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Rotary wheel blow molding systems bring the high-output production of a wide number of plastic extrusion blow molded articles. Containers may be made of small, single serve bottles to large containers up to 20-30 liters in volume – but wheel machines normally sized for the actual and dimensional demands of a specific container, and are dedicated to a narrow range of bottle sizes once built. Multiple parison machines, with high numbers of molds are capable of producing over 1 million bottles per day in some types.


Rotary blow molding heels are targeted to the high output production of folders. They are used to produce containers from one to seven sections. View stripe and In Mold Labeling (IML) options are found some configurations. Rotary wheels, which might have from six to thirty molds, feature continuously extruded parisons. Revolving sets of blow molds capture the parison or parisons as they pass over the extrusion head. The revolving sets of molds are discovered on clamp tations.

Rotary wheels offered different variations, including both continuous motion and indexing wheels, and vertical or horizontal variations. Wheel machines are favored for their processing ease, due getting only single (or in some cases, two) parisons, and mechanical repeatability.

Rotary wheel blow molding machine operation

In some machinery configurations, the molds take using a shape of an ie niche. Thus, if two or more parisons are used, each blow molded og provides an unique length, requiring special downstream handling and trimming requirements. Some other machine configurations, the molds utilize ook style opening mechanisms, allowing multiple parisons of equal length. However, machines for the style normally have lower clamp force, limiting the available applications.

The mold close and open actuation is typically carried out through a toggle mechanism linkage that is activated your rotational process by stationary cams. This mechanical repeatability is considered an advantage by most processors.

The method of wheel rotation is typically conducted through an electric motor with an inion gear or small gear to or in mesh with a rotating ull gear or large gear. All utilities for blowing containers and for mold cooling are carried through key shaft or maybe axle that the wheel rotates all around. These utilities include compressed air and this type of water. Sequencing functions necessary to inflate the parison, hold the container prior to discharge and discharge are completed by mechanical actuation to pneumatic valves resulting in a high degree of repeatability.

Advantages & disadvantages

Schematic showing captured parisons in a dual parison rotary wheel mold

Very tight weight and dimensional tolerances can be obtained on wheel equipment, as the parison is captured on both ends. Is actually always pinched the actual world preceding mold on the cutting edge end, and positioned the actual stationary flowhead die conversely. In shuttle machinery and reciprocating screw machinery multiple parisons are extruded for that reason free installing. Because there is always some variation inside the parison length on these machines, bottle weight and tolerance consistencies are less tight as on rotary wheel system.

Other features about wheel equipment include:

Continuous extrusion

Multi-layer coextrusion, with one to seven layers of plastic in the finished part

In some applications, In Mold Labeling (IML) could be integrated with little or no cycle time penalty

Parison programming capability, for optimization of wall thickness

Reduced cycle time on light weight containers, when shuttle devices. Conversely, wheel equipment may suffer cycle time penalties on thick containers

Easily implemented view stripe capability

Ability to accomplish very high outputs from a single machine – lowest “cost per bottle” when when other blow molding equipment

Higher production efficiencies than most other extrusion blow molding equipment types


Inability to create bottles with calibrated neck finishes

Downstream trimming required

Machines typically dedicated with narrow associated with sizes. Product change can be difficult, especially when downstream trimming changeovers are required.

High initial capital investment


The involving wheel machinery in the particular was spurred by the conversion of motor oil containers from paperboard cans to plastic bottles, along with the conversion of laundry detergent from powder to liquid form. Laundry Detergent Fundraiser have included single-serve juices and drinkable yogurt, condiments, and household cleaning supplies.

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