Choosing a Pad Printing Machine

Choosing a Pad Printing Machine - Introduction

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

The president of a campany will see a padprinting machine prinung nuts at an exhibition and be suckered by the sales person into believing that. This process will print on anything. And when asked how fast the machine will print the sales person replies, 1500 per hour, hand fed. Dream on!

During more than 20 years of involvement with pad printing, I have not come across a truly bad press, I've also never encountered an ideal one. A variety of different press styles are: available today, each with strengths and weaknesses. Understanding the differences between the press styles and how they may affect the application at hand will help you determine which press is best for your needs.

Pad-printing applications tend to fall into three main categories, listed in descending order in terms of quality demands:

  • Printing involves the precise application of ink onto a substrate. Images normally contain lettering or symbols and may be single or multicolour.
  • Decorating is where a design or effect is applied to a product to enhance the look of the product. Designs are purely artistic, serving no functional purpose , and may again be either single or multicoIour, EfFects include unusual patterns, simulated wood grain, etc.
  • Coding involves printed information that must be legible, but not necessarily of high quality. An example is date stamping on containers and other packaging. Coding should not be confused with barcoding, where print quality is very important, particularly with regard to contrast and edge definition. Barcoding is considered a printing application.

Some machine requirements are consistent for all pad-padprinting applications. The machine has to transfer Ink from an image carrier (cliche) via a flexible (.silicone) pad onto a substrate. It must be able to carry out this pick-and-place function as accurately as possible, ideally within $0.0001 in. (+0.025 mm). It should operate smoothly, free of unwanted vibration at production speeds.

The press should be designed in such a way that the operator can simply regulate the ink conditions and contain the drying rate of the solvents h the Ink. The ability to malntain the ink, and therefore the printing conditions, ts of prime importance and is a feature that many machines lack. Althollgh well engineered, some machines use large open ink troughs that exaceFbate the problems of ink control for the printer. There are basic requirements for a pad-printing press. To get the right press for your work, you must understand the differences in the types of machines currently available.

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.