Abstract: An injection molding machine includes an actuating drive in form of an electromotive spindle drive and an energy storage device associated with the spindle drive. The energy storage device stores kinetic energy and can include two counteracting compression spring assemblies. The energy storage device is hereby loaded, as the spindle drive moves to a first end position, and unloaded, as the spindle drive moves in opposite direction to a second end position, wherein unloading of the energy storage device is accompanied by a power boost of the electric motor, and wherein the first force is equal to the second force at an equilibrium location distal from the end positions of the spindle drive.

Abstract: A bladder shell for inflatable balls having a layer of blended synthetic latex and natural rubber latex compounded with an anti-oxidant, an activator, an accelerator, a thickening agent, a wetting agent, and a stabilizer etc. to form a low air permeability and high bounce bladder shell having thickness of between 0.25 mm to 3.0 mm. Also disclosed is a process for the preparation of the bladder shell that includes dipping former in a bath of blended natural rubber latex and synthetic latex.