The expanding market for plastic tubes is projected to grow to $1.56 billion by 2031 with a five per cent compounded annual growth rate (CAGR). This represents an immense opportunity for industries to switch to small-diameter composite tubes, renowned for their strength, durability and versatility across industries. Here, Lauri Turunen, product business owner for tubes and telescoping poles at composite manufacturer Exel Composites, explores the pivotal role of pull-winding in shaping small-diameter tubes, their remarkable resilience, and the future of these tiny-tubes.

Small-diameter tubes are integral components in diverse industries, offering lightweight yet resilient solutions tailored to specific applications. In robotics, these tubes form articulating arms and manipulators, providing high axial stiffness for precise movements and structural integrity essential for intricate tasks.

Similarly, in drones, they serve as lightweight yet sturdy frames, enabling agile flight maneuvers and payload management while withstanding dynamic forces. Customizable to meet design needs, the tubes find applications in both hobbyist drones and commercial UAVs for tasks like aerial surveys and package delivery.

Precision instruments, such as surgical robots, also rely on small-diameter tubes for stability and support during delicate procedures. Their role in maintaining rigidity minimizes vibrations, ensuring surgeons perform surgeries with precision and safety. Across these applications, small-diameter tubes strike a balance between weight and strength. This versatility highlights their ability to enhance performance and efficiency across industries.

Composite materials offer several advantages over traditional materials. Their superior stiffness and strength-to-weight ratio make them ideal for applications requiring lightweight yet robust solutions. To put it into perspective, glass fiber composites have a density of 2g/m3 compared to aluminum’s 2.7g/m3, making it almost half the weight of aluminum while maintaining a similar mechanical strength. Carbon fiber, on the other hand, has a density of 1.55g/m3, with a much greater strength and stiffness than aluminum or glass fiber composites.

Continuous manufacturing technologies like pultrusion and pull-winding offer significant benefits for small-diameter tube production. Pultrusion typically results in wall thicknesses of two millimeters and above, whereas pull-winding, a form of continuous filament winding, can achieve much thinner walls, as thin as 0.5 millimeters.

Pull-winding involves the simultaneous application of resin and reinforcement fibers, such as glass or carbon fiber, onto a mandrel. As the crosswinder winds fibers helically around the static mandrel, a composite material is formed, exhibiting augmented strength and resistance to bending. Additionally, axial fibers along the length of the small-diameter tube ensure the mechanical integrity of the tube and, together with wound transverse fibers, gives the possibility to optimize the structure of the tube while concurrently reducing both weight and material usage. This combination of techniques ensures a high output rate and consistent quality, making pull-winding an ideal choice for industries requiring lightweight yet durable solutions.

Small-diameter pull-wound composite tubes offer tailored solutions across industries, including robotics, aerospace, and medical technology, meeting specific client needs with customizable parameters for the specific application. This adaptability ensures tubes are precisely suited for each application, from precise movements in robotics to agile flight maneuvers in drones.

Quality control is paramount throughout manufacturing. Rigorous measures ensure reliability and consistency, with advanced testing techniques verifying dimensional accuracy, mechanical properties, and adherence to any industry standards. This approach guarantees that tubes meet or exceed performance expectations.

The future of composite tubes

As Industry 4.0 continues to revolutionize manufacturing processes, the demand for lightweight yet durable materials, such as small-diameter tubes, is expected to soar. Small-diameter pull-wound tubes offer exceptional strength-to-weight ratios, making them ideal for applications in robotics and automation. These tubes provide the structural integrity needed for precise movements and intricate tasks, contributing to the efficiency and flexibility of automated systems. As industries increasingly adopt robotics and automation technologies to enhance productivity and reduce costs, the role of small-diameter tubes in driving innovation and efficiency is poised to expand significantly.

Small-diameter composite tubes, often underestimated, prove their might across industries, whether it be in robotics, medical science or even in drone design. It’s clear to see that good things truly come in small packages and may even be delivered by a drone made of composite materials.

To find out more about pultruded and pull-wound composite tubes and the engineering solutions they present to common problems, visit and enquire about how these tubes can be used in your industry.

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