Previous series) How do I use the air valve to prevent liquid from spilling out at the end of the straw when I open the straw hood?
When drinking hot liquids, there is a danger of them spurting out, so open the cap after setting the valve to “Open.” In addition, since babies who have just begun straw training are not able to sip very strongly, opening the air valve (by pushing it to “Open”) makes it easy to sip the liquid. When transporting the cup or when your baby has become accustomed to the straw, set the valve to “Close” to prevent leaks. If you wait a little while after pouring hot or cold drinks into a cup, the change in temperature within the cup causes the air pressure to rise, pushing the beverage up through the straw. (Avoid putting hot water into the cup, since there is danger of it spurting out.) At such times, if you open the hood too quickly, liquid spills out at the end of the straw. (In addition to temperature changes, changes in air pressure inside airplanes or at high elevations or internal pressure from carbonated beverages or similar substances may cause the contents to spill out.) Before openi
