Abstract: A powdered leather which is composed of at least 85% by weight of cortex, at most 2% by weight of oil and fat, and at most 0.5% by weight of Na.sup.+ and Ca.sup.2+ ions capable of being eluted by water and which has an average particle size (D.sub.50) of at most 7 .mu.m, a standard deviation of the average particle size being at most 3 .mu.m. With this powdered leather, it is possible to thin films, coatings, fibers, etc. which would hardly be deteriorated with time.

Abstract: A cylindrical stabilizing means (stabilizer) for resin bubbles useful to perform shaping of tubular films without causing the fluctuation or breakage of resin bubbles even in case where a take up velocity of the tubular film is relatively large, cooling of tubular body of molten resin extrudated from a die is not sufficient or amount of extrudate from a die is relatively large, is provided. Said stabilizing means has penetration holes on the circumferential wall close to the annular slit 16 of die, which communicate with an opening of the tip of the means, and also has continuous deep grooves of a depth of 0.5 mm or more extending from the portion of the circumferential wall close to said annular slit to the opening of the tip, which grooves are formed on the whole outer circumferential wall having fine concave and convex engraved patterns of the difference of height or depth of from 0.1 mm to 0.5 mm.