Conversely, every set-up will have its faults, and unfortunately, the standard long radius bend is no exception. They are far more prone to wear and abrasion and product degradation and damage.
Typically fragile and friable products like granulated sugar or grits and flakes can damage as they travel around the outer face of the bend at high velocity and break down into smaller particle sizes and even dust.
Also, low melt temperature products such as certain plastics and chemicals heat up due to friction as they pass around the bend at high velocity and the elevation in temperature causes the particles to partially melt and deposit on the bend. Typically Polypropylene pellets can generate heat causing them to partially melt and leave deposits on the inside face of the bend called “snakeskins” (when they fall off the bend they look like a snakeskin) and as the pellet skids around the bend and heats up it generates a tail sometimes called “angel hairs”. When many of these angel hairs have been formed and they break off the pellet they can gather together in cyclones, hoppers and receivers and they can knit together into a mat and are sometimes called “birds nests”.
Also, the internal integrity of the bend itself is more prone to wear and abrasion after substance exposure from abrasive products like sand and products with high silica / mineral content. As the particles move at high velocities around the outer internal face of the bend, scouring occurs causing wear and eventual puncturing of the bend.