For today’s Practical Print, we’re going to be focusing on a tool that’s going to be extremely useful to us in the warehouse in managing and organizing our inventory: a screen pack holder. While our usage may not be applicable to everyone, you can easily take our screen pack holder design and customize it to your own storage needs. So let’s dive in!
Screen packs, what are they?
Screen packs (or screen mesh) are an essential component of extrusion processes. They assist in removing any foreign contaminants from the filament during extrusion. Typically, the screen packs come in circular shapes and can either be a single layer or multiple layers and are made from stainless steel wire mesh.
CLP incorporates the use of screen packs as an additional decontamination step to ensure granulate objects are filtered out of the filament down to a size of 0.007” (that’s roughly the diameter of a human hair!). This is just one of the many steps we take to ensure no contamination sits inside the filament when it arrives at your door.
Right now, the screen packs we use are housed inside plastic zip bags with their corresponding sizes. This can be a bit inconvenient as we prepare and run our extrusion process since we’ll need to sort through the bags to find the appropriate mesh sizes, un-tape the stacks, re-tape the stacks, and put the bags away. So what we’re going to do is design and build a screen pack holder so that we have a set of screen packs ready to go without having to go through each bag or just leaving them on a paper towel until we need them.
3D printing to the rescue!
I didn’t start off with a sketch but I had an idea of a rectangular piece that had slots for prepared screen packs. One thing to also consider was the size; it needed to be relatively compact in design. So I fired up Rhinoceros 3D and began modeling! The modeling wasn’t too complicated since essentially, it was just a square extrusion with some disks cut out from it.
I set an array of the slots with about a ¼” (or 6.35mm) distance between them to create a dozen slots evenly spaced out.
Once that was set, I also created a cover to make sure that there was an enclosure for the screen packs to prevent any dust from settling on them while in storage. I simply added an offset of about 0.2mm which is usually what I do for snug fits. Since I don’t need this to be super tight, the 0.2mm offset was enough space to fit the main body.
Next up was printing! Although this was a very basic shape, the print took a whole 13 hours to print. Check out that gyroid infill.
After the print finished, I tried putting in a single screen pack and it didn’t fit. Oh no! I realized I didn’t do a verification of my measurements. During my first design, I was going off of memory for the diameter of the screen pack. I should have grabbed a caliper and actually measure out the part and add a little more space to house the other screen packs.
Luckily, Rhinoceros 3D has this great feature called “dupedge” where I can duplicate the edges of the slots then offset them by the amount I need.
And with that new adjustment, I printed a new one and it fit quite well. Even with all the screen packs in place, every one of them fit snuggly right in place.
And finally, I was also able to print the cover and it fits very well without using excessive force. Storing our screen packs is now super convenient and has made for a truly practical print in our manufacturing space.
Useful tips from this Practical Print:
Measure twice so you don’t have to print twice! (Then check another time)
For snug parts, an offset or space of about 0.2mm is usually a good place to start and you can make it tighter or looser depending on your application.
Got any suggestions? Feel free to email us at firstname.lastname@example.org with the subject line Practical Prints!