Compression Molding
Many functional designs are greatly enhanced by the inclusion of compression-molded tabs, locks or mounting surfaces.

Compression molded tabs can be added at any point along the mold parting line on the same plane as the pinch-off. To change the angle of a tab relative to the basic parting plane, you must create a mold parting line at the desired angle. This can be done with angled parting line steps or inserts along the perimeter of the part or moving inserts within the part.

When blow-molded parts are to be combined with other parts through the use of mounting screws, bolts or rivets, an exceptionally strong mounting surface can be provided by compressing the inner and outer walls together. The two walls can be compressed together at nearly any angle or location as long as there is ample room surrounding the compression for good airflow and as long as the mold halves can close without interference.

By compression molding inner and outer walls together, the part rigidity and straightness can be improved significantly. It is also an excellent way to provide stacking strength when dealing with heavy loads