Polyolefin Fibers

Polyolefin fibers are used in a wide range of applications. The most common material for such fibers is low melt Polypropylene. Polypropylene is the fourth most commonly used material for fiber production after polyester, nylon and acrylic fibers. Unlike polyester and nylon fibers that are used in the apparel textiles, Polypropylene fiber is used in industrial applications and non-woven textiles. 

Picture: Example of Polypropylene non-woven material that many people are familiar with

They are very diverse, with uses in several industries including but not limited to:

Carpet industry - These fibers are used as the primary material for most of today’s carpets as they are durable, strong, and suitable for a home environment.

Hygiene and Health Care – These fibers are used in tissue production and health care such as sterilization wrap – typical non-woven applications.

Agriculture and gardening - Agrotextiles are materials with applications in the agriculture and gardening industry. These materials, commonly made of polyolefin fibers are developed for their permeability to air, water, chemical treatments, and insulation while maintaining strength and barrier properties. The most common example of an agrotextile is the material you put in your garden allowing the plants to grow while keeping the weeds under control.

Civil engineering - These fibers are often used in geotextiles, civil engineering material designed for separation, filtration, drainage, and reinforcement. Geotextiles are commonly selected for their puncture resistance, tensile strength, permeability, and frictional resistance.

Building industry - Used as membranes under roofing for their insulating and waterproof properties.

Challenges

While Polyolefin fibers vary greatly in use, one common problem for recycling polyolefin across all sectors is spinning oil. Spinning oil is introduced in the manufacturing process of the fibers as they are spun and is particularly difficult to recycle back to the beginning quality. Efficient degassing is the best way to ensure full removal of the oil and in turn the best product quality. In this process, the majority of the spinning oil is extracted in the pre-conditioning unit of the Intareama machine.

In the case of agricultural film recycling the system must be able to deal with sand contamination. Melt filtration comes into play to ensure that non-plastic particles are removed as well as possible prior to introducing the recycled pellets into a new manufacturing process.

Recycling non-woven textiles such as the sterilization wrap used in hospitals provides additional challenges to ensure recyclers personal are not exposed to biohazards. Key is having the right process in place to ensure such.

While there are challenges from a processing, contamination and material handling point of view – I want to stress that all of these can be resolved. Polypropylene fiber materials can be recycled, it is just important to choose the right configuration of system and process control to enter these materials into the circular economy.