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"Year of the Productive Diversification and Strengthening Education"

PRIVATE UNIVERSITY

"NORBERT WIENER"

Subject                   : English for Engineering

  Teacher                     :      Lic. José Urbizagástegui Vásquez

    MEMBERS                    :                  

• Ayma Chaupis Edward
• Carhuarupay  Alarcon Juan Carlos
• Escajadillo Quispe Jamir
• Méndez Marcelo Aracelli
• Ochoa Luyo Irwin

                        FACULTY               :      Industrial Engineering and Management

TURN                    :     Night

CYCLE                   :      V

LIMA – PERU

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Index

Presentation

What laser welding of polymers?..............................................................3

Applications of laser welding of polymers……………………………………………….4

The advantages of laser welding of polymers……………………………………………5

Welding techniques ……………………………………………………………………...6

Process description………………………………………………………….……………7

Conclusions...………………………………………………………………..…….……15

Bibliography...…………………………………………………………………......……15

PRESENTATION

Laser welding of plastic parts has established itself as a robust, flexible and precise joining process. Laser welding enables highly efficient and flexible assembly from a small-scale production of parts with complex geometries to a high volume industrial manufacturing, where it can be easily integrated into automation lines.

This highly repeatable and clean process with no relative parts movement during the welding cycle offers numerous advantages. Thanks to its localized heat input and low mechanical stresses, this process enables welding of sensitive assemblies in medical device manufacturing, industrial and consumer electronics and automotive components without damaging delicate inner components by heat or vibrations.

LASER WELDING OF POLYMERS

1.  What Laser Welding Of Polymers?

Plastic welding is a process to join parts of thermoplastic materials incorporated. Welding takes place by softening of the areas to be joined. The polymer molecules acquire a certain mobility action of an external agent (heat, vibration, friction, solvents, etc.). When both pieces together and applied pressure, the interaction of the molecules on both sides to be joined, interlacing is achieved. Upon cessation of the action of the external agent, it decreases the movement of molecules being formed an interlocking structure thereof, forming the union of both plastic parts.[pic 6]

With this technology only binding region is heated and no mechanical stresses, and the process is suitable even for sensitive components such as electronics or medical technology.

Because the surfaces are to be thermo plastic state, by this method and thermoset elastomers own disadvantage welding method excludes materials, in addition to this should be ensured in case they are two different thermo stable materials your melting point is near, and its coefficient of viscosity is similar to melt, allowing a homogeneous combination of materials.

1. Applications of Laser welding of polymers

• Transmission parts in the automotive industry.
• Parts transmissions in medicine industry 
• Large individual parts.
• Large and with good finishes Series.
• Appliance parts.
• Parts for the aviation industry of aluminum, titanium or nickel.
• Railroad industry.
• Pressure vessels.
• Food industry, when making food packaging, cutting blades.
• Medical and surgical instruments.
• Dentistry.[pic 7]

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1. The advantages of laser welding of polymers

     Laser welding of polymers offers unique advantages as

• contactless processing without leaving any traces on the joining components.
• No particles released in the welding area; and generation of a reduced heat affected zone
• Moreover, it is the most precise of all welding methods.
• Non-contact and vibration-free energy input, the precise control of the deposited energy and thus the related reproducibility and low thermal load of the parts
• The decreasing costs for laser source and beam guiding system are enhancing these advantages and making laser welding even more competitive compared to other joining technologies.

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1. WELDING TECHNIQUES

A number of techniques are used for welding of plastics. In general, the different ways of joining plastic parts by welding can be grouped into four main sections:

• Using a heat input external heating element: a technique that is intended to thermoplastics, before the temperature rise, merge, join being able molten compression surfaces;
• For high frequency emission of ultrasound: a method that is to issue waves of a certain frequency in the bonding surfaces, creating an effect of vibration between molecules of the material, which causes an increase in temperature and softens.
• By issuing laser beam, a system which reserves to attach small parts in certain areas, emitting a laser beam heats the surface to be welded;
• By vibration: a highly reliable process that can handle large pieces of demanding materials or multiple parts per cycle with ease.

• Another plastic welding technique which we should mention, quite used both industrial and domestic, is the chemical welding using solvents.[pic 11]

1. Process description

The bonding process in laser welding is based on converting radiant energy into heat via absorption in the material, leading to local fusion junction region. The basic requirement for the transmission process is therefore a convenient combination of materials.

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