Describe the extrution process, Mechanical Engineering

Assignment Help:

Q. Describe the extrution process?

The extrusion process, in many cases produces material in an intermediate form for subsequent reprocessing to its final component form. The process is the same as for metals, that is, the expulsion of material through a die of the required cross-section. Simplicity in operation and a controlled pressure which can be virtually high as required. If the polymer can be plasticized by pressure, then the ram extruder is advantageous in view of its simplicity. But for plastics which require heat, the separate pre-processing mat be regarding as a draw back. Another major drawback of this type of machine is the reciprocating action of ram which is time wasting since the ram must be withdrawn after its power stroke and a new dolly of material inserted in the container. Also, with many materials, the die office must be cleaned between each working stroke.

Nowadays, the ram machine is mainly used for "wet extrusion" that is for extruding plastics which have been softened by the addition of solvents. Solvent has to be removed.

For extrusion of plastics, single-screw machine has completely replaced the ram type machine. There are two basic types of screw extruders: the melt extruder and the plasticizing extruder. In the formal, the material is delivered to the extruder already melted and thus the function of the extruder is merely to push the material to the die and through the orifice. In the plasticizing extruder the material is in the form of granules or particles and so the extrude has to compress and work it until it melts before delivering it, under pressure, to the die orifice.


Related Discussions:- Describe the extrution process

Higher engineering mathematics by bs grewal, give me the solutions for high...

give me the solutions for higher engineering mathematics by bs grewal

Determine mass of air needed for complete combustion, How are fuels divided...

How are fuels divided ? Write disadvantages and advantages of each types. (b) A sample of coal supplied to a boiler has the following composition by mass : Carbon = 88%, Hydr

Plate clutch lifter bolts for even tightening, Plate clutch lifter bolts fo...

Plate clutch lifter bolts for even tightening : Reset clutch assembly using plate lifter clutch alignment tool.

Time and cost analysis, Time and Cost Analysis This discusses about ce...

Time and Cost Analysis This discusses about certain basic activities that must be carried out in a factory to convert raw materials into finished products. These activities br

What are combined footings, What are combined footings? COMBINED FOOTIN...

What are combined footings? COMBINED FOOTINGS: When a footing supports two or more columns in the same line, it is called a combined footing. The combined footing which supp

Determine the heat addition, Describe carburetion. What are the basic diffe...

Describe carburetion. What are the basic different air-fuel mixture on which an engine can be operated ? Write a short note on sterling cycle. In an engine working on inlet pres

Determine net force acting on the piston, A Single Cylinder Vertical Engine...

A Single Cylinder Vertical Engine has a stroke of 40cm and a bore of 30cm. The connecting rod is 100cm long. The mass of the reciprocating parts is 140Kg on the expansion stroke wi

Determine elongation of bar, Determine elongation of bar: A conical b...

Determine elongation of bar: A conical bar tapers uniformly from diameter of 4 cm to 1.5 cm in length of 40 cm. If axial force of 80 kN is applied at each end, determine elon

Advantages of using cam, 1. Greater Design Freedom : Any changes that are ...

1. Greater Design Freedom : Any changes that are required in design can be incorporated at any design stage without worrying about any delays since there would hardly be any i

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd