Polymer Processing and Material Properties: A Comprehensive Look
Polymer Forming Processes
- Extrusion: Circulating granulated plastic inside a heated tube. The plastic mass is pushed out at one end of the tube, where it is given shape and cooled.
- Blow Molding: A tube is extruded and enclosed inside a mold under pressure.
- Injection Molding: Granulated plastic is circulated inside a heated tube. When the melt reaches the end of the tube, the screw is removed, and then the finished piece is ejected.
- Foam Molding: The material is placed within a mold and heated. The
Capacitors, Magnetic Fields, and Transistors: Electrical Components
Capacitors
Condensers are composed of two metal plates, called armatures, separated by an insulating material called the dielectric. When a voltage is applied, the dielectric prevents current flow, causing charge accumulation on the armatures. Negative charge accumulates on the armature connected to the battery’s negative pole, and positive charge accumulates on the armature connected to the positive pole.
The dielectric becomes polarized due to the accumulated charge. When the voltage is disconnected,
Read MoreMeasurement and Detection Devices: Types and Uses
Types of Measurement and Detection Devices
Detection Devices
Detection devices are responsible for perceiving the proximity of an object or its position. If the detection is performed by physical contact with the object, they are electromechanical switches. These are the most used position switches and they detect the position of an object. If the detection is done without physical contact, it is called proximity detection. Within the latter, there are AC, DC, and photoelectric types.
Measuring Apparatus
These
Read MoreKey Alloying Elements in Steel: Properties and Uses
Nickel
Nickel was one of the first metals used as an alloying element in the manufacture of special steels. This element was first used in the late nineteenth century. It was noted that adding 2-5% nickel to carbon steels increased their strength and yield strength without reducing toughness.
Nickel is an extremely important element in the manufacture of stainless steel and provides resistance to high temperatures. These steels are austenitic at room temperature and do not support tempering. The iron-
Read MoreElectrical Machines: Types, Composition, and Operation
1.1. Electrical Machines
Electrical machines are devices capable of converting electrical power to create or use mechanical energy, or vice-versa.
Rating
Generators
Generators convert mechanical energy into electrical power.
Types:
- Dynamo: Generates direct current (DC) power.
- Alternator: Generates alternating current (AC) power.
The induced electromotive force (EMF) is calculated to determine the power generated.
Transformers
Transformers convert alternating electrical current at one voltage and current level
Read MoreMechanical Joints, Welding, and Manufacturing Processes
Types of Joints
Demountable: These joints allow you to separate or remove parts without damaging or breaking the union.
Fixed: These joints do not provide for the separation of parts.
Threads
A thread is any mechanical element that has a propeller-shaped channel constructed on a continuous cylinder.
Types of Threads
- According to the shape: Triangular, trapezoidal, square, round.
- According to the number of entries: 1 to 2.
- According to the direction of turn: Right or left.
Classes of Studs
Cylindrical pins,
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