HP MJF Surface Treatment Simplify explained

This article helps you choose a suitable surface treatment by introducing the post-processing process of MJF 3D printing.

There are five common MJF surface treatment processes

MJF prints with natural color

MJF prints with dyed black

MJF prints with vaporfuse smoothing

MJF prints with graphite blasting

MJF Prints with polishing & painting

MJF Prints with Natural color

The natural color of MJF 3D printing is gray, but it is not pure gray, some white powder will be seen on the surface. Why is there a slightly white powder? Did you know that the natural color of its material is white? This has to start with the principle of its craft.

So what is MJF 3D Printing?

HP Multi Jet Fusion (MJF) technology is a powder-bed fusion 3D printing technology that allows for the production of accurate, functional prototypes and final parts

The HP MJF 3D printing process begins with a thin layer of uniformly pre-heated polymer powder particles that is spread across the build platform.

Then, to achieve part quality at a high speed and produce truly functional parts, HP MJF technology uses the HP multi-agent printing process. HP’s in-depth knowledge of 2D printing solutions and the capability of HP’s proprietary architecture makes it possible to
print millions of drops per second along each inch of the bed width, thus enabling extreme precision and dimensional accuracy.

HP Multi Jet Fusion’s multi-agent printing process can control the exact amount of each agent that is deposited in each voxel of the intended part. This printing process involves two different types of agents that are applied across the build platform: fusing agents
and detailing agents.

A fusing agent is applied where the particles are meant to fuse together in the powder in order to create the corresponding part cross section, leaving the rest of the powder unaltered. A detailing agent is applied to the edges of the part in order to modify the
fusing process and create fine detail and smooth surfaces.

Next, an energy source passes over the build platform, provoking a reaction between the agents and the material that causes the material to selectively fuse to form a complete layer, thus resulting in production throughput, material density similar to common Injection Molded plastics, and consistent mechanical properties in all directions.

The process is then repeated until a completely functional part has been formed.

The 3D printing process using HP MJF is summarized in the following figure:

So you will that the fusing agent is black color, black and white color results in gray color. That’s it. If you break the parts, you will find that the interior is actually black.

MJF prints with dyed black

This is easier to understand, so we don’t need to explain too much.

MJF prints with Vaporfuse smoothing

This is a good choice if you want to increase the strength of your part while improving the smoothness and water resistance of the surface.

Vaporfuse smoothing is to hang the parts first, and then place them in a chamber filled with chemical solvents. Therefore, it is best to design parts that allow hanging parts, otherwise they cannot be completely fumigated.

Because chemical solvents are fluid so it is also suitable for container type parts.

What is vaporfuse smoothing? Please click HERE to learn more about it.

MJF prints with graphite blasting

What is graphite blasting?

Graphite sandblasting uses the same process as bead blasting, but the purpose is to make the parts have a uniform metal appearance, and project glass bead and graphite on the parts. it results a dark grey surface.

This can also reduce friction between moving components, but it is not recommended to use it for frequently handled because it will slightly fade.