Harvesting and handling of flax for the production of short fibres under Swedish conditions

The increased awareness of sustainable production in our society in recent decades has led to the search for new environmentally-friendly products. Natural fibres from flax (Linum usitatissimum L.), which are renewable and can be degraded biologically after their use, are an alternative that has been considered as a replacement for synthetic fibres in many industrial applications, for example, as reinforcement in composites, rubber and concrete. The objective of` this work was to carry out a thorough literature review on the production and use of flax for non-textile applications in general, and on aspects related to harvest and handling in particular. The report starts with a review of earlier Swedish research and development projects and then focuses on harvest and handling methods. Thereafter, quality aspects related to harvest and handling of flax, i.e. straw moisture contents and degree of retting, are reviewed. A summarising discussion and proposals for future research are presented in the last chapter. After the closure of the last flax long fibre processing plant in 1966, there has been no commercial production of flax fibres in Sweden. However, interest in using flax fibres in non-textile applications was stimulated in the late 1980s, and a number of projects started in the 1990s with the aim of restoring Swedish flax fibre production. Today, there are no flax processing plants in operation, but it is recommended that new research and development projects be directed towards the creation of a demand for biofibres before such plants are established. This would be a first step towards creating a future market for short natural fibres obtained from flax, and also from other fibre crops such as hemp. The harvest and handling operations constitute an important part of the total production costs, Computer simulation of these operations is recommended in order to find more cost-effective and reliable delivery systems, Such simulations should include quality aspects regarding the straw moisture content and the degree of retting, provided that reliable, quick and inexpensive methods to assess the degree of retting are developed, and that models describing the moisture content changes and the progress of retting are constructed