seen in framstellning of kernor for gjutningsendamal

摘要

Core box for water glass bound sand core cured by microwave energy has a prefabricated body of plastics with a moulded in-situ plastics or rubber lining and is transparent to microwave radiation. The body has a tensile strength of at least 55 Mpa and a bending modulus of at least 2.5 Gpa and the lining gives a tear resistance of at least 10 N/mm. The body has a coefft. of thermal expansion of at most 6.5 x 10 power -5 mm/mm deg.C and is self supporting.