Causes of yellowing or discoloration on the surface of blister packaging
(1) The heating temperature of the sheet is too low
(2) The heating temperature of the sheet is too high
(3) The mold temperature is too low
(4) The temperature of the pressure-assisted plunger is too low
(5) Excessive stretching of the sheet
(6) The sheet is cooled prematurely before it is fully formed
(7) Improper mold structure design
(8) Too much recycled material
(9) The raw material formula does not meet the requirements of thermoforming
