Manufacturing process for rough-surfaced bars for reinforcing concrete uses extruded thermoplastic rod with rough coating sleeve

摘要

The process consists of introducing a solid rod (13) based on an organic (thermoplastic) material with reinforcing fibres (11) and a molten thermoplastic mixture with a reinforcement and/or filler simultaneously into a sleeving unit (200). The sleeved rod is drawn by a downstream traction system (120), with the roughness of the sleeve created by its departure from the sleeving unit. The sleeve coating mixture is under pressure during application, with the pressure level adjusted as a function of the ingredients and one or more of the following parameters: rod traction speed, dimensions of the layer forming zone, and the size of the sleeving unit's outlet aperture. The sleeving mixture is reinforced e.g. with alkali resistant glass fibres, chopped and fed into an extruder feeding the sleeving unit, or with organic or mineral grains, spheres or flakes.