ITW Trans Tech: PADPRINT Notebook: High-Speed MHS Machines


	PADPRINT NOTEBOOK Useful Tips & Information © ITW Trans Tech An ITW Decorating Company

Right side of MHS 90 machine viewed with cover open and pad removed, showing gearmotor drive, higher speed cam, encoder and inkcup.

Improved Automation Integration
Faster MHS Machines Debut

TO MEET or exceed the higher speed requirements of automated pad printing systems, ITW Trans Tech offers two special sealed ink cup machines: MHS 60 and MHS 90. These modifications of our standard workhorse Sealcup 60 and 90 units are aimed at reducing unused or redundant components, achieving higher cycle rates, and within a more compact external profile.

Improved Functions
Major functions of the popular Sealcup line that have been enhanced with the MHS (Mechanical High Speed) machines are: control architecture, process cycle rate, X-Y table and pad clean-off device.

• Control architecture is significantly changed from the stand-alone configuration. Cams and proximity switches for determining Sealcup position are replaced by an encoder. All operator controls, except for the emergency stop button, are removed from the front of the enclosure. The flip-up plastic shroud on the front of the machine is also gone. These changes enable easier integration to automated systems.

The high-speed MHS 60 pad printer is shown with optional pad clean-off device in front (disengaged) position.

• Process speed capability is increased via cam, follower and drive modifications. A special gearmotor drive is designed to meet the higher speed requirements of these machines. The physical limit is 100 cycles per minute, though other process factors such as ink transfer may limit the practical speed to 60 cycles per minute.

• Cliché & printer adjustment has been changed to allow much tighter placement of printers, and to reduce overall parts count and cost. The top plate of the X-Y table also serves as the bottom plate of the printer. The adjustments are made via screw knobs, and no longer use readout displays.

Pad Clean-Off Device

Pad Clean-Off Tape Device:
This optional feature can be mounted to either side of the MHS machines. The compact design allows much closer positioning of other devices on each side of the printer.

• The Pad Clean-Off Tape Device is unique to the MHS automation printer versus the standard Sealcup. The design allows much closer configuration of other devices on each side of the printer. On the smaller MHS 60 this somewhat inhibits physical access to the part being printed, but is not normally a factor in most automations. The work-piece is still readily viewable from the front of the machine for test prints.

Controls Designed With Automation In Mind
The main difference between the controls on this line of printers and the previous models is the emphasis on automation system integration. Previous models were stand-alone with some integration capabilities. However, this led to some duplicate controls on the printer and the automation system, dissimilar control components and concepts between the two, and difficulty satisfying customer requirements for alternate controls manufacturers.

X-Y Adjustment Table, NEW

X-Y Adjustment Table:
The optional X-Y table now also serves as the bottom plate of the printer. The adjustment is via screw adjustments, and no longer utilizes readout units. This change to cliché & printer adjustment allows much tighter placement of printers and reduces overall parts count and cost. It is available on either the 60mm or 90mm MHS machines.

The MHS automation printers have a minimum amount of control components on board and are starting out with two options for controls manufacturers: Mitsubishi and Allen-Bradley. Substituting another brand at customer request, such as Siemens or Fanuc, would require changing only a single component, the controller and transcribing a short program. The automation system then can be designed with greater uniformity in both hardware and software – since the printer makes no assumptions about the automation system requirements.

Communicates Well With Automation
The internal controller and drive take charge of the actual motion control of the printer, thereby relieving the automation system of precise control and logic cycle time issues. The automation system makes all decisions as to what type of motion is required and when to initiate the motion. The commands for type of motion and start command are communicated to the printer via simple cable interface. Should there be a problem, the printer will generate one of several faults to inform the automation system. Once a start command is issued to the printer, the automation system needs only to wait for a “motion-complete” signal from the printer.

The MHS 60 and MHS 90 enable an increase in speed up to 50% over the Sealcup 60 and 90 models.

In addition, the printer’s drive is a highly accurate and repeatable VFD (Variable Frequency Drive). The VFD includes features that allow the printer’s software to be more efficient and gives the printer greater repeatability over its entire speed range. This is particularly important when the printer is being run in synchronous mode within a system. The automation has full access to the printer’s encoder if required as well.

To learn more about how we can design and build an automated pad printing system for you using the MHS machine series, contact us at: www.itwtranstech.com

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