title_body: Why do aeropress columns get abrasions, or scars, near the top?
upvoted_answer: However I cannot understood the scars definitely, I would like to offer a solution to the scars I thought:
  
  There is a possibility that coffee grounds may stick to the rubber ring and scratch the plastic column when pressure is applied as they stay in between the rubber ring and the plastic column. Still, these scratches do not affect the performance of the gadget if they are not large enough to leak.
  
  Easiest way to clean the grounds is rubbing the surface of the rubber ring by your finger under warm water for a few seconds.
  
  Edit: After I see the photos, my guess is, these scars are caused by the scratches first, then the polished surface of the plastic is peeled off by heat. I assume you may continue to use it without problems. For other people with brand new aeropress, my previous advice still holds: try to wash away residual grounds off the rubber ring.