Blow moulding

For bottles and containers. Reliable conveying, dosing & mixing systems for high-volume production of bottles and other containers.

Blow moulding processes are used to make hollow parts from thermoplastics, such as containers, barrels, tanks, or bottles. Depending on the specific process, an injection moulded preform is manufactured, or a tube is extruded and, in a second inline step, is blown into a finished product using a mould. This us then cooled and ejected once it has hardened.

Blow moulding describes the general method of manufacturing hollow parts from thermoplastics. The process always consists of multiple steps and can be either continuous or discontinuous. One usually differentiates between injection stretch blow moulding and extrusion blow moulding. For both processes the plastic moulding batch, as the basic raw material, is plasticized and homogenized in a cylinder using a screw.

The next steps depend on the specific process:

For injection stretch blow moulding, one or more preforms are made, in the same way as injection moulding, using the first tool and are then passed on automatically in a contour-stable but still hot state to a second tool for the blow moulding process.

For extrusion blow moulding, similar to profile extrusion, one or more lengths are extruded hanging parallel to each other and are placed in the moulds of the blow moulding tool while still hot.

The moulds of the blow moulding tool correspond to the final shape of the manufactured product. By applying compressed air via one or more blow pins, the preforms or tubes a blown up and take on the predetermined final shape. Once cool, the moulded parts are ejected from the moulds. Any protruding remainders are automatically cut off or are manually removed afterwards. No subsequent work is usually necessary for injection stretch blow moulding.