Top 10 Research Papers on Hemp Fiber & Composites


During the last few years, the need to protect our environment has become a major concern on a global scale.

Our planet is dying. Yet, we continue to exploit the few resources we have left.  

The aggravating need to protect our future has led researchers to study natural, eco-friendly resources like hemp.

Hemp is a low input, high-yield crop which has the potential to save our future. Each part of the plant has some commercial use. Compared to its widely cultivated alternatives, it is sustainable and can be cultivated on infertile lands. 

So, what role can you play to facilitate this shift to hemp?

As a consumer, I encourage you to look for hemp-based alternatives to your usual everyday products. This creates a market that the producers will want to sell to.

However, producers and consumers need reliable information to produce/purchase the best possible commodity.  

If you want to gain insight into what the leading researchers and institutions are saying about the properties of hemp and how you can use it, read on.

To tap into a market, like hemp, you must rely on credible research. 

I have outlined some useful insights from research papers that can prove beneficial to you. 

  1. Use woven hemp fiber for composite reinforcement to provide strength

Did you know that plant fibers are used in composite material components?

What if I tell you that the potential of these plant fibers can be enhanced by using hemp fibers? This applies to the composites that use aligned fibers.

This paper has used two different batches of woven hemp fabric with similar quality and physical properties. And concludes that both woven hemp fabrics are suitable for composite reinforcement.

If we use hemp fibers for composite materials, we can enhance the fiber alignment and reinforcement handling during the composite fabrication. Reinforcement constituents provide strength to the composite. 

Read the paper here: URL

  1. Use ammonia on Hemp Fabric to reduce washing shrinkage and increase moisture regain

In this experiment, designed and sourced hemp ramie and linen fabrics were treated with liquid ammonia. The fabrics were saturated with ammonia for 2 seconds and dried on steam cans, during which residual ammonia was removed by hot water. After this, the Resin treatment was performed.

The treatment with liquid ammonia increases wrinkle recovery in the fabrics. Hence, if you use a fabric like hemp, it will not wrinkle easily in wet conditions and maintain its appearance.

You can also use the ammonia treatment to reduce washing shrinkage. 

Liquid ammonia treatment increases the cantilever bending stiffness of hemp, ramie, and linen fabrics. However, the resin treatment decreases it. You can determine the fiber rigidity by the bending modulus. 

You can use ammonia to increase the moisture regain of hemp. It also makes the fabric more breathable.

If you use the resin treatment for cross-link finishing, the tear strength of the hemp fabric increases. 

Read the paper here: URL

  1. Use hemp fabrics for composites instead of flax cross-ply laminate

Till today, the field of bio-based composite materials mainly focuses on the use of unidirectional reinforcements. 

Unidirectional reinforcements use fibers that run in one direction only. 

Use of woven fabrics like hemp is still complex because of the finite length of plant fibers and the high number of process parameters that can be tuned. 

However, by not using hemp fabrics, we are missing out. 

This paper outlines how the weave pattern and process parameters influence material properties at different scales.

The use of X-ray nano-tomography shows us that hemp fabric can achieve better results than its alternatives, especially the front-runner flax cross-ply laminate.

Woven hemp fabric can give us tensile properties in bio-based composite materials. We just need to use the hemp fabric made from low-twisted rovings. 

Lower twist rovings also provide better draft performance due to less fiber-to-fiber friction. 

Read the paper here: URL

  1. Use hemp fiber reinforced unsaturated polyester composites for use related to room temperature water

In this experiment, they subjected hemp fiber reinforced unsaturated polyester composites to water immersion tests. This enabled the study of the effects of water absorption on the mechanical properties of this composite. They conducted the experiment with both, room temperature and boiling water.

When hemp fiber absorbs room temperature water, moisture intake increases. This happens due to increased voids and cellulose content.

We find that when hemp fiber comes into contact with boiling water, water uptake behavior is radically altered. This is because the moisture causes degradation of the fibers. 

However, if the fabric is exposed to moisture there is a significant drop in tensile and flexural properties.

Hence, if we want to use the composite material for situations that come into contact with boiling, instead of using hemp fiber, we should use an artificial source. 

If our use for the composite is related to no or room temperature water, we can use hemp.

Read the paper here: URL

  1. Use Sambucus plant for dying 100% hemp fabric

Previously, natural fibers like hemp were dyed with natural dyes. However, today they have been replaced by chemical dyes. This study examines the use of natural dye obtained from Sambucus Ebulus L. plant for dyeing hemp fabric.

The study uses 100% natural hemp fabric. This fabric is dyed with 15 different concentrations of 3 different mordant substances, one of which was natural.

You may already know that synthetic dyes cause immense harm. However, metal salts cause much more damage to your health and the environment. 

This environmental harm has piqued the interest of consumers and researchers to look into alternative natural dyes. 

As per the results of the experiment, we see that the best dyeing features were obtained using Quercus Aegilops natural mordant in 15% concentration. 

You can obtain a natural dye and natural fabric by this method. 100% hemp can be dyed with Sambucus with minimum color difference and maximum color efficiency. 

Read the paper here: URL

  1. Treat woven hemp fabric with Francium and a combination between Sodium Hydroxide and Francium to improve its fire-retardant properties.

In this paper, Woven hemp fabric was treated with sodium hydroxide, commercial flame retardant chemical, and a combination of both to increase its fire-retardant properties. 

As you might already know, the fire retardant properties of materials have become an important issue nowadays in many industries. The textile industry is no exception. 

This paper gives you insight into which treatment should be applied on wove hemp fabric, commercial fire retardant, sodium hydroxide chemicals, or a combination. 

For the best results, treat the fabric with Francium and a combination of Sodium Hydroxide and Francium. This alters the physical properties of hemp. The densities increased from 1.47 to 1.53 g/cm3 depending on the treatments. The fabric also shrunk within the range of 1.67 to 5% and 0.67 to 3%.

Although this method reduces the mechanical properties, it improves the fire-retardant properties.

Read the paper here: URL

  1. Use hemp fabric to increase the tensile strength of pure polypropylene for semi-structural applications

This study examines hemp fabric reinforced polypropylene composites. The process used to make the composite was film stacking. The study proves that we can use woven hemp fabric to create high-performance polypropylene composites.

We can use this in semi-structural applications such as automotive or aeronautical interior parts. 

The polymer matrix composites that are currently used are highly prone to internal damages such as those caused by low-velocity impacts. 

We can use hemp fabric to increase the tensile strength of pure polypropylene by 38%. These composites are also low weight, have energy-absorbing capabilities, and are environmentally friendly.  

Read the paper here: URL

  1. Use Hemp Fiber Reinforced Concrete Composites for applications like pavements

This research examines the mechanical and physical properties of hemp fiber reinforced concrete. The influence of these factors- mixing method, fiber content by weight, aggregate size, fiber length on the composite was also studied. 

Natural fibers like hemp vary in properties more than steel or glass fibers, which results in variations in concrete quality.

What we can get from hemp fiber is high tensile strength and a strong tolerance for an alkali environment. Hence, it can be useful as a concrete composite. 

When we add hemp fiber into the concrete matrix, there is a linear reduction in the specific gravity and the water absorption ratio of the HFRC.

Regardless of the mixing method we use, compressive strength of the HFRC is weaker when compared to the conventional concrete.

However, we can still use this composite for applications like pavements. Wet mix has a more positive influence on the composite’s flexural properties (flexural 

strength, toughness and toughness index).

Read the paper here: URL

  1. Use hemp fiber instead of glass fiber composites for better endurance 

This paper studies the fatigue properties of nonwoven randomly oriented short hemp fiber mat and chopped strand mat (CSM) glass fiber reinforced polyester composites in tension.

Fatigue property refers to the stress/ endurance limit of a material. 

Hemp fibers have poor absolute strength. However, the fibers exhibit less fatigue sensitivity than CSM glass fiber composites. 

Hemp fibers show little change in stiffness before sudden brittle fracture.

We can use hemp fiber composites instead of glass fiber composites. Especially, where components are subjected to fatigue loads but the stress levels are of moderate value.

Hemp fiber composites were better at resisting crack formation and growth than glass fiber composites.

Read the paper here: URL

  1. Use different types of hemp for insulation depending on wall types and weather conditions

The paper studies the hygric properties of five hemp insulation materials commercially available. Hygric refers to moisture-retaining capacities. 

The hemp fiber content varies between 30% and 95% in the total fiber content of the insulation materials examined.

We need to understand the hygric properties as it affects heat flux, heat capacity, condensation, mould growth and structural integrity.

The hygric properties of the hemp insulation materials could vary widely. It depends on the constituents and fibrous structure. 

With the relatively dense hemp insulations, we get less standard deviation in adsorption capacity. And, with hemp insulations of relatively lower density, we get a higher standard deviation in adsorption capacity.

Once we identify the key hygric parameters, we can explore the suitability of these insulation materials for different wall types and weather conditions. We can always optimize these materials based on initial results

Read the paper here: URL



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