The Society of the Plastics Industry, or SPI, establishes standards for the United States plastics industry. Among the SPI standards is one defining the degree of polish on the inner surfaces of the molds used to form plastic products. The SPI standards specify 12 grades of mold finish ranging from mirror-perfect to dull. Various companies offer illustrative sample kits consisting of steel discs or strips polished to the different SPI grades.

SPI 中抛光的表面等级对应的砂纸和钻石膏

SPI Finish A-1 -- Grade #3, 6000 Grit Diamond Buff

SPI Finish A-2 -- Grade #6, 3000 Grit Diamond Buff

SPI Finish A-3 -- Grade #15, 1200 Grit Diamond Buff

SPI Finish B-1 -- 600 Grit Paper

SPI Finish B-2 -- 400 Grit Paper

SPI Finish B-3 -- 320 Grit Paper

SPI Finish C-1 -- 600 Grit Stone

SPI Finish C-2 -- 400 Grit Stone

SPI Finish C-3 -- 320 Grit Stone

SPI Finish D-1 -- 600 Stone Prior to Dry Blast Glass Bead #11

SPI Finish D-2 -- 400 Stone Prior to Dry Blast #240 Oxide

SPI Finish D-3 -- 320 Stone Prior to Dry Blast #24

Oxide

SPI-SPE 工件表面光洁度标准

A-0 #1 钻石膏(光学要求)

A-1 #3 钻石膏抛光(镜面)

A-2 #6 钻石膏抛光(镜面)

A-3 #15 钻石膏抛光(镜面)

B-1 600 沙纸(光面)

B-2 400 沙纸(光面)

B-3 320 沙纸(光面)

C-1 600 沙纸(光面)

C-2 400 油石(哑面)

C-3 320 沙纸(光面)

D-1 喷#11 粗玻璃珠