Walkerton, Ind.βPolygon Co. has announced their new pneumatic cylinderΒ known as Constrained Tube Technology (CTT). CTT is a complete pneumatic system thatΒ allows the composite tube to be fitted within the confines of a thin-walled outer host. TheΒ composite tube carries greater than 90% of the pressure vessel loads while the metallic hostΒ enables traditional assembly techniques such as welding, threading, retention rings, etc.
A housing must be used to handle the additional pressure load for the complete tubeΒ assembly.
βHousings can be 80/20 aluminum or other machined metal. It could be anyΒ material, even a wooden box,β said Paul Lashbrook, lead CTT engineer.
Containing housingsΒ do not need to be cylindrical nor do they need to be honed or plated, and can even be a lowgradeΒ steel.
βThe housing provides a durable casing for CTT, supporting and protecting the lightweight cylinder,β Lashbook said.
The CTT cylinder is an entire thin-walled actuator system utilizing a new end cap attachment system.Β The approach enables the design engineer to achieve the benefits of composite cylinder tubing such as corrosion resistance, improvedΒ seal life and unique fluid flow properties without manufacturing assembly changes.
For non-housed units, lower cost polymeric cylinders can provide the needed structure. βIn traditional cylinders, the metal walls provideΒ both pressure containment and structural strength. With CTT, the inner composite sleeve does all the load work while the thermoplasticΒ outer tube and connection elements provide seamless and cost-effective assembly,β said James Shobert, Polygon Co. CEO. EndΒ caps can be fitted to secure the host tube and provide a very traditional cylinder outline for non-housed units as illustrated. This blendsΒ the high performance characteristics of advanced composites with the durability and economics of standard polymeric materials.
One consistent Achilles Heel of retrofitting composites into existing applications is being able to assemble the finished product usingΒ traditional metalworking techniques. Composite cylinder tubing cannot withstand drilling and maintain structural strength. This limitedΒ previous composite tubing to tie-rod cylinder applications almost exclusively. CTTβs tubing is not immune to this attachment problem.Β However, the required housings can be chosen to provide ample attachment points for mounting the assembly.
CTT has surpassed 27 million cycles under elevated testing pressure and is the perfect solution to demanding pressure vesselΒ applications. Balancing performance and cost, it is uniquely suited for todayβs lean operational environments.
