Posted by Ed Tyson on
What do you do when you want to print a more complicated design, one that has overhanging parts that require support or involves a lot of detail? How about a situation where you want to print a prototype, one where painting or gluing will be involved.
Or maybe you simply want to stretch the envelope a bit and try printing with a thermoplastic that you haven’t tried before, one that’s fairly easy to use.
If any of these situations apply to you, then HIPS could be the support filament you’ve been looking for.
However, HIPS isn’t just a support material. It’s also a very capable 3D printing material in its own right. In fact, we think it’s one of the most underrated available.
In this article were going to take a look at HIPS and see what it is, examine its main features and benefits and give you some tips on how to 3d print with HIPS so that you get the best results.
HIPS stands for high impact polystyrene. High impact polystyrene is a synthetic copolymer that is strong, durable, non-toxic and recyclable. In addition, HIPS is soluble in Limonene, an easily obtainable solvent that is derived from the skin of lemons.
Chemically, HIPS is a graft copolymer incorporating pure polystyrene and polybutadiene rubber. It combines the hardness of polystyrene with the elasticity of rubber to produce a high impact thermoplastic that is tough and strong without being brittle.
Commercially known by the trade name Bextrene, HIPS is widely used to manufacture toys and appliances. It is also used for product packaging and cases.
In 3D printing, HIPS makes an excellent soluble support material.
When is support material needed? Well, all 3d printers, by necessity, start printing an object from the bottom of the design and then progress upwards.
Because of this, if you have a design that incorporates overhangs, areas in the print job that don’t have any underlying support, you’ve got a problem. You see, your printer can’t successfully extrude filament onto thin air.
HIPS can be used to provide the necessary support that these overhanging areas require. The printer first lays down HIPS under where the overhang will be and then lays the selected printing material down on top of the layer of HIPS. The HIPS supports the overhanging material and prevents the warping, deformation and collapse that would occur without the support.
Once the printing is complete and the object has cooled, you remove the HIPS by submerging the object in Limonene. After 24 hours, the Limonene will have dissolved the HIPS leaving you with a print job that has clean, crisp angles, corners and overhangs.
There is no need for knives, scraping or sanding. The solvent does all the work leaving you with beautiful results.
HIPS works really well as a soluble support material when ABS is used as the printing material. If your support material and your printing material have significantly different printing temperatures you run the risk that the one will warp and deform the other due to this difference. HIPS and ABS share nearly identical printing temperatures. This means they will lie together cleanly without any warping or deformation due to heat.
HIPS also makes an excellent printing material in its own right. It is harder and stronger than either PLA or ABS, but is just as easy to use. It won’t warp as easily as ABS.
HIPS 3D printer filament can be glued using any one of number of specialty adhesives. It also handles sanding well and can be painted with ease. This makes HIPS an excellent choice for mockups and prototypes.
Now that we know some of the benefits of using HIPS, let’s take a look at its features:
- Strong and durable printing material with good impact resistance;
- Excellent soluble support material;
- Good machinability, easily paintable and works with a wide variety of adhesives;
- Food safe, non-toxic and recyclable;
- Printing temperature from 230C – 240C;
- Recommended printing bed temperature of 90C to 100C.
The data stats of HIPS back up its ability to be used in a wide variety of applications. HIPS has a specific gravity of 1.05 g/cm³. This is comparable to the density of ABS but is less than other thermoplastics such as PLA or PMMA.
HIPS has a Rockwell hardness of R 95 which, again, is comparable to ABS, slightly more than PLA and significantly less than PMMA.
It also has a maximum tensile strength of 5801 psi (40 MPa) which is also, you guessed it, right on the money with the maximum tensile strength of ABS.
So, with HIPS you get a material that shares many properties with ABS, but is also easily soluble and can be machined, sanded, glued and painted.
It is this versatility that makes HIPS printing filament an excellent choice for a soluble support material, prototyping and as an all-round general printing material.
When it comes to comparing HIPS vs PVA (polyvinyl alcohol) as soluble support materials, it quickly becomes apparent that the two are apples and oranges. The lower printing temperature of PVA works means that it will work much better with a material like PLA while, as we’ve discussed, HIPS and ABS are more suited to each other.
Both are equally soluble, PLA in water and HIPS in Limonene, so the only reason to pick one over the other as a support material comes down to what printing material you are using for your job.
When it comes to printing with HIPS, there are a few things to keep in mind in order to get the best results possible. First, HIPS prints best at a temperature between 230C and 240C. Don’t be afraid to play around with temperatures in this range to see what works best for you.
Next, your printing bed should be set to a temperature of anywhere from 90C up to 115C. Again, experiment with temperatures in this range to find the sweet spot that allows HIPS to properly adhere without curling or warping.
After your print job has finished, wait for it cool completely before removing it from the printing plate. HIPS can still be workable when warm and it will bend if you try and remove your object too early.
If you’re using HIPS as a soluble support material, you want to immerse your printed object completely in Limonene and wait at least 24 hours for the HIPS to completely dissolve. It can help move things along if you give the container the object is in a couple of gentle shakes now and again.
When a print job that you’re running gets ruined because of inferior product, you’ve not only wasted your time, you’ve also wasted money. Low quality filament yields low quality results.
In the end, you’ll actually spend more on replacement filament than you would have spent stocking up on quality product. Make sure you choose a high quality HIPS filament (or any filament, for that matter) when printing.
We carefully manufacture our HIPS to super-tight tolerances of just +/-0.03mm either side of the diameter you purchase. All of this means that when you use our HIPS you save time and money and get a successful print run, time after time.
If you have any questions about HIPS, please comment below, or email us for more details. We’ll only be too happy to help.
Posted by Ed Tyson on
Has this ever happened to you? You set up a print job to run. Everything starts smoothly and looks good. The material is flowing well. There appears to be adequate adhesion to the print bed and everything seems to be layering just as planned. You leave the room thinking all is right with the world.
Sometime later, you come back to see how the job is progressing only to find that something has obviously gone wrong. The object you’ve been printing may look like it’s been exposed to an erosive or corrosive process. There are missing print layers, thin printed layers, or even layers that have gaps and holes.
What you’re looking at are the effects of under extrusion.
Every 3D printer's worst nightmare, waking up to this after an overnight print.
Under extrusion occurs when your printer is unable to supply the correct amount of material needed to correctly print a layer. There can be various reasons why under extrusion is occurring, which can make it a somewhat thorny issue to deal with.
Nonetheless, in many cases, you can solve the problem in short order simply by knowing what to look for. In this article we’re going to examine some of the common causes of under extrusion, and give you a quick fix for each.
Printer Filament and Settings
The most common cause of under extrusion is printing at temperatures that are either too high or too low for your material. If a material is being printed at too low a temperature, it does not melt evenly. The thermoplastic being used becomes thick and viscous. It takes more force to extrude and the flow of the material is uneven as a result.
Likewise, if the material is being printed at a temperature that is too hot, it can begin to fuse or bind to the inside of the hot end. This causes a partial blockage of the nozzle, and under extrusion is the result.
Sometimes, PLA or PVA filaments if printed too hot can burn or crystalize in the nozzle, blocking it.
Check to be sure you are printing within the recommended temperature parameters for the material you are using. That being said, it should be noted that it’s common for thermistors and heated thermostats to be somewhat inaccurate. So, if you are printing at the correct temperature and you’re still having problems, it’s not a bad idea to try slightly raising or lowering the temperature that’s displayed to see if that clears up the under extrusion issues.
Often, it can just all be about finding the right temperature for your filament, with your printer.
Your printing material passes through the feeder, the bowden tube, and the extruder on its way to becoming a printed object. A malfunction at any one of these points can cause insufficient material to be available for printing when it is needed. The result is under extrusion.
So, if you’re experiencing under extrusion while printing, it’s a good idea to take a look at all of these areas to see if one of them is causing your problem.
The feeder is so named because it feeds the print material into the extruder. Therefore, a malfunctioning or misadjusted feeder will cause the print material to be sent to the extruder in a non-uniform manner. This, in turn, will result in uneven extrusion during the printing process.
One of the first things to look at is the feeder tension settings. If the tension settings are too low, the knurled wheel inside the feeder that grabs the material and moves it towards the print head can’t get enough purchase to steadily move the material.
On the other hand, if the tension is too high, the feeder will grab the material with too much force, causing it to deform. This flattening makes it harder to move the material through the bowden tube and the print head, which causes insufficient material to be available for printing when needed.
Furthermore, high tension can cause the feeder to grind away at the material, causing more deformation and even slower movement.
Look familiar? Your feeder gear might have too much pressure, or simply slipping on the filament instead of feeding it.
After you’ve checked your tension settings, make sure that there isn’t a loose or intermittent power connection to the feed motor. A bad connection can cause the motor to run irregularly, slowing the feed to the print head.
This can often be the cause of a clicking or knocking sound when printing – some printer manufactures are prone to this fault because the cables they use won’t drive the motors reliably enough.
Also make sure that the knurled wheel isn’t slipping on the feeder motor shaft by tightening the key or grub that holds the wheel to the shaft. This is another common design fault with other manufactures of printers. You can minimise this if you have one of these machines by upgrading it.
If your tension and feeder mechanics are ok, but you’re still experiencing problems, the issue could be due to increased friction in the bowden tube or a partial blockage in the print head.
Bare in mind, if you’re having under extrusion problems with flexible filaments – the filament could be bunching up between the feeder and the hot end (think ‘pushing string’) – so you might find that your filament isn’t compatible with your feeder. On a side note, we do slightly stiffer flexible filaments that work in a larger variety of stock hot-ends.
Bowden Tube Problems
Once your material leaves the feeder, it enters the bowden tube which guides the material to the print head. If your feeder tension was too high and your material was being ground up, dust from that grinding can collect in the bowden tube causing friction when the print material passes through.
This friction can cause the material to slow in the tube which results in under extrusion. You can solve this problem by regularly cleaning the bowden tube to remove any buildup of dust.
Print End Problems
Another common cause of under extrusion is a partial blockage of the print end nozzle. There are various reasons why this type of blockage occurs. There could be a buildup of carbon or carbonized material in the nozzle.
Alternatively, if you’ve previously used a high temperature printing material and now are using a lower temperature material there could be unflushed residue of the higher temperature material that’s remained in the nozzle.
Another possibility is that there is a debris particle or particles blocking the nozzle. This is especially common when using a smaller nozzle head with a diameter of 2mm or below. Finally, you may simply be using a poor quality printing material that isn’t melting evenly and consistently and clogging the nozzle.
Luckily, there are a couple of relatively easy fixes that can take care of a partially blocked print end nozzle.
The first method requires you to first reverse feed all the print material out of the print head. Once this is done, heat up the head to about 260C. Then take a long thin needle that is the same size, or slightly smaller than your nozzle diameter (surgical or acupuncture needles work well) and insert it into the nozzle, taking care not to burn your hands.
Simply move the needle in and out of the nozzle several times to make sure that the blockage has been thoroughly cleared.
The Atomic Method:
The next fix has been nicknamed the “atomic” method because it uses print material to clean out carbonized gunk and other built up debris from the top end down. The key to a successful atomic cleaning is to use the material that you last printed with as the material you use for the cleaning.
This is a very effective trick if you've got particles or carbon build up behind the actual nozzle hole, as it pulls it out from the back.
The first step is to once again reverse the print material out of the print head. Next, remove the clamp that holds the bowden tube to the print head and gently pull the tube from the head.
Next, heat the print head to the temperature of the material that you last used. While the head is heating, cut about 20cc of the print material from the spool. Use a straight cut and try to straighten the material as much as possible.
Now, take the cut piece of material and insert it all the way down into the print head. Apply a bit of pressure until the material begins to extrude from the nozzle or can’t be inserted further. Lower the print head temperature down to about 145C for nylon or other higher temperature materials, 110C for ABS and 90C for PLA.
Wait for the print head to cool to the desired temperature and then quickly and cleanly jerk the print material out of the print head. The goal is to have a clean tip when you remove the material from the head. Repeat the process as necessary until the tip of the removed material is clean.
We cover more in depth cleaning and unblocking methods in this article. Hopefully this guide has shed a bit more light on the “Why is my printer under extruding” question that may have brought you here. These tips should allow you to diagnose the issue that you’re having, so you can get fixed up and back on track in no time.
Please comment below if you have any tips or suggestions of your own, or especially if you still have questions – we want to help.
Though this was helpful? Enter your email below to be occasionally updated when we publish other helpful guides. Don’t worry, we hate spam as much as you do – so we’ll only every send you content we believe is useful to you.
Posted by Ed Tyson on
We’ve all been there. You start a print job and right away things begin to go off the rails. The first layer of your print material isn’t properly adhering to the surface of your print bed. As a result, it begins to move or slide.
Subsequent layers are laid down on top of this unstable substrate. They too move or deform. In the end, instead of ending up with a cleanly printed object, you’re stuck with a monster made of spaghetti or a semi-shapeless blob of thermoplastic. Not quite what you were envisioning.
Alternatively, your initial layers seem to adhere fine. The object seems to be printing out nicely. However, as the print head begins moving upward further away from the print bed, and those initial layers begin to cool, you notice that the corners of your object begin to pull up and inward.
Instead of clean angles, you end up with an object whose bottom edges are warped. At best, this makes your object unsightly. At worst, it makes it unusable.
Those first few layers really are the most important of the whole print. Get them wrong and it’s clean up and restart time. Which all wastes your valuable time, and at best is just disappointing and frustrating.
The problem here is build plate surface adhesion.
Most 3d printers come with a print bed that is made of glass of aluminum. Both of these materials are quite durable and relatively impermeable. Therein lays the problem. Glass and aluminum, by themselves, both have extremely smooth surfaces.
This smooth surface offers the print material very little purchase to grab onto. As a result, the material tends to resist adhering to the surface of the print bed. The result is movement of the initial print layers or warping of the material as it cools.
Heated print beds have tended to somewhat reduce this problem, especially for materials with a lower printing temperature like PLA. However, even a heated bed does not eliminate all adhesion problems all the time, especially for materials that need a higher printing temperature, like ABS.
The solution to the problem is to find a build plate surface that will provide greater adhesion for the print material to hand on to as the job progresses. In this article, we’re going to take a look at some of the more common and successful build plate surface solutions out there, so that you can choose one that’s right for you and the print material that you’re working with.
Before we look at the common 3D printer bed surfaces available to you, you may be wondering "What is a 3D printing raft, and when should I print with one?"
A raft is a couple of layers printed before your main print. Some printers (like the Zortrax M200) have a perforated heated bed, requiring you to print with a raft every time. This does work well, because you never have to worry about bed adhesion with a raft on a perforated bed.
For anyone with a regular solid bed, we think the only times you’ll likely want to print with a raft is when you’re printing objects with a very small contact area on the bed and you’re worried the print might unstick during printing. But for most instances, if you get the right surface for your bed – you shouldn’t need to worry about rafts.
Let’s deal with this one right away. Some people swear by hairspray as a great way to get adhesion on your build plate surface. We’re not that much of a hairspray fan for a couple of reasons. First, hairspray was a great solution to adhesion problems back when most printers didn’t have heated beds. Today, not only do most printers have heated beds, but there are also better and more durable solutions available.
Second, let’s face it, hairspray is a mess to use. It gets on your printer, it’s a pain to clean up and you have to reapply it for every new print job. We recommend you go with different adhesion solution, but if you’re set on trying hairspray, make sure you choose one that’s extra hold and contains plenty of vinyl, acetate and copolymer.
Blue Painter’s Tape
Blue painter’s, or blue masking tape is an easy way to give your build plate surface more adhesion, especially if you’re using a material with a lower print temperature like PLA. This is a commonly used bed, because it’s not too messy, works OK and is relatively easy to get hold of.
Because it is easy to remove at the end of a job, many people apply it directly to the surface of their print bed. It is easy to apply, mainly because it can be easily placed and replaced, over and over, to ensure that it lies evenly with no bubbles and with tight seams between rows.
One problem with painter’s tape is that no matter how careful you are, the seams between the rows will still be slightly raised. This will, of course, affect the look of the bottom of your printed object. For some objects, this presents no problem. For other objects, where the look of the bottom is an issue, you can use super wide painter’s tape. Its 6 inch width can give a seam-free print surface to smaller objects and cut the number of visible seams in half for larger objects.
Kapton tape is a great solution for bed adhesion if you’re working with a material that has a high printing temperature, like ABS. Kapton tape was developed by NASA for use in space. It is a super thin, film-like material that is extremely heat resistant. Kapton can be difficult to apply and remove. To solve these problems, many people have a 1.5mm piece of window glass cut to the size of their printer bed. They then apply the Kapton tape to the glass using the “water method” and then attach the Kapton coated glass to the print bed using clamps or adhesive. Make sure that your build surface is level after attaching it to the bed. Like painter’s tape, Kapton comes in a 6 inch wide roll that makes covering surface quicker and easier.
Pritt stick is another great way to get adhesion on your build surface. It works well with both our PLA and ABS and it’s neat and easy to use to boot. You simply apply a layer of the Pritt stick to a 1.5mm piece of glass cut to the shape of your print bed (or your print bed itself, if the surface is already glass). Let the glue air dry and then attach the glass to your print bed using clamps or an adhesive. Double sided tape works well. Heat your bed to the proper temperature, as normal and wait about 30 minutes before beginning your print job.
The key to Pritt Stick and similar, is that you get an even coating, without blobs. If you apply in too cold environment, the coating will be too thin. And if you apply with the heated bed too hot, it can get gloopy and leave blobs everywhere.
The good news is once a good layer is applied, it should last a good few prints before it needs re-doing. Essentially though, like the above methods, it’s still some degree of messy and not exactly ‘plug and play’.
Buildtak is a thin plastic material that self-adheres to the build surface and, according to its manufacturer, “provides an optimal printing surface for 3D objects to adhere to for the duration of a print, while allowing for a clean, easy removal of completed builds.”
Buildtak is manufactured and marketed by the Ideal Jacobs Company who, interestingly enough, developed Buildtak after purchasing an in-house 3d printer and finding that it was difficult to get objects to adhere to the build surface.
Buildtak comes in 13 different sizes, so finding a size that fits your build surface shouldn’t be an issue. It comes with a self-adhesive backing that can be somewhat easily applied to the build surface. As always, make sure that the build surface is leveled after installation. Buildtak works with both PLA and ABS, as well as more exotic materials like HIPS and PET and users report that you can expect to get about 50 to 100 hours of use out of one Buildtak sheet.
It’s worth noting that with Buildtak and PEI (below) you may need to increase your heated bed temps by a few degrees – as these surfaces can very slightly insulate the heat from your bed.
PEI, or polyetherimide, is a thermoplastic that provides a good build plate surface adhesion solution for a wide variety of printing materials, including both PLA, ABS, Nylon and others. It is extremely heat resistant, performing well in temperatures up to 170C. It is also reusable, relatively inexpensive and requires almost no maintenance between print jobs, other than a wipe down with an isopropyl alcohol and water solution.
You want to use a sheet of PEI that is between 0.5mm and 1.0mm thick (approx. 0.03”) and around the size of your bed. Common sizes are 200mm x 200mm up to 300 x 300mm (12” x 12”). Thicker sheets will only be harder to apply to your build surface, require more heat, and due to the raw material cost – are more expensive.
Once you’ve got your PEI sheet, you can easily cut it to size with a box cutter or exacto knife. The sized sheet can then be laminated to one side of a two sided adhesive transfer sheet like these. Once laminated, the sheet can then be attached to your build surface using the other adhesive side of the transfer sheet. A short video tutorial detailing this process can be found here. Once you’re finished, remember to re-level your print bed and you’re ready to pretty much kick you surface adhesion problems to the curb.
PEI is our favorite; mess free, fit & forget print surface that more or less copes well with every material we’ve thrown at it.
If you’ve liked this article, we’d love to hear from you about your own experiences finding a reliable 3D printer surface adhesive for your prints in the comments below.
Also, remember to sign up to our blog for a wealth of relevant 3d printing info and absolutely, positively no spam.
Posted by Ed Tyson on
Are you and your printer hungry for something new? Do you want to try printing with a thermoplastic that opens up new creative possibilities? Maybe you want a material that will give your designs impressive tensile strength and impact resistance, but also is easy to work with and provides impressive results.
If that’s the case, then polycarbonate filament could be the thermoplastic material that you’ve been looking for. In this article, we’re going to take a look at polycarbonate, what it is, what it does, how it performs and some of the best ways to get great results when printing with it.
Polycarbonate (PC) is an extremely strong, lightweight and transparent thermoplastic. Marketed under the trade name Lexan, it is used to make products as varied as CDs and DVDs, bullet proof glass, riot gear, sunglass lenses, scuba masks, electronic display screens, phone and computer cases and much more.
PC has a very high impact strength, far greater than glass and more than ten times that of an acrylic material like PMMA. At the same time, it has less than half the density of glass, but with comparably high level of transparency. In fact, polycarbonate transmits visible light better than many kinds of glass. It is this relatively light weight and transparency, combined with incredible strength, which makes polycarbonate such an attractive material choice for a wide variety of commercial uses.
Or even, just miniature vases like this one that we 3D printed at the TCT Show:
Polycarbonate is also an attractive choice as a 3d printing filament.
Its high impact resistance insures that it can stand up to a variety of demanding applications. It also has a relatively high heat resistance and can be bent at room temperature without cracking or breaking. Other transparent thermoplastics, like PMMA, have a lower impact resistance and will crack and break if bent. This makes polycarbonate an excellent choice for making functioning prototypes, especially where transparency and non-conductivity are desired.
In addition, PC can stand up to wear and tear. It is not delicate and won’t deform or break when handled. Finally, its clarity and ability to transmit light means that polycarbonate printing material will produce beautiful printed objects when used correctly.
We’ve taken a look at some of the benefits of using polycarbonate printing filament, now let’s take a look at its features:
- Strong, impact resistant thermoplastic;
- Machine bendable at room temperature;
- Extremely durable;
- Transparent with excellent light transmittance;
- Dichloromethane soluble;
- Printing temperature from 260C – 300C;
- Recommended printing bed temperature of 90C or higher.
A look at the data stats of polycarbonate confirms the impressive strength of polycarbonate. Polycarbonate has a specific gravity of 1.18 g/cm³. This density makes it comparable to PMMA and PLA and about one fifth denser than ABS. It has a Rockwell hardness of R 121, making it harder than PMMA, ABS and PLA.
Yet, as we’ve been discussing, it’s the category of overall strength that sets polycarbonate apart from other thermoplastics. It has a maximum tensile strength of 11,200 psi (77.22 M/pa) which is comparable to PMMA. However, it has a tensile break strength between 75% and 150%. Compare this to the tensile break strength of PMMA (1.8% - 7.2%), PLA (1% - 12%) and ABS (4.6% to 27%). What this means is that while both polycarbonate and PMMA are strong and hard, the ability of polycarbonate to withstand torsional stress far exceeds any other thermoplastic.
So, with polycarbonate you get a strong and durable material that can carry weight and survive rough handling, but is also flexible enough to withstand tensile forces that shatter, deform or break other materials. It also transmits light better than most types of glass. So, if you’re looking for a strong, tough and flexible 3d printing material that’s also transparent, you need to give polycarbonate printing filament a spin.
3D printing with polycarbonate isn’t hard, as long as you keep a few things in mind...
First of all, polycarbonate is heat resistant up to 116C. It also has a glass transition temperature of 150C. Therefore, polycarbonate needs a high printing temperature, the closer to 300C the better.
If your extruder has a problem with temperatures this high, don’t worry. Polycarbonate has a relatively slow transition temperature. This means that it will successfully print at a lower than optimal temperature, albeit more slowly. This brings us to our second “How to 3d print with polycarbonate” tip.
In general, the lower your printing temperature, the slower your printing speed should be. We’ve found that 30mm/sec at a temperature of at least 265C will produce good results. If you can get a higher temperature out of your extruder, you can experiment with a faster printing speed, say 60mm/sec. However, at the end of the day, slow and steady wins this particular race.
You also want to keep the temperature of your printing bed at 90C or higher to avoid warping of the polycarbonate printing material. A higher printing bed temperature will also help to eliminate any delaminating issues that might arise.
When printing, keep in mind that polycarbonate filament is extremely hygroscopic. This means it will absorb moisture from the air. The more water there is in the air, the more moisture the polycarbonate will absorb.
Polycarbonate that has been exposed to humidity will exhibit problems when being extruded, mainly bubbles and inconsistent flow that will tend to ruin your design. Storing your filament in an airtight container will minimize these problems.
It’s our goal to make sure that your print jobs are a success the first time, every time you print. When what you print is less than successful you not only waste material, you also waste time.
Low cost filament seems like a bargain, but it’s not.
Yes, you don’t pay as much upfront for your printing material. However, when design after design is ruined because of imperfections in the filament, the cost of buying replacement filament begins to add up.
If this article was useful to you, and you'd like to get updates when we occasionally write new help guides on 3D printing, please enter your email address below. Don't worry, we hate spam as much as you do and we'll only ever send stuff we think is helpful to you. Promise.
Our polycarbonate printing filament is the best you’ll find. Sure, everyone says that. But we carefully manufacture our polycarbonate to super-tight tolerances of just +/-0.03mm either side of the diameter you purchase. This means that when you use our polycarbonate you save time and money and get a successful print run, time after time.
What's more, we back it up with excellent service, and a 60-day moneyback guarantee.
Posted by Ed Tyson on
If you’re like me, you are very aware of your printer settings when you’re setting up a print job. You’re meticulous when it comes to the print temperature, bed temperature and print speed.
You make sure that all is right with your output program.
You try and use the highest quality printing filament. In short, you do everything you can to make sure that you end up with a printed object that is as close to perfect as possible.
Yet, despite all this careful preparation, you come back and find that your print has distorted, layers have stopped binding and instead of a perfect print, you’ve ended up with a mess. What the heck happened?
If this has happened to you, the likely culprit is water, specifically humidity infiltrating and breaking down your printing material. In this article, we’re going to take a look at why thermoplastics are susceptible to water damage.
We’ll also look at some best practices that you can use to keep your printing filaments as dry as possible. Finally, we’ll look at some of the ways you can detect water damaged filament before you print as well as techniques that you can use to try moist filament out so that you can safely use it again.
Why Water Damages Thermoplastics
All plastics are polymers or copolymers. Simply put, a polymer is a material that is made up of multiple long molecular chains of a single substance. For example, PVC or poly vinyl chloride consists of a bunch of vinyl chloride molecules.
A copolymer, on the other hand, is a material that is made up of several substances, each of which exists in long molecular chains. ABS is a copolymer and consists of strands of acrylonitrile, butadiene, and styrene molecules all bound together.
Polymers and copolymers are complex substances. They are designed to act in certain ways under specific conditions. For the most part, they fulfill this task admirably.
However, that task specific complexity comes with a price. What can be built up, can also be broken down and nothing breaks certain polymers or copolymers down quicker than water.
If you looked at a polymer or copolymer under a strong microscope, you’d see that the long molecular strands that make them up are woven and braded together, almost like rough cordage or rope. This means that there is plenty of space between and round these strands.
Because of this, most polymers and copolymers are hydroscopic. This means that as air circulates around and through these strands, the spaces between them pick up and hold the molecular water that is naturally present in the air.
The more water vapor there is in the air, the more molecular water the copolymer can pick up or absorb.
These water molecules in the spaces between the strands not only increase the size of the material, they also tend to break down and alter the length of some of the molecular chains that comprise the polymer.
This process is caused hydrolysis. The result is an extruded copolymer plastic that doesn’t perform to design specifications.
How to Prevent Water from Damaging Your Thermoplastics
Even a small amount of absorbed water will negatively affect the end result of your print jobs. The best wat to avoid this problem is to prevent your print materials from coming into contact with water vapor in the first place.
The easiest way to do this is by storing you filament in an air tight container that contains desiccants.
When it comes to air tight, however, all containers are no created equally. When most people think of airtight, they think of plastic containers and bags. These are fine short-term solutions for the most part.
It’s better to store your materials in a plastic bag than leaving it unprotected in a drawer or box.
However, over time, plastic containers and bags are slightly water permeable. This means that the longer your printing materials sit in the plastic bag, the more water they are slowly absorbing.
If you live in a humid climate, this process is accelerated. Eventually, even with the use of desiccants, you wind up with filament that is water damaged.
A better solution is to use Mylar bags, or bags made of a similar material, to store your thermoplastics. Mylar, as you know, has a metal layer that is embedded between two layers of plastic.
This metal layer keeps any water vapor that permeates the plastic layer away from your printing materials. The result is dry materials that are ready to give you great results every time you print.
Here at rigid.ink, this is the reason we provide metallic, sealable bags, along with desiccants, with every order we ship. It makes no sense to sell our customers the highest quality thermoplastics available and not give them the best means to protect those materials when they are not being used.
How You Can Tell That Your Printing Material Has Absorbed Water
There are two easy methods that you can use before you print in order to determine whether your material has absorbed water. First, you can measure the diameter of the material itself.
Remember, when a polymer absorbs water it begins to increase in size. The more water it absorbs the bigger the size increase will be. If the diameter of your filament has increased by 10% or more, it is likely that absorbed water is the cause.
The other way to determine if your filament has absorbed water is to extrude a small amount of filament prior to printing. We’ve probably all had the experience of sitting next to a fire and listening to it pops and crackles. This occurs because there’s water in the wood that is turning to steam as a result of the heat.
When you extrude thermoplastic that has absorbed water, the same phenomenon occurs. The heat of the print end causes the water in the plastic to expand. As the plastic extrudes, you will hear hissing or popping that is a result of the steam escaping. You may also see bubbling.
If you suspect that your filament has absorbed water you’re going to need to dry it out. In the next section, we’re going to show you how.
How to Dry Printing Material that Has Absorbed Water
If your filament has absorbed water, you’re going to have to dry it out before you can use it to print. The easiest way to do this is by using your oven to get the job done.
The first thing to do is check out the glass transition temperature for the filament that you are going to dry. You want to make sure that you keep your oven temperature below the transition temperature. In general, about 100C is just about right for a material like ABS.
For a harder material, like polycarbonate, 150C should do the trick. On the other hand, a material with a lower transition temperature, like PLA, doesn’t lend itself well to oven drying. This is largely because that lower temperature will cause it to deform even at your oven’s lowest setting.
Once the oven it up to temperature, place the spooled material inside and leave it there for four to six hours. If you have a convection oven, this drying time may be shortened since the circulated air removes more moisture from the material more quickly.
You can also 'recharge' the desiccant this way too, placing it in the oven over a low heat.
Once the time is up, remove the material from the oven, allow it to cool and place it into a water impermeable container or bag along with desiccants. Make sure that the container or bag is completely sealed.
When you use any material that you have oven dried to print, be aware that it will slightly more brittle than normal. If you handle the material with care this should pose no problem, especially when you consider the superior results that you can achieve when using a properly dry print material.
If you've tried everything above, and that's still not help (and your filament is less than a few months old) we recommend getting in touch with your filament supplier and asking for a replacement. If they're worth their salt, they'll do this for you.
Well, we would anyway.
Bags like the ones in the images above are delivered free with every order of rigid.ink, even the free samples. We hope you found this article useful - if you have any questions please don't hesitate to ask in the comments below.