Natural Fiber-Reinforced Composites

Natural Fiber Reinforced Composites Sustainability is becoming increasingly important in our world due to the climate crisis we are facing. As this concept gains significance, many chemical companies are working towards more sustainable production and materials. In this regard, by choosing recyclable materials, they reduce energy costs while achieving environmentally superior products. More environmentally friendly and sustainable solutions exist for composite materials created by combining multiple materials, and therefore interest in natural reinforced, more eco-friendly composites is steadily increasing. In composite materials created by combining multiple materials, natural products also emerge. Natural materials are biodegradable and recyclable because they decompose in nature. In this article, we have compiled the properties and applications of natural fiber reinforced composites, whose use is increasing. One major reason for high usage rates of natural fiber reinforced composites is that they are stronger when compared to fiberglass. At the same time, composites produced using natural fibers are lighter, thereby providing savings in terms of energy consumption. These composites, also referred to briefly as NFC, have significantly lower production costs compared to fiberglass. The primary reason for this is that NFCs can be molded more easily than fiberglass. However, besides these positive properties, disadvantages that NFCs possess, such as moisture sensitivity, have limited their use and the development of the NFC market. Looking at applications, we can say that these materials are mainly utilized in the interior parts of automobiles. At the same time, since they provide sound insulation, they can be used in this area as well.

Wood

When producing natural fiber composites (NFC), wood, cotton, flax, kenaf and hemp are mostly used. Looking at conducted research, in 2015, wood was used at 59% as a natural fiber and held market dominance. The primary reason for wood being the most commonly used material in NFCs is that it is more robust and durable. According to research, due to these properties, this trend is expected to dominate natural fiber composites through 2024.

Flax

Another commonly used material in NFCs is flax. Flax's market share in 2015 was 13%. The primary reasons for widespread flax use are that it reduces vibrations, has high tensile strength and can block ultraviolet rays. Another property with its contribution to sustainability is that it does not emit carbon dioxide. Due to these advantages, flax reinforcement is used in NFCs.

Cotton

As is known from composites, they are utilized in many sectors, one of which is textiles. In NFCs used in textiles, cotton is mostly used. The advantage of cotton is that it has high moisture absorption properties, but compared to other materials, its durability is lower. With the increase in the use of composites in the textile sector, it is thought that the use of cotton as natural fiber reinforcement will also increase.

Kenaf

Kenaf may not be familiar to many people when mentioned. Kenaf fiber is a soft bast fiber obtained from the kenaf plant. The use of kenaf is steadily increasing in sectors such as construction, food packaging and automotive. This material is sustainable and easily recyclable. This has been a primary reason for the increase in kenaf use in recent years. The increasing demand for biodegradable products has also increased the use of kenaf.

Hemp

Hemp, which is biodegradable in nature, is also frequently used in natural reinforced composites and is particularly used in the automotive and construction sectors. It is even thought that it could replace fiberglass in the future.

Applications of Natural Reinforced Composites

Looking at the sectors where NFCs are used, we see automotive, construction, electronics and sports products, and textiles. Specifically, NFCs are utilized in door panels, seat backs, coverings and windows. Again, it is thought that the use of NFCs in sports and electronics sectors will increasingly grow.

NFCs in the Automotive Sector

As mentioned above, natural fiber reinforced composites are frequently utilized particularly in the automotive sector. The primary reason for this is that this material is both sustainable and lightweight. Due to its lightness, it helps reduce automobile weight and thus provides fuel savings and helps reduce CO2 emissions. In NFCs used in the automotive sector, wood fibers, flax and hemp, and cellulose are mostly used. The use of these materials in production processes also relatively reduces costs.

NFCs in the Construction Sector

The primary reason for preferring NFCs in the construction sector is again that they are biodegradable. Appearing as a sustainable alternative, NFCs offer advantages such as crack and impact resistance and flexibility. Again, compared to synthetic and metallic fibers commonly used in the construction sector, they are lower in cost.

Sound and Thermal Insulation

Particularly in the structure of flax and hemp fibers, there are cavities called lumens. Due to these cavities, the fibers have both low weight and provide sound and thermal insulation. Fibers from flax and hemp fibers, which can particularly be used in sound insulation, have properties of making sound wave movement difficult, providing less sound wave movement and absorbing sound waves through their pores. In sound insulation, textured and porous products are generally preferred. For this reason, flax stands out. To create a more sustainable alternative, flax fibers that are unsuitable for use in the textile sector or that emerge as waste as a result of textile processes can be used. When the sound insulation performance of natural reinforced composites is evaluated, it has been determined that they show high performance in terms of sound transmission loss but have low performance in terms of sound absorption capacity. Again, looking at the performance of flax fibers, it has been determined that they are successful in absorbing impact-induced sounds but are not as successful with airborne sounds. For the sound insulation performance of composite panels produced with flax reinforcement to increase for airborne sounds, they need to be used together with porous structures or in various geometric forms. It is thought that with sectors turning towards sustainable choices, an increase will be observed in the use of natural reinforced composites. Currently, NFCs used particularly in the automotive and construction sectors may also be used in other sectors with this increase. As a result of further research, this biodegradable material could be utilized more frequently. Bibliography Compiled by: Nilsu Kotil