Metal-organic frameworks (MOFs) are well known for their outstanding sorption properties and therefore under consideration as new high performance adsorbents. [1] A lot of applications in different fields seem feasible. [2] Especially gas storage, [3] heterogeneous catalysis, [4] and separation/purification processes [5] are the fields under intense research and most mentioned in the literature. Describing exclusively the performance of the materials, only little attention is paid to the morphology and size of the particles, which is crucial for the different fields of applications. A few of the known MOF materials appear in form of small single crystals while often fine powders with particles on the lower micrometer scale are the product. For certain applications they have to be better processable. Methods under consideration, like pelletizing [6]

The renewable characteristic of natural fibres, such as flax, and the recyclable nature of thermoplastic polymers, such as polypropylene, provide an attractive eco-friendly quality to the resulting composite materials. Common methods for manufacturing natural fibre-reinforced thermoplastic composites, injection moulding and extrusion, tend to degrade the fibres during processing. Development of a simple manufacturing technique for these composites, that minimises fibre degradation, is the main objective of this study. Flax fibres were conditioned, cut into lengths ranging from 1 mm to 30 mm with scissors and a pelletiser, and shaped into randomly oriented mats using a drop feed tower. Polypropylene in sheet form, was added to the fibres to furnish polypropylene/flax/polypropylene sandwiches with a fibre mass fraction of 25%, which were then consolidated by the hot pressing technique. Tensile, flexural and impact properties of these composite sheets were determined as functions of fibre length and processing temperature.