Carbitex's flexible carbon fiber/thermoplastic composite panel uses innovative engineering design to eliminate design flaws in sports shoes.
Enhanced high-performance sports shoes
The carbon fiber/thermoplastic composite products of the Washington startup Carbitex are designed to eliminate the concessions made by the conflict of stability and flexibility in footwear applications.
Over the years, carbon fiber midsoles, iron cores and other components have been improving performance and reducing the weight of top sports shoes. However, the relevant person explained that even with the use of composite materials, shoe developers usually have to compromise when choosing the material for the midsole: choose between materials that are sufficiently hard. Although the feet may be inflexible, heavy, or light and soft material that does not provide sufficient support, they can support the feet during the required activities. No matter which method is chosen, or the use of a compromise material between the two, the shoes (and the wearer) are inherently inefficient. The company said that by developing a flexible carbon fiber/thermoplastic composite product line, it has been able to overcome This question.
However, relevant personnel pointed out that he did not initially intend to change the shoe industry. About 10 years ago, he learned about carbon fiber composites by working in the automotive industry. He investigated the luggage market and wondered why luggage manufacturers tried to imitate the aesthetics of carbon fiber with ballistic nylon and other fabrics instead of using real carbon fiber. As he could not find a company that could produce soft and flexible carbon fiber products suitable for the luggage market, he decided to make it himself.
Focus on footwear
In the past few years, Carbitex has released two new composite technologies called AFX and DFX. Relevant personnel believe that unlike "typical composite materials" whose stiffness is controlled by fiber orientation and layer length, the stiffness of Carbitex carbon fiber sheets is uniform throughout the length. He said that while other composite materials may be composed of a resin system and fibers, Carbitex's materials are more complex, involving complex polymer sheets and fabric layers to achieve the required flexibility. He said: "A very simple version of our AFX material might sandwich two different types of carbon fiber between another two or three different types of polymers." "This is a complex layering system. You must Learn how to merge these layers together to achieve attributes."
Generally, the manufacturing process first laminates fabric and polymer sheets that can be treated with adhesives or other fabric treatment methods into the panel. Although Khan said that most of Carbitex's products contain fibers produced by American companies and often use tow fabrics produced by Hexcel, they still use a variety of fibers from different suppliers. Polymers also vary from application to application, but are usually thermoplastic to provide flexibility and formability, "although sometimes depending on the application, it is not completely thermoplastic," he added.
The panels are merged together in a hot press; once removed, the individual parts are cut and formed by a water jet. The researchers said that compared with traditional laminates, the use of panel manufacturing instead of single-part laminates can increase yield.
Manufacturing process
First, a specific woven fabric, prepreg and polymer film layers are stacked together to form a panel.
Next, the panel is consolidated in a heating press.
Cut specific components from the cured panel by spraying water
Carbitex said that avoiding the overlapping of individual parts can increase productivity.
The resulting carbon fiber composite midsole will be assembled into the final footwear application.
However, in addition to balancing rigidity and flexibility, the development of footwear also faces another challenge: human feet can only bend in one direction without excessive stretching or breaking, so shoe materials need to bend more in certain directions. Functionality, but no flexibility in other directions. Related personnel said that Carbitex achieved this goal by controlling the bending or bending of the laminate. A related person said: "Usually in composite materials, the term "buckling" is attributed to failure, but we came up with a way to make the fiber buckle without breaking." He added that this invention was originally created by accident because A colleague realized that a certain combination of fiber and polymer layers caused a material to bend in only one direction. We realized that there must be some kind of benefit in doing this, so we started to peel off these layers, understand how it happened, and then understand how we did it purposefully.
Buckling design
According to the shape of the foot, the design of AFX material can only bend in one direction.
The resulting product is called AFX, where "AF" stands for "Asymmetrically Flexible", meaning that it bends in one direction and is completely rigid in the other direction. Carbitex's AFX product includes a woven fabric layer, a prepreg layer and at least one polymer layer between them, which are combined into one component, which is then shaped and cured. The patent says: "The layered structure has a higher resistance in the first direction and a lower resistance in the opposite second direction."
"Our technology can achieve a certain degree of rigidity and protection in the direction you want," the relevant person added. For example, a hiking boot equipped with an AFX carbon fiber midsole has the support and stiffness required to protect the foot from bending the wrong way on uneven or vertical terrain, but "when you bend your foot to be on a flat ground When walking, boots are as flexible as running shoes," he said. AFX is also lighter than wood and rubber materials commonly used to reinforce hiking boots.
The third product of Carbitex is called DFX, which is a derivative product of AFX, which stands for "dynamic flexibility", which means that the stiffness of the material in the shoe changes with the movement of the foot. With DFX, “you can have a shoe that is super flexible at certain angles, and then becomes harder or harder exponentially at larger angles,” said the relevant person. "In footwear, this is directly related to performance." DFX consists of at least three layers and cured into a laminate: an adhesive-reinforced flexible woven fabric layer; a harder woven fabric layer; at least one layer of polymer物层。 The material layer.
Related personnel pointed out that when athletes are walking on the track and field, running shoes or cleats may be soft and elastic, and then, once the runner takes off and the feet begin to bend at a greater angle, the shoes will become harder to support movement. "Companies no longer need to compromise and choose a specific midfoot hardness-we can determine the different functions of a given activity and design the corresponding hardness."
"Another way to look at it is that DFX enhances the performance of the feet, acting like muscles or ligaments, and becomes flexible or stiff depending on how they are stretched. AFX material behaves more like an elbow Or joints such as the ankle, the design can make one-way bending very well." He added.
Dynamic flexibility
In football boots and non-slip shoes and similar applications, DFX material can provide variable flexibility according to the wearer's movement.
So far, each material iteration is specifically designed for a specific performance range and a determined manufacturing integration level suitable for the industry, within this range can also be customized, such as specific rigidity or durability requirements. The company also provides customized samples to potential customers. "We continue to collect data on composite materials and how they work and why, and have established our own modeling system that can quickly convert different versions as needed. Usually, within one or two days after receiving an inquiry, we can Made customized samples and delivered them to your door.