Choosing a Pad Printing Machine

Pad Printing with 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. A CNC system of control and actuation can be built into standard machines or modular assemblies like this one to suit almost any application.

With all of the other press styles to this point, the print station is stationan/ and parts are fed from one station to the next to achieve a multicolour print. Not so with a press that uses computer numeric control (CNC). Here, the substrate is stationary and the pads al-e programmed to print one image at a time onto the part, as shown in Figure 10.

Though the robotic action of these presses appears complicated, CNC allows simple setting procedures and enables several setups to be progr-ammed into the machine. All actuations are controlled by servo-motor drives, giving a very smooth, highly controllable print action. Stroke Eengths are infinitely variable within the dimensions of the machine. Manufacturers claim considerable energy savings over pneumatica[ly actuated machines, plus CNC presses aren’t affected by fhctuations in airline pressure.

The CNC system of control and actuation can be built into standard machines or modular assemblies (such as the one in Figure 10) that can be produced to suit almost any application. The degree of complexity is governed only by the imagination of the designer and the number of modules he wishes to use. Atl of the eEernents of component manipulation can be combined with multiple closed cups, pad cleaning, varying pad-stroke lengths, alternative pad shapes, etc. This system is often used where items must be printed in line with other assembly processes, or fol- complex multiple prints on different surfaces.

The flexibility of CNC comes close to producing the ideal machine for a particular application, but it is substantially more expensive than a conventional pneumatic press. If the workioad can justify the increased investment, a CNC press is well worth considering. Don’t be carried away by the control technology - it still must be a capable printer.

Print rates with CNC machines will not necessarily be higher, but downtime and setup should be much reduced.

The ability ta store and retrieve setting details for the next time a job is run offers more consistent quality. Of course, some pneumatic presses alIow simple production control cards (when filled out properly) will help with any machine.

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.