Questions about Pressure and Soccer Balls

Questions about Pressure and Soccer Balls

• How does the amount of air in a soccer ball affect how far it travels when struck by the same force? The amount of air or air pressure in a soccer ball effects how far the ball will travel when struck by the same force.  The higher air pressure that is put into a soccer ball improves the ball's rebound off the foot of a player. More energy is transferred to a "stiff" ball in an elastic collision. In other words, the ball deforms less during the impact, so there's less energy lost to deformation.
• Does the atmospheric air pressure effect how far a soccer ball travels when struck by the same force? The atmospheric air pressure (the air surrounding the ball) also plays a role in how far a ball travels. At lower pressure, there's less air friction. You can compare it to kicking the ball in a tank of water to kicking the ball on the moon. Balls go farther at high altitude because of the reduced drag from the air, which is thinner as you go higher up. So there's a case where "reduced" air pressure makes the ball go farther.
  Also, the materials that the soccer ball is made out of effects how far the ball will travel...but that is another question and experiment.
• How much air pressure should I put into a soccer ball?  Use Proper Air Pressure
  Do not over or under pressurize a ball. Use the manufactures recommended air pressure that is printed on most balls. Most soccer balls have a pressure rating of 6 to 8 lbs. or 0.6 or 0.8 BAR. It is recommended that you use a pressure gauge to measure the exact amount of pressure in a ball after inflating and before use. 
  BAR or PSI or LBS?
  Some soccer balls have recommended pressure values indicated in BAR while others have the values indicated in PSI or LBS.  To convert the pressure values, use the following formulas:
  To convert BAR (KGS) to PSI (Lbs.):
  Answer = 14.5037 X The amount of BAR(KGS)
  For example: A soccer ball has a recommended pressure of 0.6 BAR labeled on it.  To convert BAR in Pounds Per Square Inch (PSI), multiply 0.6 times 14.5037. The answer is 8.7 PSI or Lbs.
  To convert PSI (Lbs.) to BAR(KGS):
  Answer = .068948 X The amount of PSI(Lbs.)
  For example: A soccer ball has a recommended pressure of 7.9 Lbs. (PSI) labeled on it.  To convert Pounds Per Square Inch (PSI) into BAR, multiply 7.9 times .068948. The answer is 0.545 BAR.
• How Do I inflate my soccer balls? Soccer balls lose air pressure over time. Sometimes over a few days (soccer balls that use butyl bladders keep air pressure longer than balls that use latex bladders). Be sure to check the pressure frequently to make sure the ball is properly inflated.  Therefore, invest in a good ball pump, have a supply of inflation needles and use a low pressure gauge to measure for proper inflation. 
  Before you first inflate a soccer ball, place a couple drops of silicone oil or silicone lubricant spray or glycerin oil into the valve. You can purchase one of the oils or spray at your local hardware store. Using one of the lubricants will improve the life of the valve and lubricate the valve for easy insertion of the inflation needle.  
  Always moisten the inflation needle before you insert it into the valve. Preferably, use some silicon oil, silicon spray or glycerin oil to moisten the needle.  However; most people use spit...yuk, but that is not recommended. 
  Manufacturers recommend that you reduce the air pressure in your match balls after a game to reduce the amount of stress on the ball seams or stitching.  Be sure to inflate the ball back to proper pressure before the match.  
   
• Why do I always have to pump up even expensive balls? Many balls use bladders made out of latex. Natural Latex Rubber bladders offer the softest feel and response, but do not provide the best air retention. Micro pores slowly let air escape. Balls with natural rubber bladders need to be re-inflated more often than balls with butyl bladders. Even after one or two days, the latex bladder will leak enough air so that you will have to inflate the ball back to recommended pressure. Some balls use carbon-latex bladders in which the carbon powder helps to close the micro pores. Soccer balls with carbon latex bladders usually increase air retention to approximately one week. Of course, check the ball for punctures that may cause the air to leak out.
  Soccer Balls with Butyl bladders or PU bladders offer an excellent combination of feel and air retention and can be found in most middle to upper priced balls.  Air retention is significantly increased to weeks and months instead of days compared to balls with latex bladders.
  
• Why do some soccer balls get bigger over time?  Many soccer balls do tend to get larger over time. This is due to the pressure of the air in the bladder against the linings and cover.  Over time the material and stitching may stretch out causing the ball to become larger. Also, soccer ball abuse may cause the stitching to loosen and the ball to expand.