Acta Scientiarum Polonorum
Silvarum Colendarum Ratio et Industria Lignaria

Abstract Research was conducted in laboratory conditions on the pressure losses in film hoses made of pure polyester polyurethane with high flexibility and compressibility reinforced with a spring steel spiral. The measurements were conducted with use of 3-meter long sections, which were 80, 100, 150 and 200 mm in diameter. A mixture of sawdust, shavings and dust from working of softwood with the mass concentration in the carrying stream at the level 100 g•m^-3 was used. Velocities of air flow were changed in the range from 10 to 25 m•s^-1. The resistance of clean air flow was also determined.