- Rotary wheel blow molding systems
blow moldingsystems are used for the high-output production of a wide variety of plastic extrusion blow molded articles. Containers may be produced from small, single serve bottlesto large containers up to 20-30 liters in volume - but wheel machines are often sized for the volume and dimensional demands of a specific container, and are typically dedicated to a narrow range of bottle sizes once built. Multiple parisonmachines, with high numbers of molds are capable of producing over one million bottlesper day in some configurations.
Rotary blow molding “wheels” are targeted to the high output production of containers. They are used to produce containers from one to seven layers. View stripe and In Mold Labeling (IML) options are available in some configurations. Rotary wheels, which may contain 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 located on clamp “stations”.
Rotary wheels come in different variations, including both continuous motion and indexing wheels, and vertical or horizontal variations. Wheel machines are favored for their processing ease, due to having only single (or in some cases, two) parisons, and mechanical repeatability.
In some machinery configurations, the molds take on the shape of a “pie” sector. Thus, if two or more parisons are used, each blow molded “log” has a unique length, requiring special downstream handling and trimming requirements. In other machine configurations, the molds utilize “book style” opening mechanisms, allowing multiple parisons of equal length. However, machines of this style typically 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 during the 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 a “pinion” gear or small gear to or in mesh with a rotating “bull” gear or large gear. All utilities for blowing containers and for mold cooling are carried through the main shaft or the axle from which the wheel rotates about. These utilities include compressed air and water. Sequencing functions necessary to inflate the parison, hold the container prior to discharge and discharge are completed by mechanical actuation to
pneumaticvalves – resulting in a high degree of repeatability.
Advantages of Rotary Wheel Blow Molding
multiple parisons are extruded and are free hanging. Because there is always some variation in the parison length on these machines, bottle weight and tolerance consistencies are not as tight as on rotary wheel machinery.
Other advantages of 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) can be integrated with little or no cycle time penalty
* Parison programming capability, for optimization of wall thickness
* Reduced cycle time on light weight containers, compared to shuttle machinery. Conversely, wheel equipment may suffer cycle time penalties on thick containers
* Easily implemented view stripe capability
* Ability to achieve very high outputs from a single machine - lowest "cost per bottle" when compared to other blow molding equipment
* Higher production efficiencies than most other extrusion blow molding equipment types
Disdvantages of Rotary Wheel Blow Molding
* Inability to produce bottles with calibrated neck finishes
* Downstream trimming required
* Machines typically dedicated to a narrow range of sizes. Product change can be difficult, especially when downstream trimming changeovers are required.
* High initial capital investment
The growth of wheel machinery in the
United Stateswas spurred by the conversion of motor oilcontainers from paperboardcans to plastic bottles, and the conversion of laundry detergentfrom powder to liquid form. Additional high volume applications have included single-serve juices and drinkable yogurt, condiments, and household cleaning supplies.
There are a limited number of suppliers of rotary wheel technology. There are some converters (producers of plastic bottles) who manufacture their own proprietary rotary machinery for blow molding.
* [http://www.grahamengineering.com Graham Engineering (United States)]
* [http://www.rbplasticsmachinery.com R&B Plastics Machinery, LLC (United States)]
* [http://www.urola.com/ Urola (Spain)]
* [http://www.wilmingtonmachinery.com/index.jsp Wilmington Machinery (United States)]
Wikimedia Foundation. 2010.
Look at other dictionaries:
Blow molding — The blow molding process Blow molding (also known as blow moulding or blow forming) is a manufacturing process by which hollow plastic parts are formed. In general, there are three main types of blow molding: extrusion blow molding, injection… … Wikipedia
Package testing — Military shipping container being drop tested Testing … Wikipedia
Corrugated box design — High graphics overlap box: die cut for plastic handle and locking tabs Corrugated box design is the process of matching design factors for corrugated fiberboard boxes with the functional physical, processing and end use requirements. Packaging… … Wikipedia
Check weigher — Example checkweigher. Product passes on the conveyor belt where it is weighed A checkweigher is an automatic machine for checking the weight of packaged commodities. It is normally found at the offgoing end of a production process and is used to… … Wikipedia
Shelf life — This pack of diced pork says display until 7 May and use by 8 May … Wikipedia
Carton — Examples of several types of cartons for different products Carton is the name of certain types of containers typically made from paperboard which is also sometimes known as cardboard. Many types of cartons are used in packaging. Sometimes a… … Wikipedia
Cushioning — Package cushioning is used to help protect fragile items during shipment. It is common for a transport package to be dropped, kicked, and impacted: These events may produce potentially damaging shocks. Transportation vibration from conveyors,… … Wikipedia
Child-resistant packaging — or C R packaging is special packaging used to reduce the risk of children ingesting dangerous items. This is often accomplished by the use of a special safety cap. It is required by regulation for prescription drugs, over the counter… … Wikipedia
Multihead weigher — (28 heads) Multihead weigher (24 he … Wikipedia
Bottle — This article is about bottles in general. For baby bottles, see Baby bottle. Composite body, painted, and glazed bottle. Dated 16th century. From Iran. New York Metropolitan Museum of Art … Wikipedia