FlatFiber: Advancing Polymer Reinforcement with Cutting-edge Technology

TAGS:  Polymer Reinforcement     Sustainability / Natural Solutions    

This is a sponsored article by Nittobo.

FlatFibers have long been crucial for reinforcing plastics, enhancing their strength and durability. Enter FlatFibers, a groundbreaking evolution from Nittobo. Unlike their conventional counterparts, these fibers sport an oval cross-section, epitomizing the cutting-edge of FlatFiber technology. Their unique shape offers:

• superior tensile strength,
• minimized warpage, and
• a sleeker surface finish.

By addressing the limitations of traditional fibers, especially polyamides, FlatFibers heralds a new era in plastic reinforcement.

Nittobo's innovation in FlatFiber technology brings a transformative shift from the conventional, circular-profiled fibers.
The game changer? Its distinct oval cross-section. Compared to traditional fibers, FlatFiber not only mitigates warpage but does so without compromising the inherent strengths of fiber.

Moreover, its compatibility with polyamides ensures impeccable surface quality and absence of the imperfections that are typically seen with standard fibers. The result? A superior composite material that combines resilience and aesthetics, allowing industries to elevate their offerings.

In this article, let’s review the key features and applications of Nittobo’s FlatFibers that are a cut above the rest of the conventional fibers for the future of reinforced plastics.

Comparing FlatFiber to Conventional Fibers: A Glimpse of Advantages

Superior performance of FlatFiber

Nittobo’s FlatFiber signifies an advancement in polymer reinforcement, underlined by its revolutionary design and impeccable characteristics. Drawing upon the data presented, we discern its unparalleled attributes as compared to conventional fibers.

  
A Comparison between Conventional Fibers (L) and Nittobo’s FlatFibers (R)

Enhanced dispersion and homogeneity

While traditional fibers often clump, causing uneven distribution, FlatFiber, with its unique ratio 4 (1:4), FlatFiber shape, and fiber diameter of 7 x 28 μm, ensures optimal dispersion. This uniform spread offers consistent strength throughout the material, effectively eliminating weak points.

The physical properties of Nittobo’s FlatFibers and conventional fibers are compared in the table below:

Property Name/Conditions		Unit	Method	Conventional Fiber Chopped Strand			Flat Glass Fiber Chopped Strand
Shape and flat ratio		-	-	-			Ratio 4 (1:4) FlatFiber
Fiber diameter		μm	-	11			7 x 28
Processing temperature		°C	-	235	250	265	235	250	265
Flexural strength	Molding direction	MPa	ISO	141	161	140	171	204	174
	Transverse direction			106	109	108	148	174	157
Flexural modulus	Molding direction	GPa		6.1	7.6	6	7.3	9.3	7.3
	Transverse direction			4.9	4.9	4.7	6.5	8.1	7.1
Charpy impact (notched)	Molding direction	kJ/m2		15	17	14	19	24	23
	Transverse direction			15	15	17	19	25	24

Physical Properties of Nittobo’s FlatFibers Compared to Conventional Fibers

Reduced warpage and shrinkage

Warpage and shrinkage are challenges in polymer reinforcement. Notably, FlatFiber operates efficiently at a processing temperature range of 235 °C to 265 °C, similar to conventional fibers. However, its optimized design facilitates a significant reduction in shrinkage and warpage.

Glass Flakes and Mica Fillers Reduce Warpage at the Cost of the Physical Properties of the Composite; Nittobo FlatFibers Reduce Warpage without Sacrificing Physical Properties
Fillers, traditionally in powder or flake shapes, are used to minimize warpage in composites, often at the expense of their physical integrity. Common fillers like mica and glass flakes offer limited reinforcement due to their non-fibrous structure. Conversely, FlatFibers not only mitigate warpage but also enhance the reinforcing attributes of traditional fiber.

Enhanced surface finish

The surface finish of a product is a clear indication of its quality. With FlatFiber, products benefit from a more refined and smoother surface, which is crucial in sectors prioritizing aesthetics. For example, the surface roughness of 50% FlatFiber-reinforced polyamide 6 is comparable to that of 30% traditional fiber-reinforced polyamide 6.

Optimized impact resistance

The resilience of polymer products directly impacts their longevity. When assessed for Charpy impact in both molding and transverse directions at varying temperatures, FlatFiber consistently outperforms its conventional counterpart. Specifically, at a processing temperature of 250 °C, FlatFiber records an impact resistance of 24 kJ/m² (molding direction) and 25 kJ/m² (transverse direction), compared to 17 kJ/m² and 15 kJ/m² respectively for conventional fibers.

To verify this claim, Nittobo’s FlatFiber 4 was tested against conventional fibers at two orientations 0° and 90°. A mold was formed by the injection molding machine (SUMITOMO 75MT) at injection temperatures 235 °C, 250 °C, and 265 °C. The mold temperature and Charpy impact were measured for both materials and represented with a bar graph as shown below.

Anisotropy of Physical Property

Depending upon Temperature

Anisotropy of Physical Property by Direct Injection; Physical Property Depending on Temperature

Superior flexural strength and modulus

Strength and rigidity are key performance indicators for reinforced polymers. At a processing temperature of 250 °C, FlatFiber achieves a flexural strength of 204 MPa (molding direction) and 174 MPa (transverse direction). In comparison, conventional fibers yield 161 MPa and 109 MPa, respectively.

Similarly, in terms of flexural modulus, FlatFiber exhibits 9.3 GPa (molding direction) and 8.1 GPa (transverse direction) against the conventional fiber's 7.6 GPa and 4.9 GPa, clearly showcasing its superiority. This claim was validated by experimenting with a mold of size 100 mm x 100 mm, formed by the injection molding process. The resin was made by a 60/40 ratio (by weight).

	Flexural Modulus (GPa)	Flexural Strength (MPa)

Anisotropy of Physical Property by Direct Injection; Physical Property Depending on Temperature

Optimizing costs with FlatFiber technology

Nittobo's FlatFibers present a significant advantage in terms of cost-effectiveness. Owing to their extended residual fiber retention compared to conventional fibers, they maintain superior strength even when recycled in the compounding machine. This allows for a higher regrind material ratio, offering compounders an optimal opportunity to cut costs without compromising on quality.

Leveraging FlatFiber technology allows a transition from the pricier polyamide 66 to the more cost-effective polyamide 6, maintaining superior performance. This strategic shift reduces material costs and positions FlatFiber-reinforced polyamide 6 as a competitive alternative to high-end polymers such as PEEK and PEI, delivering both quality and cost-efficiency.

Applications of Nittobo's FlatFiber Technology

Automotive industry — In the automotive sector, Nittobo's FlatFiber technology addresses the dual demand for lightweight materials that offer superior strength. Components like bumper beams and door modules benefit from enhanced flexural strength and reduced warpage, ensuring more efficient and safer vehicles.


Consumer electronics — For consumer electronics, FlatFiber promises a blend of aesthetics and resilience. Devices integrate this technology for improved surface finishes and increased impact resistance, leading to gadgets that are both visually appealing and robust.


Industrial equipment — Nittobo's FlatFiber is pivotal in the industrial realm, ensuring machinery components exhibit uniform strength and improved heat resistance. This is especially crucial for elements like gears and structural components, ensuring durability and optimal performance.


Building and construction — The construction sector leverages FlatFiber for its unparalleled structural integrity. Its reduced shrinkage property guarantees that construction materials like panels and claddings maintain their shape over time, resulting in durable, long-lasting infrastructure.

Conclusion

Nittobo's FlatFiber is revolutionizing the way industries approach plastic reinforcement. In simple terms, here's what makes it stand out. The key benefits are:

• Stronger materials - The enhanced strength ensures products are more durable and longer-lasting.
• Better looks - Achieves a smoother and more refined surface finish, perfect for industries that care about aesthetics.
• Less warpage - Helps reduce the distortion seen in some plastic products, ensuring they retain their intended shape.
• Cost-effective - With the potential to replace more expensive materials and its recyclability, it offers a cost-saving advantage.
• Eco-friendly - Its longer residual fiber retention means it can be recycled more effectively, contributing to sustainable practices.

Together, these benefits underline why Nittobo's FlatFiber is a top choice for the future of reinforced plastics.

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