PolyJet (Material Jetting)

PolyJet (also known as Material Jetting) is an additive manufacturing process which uses UV light to cure photopolymers in layers.

How it works

Drops of liquid photopolymer resin are jetted onto the build platform in X and Y direction by the print heads. The print heads can also mix multiple materials together to achieve unique material properties and colours.

The UV lamps then follow and cure the polymer into a solid layer.

The part is encased in a gel like support material, both to support the printed part and to give the matt colour finish.

The platform then lowers by one layer at a time, and the process repeats for each layer until parts are complete.

Materials Used

PolyJet printers use Stratasys model and support materials to create multi-colour and multi-material parts. Part colours can be achieved by inputting HEX or Pantone colour codes. Parts can be set to hard plastic or soft/flexible, and the Shore Hardness can be altered to give the desired effect. VeroClear material can also be used to give a crystal clear finish on parts.

Sample parts are on show in HPO workshop if you'd like to see how your parts will come out.

Any colour can be created using HEX or Pantone colour codes

Multi-coloured parts can be printed as assemblies in one go

(yes, this was really printed!)

Flexibility can be adjusted as necessary through material settings

What can I print on it?

We have two Polyjet printers in the Digital Workshops, a Stratasys J55 in Sheaf and a Stratasys J850 in HPO.

Polyjet technology is great for rapid prototyping in different colour profiles, create everything from quick design iterations to high quality final prototypes.

The print volumes are: J55 rotary build platform ~ 140 x 200 x 190 mm and J850 490 x 390 x 200 mm.

One of the main design considerations is that we have to be able to remove any support material after printing, so if you have a hollow structure inside your part without any access holes, it will be full of support, which could change the overall effect of your part (especially if it's clear). Additionally if you have thin features, they might get damaged when removing support.

If you're unsure if the part you're designing will print, come and have a chat with one of the Digital Workshop Technicians and we can give you some advice.

Printing Workflow - How to print using the Stratasys J55 & J850

Design and Slice

Remove Supports

Design your part: Use any CAD software to design your model, and export it in a 3D printable file format (STL, OBJ or 3MF).
Set up the file for printing: Bring your file to one of the Digital Workshops technicians along with the colour codes you're wanting to use, and we will set up your file on the machine software ready for printing.
Prepare the printer: The technicians will then get the printer ready by loading material and performing machine checks.
Print: Sit back and relax as the machine does it's magic. The printed parts will be encased in support material after printing.
Support removal: Technicians will jet wash your parts to remove any support material.
Not necessary - Spray painting: Your parts will already be coloured so no need to spray paint!

Reference

How much will it cost?

The cost of printing your part(s) will depend entirely on the size of the part and how much support it requires, as well as which colours you decide to use.

All prints are charged at a price per gram of material, and you'll be given a quote before your parts start printing, so you can decide how to proceed.

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