Part per minute

Variations in cross-sectional thickness of a part introduce added complexity to the die, since for maximum density uniformity each section must have its own ram (Figure 7.23). Although there are some restrictions on the complexity of parts that can be produced by die pressing, this method is suitable to automation and can be used to produce tens to possibly thousands of parts per minute (Richerson, 1992). As a set of dies usually requires a significant capital outlay, to be cost-effective, die pressing is typically limited to high-volume or high-value production parts. 

Retsch rotary divider PT 100 consists of a feeder unit with a dividing head that rotates at 110 rpm this means that with a dividing head with 10 outlets the feed is split into 1100 aliquot parts per minute. The feed can range from a few grams to 5000 ml depending on the size of the collecting... 

Modified knee presses up to a nominal force of 6300 kN are employed to extrude the valve tappets. The output capacity is 25-40 parts per minute. As a result of the near-net-shape process, the material is utilized to a higher extent—about 80%. The sizes of slot width and hole diameter are delivered at an accuracy ready for installation, whereas the outer diameter is pressed at IT quality 9-10 ready for grinding. The number of process steps and part manufacturing time were reduced. 

Light-gauge mechanical shears operate at speeds of up 80 strokes per minute and can produce up to 30 cuts per minute. Heavier-capacity mechanical shears operate at speeds of 40-60 strokes per minute and are able to cut 20-30 parts per minute. These shears can cut up to -in. mild steel, and the shearing length can be as much as 216 in. 

Ultrasonic welding is clean and fast (20-30 parts per minute) and usually results in a joint that is as strong as the parent material. The method can provide hermetically sealed components if the entire joint can be welded at one time. Large parts generally are too massive to be joined with one continuous bond so that spot welding is necessary. It is difficult to obtain a completely sealed joint with spot welding. Materials-handling equipment can be easily interfaced with the ultrasonic system to further improve rapid assembly. 

More profits are generated by increasing productivity (parts per minute), considerably less cleaning (relative to 2C systems), lower maintenance times and reduced total cost due to lower equipment investment (e.g. no cabinet heater) and reduced scrap. 

The size and shape of the part and the type of the press determine the production rate. For large parts, the rate goes down to a mere 15 parts per minute. Small parts may be produced at a rate of several thousands per minute. The presses can be mechanical or hydraulic. Mechanical presses operate at greater speeds than hydraulic ones. 

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