They should only be used as a last resort. That is what we would like to say to health professionals that might not be fully aware of what the technology is capable off. With this post we would like to outline the risks of using 3D printed respirator masks, both for the general public, the 3D printing community, and the medical community that might not fully understand what is being pushed by a panicked, but anxious to help, 3D printing community.
If you are using crowd-sourced masks. That is, masks that are made by local individuals with garage 3D Printers. Then you essentially have hundreds of individuals handling your masks in their homes. Those people may not be tested for Covid-19. so they could be infecting the masks that they are supplying. This means that they could potentially be directly infecting you staff if you utilize these masks. Amateur manufacturing means amateur facilities and handling.
Due to the layer lines in DIY 3D printed parts these masks can't be reliably sanitized. Therefore even though they will be relatively expensive to manufacture (2-5 dollars each). They would have to be disposable, if they can reliably be used in the first place.
The vast majority of masks printed are being printed from the baseline design in rigid materials. They do not compensate for male or female. This means that they do not fit most faces. In fact most of these masks fit little better than the oxygen mask in an airplane.
The only option to make them fit is to heat them up in boiling water or in a microwave and then press the softened plastic onto the face of the individual using the mask.
The problem is that these masks are not reusable. They cannot be sterilized. So a worker has to potentially scald their face each time they put on a disposable mask. And the seal is still not viable. Because the mask would lose its seal as soon as the healthcare worker moves their jaw.
The poor fit essentially makes the mask useless except as a splatter guard.
Again, due to the rigid materials, and DIY designs. Most of these masks do not seal around the face. Admittedly many paper masks don't perfectly seal either. But they also do not force air to move through the few crevasses that exist. And again the only way to get a reasonable fit (other than a plastic part in front of your mouth) is to heat the plastic and form it to your face.
Due to this problem healthcare professionals would almost be as protected if they simply tied a dishtowel in front of their face. Maybe better protected. (Read the full study about these materials effectiveness)
At Slant 3D we have tested every publicly available 3D Printed face mask. The one that prints the fastest is complete in 2 hours. That means that a single printer could produce 12 a day. There are only about 1.5-2 million 3D printers worldwide. That means that only 24 million masks could be manufactured per day if every printer was working on it 24/7.
China has the capability to manufacture 116 million N95 masks per day right now. And then it takes 2-5 days to ship those out. The US is expected to only need 3.5 billion masks to address coronavirus for a year. That is basically 1 month of production.
3D printing is not necessary and is not viable to address the supply shortages. Supply shortages that do not yet exist. They are only projected based on worst case scenarios. Please everyone calm down and allow the supply chains a few days to catch up.
It is truly great to see the 3D Printing community stepping up to help with local manufacturing. But respirators are not the item to manufacture. There is not yet a need, and when there is, 3D printing is not a viable solution. Please believe us we do mass manufacturing with 3D Printing for a living. Time would be much better spent on face shields, potentially ventilator parts, and general everyday aides.
To the medical community. If you have a drastic need for facemasks please use your knowledge to make a call. At this point there is no magical antibacterial 3D printing material that makes 3D printed masks much better than a torn tshirt tied across your mouth.Use your own judgement. It is possible that 3D Printed masks can help to limit the spread from covid-positive patients. But again, tshirt.
Please feel free to reach out to us here at Slant 3D if you have any questions or need to have some other part manufactured. We are standing by and reserving capacity when viable solutions become apparent.
As COVID-19 continues to spread, 3D Printing can help to mitigate supply shortages of parts and devices needed to help. Slant 3D is comitting a large portion of our production 3D Printing capacity of several hundred printers to help as needed. But there are thousands of other printers in the world that can also contribute.
Here are several 3D printing files that can be printed to help deal with the Coronavirus epidemic.
We would like to take this moment to say that masks are largely ineffective. It is assumed at this point that is Covid-19 is tranmitted predominantly through direct contact with body fluids. This makes a mask useless unless you are in a crowded area among those who are infected and symptomatic. This means that masks are mainly needed in hospitals.
But if you or a person you know becomes symptomatic you can protect the people around you by wearing a mask because droplets can be spewed around an area through coughing and sneezing. So a mask does help but mainly as a catcher. You do not need to have a HEPA filter simple fabric like a handkerchief in the mask helps a huge amount.
Another interesting mask for holding a cloth cover in place. This mask is printed flat with PLA and then heated with a hairdryer or in boiling water to then form to the face. It will create a more comfortable fit and likely a better seal.
Since the COVID-19 seems to be transfered through direct contact door handles and other common touch-points can be contaminated. Materialize has created a design to be a used with round handled doors which can be easily printed and installed. These fixtures make is easy to open the door with an elbow.
Helping with more general tasks this device allows you to interact with commonly touched surfaces in order to avoid contact. A Simple hook lets you open doors and you can also use it to turn on lights and maybe even the knob in the bathroom.
We will update this list with new posts as more designs are created. We are aslo comitting capacity to the production of such devices. We hope that we can help in some way limit the supply shortages that are arising. If you a have a part that needs to be produced please submit it to us and we will do our best to help.
Most of all we would like to say "Please stay calm." Supply chains are functioning. Infrastructure is fine. It is the burst of panic that has limited toilet paper in the stores. Please only take what you need and plan food and consumables for a potential 2 weeks shutdown. Please do not do more as you will add to a vicious cycle of hoarding. We will come through this epidemic.
Production 3D Printing is a new technology. And not everyone has interacted with it or understands what kind of pieces and features can be made with it. That is why we designed the Slant 3D Sample Brick. This 3D Printed part demonstrates many of the key features and capabilities of the additive manufacturing process. Everything from complex internal geometries to complex surface textures.
The sample Brick can be ordered for free with the form below. Just let us know where to send it and we will get it to you.
Clients may use the 3d printed sample brick as a reference for proper design of 3D printed parts. As well as a way to evaluate our high volume 3D printing processes.
Features on the Brick
What is the Process of preparing a product to be manufactured with high volume production 3D printing?
Production 3D Printing is able to produce 100,000's of parts more affordably than injection molding. This savings is a result of the eliminated upfront cost of tooling and reducing design time and the long terms costs of warehousing.
But what is the process of moving a product into Production 3D Printing? It is very important to know this process to ensure that there are as few delays as possible as you are going into production.
I have an Idea/Sketch
I have an Engineered Design
I have a Physical Part I need Re-manufactured or is no Longer in Production
The Most Important Thing
The most important thing is to make sure that you part is designed and optimized for production 3D printing. This makes sure that the quality, performance, and cost of the part is the best case possible. Additive manufacturing is rarely an exact replacement to injection molding. It is an alternative process that must be considered during design. That is why we keep a team of engineers who are the world leaders in design for additive manufacturing and they are here to make sure that your part meets your needs.
Use 3D printing to vary the density of production plastic parts.
Most 3D printed parts have the option of varying their percentage of infill. Infill is the honeycomb-like patter inside of an FDM printed part which helps to reduce material used while still creating a structurally sound part. But this infill has another advantage. It allows a part to be created with basically any weight needed (up to the solid density of material) without changing its dimensions. This means that 3D printed parts can emulate the density of other materials like various types of wood.
We recently had a project where this was a great resource. Our client had a prototype of several pieces of their product. The pieces were created to interact with each other in a particular way based on weight. Their prototypes had met their needs, but they were made out of wood. Going into production with any process the client needed a means to match the weight of the wooden prototypes. This was only possible with 3D printing.
Slant 3D was able to create a part with the same overal dimensions of the wooden prototype and then vary the infill density until the production part weighed exactly the same as the wooden piece. This isn't possible with injection molding. The client was elated.
The control of density that 3D printing allows is an incredible advantage of the technology. It allows the possibility of created pieces with the density varying throughout to create parts like self-righting chess pieces. Or one can create parts with high or low densities that they sink or float with the same volume. Nothing else can do that.
3D Printing is an ideal means of manufacturing custom electrical enclosures.
We have worked with many industrial clients that have utilized our large format 3D printing capacity to produce electrical enclosures. The reason they prefer 3D printing is to traditional machining is primarily based on cost.
The additive nature of 3D printing reduces the amount of material needed to create an enclosure when compared to subtractive machining. After all a delrin block is far more expensive than a kilogram of ABS. Injection molding is not an option because with larger enclosures, greater than 12 inches cubed, the cost of the mold is very prohibitive. Not to mention the time to have just 10-20 enclosures produced is too long. But 3D printing can produce the pieces in 1-2 weeks.
But as is the problem with most items submitted for 3D printing, the engineer of the enclosure does not design for 3D printing. They take a traditional enclosure and expect 3D printing to create a result that is identical to other processes. It will not be. So we wanted to compile some tips for designing electrical enclosures.
Design a Foundation Layer
When printing any part a decision must be made about what side of the part will be against the print bed. Traditionally this will be the largest single flat surface. This is used to have maximum bed adhesion which limits warping and failure of parts. Generally this side is the back or bottom of the enclosure that might be mounted against a wall.
Ideally this side should have no complex features such as text. Just holes. If there is text, they it can become unreadable as the first layer is often "squashed" in order to help with adhesion.
When designing your enclosure try to create a large simple side which can serve as the foundation
If all side of an enclosure require critical details there are multiple solutions.
Printing the part with the open face down will require a longer set-up period. This orientation is difficult tp print reliably. It also requires that the enclosure be printed with support material throughout. This results in a rough interior texture and more expense, due to the support material. There is also the risk of any interior bosses or features losing detail because they printed on support material. You can see a comparison of sections of the same part printed open side down and up in the photos below.
Infill or Ribs
When a part is 3D printed there is the ability to either create a solid piece or reduce the density of thick areas of the part by using internal lattices. This "infill" reduces print time and material used and is highly recommended.
The infill makes the part behave like a sandwiched composite. So even though it uses less material it is structurally very strong at low infill percentages of less than 50%.
However if more structure is required we recommend adding ribs. These are simple to print and provide a large amount of strength. Using ribs with thin walled enclosures are ideal as they result in even less material used than infill and better control the structure of the enclosure.
Since electrical enclosures are generally purely functional, they are often printed at the lowest resolution possible. The layering is visible, but it reduces lead time and has not structural downside.
If a more refined surface is necessary the layering can be be made to nearly disappear with high resolution printing. The downside is that the printing time per part can go up as much as 300%. And the smooth surface can only be created on straight vertical surfaces. Any sort of incline or vertical curve will make the layering more visible. All of this is well defined in the part below, where it was printed with high resolution.
Reduce Rims and Overhangs
It is very common to create a rim around the top of an enclosure or case. This improves rigidity for a lid or for ejection from a mold. These rims often protrude some distance horizontally from the part with little filleting below them. This is done to reduce material used, but that is unnecessary for 3D printing (infill eliminates excess material from thick areas).
These rims in fact increase the cost and difficulty in manufacturing the part with 3D printing, because they must be supported. In the case of the part above an entire secondary structure of support material from the base of the case to the rim must be built simply to support the rim in the last 0.25 inches of the part. This adds a great amount of print time and material, therefore increasing the cost of the part.
The way to avoid this is simple to add a chamfer of fillet underneath the rim, so that it seems to gradually protrude from the case as it is grown layer by layer. Examples of this filleting are shown below.
In this particular case, the enclosure actually has an overhang angle of 90 degrees, thus requiring support. If a 45 degree chamber was adding it would greatly reduce the cost of the part.
Hopefully these pointers will help you when working on your next enclosure. When working with Slant 3D one of our engineers is always available to help you through the process. And when you submit a design for quotation we will always be willing to make recommendations in order to reduce cost.
3D Printing is a very viable manufacturing option for electrical enclosures. But to use the process effectively you must design for it. Pressing an part designed for injection molding into a 3D printer will never created an injection molded part. Better to design a part for 3D printing.
3D Printing has an incredible ability to not require certain geometries. But if you are designing a piece from scratch for 3D printing, there are several rules-of-thumb to follow in order to create a parts that address the advantages and disadvantages of 3D printing. The graphic below is a good start when designing for 3D printing.
If you have any questions or would like to see if your part should be 3D printed. Submit it for a quote. We will determine cost and give you a full design evaluation.
The original source of this graphic can be viewed here