Choosing a Pad Printing Machine

Open Ink Trough (inking mechanism mounted above the cliche)

In these original semiautomatic machines, the inking mechanism is mounted above the cliche. Although more modern models ha we better features, contro/lirrg ink condition fluctuations.

Many machines of this type (Figure 2) are out in the field. This was the original semiautomatic system, dating to the late 1960s/ early 1970s, and has been the basis of many clones. The originaI machines were mechanically operated, giving little opportunity, for adjusting individual press functions because the inking mechanism and pad stroke were tied together on the same drive. Printing speed was controlled by adjusting the speed of the main drive motor. Later, more sophisticated mechanically driven machines gave greater flexibility of adjustment. This is a very robust system with a smooth printing action that is unaffected by fluctuations in air-line pressure.

Over the years, this style has been further developed, and a host of machines have been produce using electro-pneumatics and even servo-motor drives. Also, PLCs (programmable- logic contrallers) are common, providing a wide range of sequencing options.

No matter how sophisticated these presses are, though controIling ink conditions is probIernatic due to the large surface area exposed to the atmosphere.

This can be ameliorated In different ways. Some manufacturers help reduce evaporation by shrouding the inking mechanism and inkwell. Other manufacturers us ink pumps and solvent-addition systems to compensate for the evaporation. Still, it's surprising to me that this press design is so widely used, given the ink/solvent balance.

Changeover of ink and cliche can be carried out relatively quickly by removing the entire ink tray, ink tray, includlng the cliche, and replacing it with another that has already been prepared. You must consider the cost of spare ink trays, which can be very expensive. The ink tray can be designed to catch ink that spills over the front of the cliche, thus keeping the machine cleaner.

Choosing a Pad Printing Machine - Introduction

In the padprinting industry purchasing decisions are often based on asswnptions that are simply nuts - literally.

Manually Operated Pad Printing Presses

Except in cases where pad printing will be done on a very small scale, manual machines are not even entry level anymore. However, some may be useful for testing purposes.

Open Ink Trough Pad Printing Machines

In these original semiautomatic machines, the inking mechanism is mounted above the cliche. Although more modern models ha we better features, contro/lirrg ink condition fluctuations.

Partially Covered Ink Troughs

In these machines, ink is contained in a trough behind the cliche. The ink is pulled forward by a spatula mounted on a horizontal carriage with the doctor-blade assembly.

Sealed Ink Cup Pad Printing Machines

These presses are designed to contain the ink in a cup that is turned upside down and pressed firmly against the cliche, sealing in the ink.

Reciprocating Cliches Pad Printing Machines

In these models, instead of the pad moving back and forth from cliche to substrate, the cliche moves out of the way, while the pad remains stationary.

Rotary Pad Printing Presses

These presses use a rotary drum-type sllicone pad, usually in conjunction with a steel cylinder cllche into which the desfgn is etched.

Total Colour Transfer System

This technique, used almost exclusively in ceramic decoration, combines pad and screen printing.

Carousel Style Pad Printing System

This multicolour pad-printing system uses a cambination of two rotary tables and a rotating pad carousel.

Non-Horizontal Pad Printing

Machines such as this are suited for printing onto surfaces that are vertical or angled.

Computer Numeric Control (CNC)

In presses with computer numeric control (CNC), the substrate is stationary and the pads are programmed to print one image at a time onto the item.

Pad Printing Press Options

Most manufacturers provide a variety of add-ons for their presses.

How to decide what machine to buy

To enable you to judge which press to buy, you will at least need answers to all of the questions shown under Purchasing Considerations.

Pad Printing Machine Purchasing Considerations

Trying to decide which pad-printing machine to buy? Start by answering the following questions.