EP7: Alexandra Deraeve, HOGENT, Hemp as a driver for circularity in fashion

In many industrialised countries, there is renewed interest in hemp as sustainable textile fibre from a perspective of bio-renewability, circularity, and local (European) cultivation. The range of hemp products in textile and fashion is expanding.

However, the origin of commercially available hemp products is not always transparent and often involves Asian imports. The revival of locally harvested hemp fibres is still being held back by the fact that no homogeneous fibre quality can be guaranteed.

With the projects Eigen Kweek and Hemp4all, HOGENT wants to tackle the problems and support the revival of hemp as a circular driver for the textile and fashion industry.

During this Ellie.Talk Tex, expert Alexandra Deraeve of HOGENT talks about the projects set-up, the findings, and perspectives for the future.

Key Take-Aways

HOGENT is involved in different projects around the optimization of hemp cultivation. For the cultivation and fiber extraction part, they work closely together with the Agrifood Nature Research center.

How Green is your closet?

Materials:

• Look at the clothing you’re wearing today, chances are high you are wearing cotton, polyester, or a blend of both.
  • Synthetics account for 60% of the raw materials used in the textiles sector today
    • But…
    • Often not renewable
    • Generate microplastic, an important source of water pollution
  • Cotton accounts for 24% of materials used
    • Known to be comfortable and renewable
    • But…
    • Cultivation is limited to warm areas, and can not grow locally
    • Needs high input of pesticide and water during cultivation

Recycling:

• Today only 1% of textile waste is recycled back into new textiles, most are still for down-cycling like isolation
  • Pressure to become more sustainable is growing really fast
  • European initiatives urge the sector to diminish its environmental footprint, and withstand recycling without loss of quality.

The growing interest in alternative raw materials

• Flax
  • Known as a sustainable, organic, raw materials
  • But… Availability is not very high, lower than the demand
  • Regio for high-quality flax is rather limited, in Belgium/Flanders, up North in Holland, and North of France

• Hemp
  • Has disappeared as a fiber for textiles for many years
    • The first traces of hemp in textiles already date back to the Egyptians, for sailing clothes
    • Marihuana Tax in the United States destroyed the entire Hemp for textiles industry as the cultivation of all types of Hemp became prohibited
    • Only in the nineties cultivation was permitted again in Europe
    • Hard consequences as the long-term ban put a hold on all investments into processing technologies

The Revival of Hemp

• Interest in back, and bigger than before
• EU: hemp fibers are mainly used for the pulp and paper industry: low-end applications

Challenge

• Increasing the European Hemp Cultivation
• Improving the processing into the high-quality textile applications
• Improving both the fiber yield and the quality of applications

Different factors play a role

• Field: choice of the hemp variety
  • Selected several fiber-rich varieties
  • Sewing and harvesting conditions prove to be very decisive in the final fiber quality

• Retting processes
  • Traditionally Hemp is still retted on the field
  • Very sensitive to climatic conditions
  • Looking at the possibilities to make to process less dependent on the weather conditions
  • Retting has a big impact on colour, fineness, and strength of the hemp fibers
  • Enzymatic field retting seems a better alternative than the traditional process
    • Still needs some adjusting -> still being investigated in ongoing research

Potential for recycling

• The tenacity of hemp fibers is quite high
• Hemp has a potentially long lifetime and could be very successful for recycling textile products end of life.

The processing of Hemp

• Today, there are no specialized processes yet for cultivation, the flax industry offers a good start but needs some minor adjustments
• Different types of fibers and processes
  • Long fiber spinning
    • Are just like flax fibers and can be wet spun
    • But… only 5 remaining spinning mills that have this technology
    • The situation is improving, in the north of France ongoing investments to install new factories with this technology.
  • Short fiber spinning (after cutting, you always have both long and short fibers, regardless of the hemp variety)
    • Also very valuable raw material
    • Can be transformed into fine yarn
    • Process:
      • Fiber preparation: considered as the most important step: obtain nice quality
      • Carding
      • Drafting
      • Spinning: lab scale, non-traditional hemp spinning equipment but adapted to the longer, coarser, and stiffer hemp fibers. After this, processable on cotton spinning equipment. Interesting as the infrastructure is still here
      • Weaving/knitting
      • Dyeing/finishing

A lot of research is being done to really drive the cultivation & processing of hemp in Flandres. Where a lot is still done on a smaller scale, the aim is really to scale up to industrial levels.

The final goal of the HOGENT projects is to present a collection of hemp garments, designed for circularity.