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4D Printing in China: Shape Memory Polymers and Continuous Carbon Fiber

Researchers have been looking further into the benefits of shape memory polymers (SMPs) with the addition of raw materials in the form of continuous carbon fiber (CCF). Authors Xinxin Shen, Baoxian Jia, Hanxing Zhao, Xing Yang, and Zhengxian Liu have studied mechanical properties in composite samples, along with performance—outlining details in the recently published ‘Study on 3D printing process of continuous carbon fiber reinforced shape memory polymer composites.’

SMPs are a ‘hotspot in academic research’ today as scientists embrace a growing fascination with materials that can deform and return to their natural state as required by users. Refining SMPs continues also, especially with materials like carbon fibers for overcoming challenges regarding strength and stiffness. While continuous fibers have been shown to be more effective than short fibers, the authors point out that forming processes are complex, and better ways are needed for creating continuous carbon fiber-reinforced composites. Here, they turn to FDM 3D printing as a solution:

“The composite 3D printer was mainly composed of motion platform, printing nozzle, fiber feeding mechanism and control system,” stated the researchers. “Compared with conventional printers, the nozzle of this printer can feed resin and fiber from two channels simultaneously and extrude them from the same nozzle.”

Printing principle of continuous carbon fiber reinforced SMP composites.

“In addition, the fiber feeding mechanism was designed to continuously feed the fiber at a suitable speed by adjusting the rotating speed of the stepping motor to avoid breakage of the fiber during printing.”

Four ply angles of carbon fibers, (a) 0° (b) 90° (c) 0° /90° (d) ±45°.

In using orthogonal experimental design, the authors studied influences such as:

  • Printing temperature
  • Printing speed
  • Scanning pitch
  • Ply angle

Partial printed specimens with different process parameters.

In examining issues with mechanical properties further, the researchers found that the ply angle of carbon factors was a key factor. As they varied ply angles, changes in tensile strength and modulus of the specimens resulted, showing tension along the fibers at 0 degrees, but at 90 degrees it was perpendicular, opening the potential for problems with adhesion.

The study also showed that mechanical properties were more suitable at about 200℃, with excessive printing speed affecting ‘impregnation’ of fibers and resin. The authors also noted little effect on SMPs due to changes in fiber content.

SEM of fracture cross section of specimens under different temperatures

“The rapid manufacture of shape memory carbon fiber composites has potential use in the field of aerospace,” concluded the researchers.

While researchers, engineers, designers, and users around the world still may have yet to scratch the surface of the potential of 3D printing, many are delving further into the next level with materials that are able to morph to their environments, from soft actuators to 4D printing with wood composites, to exceptional new metamaterials.

Find out more about carbon fiber and SMPs here. What do you think of this news? Let us know your thoughts! Join the discussion of this and other 3D printing topics at 3DPrintBoard.com.

Shape memory performance test with different fiber contents.

[Source / Image: ‘Study on 3D printing process of continuous carbon fiber reinforced shape memory polymer composites’]

 

The post 4D Printing in China: Shape Memory Polymers and Continuous Carbon Fiber appeared first on 3DPrint.com | The Voice of 3D Printing / Additive Manufacturing.

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Dan Wellers, Digital Futures Lead at SAP “3D Printing will Expand into 4D Printing”

We’re seeing an increased focus by software firms in our teeny tiny industry. Simulation, PLM, CAD, the Digital Twin, Industry 4.0 have some very large and influential firms salivating about that peanut butter and jelly sandwich that is the combination of the digital and manufacturing. If we are to grow digital manufacturing and 3D printing then our soft and hard assets will have to be managed and controlled through software. The more conventionally manufactured parts we replace with 3D printing the more files, settings, and process information will have to be monitored and accessed through software packages. This in part explains Dan Wellers’ interest in 3D printing and enthusiasm around the technology. He leads Digital Futures at SAP Global Marketing where in effect he has to be SAP’s Nostradamus and predict the impacts of technologies such as ours.

What is 4D printing?

Building upon existing 3D printing technology, 4D printing uses dynamic materials that perform differently when they encounter changing conditions such as water, light, heat, or electrical current. These materials—hydrogels, shape memory polymers, carbon fiber, custom textile composites, and more – have properties that enable objects to self-assemble, reshape themselves, or otherwise react to changing events or conditions. It’s called 4D printing because it incorporates what’s often referred to as the fourth dimension: time.

Why is it important?

4D printing can expand what is currently achievable in prototyping, design, manufacturing, and post-production adaptability and usage. Examples include: self-flattening boxes to be used in warehouses and logistics companies; plumbing system pipes capable of changing their diameter in response to flow rate or water demand. 4D printing has opened up entirely new innovations, such as medical implants made of dynamic biomaterials, which are already saving lives.

Because of its self-assembling capability, objects too big to be printed via conventional 3D printers can be compressed for printing and then expand after manufacturing. 4D printing could also be used to eliminate the mundane problem of furniture assembly. In addition, researchers have demonstrated how smart materials used in 4D printing can enable an object to “remember” its shape. That capability could be used to flat-pack a self-assembling shelter that springs into place after a natural disaster, or develop bridges and temporary roads made from materials that expand to heal damage and cracks.

How important will 3D printing be?

3D printing represents the digital transformation of both design and production in the manufacturing industry and will have a profound impact on everything from logistics to extended supply chains to trucking. 3D printing eliminates many of the design and production constraints inherent in traditional manufacturing. Product design can now be optimized for customer need and function, instead of production efficiencies.

Over the last few years, 3D printing has advanced in the way it employs different materials—not only plastic, but also metal, resins, sandstone, wax, and ceramics—increasingly incorporating multiple materials at once. These improvements are paving the way for significant benefits, including cost reductions, streamlined supply chains, faster time to market, increased personalization, optimized resource usage, improved prototyping, and the manufacture of new designs not possible in the past.

Commercial applications continually emerge to power 3D printing of everything from everyday household products to customized medical devices and prosthetics to nearly all the components of a house. 3D printing will expand into 4D printing in the coming years by adding a fourth dimension: time. By using specially engineered materials that perform differently when they encounter changing conditions, 4D printing promises to further shift the shape of manufacturing.

How will people and machines work together in the future?

Artificial intelligence is getting better at solving increasingly complex problems. If we want to retain humanity’s value in an increasingly automated world, we need to start recognizing and nurturing skills that are uniquely human.

To learn more, read “The Human Factor In An AI Future” and “Human Skills for the Digital Future”.