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  Tube Sinking (Manufacturing Process)

Tube Sinking (old)

There is no old answer.

Tube Sinking (new)(better)

Thick-walled tubes and those less than 12 mm (0.5 in.) in diameter are often drawn without a mandrel in a process known as tube sinking. Precise control of the inner diameter is sacrificed in exchange for process simplicity and the ability to draw long lengths of product. The wall thickness can increase, decrease, or remain the same, depending on the die angle and other process variables. Low die angles tend to favor wall thickening, while larger angles promote thinning. Because a mandrel is not used, long lengths are possible.

(DeGarmo's Materials and Processes in Manufacturing, Yazar: J. T. Black,Ronald A. Kohser, page:426)

Extruder (Blow Molding Equipment)

Extruder (old)

There is no older definition.

Extruder (new)(better)

The extruder is the heart of the melt preparation sytem and must deliver a homogenous and stable melt to the accumulator head. Typical extruder sizes for blow molding range from 64 mm (2.5 in), 76 mm (3 in), 89 mm (3.5 in), 114 mm (4.5 in), to 152 mm (6 in) diameters and usually have 24:1 or 30:1 L/D ratios.

From the exa mple discussed earlier in this sect,on, 272.4 kg/h (600 lb/h) are required. A 89 mm (3.5 in) 24:1 extruder has the capacity to produce at this range at 100% output. The logical choice is to size the extruder to be 114 mm (4.5 in) 24:1. This will allowfor future output expansion.

During operation, 80 percent of the heat developed in the process is developed by frictional heat from the feedscrew revolving within the barrel. Therefore, it is preferable to run the extruder at lower speeds to produce the desired output.

(Understanding Blow Molding,Yazar: Norman C. Lee, page:44)