Method and device for pouring plastic raw material liquid

Abstract

Liquid sending portions ( 7 a , 7 b ) of an intermittent fixed displacement pump ( 6 ) intermittently sucking and discharging a fixed amount of fluid are parallelly arranged, plastic raw material liquid is discharged from the liquid sending portions ( 7 a , 7 b ) with the timing of suction and discharge of the liquid sending portions being shifted from each other, plastic raw material liquid discharged from each other, plastic raw material liquid discharged from each of the liquid sending portions ( 7 a , 7 b ) is joined, and the plastic raw material liquid joined is poured in a casting/polymerizing die ( 4 ). Plastic raw material liquid can be stably sent even if its viscosity becomes higher, air bubbles are prevented from being produced in raw material pouring, and an excellent production yield is achieved.

1 . A method of introducing a plastic raw material liquid, characterized by: 
 positioning a plurality of liquid delivery units each for intermittently drawing in and discharging a fluid at a constant rate, parallel to each other, discharging flows of the plastic raw material liquid at different times from said liquid delivery units, combining the flows of the plastic raw material liquid discharged from said liquid delivery units, with each other, and introducing the combined plastic raw material liquid into a casting polymerization mold.    
   
   
       2 . A method of introducing a plastic raw material liquid according to  claim 1 , characterized in that: 
 said liquid delivery units draw in and discharge the plastic raw material liquid by progressively pressing a flexible resilient tube with presser rollers, changing the shape of a diaphragm made of a resilient material to move the diaphragm back and forth, or moving a plunger back and forth in a cylinder to change the volume of the cylinder.    
   
   
       3 . A method of introducing a plastic raw material liquid according to  claim 1 , characterized in that: 
 an accumulator for changing the volume of a fluid depending on the pressure of a fluid is disposed in a flow passage for the combined plastic raw material liquid.    
   
   
       4 . A method of introducing a plastic raw material liquid according to  claim 1 , characterized in that: 
 a filter is disposed in a flow passage for the combined plastic raw material liquid.    
   
   
       5 . An apparatus for introducing a plastic raw material liquid, characterized by 
 an inlet pipe interconnecting a raw material tank storing a plastic row material liquid and an inlet port of a casting polymerization mold, and an intermittent constant-rate pump disposed in said inlet pipe and having a liquid delivery unit for intermittently drawing in and discharging the fluid at a constant rate,    wherein said intermittent constant-rate pump has a plurality of said liquid delivery units disposed parallel to each other and actuatable simultaneously for discharging the plastic row material liquid at different times, respectively, and    said inlet pipe having a junction interconnecting respective discharge ports of said liquid delivery units.    
   
   
       6 . An apparatus for introducing a plastic raw material liquid according to  claim 5 , characterized in that: 
 said intermittent constant-rate pump comprises a pump selected from a roller pump, a diaphragm pump, and a plunger pump.    
   
   
       7 . An apparatus for introducing a plastic raw material liquid according to  claim 5 , characterized in that: 
 said liquid delivery units are actuatable by a single drive shaft.    
   
   
       8 . An apparatus for introducing a plastic raw material liquid according to  claim 5 , characterized by: 
 an accumulator disposed in the inlet pipe downstream of a discharge port of said intermittent constant-rate pump, wherein a volume of the fluid in the accumulator is variable depending on the pressure of a fluid.    
   
   
       9 . An apparatus for introducing a plastic raw material liquid according to  claim 5 , characterized by: 
 a filter disposed in the inlet pipe downstream of a discharge port of said intermittent constant-rate pump.    
   
   
       10 . An apparatus for introducing a plastic raw material liquid according to  claim 5 , characterized in that: 
 said casting polymerization mold comprises two mold members confronting each other for molding a plastic lens, with a gap between the mold members being sealed, and    an inlet nozzle is mounted on a tip end of said inlet pipe and inserted into the inlet port of the casting polymerization mold.