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major drawback of this type of machine is the reciprocating action of ram which is time wasting since the ram must be withdrawn after its power stroke and a new dolly of material inserted in the container.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

Write the types and functions of column, Write the types and functions of c...

Write the types and functions of column. a) Explain surveying. Brie?y describe about the chain and accessories

Screw jack, give equivalence of screw jack and friction on an inclined plan...

give equivalence of screw jack and friction on an inclined plane

Clearence, what is clearance?what is the need of clearance?differences betw...

what is clearance?what is the need of clearance?differences between with clearance and with out clearance?

What are the several factors affecting tool life, (a) Draw a single point c...

(a) Draw a single point cutting tool and label clearly the several parts of it. Illustrate them in brief. (b) What are the several factors affecting tool life ? (c) List char

If engine does not start in wet or damp weather, If Engine Does Not Start i...

If Engine Does Not Start in Wet or Damp Weather Causes of Problem Remedy   Insulators are not clean and dry Fuel t

.VIABRATIONS, WHAT IS DAMP VIBRATION FACE ANGLE SIMPLE HARMONIC MOTION NAT...

WHAT IS DAMP VIBRATION FACE ANGLE SIMPLE HARMONIC MOTION NATURAL CIRCULAR FREQUENCY FORCE VIBRATION

Find the velocity and acceleration of the slider, Question: The disk 3 ...

Question: The disk 3 shown in the figure rotates at a constant angular velocity ω 3 = 2.0 rad/s. A slider in a slot in the disk causes rod 2 to rotate.  When the slider is

Vibration, A bump/impact test is a simple technique used to determine a str...

A bump/impact test is a simple technique used to determine a structure’s natural frequency. Sketch a typical time wave response curve of such a test, then label the impact point an

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.

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