| 摘要 |
<p>A process for manufacturing plastic blasting media includes the steps of extruding a material under heat and pressure to fuse the material into a substantially dense, solid mass; and cutting or grinding the mass into pieces having an appropriate size and shape for use as an abrasive blasting material. The material to be extruded is a thermosetting material that includes at least one member selected from the group of polyamine-aldehyde-containing materials and polyphenol-aldehyde-containing materials. In one aspect of the invention, the extruding step takes place in a screw conveyor (14) and, preferably, in a screw conveyor having multiple screws. Prior to extrusion, the thermosetting material can be prepolymerized to a predetermined degree. The thermosetting material also can include at least one further ingredient selected from the group of a filler, a lubricant, a catalyst, and a pigment.</p> |
