Question : How does it work?

Answer : The print head is an array of nozzle jets that can fire droplets of viscous liquids at a moving surface. Just like pixels of an inkjet, the FoodJet builds a pattern from hundreds of small drops that flow together in one shape. By placing the print head at an angle, the across resolution can be enhanced. The integrated embedded controller inside the print head calculates the required individual lag compensations per nozzle automatically.


Question : What sort of patterns are possible? How much time does it take to setup from scratch?

Answer : Any pattern can be programmed, but depending on the material some patterns get a better finish than others. Decorations with surface fills will be easier to produce than thin line drawings, as it all needs to be built from separate droplets. By using the Foodjet Designer software, simple decorations can be made within 1 minute.


Question : How flexible is the system?

Answer : The patterns can switch over with the flip of a dial, the print head can operate from both directions and the resolution can be set mechanically and electronically.The configuration of the print heads can be changed by swapping the tray plate they are positioned on.


Question : What is the dosing accuracy regarding weight, shape and position?

Answer : The repeatability is very high. A weight variation within 1% is possible and the shapes and positions are accurate up to 0.1mm


Question : What materials can be printed? Does it need to be foodstuff exclusively?

Answer : On the website there is a list of printable liquids that already have been successfully implemented for industrial purposes. As a rule of thumb the linear viscosity needs to be below 1000 CPS for good printing results.


Question : What are the limitations regarding particles?

Answer : That depends on the chosen nozzle size. Obviously particle size in the liquid can’t be bigger than the nozzle size as it will block the nozzle. A maximum particle size at 50% of the nozzle size is preferred.


Question : What is the level of detail that can be achieved?

Answer : The smallest droplet that a FoodJet printhead can make is a sphere of about 0.5mm in circumference. Drop size on the surface will be at best a little below 1mm in diameter.


Question : How much material can one print head deposit?

Answer : FoodJet has all kinds of print heads for any dosing requirement. Quantity is never an issue.


Question : What is the maximum allowable conveyer speed?

Answer : Depending on the material and application the FoodJet print head can attain production speeds unsurpassed by any conventional dosing machine. Tomato sauce application can run up to 25  30 meters per minute, while chocolate decorating one can go up to 10  15 meters per minute.


Question : Do the products need to be aligned?

Answer : Without the use of a camera the products need to be aligned in lateral position, in the transport direction.


Question : Can the FoodJet do a “No Product No Deposit”?

Answer : The print head always requires a trigger from a sensor or camera to perform a dosing task onto a product. If this trigger is not given because of the absence of a product or that it does not meet quality requirements, in case of using a camera, no deposit is done.


Question : Do the products need to be the same height?

Answer : The application of the liquid is done contact-free so the height of the top surface may vary.


Question : Can the printer deposit onto sloped surfaces?

Answer : Yes the print head will dose onto sloped surfaces, but it comes down to the yield value of the deposited material if it will run off or not.


Question : Can the printer do multi-colours?

Answer : One print head can only do one colour, as it is connected to one material supply. However, it is possible to use several print heads directly after each other, each with their own material supply, to add different colours.


Question : Is the nozzle size fixed for a printhead?

Answer : The bottom part of the print head, the “carrier” containing the nozzles, can be swapped for a version with another size orifices.


Question : How are the print heads programmed? What graphical formats can I use?

Answer : FoodJet has developed a user-friendly PC tool to set up droplet patterns based on all conventional graphical formats like .bmp, .jpg, or .png. The FoodJet designer software enables the user to program the print heads flash memory with a number of patterns over the USB connection.


Question : Should the product always travel at a continuous speed?

Answer : This is not required. The displacement of the products to be printed on is measured by an encoder. In this way the print head can keep track on the product whilst the speed of the belt may vary. It is important that the conveyer direction stays the same.


Question : How is the print head connected to the main line?

Answer : The print head has a pneumatic connection for compressed air, an electrical connection for power and data transfer and the feed and return lines for the printable liquid material.


Question : What does an operator need to do in case of a blocked nozzle during production?

Answer : The operator can easily isolate the faulty print head by closing the dry-break couplings on the print head terminal and releasing the print head from its bay, while the other print heads remain in production. The faulty head can be easily swapped for a spare print head.


Question : What maintenance is needed to the print head?

Answer : The print head does not have any real wear parts. Depending on the abrasivity of the liquid, the rubber membrane parts needs replacement sometimes. This is a low-cost part and it only takes a minute to change.


Question : How do I clean the print head?

Answer : The print head carrier, the bottom part, can be cleaned by flushing with hot water or a mild cleaning agent (CIP). Ensure thorough rinsing with water to remove all detergent and fully dry the carrier prior to use. 

The manifold, the top part containing the electronic parts, is when unconnected from the machine not protected against water, so do not expose to a water source! The manifold can be cleaned with a lint-free cloth slightly moistened with water taking care not to damage the membrane.


Question : Can the print head print on several products at the same time?

Answer : Yes it can, along the length of the print head. The print head can work on as much as 10 tasks at the same time. Those tasks can also be individually different patterns.


Question : Can I store different patterns inside the print head’s memory?

Answer : The Flash memory of the print head is able to store up to 8 different patterns. These “preset” memories can be selected by the position of a 8-stage dial switch.


Question : What if the conveyer stops suddenly while the printer is decorating?

Answer : The product gets decorated up to the point where the displacement stopped. As soon as the conveyer starts moving again, the decorations are finished just as the other ones.


Question : Can the print heads be heated? What is the maximum material temperature?

Answer : With heating elements the print heads can be heated up 60 °C.


Question : Can a multi-lane system produce with a variety of patterns?

Answer : It certainly can. Not only can the decoration per lane be different, but every single lane can produce a sequence of patterns. Theoretically the variations even in mass production can be endless.


Question : Can a Vision camera system be integrated with the print heads?

Answer : Yes it can and it delivers great advantages in daily production. The assistance of camera information can make the print heads compensate for individual misalignments. Even freeform shape recognition is possible.


Question : How does the liquid foodstuff get fed into the print head?

Answer : This can be done with a pressure drum (for ambient temperature liquids) or via a recirculating pump (for heated materials such as chocolate). When using a pump, the pressure in the print heads is set with a backpressure regulator on the return flow of the liquid.


Question : What happens when the power or compressed air fails?

Answer : When the power fails, the printing process stops and the liquid stays in the print head. When the compressed air fails, the print heads will dump a little liquid from the nozzles.