Feasibility of hemp textile production in the UK

About the report

A report of practical trials carried out in the UK and Australia during 2003-4

Published November 2004
Pages 131

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BioRegional is a registered charity – if you would like to make a donation for this report please visit www.justgiving.com to do so securely on-line – suggested donation £4.00.  

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Executive summary

This report aims to assess the technical and economic feasibility of growing and processing hemp fibre in the UK for textiles. This was not possible using currently available technologies and methods so BioRegional set out to test new technology developed by Fibrenova Limited, an Australian company, for this purpose and to review other projects and developments in this field. The Australian technology is designed to harvest and separate the fibre in one operation in the field, cutting out the need for field or “dew” retting. Dew retting is a commonly used method of breaking down the pectins and gums which bind the fibres to the stem. BioRegional also commissioned an ecological footprint analysis of hemp compared to cotton and polyester in order to assess the environmental case for hemp as a textile fibre.

This work builds on earlier work by BioRegional in the area of hemp textiles (Riddlestone et al 1995) where weather dependency of dew retting and the old-fashioned inefficient nature of subsequent processing were identified as significant issues discouraging attempted production of hemp textile fibre in the UK using traditional methods.

Based on samples provided to BioRegional by Fibrenova of white short staple fibre suitable for spinning and samples of yarn which it was claimed was produced in previous work, field trials were organised by BioRegional aiming to evaluate the feasibility of the Fibrenova process from field through to producing a textile fibre. Experts in agronomic engineering from Cranfield University were commissioned by BioRegional to carry out an independent study evaluating the technical and economic feasibility of the machinery presented by Fibrenova and its implications for use in the UK. BioRegional worked with the textile industry to evaluate the fibre produced.

Initial field trials were carried out in Battle, East Sussex with crop grown for UK hemp contractor and processor Hemcore. An open day was held in July 2003; farmers, industry and retailers viewed the harvest in operation and discussed potential for future UK industry. During the four week trial 80kgs of fibre was produced.  As presented, this fibre could not be used by UK spinners. BioRegional explored many options for further opening and cleaning to enable its use by UK spinners. This is documented in the report.

It was decided to carry out a second trial because the results from the UK trial were limited by pilot machinery that was not fully operational and only small quantities of fibre were produced. In addition a replicable process had not been demonstrated. BioRegional secured further funds to repeat the field trial using an Australian crop in February 2004. The field trials were held in New South Wales, Australia in February 2004, again evaluated by BioRegional and Cranfield University. Some of the pilot machinery was not fully operational in the Australian trial.  BioRegional staff worked in the field with Fibrenova staff for three weeks and 250kgs of additional fibre was produced. This fibre was not suitable for immediate textile processing.  However, Australian textile processors who had previously prepared fibre supplied by Fibrenova did demonstrate to BioRegional methods of post field processing to prepare fibre for spinning. These methods appeared very similar to published methods used to complete processing of hemp or similar fibres prior to spinning.

The fibre produced in Australia was sent after harvesting to the textile dyer in Melbourne for cleaning and opening as demonstrated, however it was not returned to the UK for testing and evaluation.

The fibre produced in the UK field trial was processed for BioRegional by the UK textile industry using published methods for preparing hemp or similar fibres. Meetings and discussions with the UK textile industry are described. It was found that the fibre produced in the UK field trial could be cleaned and opened in the UK, but that the resulting fibre was unsuitable for spinning by the textile industry in the UK (or indeed in Europe) due to its low quality and lack of homogeneity. A low quality spun yarn was produced but only by blending with 50% viscose. However, BioRegional has established an interested consortium of stakeholders encompassing the cultivation, opening, cleaning, spinning, weaving and retailing of hemp for textiles for future development in the area.

In addition, raw fibre was provided to the BioComposites Centre in Wales for evaluation for use in composites and fibreglass replacement.

An ecological footprint analysis of hemp compared to cotton and polyester by the Stockholm Environmental Institute found that hemp does indeed have a reduced environmental impact when compared to these fibres. A summary is included in this report.

Economic analysis suggests that hemp textile fibre as processed by the new technology and methods used in the trial documented in this report would be expensive compared to other textile fibres such as cotton or flax. However, in line with the conclusions of the previous 1995 BioRegional study, it is considered that the green decortication approach could potentially yield a quality textile fibre at a competitive price, if a more controlled post-field process incorporating storage and cleaning to remove pectins and gums could be developed.

Download report PDF
........................................................................................................
BioRegional is a registered charity – if you would like to make a donation for this report please visit www.justgiving.com to do so securely on-line – suggested donation £4.00.  

Your support will help us to continue developing vital solutions for sustainable living.