Composites Classroom

October 13, 2022

As a leading provider of composite materials in Salt Lake City, we frequently sell products to home fabricators. This includes glass and carbon fiber fabricstubesplatesepoxy resins, and even adhesives. Working with any of these materials does pose some amount of risk to human health. As such, we recommend our home fabricating customers be smart about using personal protective equipment (PPE).

The pros use appropriate PPE whenever working with carbon or glass fiber. We use PPE at all of our facilities. If you are a home fabricator, you should too. Do not take any chances with your health. There is no valid reason to risk injury when a few pieces of PPE will keep you safe. We recommend the following four types of PPE:

 

4 Pieces Of PPE For Carbon Fiber And Fiberglass Home Fabricating
4 Pieces Of PPE For Carbon Fiber And Fiberglass Home Fabricating

1. Protective Clothing

At the top of the list is protective clothing that will keep both carbon and glass fibers from contacting the skin. The fibers can be irritating to the skin even among people who don’t normally have reactions to potentially irritating materials. Why? Because both glass and carbon fibers are extremely small. If they get stuck to the skin, they can irritate pretty easily.

Protective clothing should include long pants and a long-sleeved shirt. A hat and work boots are also advised. After working with glass or carbon fiber, your protective clothing should be washed. Do not hang it up dirty and reuse it later as you run the risk of transferring fibers stuck on the clothing onto your skin.

2. Nitrile and Work Gloves

Next, we recommend two different types of gloves. During the fabrication stage, use nitrile gloves to prevent contact with epoxy resin and loose carbon and glass fibers. Nitrile gloves do the job and are very inexpensive. Best of all, they are disposable. That means you do not have to try to clean your gloves after handling epoxy.

Post fabrication, we recommend a pair of heavy-duty work gloves to protect your hands during grinding, cutting, sanding, etc. The purpose here is to protect your hands against any splinters that may result from machining finished parts.

3. Eye Protection

It is absolutely imperative to protect your eyes whenever you are working with composite materials. During the fabrication stage, you don’t want glass or carbon fibers in the air to make contact with your eyes. You do not want epoxy to accidentally splash up into your face either. During machining process, eye protection keeps you safe from carbon fiber dust and splinters. In both cases, safety glasses are the bare minimum.

4. Face Masks

Finally, it is wise to protect your respiratory system by wearing a face mask. A mask reduces the risk of exposure to small carbon fibers and carbon fiber dust. A filtered mask can protect you against the sometimes-overwhelming fumes put off by epoxy resins.

In addition to a mask, it’s advisable that you fabricate with carbon and glass fiber in well ventilated areas. Ventilation allows for faster dispersal of annoying fumes. With good ventilation, you will breathe easier and have a lower risk of being overcome.

One last thing we advise: familiarize yourself with appropriate first aid. For example, it’s best to treat skin irritation and rashes by washing the affected skin with soap and warm water to remove fibers. There is no need to scrub, and you probably shouldn’t if your skin is already irritated.

 

We applaud your desire to fabricate with glass and carbon fiber at home. Both materials offer a tremendous number of applications for home fabricators. Just do yourself a favor and be safe. Wear the appropriate PPE whenever you are working on composite projects.

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October 13, 2022

If you can build something out of steel, aluminum, or wood, you can probably build it with a composite material as well. Take utility poles. Composite utility poles make up about 1% of the total now deployed around the world. One company in Turkey aims to increase that.

Ankara-based Mitas Group was originally established as a steel company back in 1955. It was formed by the Turkish government to help build the nation’s energy infrastructure. Privatized some 30 years ago, the company produces steel utility poles that are used domestically as well as being exported throughout Europe and to North America, the Middle East, and Africa.

Mitas recently took possession of a filament winding machine that it will use to produce up to 1,000 composite utility poles per month. The automated machine will make Mitas the first such company in Turkey to produce composite poles.

Why utilize composite poles instead of steel and wood? Below are the top five reasons. The rest of the world should pay attention to what Mitas is doing here.

5 Reasons The World Needs To Switch To Composite Utility Poles
5 Reasons The World Needs To Switch To Composite Utility Poles

1. Composites Don’t Corrode

Composite materials do not corrode like steel. For the purposes of this article, we will assume that Mitas poles will be made of carbon fiber. The poles can be installed with complete confidence that they will not rust. That makes them ideal for coastal areas exposed to salty sea air.

2. Composites Don’t Need Regular Maintenance

Both steel and wood utility poles require regular maintenance. Wood needs more maintenance than steel for obvious reasons. However, a composite utility pole requires no maintenance at all. Once installed, nothing more than routine inspections need be done. A composite utility pole does not need to be re-coated with a protective layer. It does not need to be painted.

3. Composites Are Pest Proof

Wood utility poles are vulnerable to a long list of natural hazards. One such hazard is pest infestation. Everything from termites to wood boring beetles can be problematic for wood utility poles. Replace them with composite poles and the problem is solved.

4. Composites Are Lightweight

Utility poles made of carbon fiber are exponentially lighter than both steel and wood poles. This is important in terms of installation. Imagine attempting to install new poles in a remote, rural location without road access. Getting the poles into position becomes a logistical nightmare. On the other hand, composite poles can be carried by hand and assembled on site.

Because composite poles are so light, they are also easy to install in dense urban environments without the need for heavy cranes and other large equipment. A single pole can be installed in just a couple of hours without major disruptions.

5. Composites Are Strong

Finally, carbon fiber is stronger than both steel and wood. Carbon fiber utility poles will hold up better against everything mother nature can throw at them. For example, they are better able to withstand high winds and the heavy loads such winds generate. Where wood poles might snap, carbon fiber poles will stand tall.

Given that Mitas exports their utility poles around the world, it could be only a matter of time before their products reach our shores. Maybe their success will prompt American manufacturers to secure their own filament winding machines to make composite utility poles domestically.

Image Source: Mitaş Composites

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October 13, 2022

A bicycle maker purchasing carbon fiber tubing for the first time from Rock West Composites will likely inquire about the grade of the carbon fiber in our products. That’s because we offer four different grades: standard, intermediate, high, and ultra-high modulus. When it comes to grades, tensile modulus is the defining factor.

Standard modulus carbon fiber is the most commonly used grade across industries. It is used for items like sporting goods, bike frames, and general-purpose tubing, as well as aerospace applications. Standard modulus carbon fiber is rated at 33 MSI. This means the resulting material has a tensile modulus of 33 million pounds per square inch. Ultra-high modulus fiber is the least utilized and most expensive of the grades. With a modulus rating up to 135 MSI, this grade is rather brittle and is used primarily for space applications. Remember, tensile modulus is a measurement of stiffness and should not be confused with tensile strength.

Carbon Fiber Grades: It's All About Tensile Modulus

Carbon Fiber Grades: It’s All About Tensile Modulus

HOW WE GET TO MODULUS RATINGS

To make most types of carbon fiber, manufacturers start with large groups of carbon atoms that are aligned in a long plastic string. Through a pyrolyzing process that applies extreme heat to the carbon atoms, impurities are gradually burned away leaving just the carbon atoms. Modifications to the pyrolyzing process can produce higher purity strands with higher MSI ratings.

High modulus and ultra-high modulus fibers are sometimes called pitch fiber. Pitch fiber starts as a different raw material than standard or intermediate modulus fibers and uses a different manufacturing process. High modulus carbon fiber has a rating of at least 42 MSI while, ultra-high modulus is rated beginning at 65 MSI.

The downsides to creating more pure strands of carbon fiber are increased cost, increased brittleness, and decreased strength. However, the upsides outweigh the downsides for some applications. High and ultra-high modulus carbon are often used when maximum stiffness is the priority.

Modulus Carbon Fiber

 

Carbon Fiber Olates

Modulus Carbon Fiber

CARBON FIBER TOWS

As impurities are burned away from the carbon atoms, the remaining material is reduced in size. Once fully pyrolyzed, the diameter of a single carbon fiber is a fraction of the size of a human hair. Since a fiber that small isn’t very useful, they are bundled into groups called “tows.” A carbon fiber tow is like a string made up of thousands of carbon fibers. Tow sizes are typically 1K, 3K, 12K, and 24K. The “K” refers to how many thousands of fibers are in a tow.

The weave typically associated with the “carbon fiber” look consists of 3K tows in a twill weave. 3K makes up the majority of carbon fiber materials since it can easily be woven or spread flat into a thickness that’s convenient for making laminates. If thicker layers are required, a 12K tow might be used, or for thinner layers a 1K tow is often used. You may see some materials referred to as “spread-tow” which means that the tow has been spread especially flat to reduce the thickness of the layer. An example of spread-tow can be found in the 12K plain weave on the outside of Rock West Composites’ intermediate modulus tubes.

HOW GRADE RELATES TO TOWS AT ROCK WEST

Rock West Composites uses different tow sizes and weaves to help you identify the grade of fiber used in a tube. Tubes with a 3K twill weave are made with standard modulus fiber, and tubes with 3K plain weave are made with high modulus. As previously mentioned, tubes with spread-tow 12K weave are made with intermediate modulus fibers. 1K plain weave can be found on our ultra-high modulus tubes.

We hope this helps explain the difference between the grades of carbon fiber, and helps you spot the difference when looking for your ideal tube. Remember though, higher modulus fiber means a stiffer fiber but almost always a weaker and more brittle fiber. If you still have questions, give us a call or send us an email. We would be happy to help you select the right carbon fiber grade for your application.

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October 13, 2022

Customers routinely call Rock West to inquire about tubing materials. We tell them that we carry both carbon fiber and fiberglass tubing, then ask which material they prefer. Most already know what they want when they call, but how about you? Do you know the difference between carbon fiber and fiberglass? And do you know whether one is better than the other?

Fiberglass is definitely the older of the two materials. Its Created by melting glass and extruding it under high pressure, then combining the resulting strands of material with an epoxy resin to create what is known as fiber-reinforced plastic (FRP).

Carbon fiber consists of carbon atoms bound together in long chains. Thousands of fibers are then combined to form tow (aka strands of bundled fibers). These tows can be woven together to create a fabric or spread flat to create a “Unidirectional” material. At this stage, it is combined with an epoxy resin to manufacture everything from tubing and flat plates to race cars and satellites.

Carbon Fiber VS. Fiberglass Tubing: Which Is Better?

 

Carbon Fiber VS. Fiberglass Tubing: Which Is Better?

STIFFNESS

Fiberglass tends to be more flexible than carbon fiber and is about 15x less expensive. For applications that don’t require maximum stiffness – like storage tanks, building insulation, protective helmets, and body panels – fiberglass is the preferred material. Fiberglass is also frequently used in high volume applications where low unit cost is a priority.

STRENGTH

Carbon fiber truly shines with respect to its tensile strength. As raw fiber it’s only slightly stronger than fiberglass, but becomes incredibly strong when combined with the right epoxy resins. In fact, carbon fiber is stronger than many metals when fabricated the right way. This is why manufacturers of everything from airplanes to boats are embracing carbon fiber over metal and fiberglass alternatives. Carbon fiber allows for greater tensile strength at a lower weight.

DURABILITY

Where durability is defined as ‘toughness’, fiberglass comes out the clear winner. Though all thermoplastic materials are comparably tough, the ability of fiberglass to stand up to greater punishment is directly related to its flexibility. Carbon fiber is certainly more rigid than fiberglass, but that rigidity also means it is not as durable.

PRICING

The markets for both carbon fiber and fiberglass tubing and sheets have grown dramatically over the years. With that said, fiberglass materials are used in a much broader range of applications, the result being that more fiberglass is manufactured and prices are lower.

Adding to the price difference is the reality that manufacturing carbon fibers is a difficult and time-consuming process. In contrast, extruding melted glass to form fiberglass is comparably easy. As with anything else, the more difficult process is the more expensive one.

At the end of the day, fiberglass tubing is neither better nor worse than its carbon fiber alternative. Both products have applications for which they are superior, its all about finding the right material for your needs. Here at Rock West we pride ourselves in maintaining an extensive inventory of composites to meet the needs of each and every customer.

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October 13, 2022

Take a close look at a section of carbon fiber or fiber glass tubing or plate and you will see that the fibers go in different, specific directions. Comparing different styles of tubing you might notice that fiber direction, also known as orientation, is not always uniform. Composite tubing and plate manufacturers use different orientations depending on what they want to accomplish with the finished product.

In this post, we will explain how fiber direction influences the properties of carbon fiber and fiberglass tubing. Specific properties are often ideal for specific applications. By the end of this post you’ll know how fiber orientation affects the tube and how to pick the right fiber orientation for your project.

TOP THREE FIBER ORIENTATIONS

Fibers can be oriented in any direction between 0° and 180°, although fiber orientation beyond 90° is usually referred to as a negative angle value. For example, a 135° fiber angle is equal to a -45° angle. Most carbon fiber and fiberglass tubing on the market today utilizes a combination of two or more of these orientations:

  • 0° – Zero-degree fiber angle is the most frequently used orientation. When fibers are oriented in the direction of the load they are the strongest and stiffest. On tubing, the zero-degree direction is along the length of the tube and contributes to bending stiffness strength.
  • 90° – Ninety-degree fiber angle is used when bending both directions is required. In a tube the ninety-degree fibers are oriented in the circumference of the tube. They help keep the tube from crushing or buckling when loaded.
  • ±45° – Forty-five-degree angles are often used in conjunction with zero and ninety-degree plies to create a quasi-isotropic layup. A positive forty-five-degree layer is almost always paired adjacent to a negative forty-five-degree layer. When used on a tube, forty-five-degree layers contribute to twisting stiffness and strength.

Woven fiber is often referred to as having a 0/90 degree fiber angle since there are fibers in both directions, but in a single piece. Some woven materials can contain even more fiber directions; for example, triaxial weaves have fiber in three directions and are usually quasi-isotropic by themselves.


How Fiber Direction Influences Tube And Plate Properties

How Fiber Direction Influences Tube And Plate Properties

THE FIBER ORIENTATION’S EFFECT ON PROPERTIES

The way fibers are oriented in a carbon fiber or fiberglass layup influences its properties for making everything from tubes to space-ships. Builders must consider those properties during their design process. Below we will explain how each of the common fiber orientations affect the properties.

1. 0° ORIENTATION

If a part will only be loaded in one direction it’s ideal to have all the fibers oriented in that direction. Pultruded rod and tubing are examples of a part that contains only 0° fibers. Since most parts aren’t loaded in only one direction we need to add other angles to maximize strength. A tube that sees only bending and no twisting would still likely benefit from some additional fiber angles. Adding 90° layers helps the tube maintain its shape better so that it doesn’t buckle prematurely.

2. 90° ORIENTATION

As previously mentioned, 90° layers are often added to tubes to make them more resistant to buckling and crushing. High concentrations of 90° or “hoop” layers can also be found in pressure vessels. Since the force is trying to enlarge the tube in a pressure vessel, 90° layers resist the force best. When 90° layers are used in conjunction with 0° layers in a plate, its referred to as bidirectional. Using woven cloth can be an easy way to quickly build parts with fiber in both 0° and 90° directions.

3. ±45° ORIENTATION

 

Carbon Fiber Olates

Carbon Fiber Olates

Carbon Fiber Olates

45° layers serve different purposes depending on the application. You’ll almost always see a +45° paired adjacent to a -45° layer. This is to keep the laminate “balanced” and from forcefully twisting when loaded. When 45° layers are used in a plate that already contains an equal mix of 0° and 90° layers the plate becomes quasi-isotropic. Whereas a bidirectional plate has equal properties in two directions, a quasi-isotropic plate has quasi-equal properties in any direction. In a tube, 45° layers perform the job of adding torsional strength and stiffness. That’s because when a tube is twisted, the force acting on the laminate is actually at forty-five-degrees. Some laminates will use angles other than 45° as a compromise between bending, crushing and torsion performance. Since 0° layers aren’t possible on filament wound tubes it’s common to see 10° or 15° layers use instead.

CHOOSING THE RIGHT FIBER ORIENTATION

Now that you know how each fiber orientation affects the properties, you can choose the right layup. If you need a tube that performs in a wide variety of conditions, a bidirectional layup is ideal. If you need a tube that performs well in twisting, pick a product with more 45° layers. If you need to increase thickness quickly, a woven material might be a good choice.

Rock West Composites offers plates and tubes with layups to meet almost any demand. If you need a custom or engineered layup for your project give us a call or shoot us an email. If you have more questions about how fiber orientation affects the performance of a part, our customer service representatives would be happy to help.

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October 13, 2022

We sell carbon fiber tubing to DIY hobbyists and commercial users alike. And while we offer to cut tubes to specific lengths, we get the fact that customers sometimes have to cut tubes themselves. This post is intended to give you a starting point for cutting tubing in your own shop.

Please note that machining carbon fiber products does take practice. Whether you are cutting, drilling, sanding, etc. it may take you several attempts to get it right. You might want to practice on scrap pieces before attempting to machine parts that will be used in finished products.

Carbon Reinforced Plastic

The first thing to understand is what carbon fiber tubing actually is. A finished tubing product you purchase from us is essentially a carbon fiber plastic. The plastic component is an epoxy resin that has been cured. Carbon fiber embedded in the plastic provides reinforcement. Why does this matter?

Cutting carbon fiber tubes generates heat. Larger, denser tubes can generate enough heat to reactivate the epoxy resin. The end result is a slight melting of the plastic material that can gum up your saw. The best way to avoid this is to choose the right saw blade. You can also use a machining liquid to keep the saw blade cool.

Choose Your Blade Wisely

Fibers embedded within a piece of carbon tubing are still fibrous in nature. They haven’t been altered by combining them with the epoxy. As such, your choice of saw blades is important. We recommend staying away from a toothed blade. Why? Because fibers can get caught on teeth. This could result in significant delamination which, ultimately, compromises the integrity of the tube. Splintering is also fairly common.

Instead, a diamond coated abrasive cut-off blade is your best bet. A segmented blade will also work, and it will not generate as much heat. Regardless of the blade you choose, pay attention to its wear. The more worn your blade, the less clean your cut.

As you cut, let the blade do the work. Go as slow as necessary to prevent forcing the blade through the material. A slow and steady approach will ensure a clean cut with very little risk of delamination. On the other hand, forcing the blade through could damage the tube to the point of making it unusable.

Secure the Tube Properly

Many a cutting job has gone awry because the fabricator did not properly secure the tube in question. It is important that you limit movement as much as possible. If tubes move even a slight amount, you will not get a clean cut. If they move too much, you risk delamination and burring.

We suggest bracing the tube against a hard edge and holding it in place with a series of clamps. If you are cutting off a small piece, no additional clamps are necessary. However, consider how you secure the tube if you’re cutting a long piece into two even sections. It would be wise to secure and clamp both ends to ensure a clean cut.

Cleaning Up

Even the best fabricators do not get a perfectly clean cut every time. Sometimes you’re left with burrs or an unusually rough edge. Not to worry. You can clean up with medium grit sandpaper using a grinder or spinning the tube on a lathe.

We carry a variety of carbon fiber tubing products in different shapes and sizes. Contact us to learn more about our unidirectional and multidirectional tubes suitable for commercial and home use. We would be happy to explain the benefits of carbon fiber over steel, aluminum, and titanium.

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October 13, 2022

It was only a couple of years ago that SpaceX founder Elon Musk unveiled an all-carbon-fiber rocket body for his interstellar spaceship to Mars. Then, seemingly without warning, Musk pulled the plug on the project. He scrapped the carbon-fiber rocket body, closed the Port of LA fabricating facility, and walked away from a lease on land he intended for a full-scale production facility.

Those who follow Musk and his SpaceX exploits were shocked. They had heard for years that carbon fiber was the key to making Mars colonization possible. Learning that he was scrapping carbon fiber in favor of stainless steel was puzzling, to say the least. Well, now we know what happened. We finally know why SpaceX abandoned carbon fiber.


We Now Know Why SpaceX Abandoned Carbon Fiber

We Now Know Why SpaceX Abandoned Carbon Fiber

A Massive Transport Project

Carbon fiber was the material of choice when SpaceX first began designing its Starship (formerly BFR) rockets. The reason was simple enough: carbon fiber’s impressive strength-to-weight ratio makes it superior to steel and aluminum for massive spaceships carrying unimaginable volumes of cargo.

Understand that a single trip to Mars will take years. The first waves of colonists will not be able to rely on regular supply deliveries similar to that which the International Space Station receives. They will have to take everything they need with them. Practically speaking, you are talking massive ships carrying everything from food to medical supplies and construction materials.

Musk determined that stainless steel would be impractical for building such large ships. Carbon fiber gave him a license to think as big as he wanted. But after a few years of research, building, and testing, he finally reached the conclusion that carbon fiber was not the way to go after all.

Two Big Concerns

Carbon fiber proved to be everything SpaceX thought it would be. However, there were too big concerns. The first is temperature resistance. While carbon fiber stands up extremely well to temperature extremes here on planet Earth, it wouldn’t do so well during atmospheric reentry. It just doesn’t stand up to that much heat.

In order to make carbon fiber work for a reusable rocket, the entire body would have to be insulated. That is certainly possible to do, but it adds to the expense. It also adds to the weight. A stainless-steel rocket body would only have to be insulated on the windward half. The rest of the body would be just fine. Why? Because stainless steel is much more temperature resistant.

The other concern was cost. SpaceX determined that it would spend upwards of $130,000 per ton to use carbon fiber as the primary rocket body material. On the other hand, it would spend just $2,500 per ton for stainless steel. It doesn’t take a mathematician to figure out that spending 50 times as much on carbon fiber would put considerable strain on the Starship project.

A Long Way Off

Musk and SpaceX are now in the process of trying to re-establish production facilities at the Port of LA. Rumor has it they want to begin manufacturing stainless steel rocket bodies and other parts from that location before shipping them across the United States to other facilities. In the end, however, a viable Mars spaceship is still a long way off.

Who knows what SpaceX will learn between now and the day it is ready to launch its first prototype? By then, the cost of carbon fiber materials will likely have dropped significantly. Perhaps improvements in manufacturing technologies will have made carbon fiber as heat-resistant steel. Who knows? SpaceX could eventually scrap stainless steel and go back to carbon fiber again.

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October 12, 2022

If you understand how carbon fiber tow and fabric are manufactured, you know that it is a complex and energy-intensive process that requires aligning carbon atoms, subjecting them to high heat, and then coating them with a chemical to help resin stick.  But how do those fibers and fabrics become Shaped Tubing?

It is easy to look at a cross section of composite tubing and assume it’s a single-piece construction. The finished product certainly is a single piece, but that is only because the resin and curing process bonds everything together. That section of tubing did not start out as a single piece. It started as multiple layers of fiber or fabric that were combined with resin to create the finished tube.

There are four primary processes for creating composite tubing. These are:

 

1. ROLL WRAPPING

Roll Wrapped is typically done with a prepreg product to ensure consistency. A prepreg is a composite product consisting of fabric or fiber already impregnated with the epoxy resin necessary to hold everything together.

The prepreg material is cut into layers of different fiber orientation. Those layers are then rolled onto a cylindrical rod known as a mandrel. The mandrel and prepreg are then wrapped in a plastic film to contain the epoxy resin and compress the layers during curing. Once curing is complete, the mandrel is removed from the center of the finished tubed.

Roll wrapping results in maximum consistency across both carbon fiber and fiberglass tubing. The process also affords more customization in terms of both fiber/mandrel configuration and production quantities. Roll wrapping is the preferred process for producing small runs.

3. PULTRUSION

The Pultrusion process gets its name from its combination of pulling and extrusion principles. Where extrusion forces material through a die by pushing it, pultrusion accomplishes the same thing by pulling the material through the die. Pultruded tubing is created by pulling carbon fiber or fiberglass tow through a heated die as it is being impregnated with epoxy resin. The material is pulled over a mandrel that ensures it holds its shape during the curing process.

The advantage of this process is that it produces a continuous, unidirectional length of tubing that can be cut to size after curing. Since pultrusion is highly automated, it’s a much more cost-effective production process than both roll wrapping or filament winding. Pultrusion makes it easy to produce tubing in various lengths and thicknesses simply by changing up both mandrel and die.

The downside of pultrusion is that all the fibers are oriented along the axis of the tube. Having all the fibers in one direction means the tube is very good in tension but can easily split in compression or torsion. The quest for an automated process that can produce balanced tubes brings us to pullbraiding.

4. PULLBRAIDING

Pullbraiding is an extension of pultrusion. This process is essentially the same as pultrusion with one added feature: the fibers are braided together as they are being pulled through the heated die and onto the mandrel. Layers of different angles can be made by varying the braid, and even unidirectional layers can be inserted.

Both pultrusion and pullbraiding create finished products with high stiffness and strength-to-weight ratios. But the main advantage of the pullbraiding process is that it creates a more balanced tube that performs under a wide range of loads. It also adds an element of aesthetic beauty since the braid is more in line with the traditional “carbon fiber” look. And since this process is highly automated like pultrusion, pullbraided tubes are often less expensive than roll wrapped or filament wound products.

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October 12, 2022

Most of the customers who purchase carbon fiber materials from Rock West Composites are pros. They use what they buy from us to fabricate individual parts and finished products they intend to sell to their own customers. But believe it or not, some of our customers are DIY fabricators. Yes, DIY fabrication is entirely possible.

It is true that carbon fiber and similar composites are complex materials with a lot of science behind them. But you don’t have to go through the expensive and labor-intensive process of creating carbon fiber for your own layouts. You can buy carbon fiber sheets and prepregs from us. Rock West and our suppliers have done all the hard work for you. You take what you purchase from us and do the layup process at home.

If you are interested in learning more about DIY fabrication, there are great videos all over the internet. We found one series demonstrating how to make carbon fiber-reinforced propellers for drones. The fabricator who produced the videos started with a foam core that he then reinforced with carbon fiber sheets to create some pretty impressive props.

1. BUILD YOUR TOOL

The first step in DIY fabrication is to build your tool. In the composites world, a tool is a mold. You can build a tool in one of two ways. The first is to make a traditional mold into which you will place carbon fiber sheets in multiple layers. Once cured, you remove the part from the mold.

Carbon fiber propellers for a quadcopter drone.

The other option is to do what the drone prop fabricator did. He created a tool that acted as both the mold for his layup and the core of the finished product. Rather than laying carbon fiber sheets into his tool, he wrapped the tool with the sheets. He was left with one solid piece after curing.

2. PREPARE THE CARBON FIBER SHEETS

The next step is to prepare the carbon fiber sheets by cutting them to size and impregnating them with epoxy resin. Note that you don’t need to impregnate if you’re using prepregs. Prepreg sheets are already impregnated with epoxy.

Cutting carbon fiber to size does take some practice. One of the things the fabricator in the drone prop video does is mark his cut lines and then apply cellophane tape on either side before cutting. That way, when he does eventually cut the material, the raw edges on either side of the cut do not start to unravel. It’s little tricks like this you learn as you go.

Carbon Fiber Drone Propellers

Carbon Fiber Drone Propellers

3. LAYUP THE MATERIAL

Step number three is to layup the carbon fiber material in or over your tool. With each layer, you are going to apply additional epoxy resin to make sure the entire surface of each sheet is impregnated. A lot of DIY fabricators use a steel roller to firmly press the layers into place and simultaneously remove air. To reduce the amount of air bubbles or “voids”, it’s also a good idea to vacuum bag your layup to remove air during cure.

The number of layers necessary to complete your layup depends on the design of your part. Some parts call for more layers than others. At any rate, the final step is to place your mold in an insulated environment and apply some heat. Typical epoxies cure at about 250F, but there are also room temperature-cure epoxies available that just require a bit more time to fully cure.

What we’ve described here constitutes the basics of DIY carbon fiber fabrication. Obviously, there’s more to it as parts get more complicated. The point here was just to let you know that DIY carbon fiber fabrication is possible.

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October 12, 2022

There are numerous ways to fabricate composite parts utilizing carbon fiber and glass fiber. One method is the manual layup, a method that sometimes relies on vacuum bagging to help the materials consolidate more uniformly. Vacuum bagging is a procedure that is utilized both commercially and by DIY fabricators.

We have written this post to introduce our readers to the concept of vacuum bagging, what it does, and how it works. Note that we sell vacuum bagging kits and supplies. In fact, we have everything you need to complete manual layups at home or in your professional shop.

The Point of Vacuum Bagging

It is not absolutely necessary to vacuum bag composite parts. So why do people do it? If you were to create a carbon fiber body panel for a classic car, you would start by creating a mold, or a tool as we call it in the industry. You would then lay carbon fiber fabric on the mold and cover the fabric with epoxy resin. Then another layer of fabric and more resin, continuing until you built it up to the thickness you wanted.

At that point, you could let it cure as-is. But if you wanted to guarantee that air is removed and the resin is equally distributed throughout the fabric, you would turn to vacuum bagging. The process of vacuum bagging is intended to fully consolidate resin and fabric so that the finished product offers consistent strength and integrity throughout.

Vacuum bagging sucks all of the air out of the layup ensuring you create a part with minimal defects. The end result is a more consistent layup that cures into a more uniform part. That is really the long and short of it.

How It’s Done

The nice thing about vacuum bagging is its simplicity. It is as easy to do as it is to understand. Once a layup is complete, you apply a peel ply layer to help remove the finished part later on, followed by a breather layer that allows air to escape while simultaneously absorbing any excess resin. The entire layup is then covered with the vacuum bag and sealed around the edges.

Next, you connect hose and pump. Turning on the pump sucks out all of the air and creates a bit of pressure. From this point, you can leave the layup alone and let it cure in place or put it in an oven. In some commercial settings, the vacuum bag layup is put in an autoclave for curing.

Pros and Cons of Vacuum Bagging

Vacuum bagging offers benefits that make it the right choice for some projects. First and foremost is consistency. You just get more consistent parts this way. Another benefit is quality. If you need a high-quality part for which structural integrity is non-negotiable, combining prepregs and vacuum bagging is the way to go. The fact that the vacuum bag creates pressure on its own eliminates the need for autoclave curing in some cases (but not all) saving money by saving energy.

In terms of the cons, let us talk about pressure again. Autoclave curing relies on a combination of temperature and pressure to consolidate resin and fabric. High performance parts are typically cured in an autoclave. Thus, the advantages of vacuum bagging are diminished. With vacuum bagging, you also generate waste.

Vacuum bagging is a great practice for DIY fabricators. There are plenty of online videos explaining exactly how it’s done. In the meantime, feel free to contact us to order your vacuum bagging supplies. Don’t forget to ask about our fabrics and resin too.

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August 17, 2022

Composites are typically used as a material that is both lightweight and strong. There are many major applications composites can be used for, like marine or space technology. Even then, it is important to admire the smaller, everyday projects for which anyone can use our composites.

Meet John Kimball, our Technical & Applications Specialist. He finds joy in working with carbon fiber and likes to utilize it in his own personal projects. Ideally, he likes to create any product that benefits from not only the capabilities of carbon fiber, but its futuristic look as well. Two years ago, John started a project utilizing one of our products to create a knife, which is a perfect application for carbon fiber.

John Kimball’s Knife

He initially began this project with Rock West’s release of a new product, carbon fiber chip board, a few years ago. This chip board is known as “forged carbon” or “Damascus carbon,” which is short strands of carbon fiber pressed into a plate.He explains his creation process as, “I just dissembled the old knife and traced the general shape from the original handle pieces, then used sandpaper and hand grinders to finalize the profile. After the shape was finished, I used fine sandpaper to remove the scratches and then used a polishing compound to give it a nice smooth finish. Locating the screw holes was the most challenging part as all three holes need to meet a very tight tolerance.” Amazingly, even after two years have passed, he says the knife remains in great condition.Rock West is always encouraging engineers and DIYers alike to try utilizing composites outside of major projects. There are many simple items that could benefit from a material that is lightweight and strong, like pens, bows, or in this case, a knife.

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