Hot Foil

Many manufacturers of injection moulded plastic parts often add decoration to the product post moulding. When db automation were approached by a manufacturer and requested to design and build a Hot Foil Stamping system, we used our experience in general machine and automation design to develop a concept for transportation and decorating of their product.

The machine had to be capable of processing at least 38 parts per minute and running a 24/7 shift.
The project team involved with this client investigated many different ‘off the shelf’ hot foil feeding and stamping presses, but after consideration realised that the standard equipment would not precisely fulfil the customer specification.

On the back of this conclusion the project team began developing the specific equipment which would fully satisfy the client’s needs. It was understood that the following aspects were essential to the design requirements for this unit:

  • Powered drive, for both foil feed and foil waste.
  • Press or Stamping cylinder capable of supplying up to 4.5KN of force.
  • Fully controllable heater functions, to allow for correct heat transfer.
  • Full feedback of the temperature and heating controls.
  • Adjustable pressure for the stamping operation.
  • Foil low, and broken detection.
  • Accurate adjustment of stamp head in 2 directions.
  • Accurate adjustment of press down position.
Foil feeding unit
Accurate Z-axis adjustment

In addition to the requirements for the stamping head and foil feed, there were other design hurdles which the project team needed to overcome.

Once the product had been marked, quality inspection was essential to ensuring that the best quality product was shipped to the end user. It was clear to all involved that the ideal solution for this inspection would be by the integration of a high resolution machine vision system.

In this instance, the client was very keen on using a specific supplier, to ensure that plant specifications were adhered to, db automation comfortably agreed to integrate this required equipment into the final system.

Machine HMI controls Reject hopper

As in all automated systems, once inspection has occurred the system needs to handle the rejected parts and segregate these from the good product. The simplest method for this segregation would be to remove the reject parts automatically from the machine via a chute or an aperture. The drawback of doing this is that you generate an accumulation of product which needs to be handled, in addition, for this particular product often the rejected part can be either re-worked, or is actually suitable for the end user, the sorting of this acceptable product from the rejects when accumulated randomly is not cost effective.

With these factors considered, the project team incorporated two reject stacks, which are populated by pushing the reject product from beneath into the stack. It was then considered an easy task to sort the true rejects from the acceptable product.

A further requirement from the client was that the machine be ‘staggered’ to give sufficient access. To affect this, the project team added a pick and place station directly after the in-feed conveyor. This station collects components in pairs and places them onto the ‘flighted’ conveyor while completing a re-pitch for the required spacing on the indexing conveyor.

Pick and Place station Indexing belt

The transport of the product through the machine is completed using a servo driven, ‘flighted’ conveyor. This provides the system with an accurate position and consistent throughput, each product is seated in a ‘pocket’ which indexes a pitch every cycle. To ensure that the product is in a consistent position every index, the product is driven past sprung loaded drag bar which maintains the position against the trailing flight.

It was essential to the client that that machine was as compact as possible and totally self-contained, the intention was to integrate this unit into a production cell which had limited space.

In order to fulfil this need, db automation’s project team refined the design to ensure all electrical and pneumatic controls were within the footprint of the machine, and that all space was used effectively.

Integrated Pnuematic panel

Fully enclosed guarding Integrated electrical panels

For more information regarding the standard hot foil stamping machine or for a bespoke version to your specifications, please contact our sales department.

Unit 7 Wycliffe Industrial Park,
LE17 4HG. United Kingdom