Material Change, we’re dropping the Carbon Fiber
As a company, we have always strived to keep our customers aware of what we’re doing as a company. Also, through these blog posts, we hope to help and encourage people who might not even be customers of ours with additive manufacturing through the sharing of this information.
From the time we started Hamre Forge, up until very recently, we thought the future of this company was in Carbon Fiber infused nylons, specifically Carbon Fiber infused powder in commercial Selective Laser Sintering (SLS) technology. When we started the process of Sintering our parts instead of the extruded 3d printing that most people know about, I was asking SLS industry professionals why there wasn’t more use of Nylon Carbon Fiber in the industry. Why was no one doing it? Are there reasons people are avoiding it? Internally, we were able to get over technical hurdles, and I thought the technical hurdles might be what pushed people away from this powder, but I think it’s more than that.
Through much deliberation, testing, advice from industry professionals, and real world testing, we’ve decided to move away from Carbon Fiber infused powder, specifically PA11-CF, and toward Polyamide 12 (PA-12 or Nylon 12).
Here are some of the reasons we found:
- Processing/Post-Processing Time
- Hardware Life
- Manufacturing Time
- Cost
- Recyclability
- Part Quality
- Color
- Standardization
- Scalability
- Availability
What it looks like today
Preparing a job, removing a job, clean up, and general powder processing is extremely time consuming. More than it should be, and more than we have manhours for. Today we have one production machine, and if/when we add a second machine, the labor on powder handling alone would be enormous. The carbon fibers inside the material make a mess. I am typing this out on a keyboard covered inside and out in small carbon fibers. They have a tendency to want to float about.
Now, aside from carbon fibers wanting to waft about a space, this poses another problem to the machines themselves. Whether the machine is the SLS device, vacuums, mixing/sieving devices, or depowdering stations, the powder is extremely harsh and unfriendly to everything. For instance, unused powder from a job gets mixed and prepared with fresh powder to create a usable mixture conducive to producing product. This mixing job is made difficult by the carbon fibers due to the desire for fibers to statically cling to one another. Through the mixing and sieving process, small carbon fiber balls are be created through static clinging of carbon fiber that can mess up a production run. We have developed proprietary processes and extra steps to ensure this doesn’t happen, which leads to a lot of powder going from bucket to bucket multiple times, through vibrating sieves multiple times, and more. It’s messy and time consuming.
If the PA11-CF takes 3-4 hours to process, the PA12 takes an hour to an hour and a half.
The hardware also takes a beating. Through the SLS process, the carbon fibers want to float around the build chamber of SLS machines. They interfere with heat lamps, laser windows, powder wiping mechanisms, and the entire process in general. Floating carbon fiber aside, the recycled powder also is quite costly to the life of the machine due to heat requirements. Once powder has been through a sintering process, the heat changes the molecular structure of the powder. To reuse this powder for part production requires the use of higher heat. The higher heat is hard on the machine, and over time, will cause more part failures and decreased machine life.
The higher heat requirements also increases production time. The laser takes more time with reused PA11-CF material due to the need for it to move and sinter slower to produce strong and even melting of the powder material, as well as allowing part cooling to prevent warpage. Jobs that would take 8 hours to run in a production machine with a non-carbon fiber infused powder can take 16 or more hours because of the addition of carbon fiber.
The costs of running this powder are also high due to the fact that we can’t use all our recycled powder from job to job. In other words, to get good parts, we need to add fresh powder to the powder mix, and the resulting good mixture leaves a lot of previously used powder left over. I have hundreds of Kilograms of used powder that I can’t do anything with. Our business has been growing, and if we continue at this rate, I don’t know what I’m going to do with all this powder. I can’t sell it, I can’t use it, and with the cost of this material, throwing it away is the same as burning cash. With PA12, the non-carbon fiber infused powder we’re moving to, we have a 100% reuse rate. We can reuse 100% of all the powder we put into the machine. There’s zero waste. All the powder we buy, we use. All the powder we buy, gets turned into parts.
We have had some issues with part quality. We essentially shut down the business for a month and a half because of discovered mechanical issues and part quality issues. We have since resolved the mechanical issues, and have in part resolved the quality issues. We’re walking a razor’s edge with our parts. If we make them look really good from all angles, they will be weak. If we make them mechanically strong, they will be ugly. We have navigated this by adjusting where we make the part ugly, namely, non-show surfaces. Some parts don’t have a lot of flexibility in this area. Our LCR grip for instance, it’s one piece. It doesn’t have the flexibility of choosing where and how to “nicely” put a low quality surface. We do our best, and we have a lot of waste, but we have accounted for this and have been shipping a lot of parts.
But what happens if our LCR sales double? Triple? Or if I get a phone call and someone wants 2000? Going through each and every LCR to fix / validate / and intensely post process them simply because of this powder choice is a hard pill to swallow. As many people have probably seen, the inside of many of our stocks has some internal surface porosity. This is an area where we’ve intentionally put some of the lower surface quality, while maintaining a “show side” on the outside of the grips. Due to a variety of technical factors involving heat, speed, melt points, and material flowability, PA12 doesn’t tend to suffer from these issues.
Aesthetics aside, there’s also the strength and durability. Because the Nylon-CF has such a tight optimal manufacturing window, the resulting products may slightly vary in strength and durability. Everything we produce and send out is strong and durable, but I question whether 100% of the parts being produced meet the standards that are published and produced in laboratory testing by the powder manufacturer. PA12 is EXTREMELY tested and vetted in both laboratory testing, real world testing, and in research papers. Through my own observations, the general every day PA12 part is as functionally strong as the general average PA11-CF part.
One of the top requests we get (other than a left handed hook) is whether or not our products are available in different colors. Since the powder we use today, PA11-CF is infused with Carbon Fiber, it is all black. Black, only black, and not dyable. It could be painted or cerakoted, but that’s not a process that we see as viable. Non-Carbon Fiber infused powders have a natural color, or are made white. The base white nylon is colorable. We will be able to offer stocks of a variety of colors, or even sell them in the white, and they can be dyed in whatever fashion you wish.
Dye them black, carve on them down to the white, and then dye them in red. That could be neat.
While this initial switch for us is a black based Nylon 12, we know that in the very short time after this switch we will switch to a white nylon, and all our products will be dyed.
This process of producing in white, and then dyeing all the objects may seem arduous. The thing is, it’s actually what almost everyone is doing. It’s essentially the industry standard. Our switch to black PA12, and eventually white PA12, puts us on a trajectory of industrial level standardization. It’s what all the research papers are written around, it’s what all the companies that sinter nylon are doing. It is the norm.
Since this switch is going toward a standardized material vs a specialized and nuanced one, this material switch allows for greater scalability. I have previously mentioned that this technology scales well, which it does, the carbon fiber infused powders don’t scale well. If I had 3 machines running 24×7, I would be producing approximately 32,120 pounds of wasted powder per year. I’d need 3 machines if my business doubled, and I can see that happening in just the next 6 months. What happens if we triple, or quadruple in size?
Staying on Nylon Carbon Fiber, I feel like I could blink and hit 100,000 lbs of powder waste a year (that would be with 6 machines). If we hit that point, we’re at 274 pounds of unusable garbage powder per day. That dog don’t hunt.
We only know of a single manufacturer of Nylon Carbon Fiber. BASF is the producer of PA11-CF, and almost all other PA11-CF offerings are rebranded BASF produced powder. We have already run into issues with the availability of this material. One woke liberal company even denied to sell me the powder when we were in a pinch because we produce parts for weapons. To avoid powder availability and potential disruptions in the future, it is in the best interest of our company and customers if we migrated processes and manufacturing to a powder that is more readily available and produced in larger quantities.
Conclusion
In conclusion, we strive to constantly improve. From day one, our focus has been on producing the highest quality product for our customer. We believe that this change is in line with this goal, in many different ways.
We haven’t stopped Nylon Carbon Fiber production just yet, but in the next week or two, all our products will switch over to the non-Carbon Fiber material, and our website will reflect this change.
If anyone has any questions or comments, please feel free to fill out the contact form, or get a hold of me in many of the various ways people have been able to reach out.
Regards,
Ryan Hamre