Infusion-Test Panel and Fuselage
Ran across an interesting Youtube video demonstrating an epoxy resin infusion process on some test panels and fuselage. It is interesting how everybody has their own terminology and technique for resin infusion. There is definitely more than one way to get the job done.
They use an interesting layup, including lots of the Soric material. I have used this before, and it is a good material to infuse with. Made by a company called Lantor, it is a non-woven polyester material that acts as a core material. It appears that the folks in the video are using the SF grade Soric, which comes in several thicknesses.
An advantage of using Soric as a core is that it flows resin very well for infusion. It is easy to cut and handles well.
Disadvantages also abound. One of them is the possibility of print-thru on the surface of the laminate. Another is the negative effect on the structural properties of the laminate. This non-woven material does not have much crush resistance such as a balsa or foam material. A serious issue that I have found is the higher risk of delamination. Like any core, this material works by separating the two skin layers to create a sort of “I beam” effect. The problem is that this material is not inherently strong within itself. Though it does become saturated with resin during a proper infusion, it is not nearly as strong as glass or carbon fiber reinforcement.
As the video demonstrates, a proper resin infusion can look easy. With proper materials, practice, and knowledge it can be.
NASA Composite Crew Module
NASA, the space agency for the U.S. government, has investigated the use of advanced composites for use in future vehicle programs. The Composite Crew Module (CCM) has been designed and built as a travel vehicle for astronauts in future space programs to travel. Drawing parallels to the Apollo program, this module will be launched on a rocket and break away as a module.
This technology and material are undergoing testing and evaluation before it is officially accepted for the Orion program. As a partnership between government agencies and public companies, this technology aims to reduce weight and improve performance of the manned vehicles.
From NASA’s website “Led by the NESC, the project team is a partnership between NASA and industry, including design, manufacturing, and tooling expertise. Partners are civil servants from nine NASA Centers – ARC, DFRC, GRC, GSFC, JSC, JPL, KSC, LaRC, and MSFC; the Air Force Research Laboratories; and contractors from Alcore, Alliant Techsystems, Bally Ribbon Mills, Collier Corporation, Genesis Engineering, Janicki Industries, Lockheed Martin, and Northrop Grumman. The CCM team operates in a virtual environment, electronically connecting participants across the country.”
This full-scale structure has strain gauges attached to monitor loads on the structure. It was announced on January 25 that it has passed a battery of stress tests to prove viability.
The structure appears to be made with carbon fiber materials, maybe with some graphite reinforcement and an epoxy resin system. Mention of aluminum honeycomb can be found in the online reading materials. The main pieces are autoclaved, while bonding of the large sections (upper and lower shells) is accomplished outside of the autoclave.
Composites technology is being developed for future space exploration structures and vehicles, and this is good news for the composites industry!
Liquid Bulk Transport Tanks
Lincoln Composites has introduced their Titan™ Liquid Bulk Transport tank. This unit is comprised of four composite tanks that meet the specifications of a universal shipping container, allowing for transport via ship, rail, or semi on existing infrastructure.
TITAN Gas Transport
The tanks are require three basic parts to complete the engineering challenge. An inner liner made of High Density Polyethylene provides an impermeable layer to hold the gas. Next, a filament-wound composite shell made with epoxy and carbon fiber contains the pressure of the gas. A Polyurethane coating on the outside of the tank protects from moisture and abrasion.
The system is designed for Natural Gas, Hydrogen, Argon, Helium, Nitrogen, etc. Existing transport via semi truck is accomplished with large steel-tanked semi trucks that are heavy and prone to corrosion. The TITAN composite solution allows for multiple transport options (rail, ship, semi) as well as lower tank weight. The gas stored versus the tank weight is a huge advantage over steel tanks.
Lincoln Composites claims that traditional steel tanks hold 4000 SCM less CNG than the TITAN™ and weigh 16,000 kg more than the TITAN™ composite tanks.
For more information, check out the Titan page at Lincoln Composites.
Moldless Car Body
Building a custom car body with fiberglass can be achieved without using a mold! This will be a truly custom, unique vehicle. It will take lots of planning and hands-on work, but is very possible as shown in these YouTube videos.
There of course are several ways to go about building a basic structure to use for the basic shape. This video gave lots of good ideas and examples of materials that are relatively inexpensive.
The second part of the video shows some of the actual fiberglass work. This video of less than eight minutes does not nearly do justice to the amount of work and effort that went into finishing this project! It was great that the author documented his work and shared with all. This was a major project that is not for the faint of heart.
He does a very good job explaining the process and materials used in this construction. Every project is unique, however. When discussing the thickness of the fiberglass skin, there are many variables that determine the finished strength. The number of layers to use is dependent on the amount of underlying support structures, part geometry, and required load bearing capacity of the structure. Some areas may need to be stronger for impact resistance and structural loads.
The video author discusses only using epoxy resin with Styrofoam as opposed to polyester resin which will react with the Styrofoam. Polyester resin can be used if separated from the Styrofoam with an additional layer. While I have only seen it advertised, there are new spray on primer materials available to cover the Styrofoam and allow polyester resins to be utilized afterward.
IH Hood Video
Several other posts have documented the work I performed on my 1993 International Truck Hood. I also took some video and recently got it all put together and posted on Youtube. Hopefully you can learn a couple of things.
The SMC hood was ground in preparation of work, and then I used epoxy and fiberglass to complete the work and restore the structure and shape back to original for this truck hood.
Boeing’s 787
Boeing’s 787 will be the first composites-intensive commercial airliner. Traditionally made from aluminum, carbon fiber composites will work to create a plane that is stronger and lighter with fewer manufactured parts. Carbon Fiber reinforcement with Epoxy resin will be the main construction of these composites, which will make use of an autoclave during processing to control the molding conditions and ensure the quality and durability of the laminate.
Composites will reduce the number of parts for the airplane, and Boeing predicts that the front section alone would normally require using 1,500 sheets of aluminum, which also means drilling between 40,000 and 50,000 holes for the nuts and bolts to attach these sheets together and to the underlying framework. Carbon Fiber composites will allow for the skin and underlying supports to be molded as one large piece. Boeing predicts that assembly line time will be reduced from about three weeks to attach all of this aluminum together to about 3 days to attach the large composites sections together for the entire plane fuselage.
Switching materials has its’ own set of problems to overcome. The customers’ mechanics will need to be trained to repair damage on these composite planes. Damage detection will be important as well. Some will be visible to the naked eye, and other damage will not. Several forms of Non Destructive Testing will be employed to test for damage and wear on the composites body to ensure a safe aircraft.
Composites have been used in aircraft before, but not as extensively in commercial airplane bodies. Existing commercial airplanes have made use of composites in other areas to help make the planes stronger and lighter. Military jets have used carbon fiber composites for many years in their technologies for strength and weight advantages. Private business jets have utilized fiberglass composites for many years in their construction. Homemade kit planes have also made extensive use of fiberglass to make inexpensive craft in personal shops.
The profile of carbon fiber composites will definitely be elevated if Boeing’s 787 becomes as successful as promised.
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