Prepreg tape, Excellent strength and rigidity

Overview and Features
UD tape UD tape

What is UD tape?

Asahi Kasei is working to develop a broad lineup of composite thermoplastic resin materials to allow unwieldy metallic components to be replaced with lightweight resin-based alternatives.
Asahi Kasei’s UD tape (uni-directional tape, a one-directional fiber-reinforced material) is a tape-like material formed by aligning carbon fibers in a single direction, then impregnating the carbon fibers with polyamide resin. UD tape can be welded to other thermoplastic resin materials, and—when combined with the outstanding shape flexibility offered by injection molding—can be used to fabricate multi-material structures. These lightweight resin-based replacements for metallic components include components that cannot be produced by conventional injection-molding due to insufficient strength and rigidity.

UD tape

Key advantages of UD tape

UD tape boasts 4 primary advantages, all of which derive from the use of specialized polyamide resins chosen from among Asahi Kasei’s extensive catalog of engineering plastics.

Superior mechanical properties, including specific strength and specific rigidity

The outstanding mechanical properties of UD tape include excellent specific strength and specific rigidity. These properties make UD tape an ideal material for lightweight resin-based alternatives to metallic components in a broad range of product sectors: automotive components, electronic and electrical components, aircraft components, sports and leisure products, building materials, and more.

Asahi Kasei’s UD tape: Typical material properties in comparison to metals
Asahi Kasei’s UD tape: Typical material properties in comparison to metals

High impregnation of polyamide resin among carbon fibers

The specialized polyamide resin used in UD tape exhibits a crucial property: when heated beyond its melting point, it enters a state of extremely low viscosity, allowing it to flow freely through gaps between carbon fibers to achieve thorough penetration. This yields a material in which carbon fibers and resin are packed densely together in a highly monolithic structure, maximizing the reinforcing impact of the carbon fibers.


Strong adhesion

The specialized polyamide resin used in UD tape exhibits precision-controlled melting and solidification behavior. 
This ensures that, when molded products are manufactured by stacking multiple layers of UD tape in a heat press, the layers of UD tape adhere to each other with high strength. Similarly, for injection-molding processes involving materials heated to the molten state on UD tape, the UD tape adheres strongly to the injection-molding materials.

UDテープ 射出溶着性データ
Adhesion between UD tape and injection

Minimal variation in material properties upon water absorption

A drawback of typical polyamide resins is that their material properties are degraded by water absorption. The specialized polyamide resin used in UD tape is carefully chosen to minimize the extent of this degradation.

Change in material properties due to water absorption
Change in material properties due to water absorption

Molding methods for UD tape


Heat-press molding

One common molding method is heat-press molding:  Multiple copies of a desired shape are cut out from sheets of raw material, layered atop one another in a mold, heated above the melting temperature of UD Tape to yield a molten state, and then cooled under applied pressure to fuse the tape layers into a monolithic molded component.

UDテープ 加熱プレス成形
Variothermal press

To reduce cycle times for heat-press molding, a separate molded slab of UD tape can be prepared, heated via infrared heating or other methods to soften the material, and then inserted into a press mold maintained at around 80°C to yield a final molded component.

UDテープ 加熱プレス成形2
Isothermal press

Layup molding

Another approach is layup molding, in which UD tape is melted by laser heating as it is being affixed to a component. This allows the UD tape to be applied only in regions and in directions where it is necessary, ensuring efficient use of material resources.

UDテープ レイアップ成形
Layup molding

Winding molding

The method known as winding molding involves wrapping UD tape around a rotating axis while heating to melt the tape. This allows fabrication of pipes, rings, and other shapes that are difficult to achieve via press molding.  

UDテープ パイプ
High-strength pipe made with UD-Tape

Hybrid molding (overmolding)

Hybrid molding is a technique in which molded bodies made from UD tape are placed in molds before injection molding, thus yielding structurally-reinforced monolithic molded components. This is an effective way to increase the strength of molded products.

Injection-molded component with inlet reinforced by UD-tape ring
Injection-molded component with inlet reinforced by UD-tape ring

Molding components from UD tape chops

Chops are rectangular fragments of UD tape that may be cut and formed into components via press molding. This approach allows extensive shape flexibility, making it a powerful tool for producing products with complicated three-dimensional shapes.
In particular, the use of tape chops simultaneously exploits two key advantages of UD tape—the contiguity of the strength-reinforcing carbon fibers and the high fluidity of the specialized polyamide resin—to allow precision fabrication of complex components, including products with ribbed shapes and miniature gears with fine-grained blades. As an additional advantage, the high clarity of the base resin ensures that products molded from tape chops are especially attractive in appearance.

Component formed from UD tape chops
Component formed from UD tape chops

Please contact us to ask any questions, discuss any concerns, and request samples regarding UD tape.

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How Asahi Kasei’s engineering plastics help to achieve carbon neutrality.
 Asahi Kasei Group is adopting policies to accelerate progress toward carbon neutrality.
We introduce our approaches to realize circular economy through our engineering plastics.
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