Rotary Wheel Blow Molding Machinery
The rotary wheel blow molding machines are the machine of choice for very high volumes of containers for markets such as liquid detergent and juice in North American markets. Wheels are typically chosen over shuttles because of processing ease (and cost) due to single parison technology and lower cost per container for high-volume applications. This is especially true for coextrusion and multilayer applications. Machines can be designed to handle a wide range of container sizes, but are typically committed to a narrow range of container variation after built. Because the containers are blow with a needle (instead of blow pin), it is not unusual to blow containers in a neck to neck configuration to increase the production output. Wheels come in various configurations including indexing, continuous motion, vertical (like a ferris wheel) and horizontal (like a merry go round). Some even now have the capability to produce calibrated
neck containers, such as a reciprocating screw (Intermittent extrusion). Most, however, rely on downstream trimming equipment to trim and finish the container. Major manufacturers of Rotary Wheel Blow Molding Machinery include Wilmington Machinery and Graham.
PROS:
- Lowest cost method for high volume production requirements
- Simple design and controls for maintenance
- Single parison well suited for multilayer application for repeatability and cost
- Easy to utilize IML
- Can achieve very high production volume from a single machine
CONS:
- Typically can not be converted to different number of cavities after being built
- High investment requires commitment to high volume production situations
- Requires secondary trimming and finishing equipment
Injection Blow Machinery
These machines inject mold a preform onto core rods and then index the core rods to a blow station to blow the container.
Machines are typically 3-4 stations to allow for condition and part removal. They are utilized extensively for very small containers
such as pharmaceutical and hotel shampoo type containers. Major manufacturers are Jomar, Procrea and Milacron.
PROS:
- Scrapless process meaning no flash to trim and no regrind
- Typically suited for containers .5 litre and smaller
- Capable of running a wide range of materials
- High quality injection molded neck finish
CONS:
- Very high tooling cost per container typically cost 40-50% of the machine cost
- Difficult to run coinjection or multilayer
- Minimum cycle time typically 15 seconds
- Can not do handleware
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