The plastic mold finish standard data:
Surface finish of SPI-SPE standard
A-0 # 1 diamond buff (optical requirements)
A-1 # 3 diamond buff polishing (mirror)
A-2 # 6 diamond buff polishing (mirror)
A-3 # 15 diamond buff polishing (mirror)
B-1 600# grit paper (glossy)
B-2 400# grit paper (glossy)
B-3 320# grit paper(glossy)
C-1 600# grit stone (glossy)
C-2 400# grit stone (matte)
C-3 320# grit stone (glossy)
D-1 # 11 coarse glass beads
D-2 # 240# Aluminum Oxide
D-3 # 24# Aluminum Oxide
polish level is defined by SPI(society of plastic industry) and called out on all PIM released plastic mold and part drawings
Parting lines should be masked during the polishing process to keep them sharp and avoid rounding edges. extreme care should be taken when polishing curves and radii.Surface must match design files.No flats or bumps are allowed.
Flat surface must be optically flat,proper preparation before high polish,such as removing stones,machining or other imperfections ,is critical.
Each grade of polish should be finished evenly prior to starting the next finer level of polish.
polished surfaces should be inspected with fluorescent tubes and a reflected grid to check for distortion.
we will specify the use of inserted cores whenever possible to facilitate a consistent,flat polish around features.
Final polished surface need precisely represent the correct surface finish level and the contours of the PIM surface files.