is larger than the area the used cup can cover. To prevent the pad printing ink from drying plate, the cup moves non-stop from side-to-side (instead of front/back) across the length of the image. This system works perfectly for medical field application, e.g printing on catheters.
Closed cup systems
Ink cups for pad printing machines have grown in popularity due to their ease of use. Closed cups reduce solvent evaporation from the pad printing ink. In addition, the require less skill level for maintenance during printing. The reason is because the chemical change of the ink is reduced. Therefore, an operator can easy predict and manage the pad printing ink mixture.
Many Ink cups for pad printing machines have the capability of having double sided pad printing rings. This has an advantage because there is less downtime when a ring is defective/ chipped. Additionally, printing companies can stock up doctoring rings. This reduces down time.
Also, an ink cup with pre-mixed ink can replace another into immediately during production. Note, spare ink cups are expensive.
Pad printer ink cup sizes:
The largest pad printer ink cups on pad printing machines are generally 135mm/ 5″ in diameter. These are ideal to print 4.5″ diameter images. Equipment with larger that 5″ are costly. Additionally, the cups and pad printing rings get quoted as specialized parts. This also require large silicone pad printing pads.
The largest pad printing ceramic rings
The largest pad printing ceramic rings are about 250mm in diameter (10″). These rings can print upto 9″ diameter image. These size rings are used to print on soccer balls, circular saw blades, and satellite dishes. These pad printing machines are very specialized and generally custom made. We can are the only company that can offer you rings and pad printing equipment with this capability.
Types of ink cups
Ink cups for pad printing machines are further classified as magnetic or non-magnetic ink cups. Any of these ink cup yield excellent results for doctoring pad printing plates.
A magnetic ink cup is a self-doctoring unit that has powerful magnets. The magnets are used to produce down-force necessary to clean the plate. A machine with this set up uses a drive pin which can tip the cup. A pro with this set up is in simplicity of multi-color pad printer construction.
Non-magnetic ink cups. A pad printer using this system uses a flange to apply the pressure on the ink cup. The pressure is applied by a spring-loaded system geared for one ink cup assembly. The spring-loaded system is compact and very effective. This system is not as simple, in addition, it is not easy to deploy on a multi-color pad printing machine.
For high speed pad printing applications, this is the type of equipment needed. You can rest assured that the cup on your pad printer lays flat with this type of equipment. These are the types of machines Boston Industrial Solutions, Inc. builds.
BENEFITS OF PAD PRINTING INK CUPS:
- Lower costs of equipment maintenance.
- Double sided rings are easily flipped over or quickly replaced on site
- Two sided ceramic rings have double the life than standard single sided rings
- Low-profile design prolongs pad printing ink life and reduces ink waste
- Our ceramic rings are robust than brittle steel rings and are less prone to damage
- Ceramic rings are easy on polymer plates and the plate life
Doctor Ring material
Pad printing ceramic rings are made of Zirconia or carbide. Therefore, what is the best material for doctoring printing plates. Both carbide rings and ceramic rings work well. In our opinion the ceramic doctor ring offers some advantages.
The ceramic ring are self-lubricating. This makes it easy for the ring to glide over think steel, thick steel, and polymer plates.
Carbide pad printing rings are generally sharp and abrasive. As a result, the wear a photo polymer plate material easily. Also, ceramic ring are generally thicker and more resistant to damage. Most ceramic rings taper from the inside and outside diameter. The point of contact is about .006 leaving plenty of material near the tip. The carbide have a point contact of .003”. This is not only easy to chip, but also easy to tip over during printing.
Lastly, If you are looking for high quality pad printer machine ceramic rings, reach out to us at +1 (781)-281-2558