The presentations helps us to understand about plastic welding and its different classifications. Further it gives a brief idea about the various industrial applications and latest developments in this field.
The presentations helps us to understand about plastic welding and its different classifications. Further it gives a brief idea about the various industrial applications and latest developments in this field.
Experimental study on ultrasonic welding of aluminum sheet to copper sheeteSAT Journals
Abstract Ultrasonic welding is devoted to weld thin sheet metals of similar or dissimilar couples of non-ferrous alloys like copper, aluminum and magnesium without addition of filler material resulting in high quality weld; it can count on a low energy consumption and on a joining mechanism based on a solid state plastic deformation which creates a very homogeneous metallic structure between the base materials, free from pores & characterized by refined grains and confined inclusions’ Ultrasonic metal welding can join also painted or covered sheet metals. Thin sheets of aluminium have been joined to thin copper sheets by means of Ultrasonic spot Welding. Results are particularly effective in order to evaluate the relevance of various phenomena influencing the lap joint technique obtained on thin aluminium and copper by the application of Ultrasonic Metal Spot Welding (USMSW). The Present study considers the experiments carried out on the aluminum and copper sheets joints at room temperature. The aim is to evaluate the relevance of various factors influencing the lap joining technique, allowing a deep understanding of the phenomena and the possibility to keep them under control; in the meantime, the feasibility and relevance of the proposed hybrid joining technology is discussed.. Keywords: Ultrasonic Metal Spot Welding, Aluminum, Copper, Fusion
Non-traditional manufacturing processes is defined as a group of processes that remove excess material by various techniques involving mechanical, thermal, electrical or chemical energy or combinations of these energies
Experimental study on ultrasonic welding of aluminum sheet to copper sheeteSAT Journals
Abstract Ultrasonic welding is devoted to weld thin sheet metals of similar or dissimilar couples of non-ferrous alloys like copper, aluminum and magnesium without addition of filler material resulting in high quality weld; it can count on a low energy consumption and on a joining mechanism based on a solid state plastic deformation which creates a very homogeneous metallic structure between the base materials, free from pores & characterized by refined grains and confined inclusions’ Ultrasonic metal welding can join also painted or covered sheet metals. Thin sheets of aluminium have been joined to thin copper sheets by means of Ultrasonic spot Welding. Results are particularly effective in order to evaluate the relevance of various phenomena influencing the lap joint technique obtained on thin aluminium and copper by the application of Ultrasonic Metal Spot Welding (USMSW). The Present study considers the experiments carried out on the aluminum and copper sheets joints at room temperature. The aim is to evaluate the relevance of various factors influencing the lap joining technique, allowing a deep understanding of the phenomena and the possibility to keep them under control; in the meantime, the feasibility and relevance of the proposed hybrid joining technology is discussed.. Keywords: Ultrasonic Metal Spot Welding, Aluminum, Copper, Fusion
Non-traditional manufacturing processes is defined as a group of processes that remove excess material by various techniques involving mechanical, thermal, electrical or chemical energy or combinations of these energies
Sarit harel date with a startup (pairup)Sarit Harel
Marketers to maximize the return on their investments
Innovators to create more successful propositions.
CEO’s to grow profits through the customer - Centricity
Plan nacional estrategico de ciencia tecnología e innovación para la competit...Γινo βoςio
En el 2005 el Perú tiene 28 millones de habitantes, de los cuales el 72% reside en áreas urbanas y el 28 % en áreas rurales. Esta población está fuertemente centralizada en Lima, donde habita el 32% de la población nacional y se produce el 45 % del PBI.
La pobreza afecta a 14 millones de personas, de las cuales 6 millones están en situación de extrema pobreza5. El Informe de Desarrollo Humano en el Perú 2002 constata severas desigualdades socio-económicas: el 20% más rico de la población obtuvo el 48% del ingreso nacional, mientras que el 20% más pobre sólo el 6% del ingreso.
Esta población pobre no tiene acceso a los beneficios del progreso científico y tecnológico para satisfacer sus necesidades de alimentación, salud, vivienda, educación, comunicaciones y recreación, entre otras; condición que les impide adquirir capacidades para acceder a empleos de calidad y a contribuir a la mejora de los procesos productivos.
El país viene poniendo en marcha diversas políticas para reducir la exclusión y la desigualdad social, sin tomar debidamente en cuenta el potencial de la CTI para lograr esos objetivos. Los pequeños productores rurales y los microempresarios urbanos, en su mayoría, no se asocian en redes y son marginales al avance tecnológico. La educación básica se encuentra entre los niveles más bajos en el ámbito latinoamericano, lo que no favorece la formación de científicos, tecnólogos y técnicos en especialidades vinculadas con ámbitos prioritarios para el desarrollo del país.
El saber tradicional ha mantenido su vigencia a lo largo del tiempo, poniendo en evidencia su integración orgánica en la realidad local, siendo ese saber compatible con el conocimiento moderno, hecho que se constata en el empleo de conocimientos ancestrales en los actuales procesos productivos y en la organización comunitaria para el trabajo. Aunque las tecnologías tradicionales están siendo revaloradas en el marco de los enfoques multiculturales, se encuentran amenazadas de perderse o debilitarse debido a la insuficiencia de los mecanismos de protección de la propiedad intelectual colectiva de las comunidades nativas.
CTI, Recursos Naturales y Medio Ambiente
El Perú tiene una posición geográfica favorable, al estar ubicado en el centro - oeste de América del Sur, en que tienen lugar importantes flujos del intercambio en las cuencas del Pacífico y del Amazonas. A través de los corredores interoceánicos ingresará en nuevos circuitos de transporte, intercambio y comunicaciones internacionales. Posee un territorio con una amplia diversidad biológica, geológica y climática, lo que le confiere una importancia estratégica para la producción e intercambio de bienes y servicios. Esta condición constituye una potencialidad que aun no es debidamente aprovechada.
Having spent the summer with 4 organisations that are developing shared leadership, happy to share my first findings of the project with Flanders Synergy.
If you would like to read further, take a look at the notes to see our further analysis.
Brand Management Final Project - Sprint Brand Audit
The University of Texas at Austin
McCombs School of Business
A unique perspective on what skills are needed for people wanting to work in or make a career of CSR
To keep updated on postings and events go to www.csrtraininginstitute.com and sign up for the newsletter. If interested the CSR Knowledge Centre http://bit.ly/CSRknowledge contains a series of short, pragmatic articles on CSR Strategy, Management and related areas.
INFORUM - VEILIGHEIDSPROBLEMEN VOOR BIBLIOTHEEK EN ARCHIEF IN HET DIGITALE TI...B.A.
Deze presentatie gaat in op de praktische uitdagingen voor bibliotheken en archieven op het vlak van informatiebeveiliging. De uitdagingen zijn veelvuldig: van de valkuilen bij het digitaliseren van traditionele documenten om ze voor de toekomst te preserveren over vaak enorme volumes aan data tot het op een veilige manier online ontsluiten van deze collecties. Een paar dingen om rekening mee te houden bij digitale archieven.
CFD INVESTIGATION OF MECHANICAL SEAL FOR IMPROVE THERMAL PROPERTY BY USING D...Er Sandeep Duran
The paper constitutes the method to improve the heat transfer rate in mechanical seal for decreasing the interface temperature of the seal face. Different factors that affect the performance of mechanical seal are friction, wear and its thermal characteristics. Concept of Fourier’s law of heat conduction through cylindrical surfaces is used for optimizing the heat transfer rate. Composite material for mating ring with different thermal conductivity is used to increase the heat transfer rate to enhance the seal performance.
Cfd investigation of mechanical seal for improve thermal property by using di...eSAT Journals
Abstract Heat accumulation is the major cause that leads to change in material properties affecting seal performance, hence heat dissipation is required. The paper constitutes the method to improve the heat transfer rate in mechanical seal for decreasing the interface temperature of the seal face. Different factors that affect the performance of mechanical seal are friction, wear and its thermal characteristics. Concept of Fourier’s law of heat conduction through cylindrical surfaces is used for optimizing the heat transfer rate. Composite material for mating ring with different thermal conductivity is used to increase the heat transfer rate to enhance the seal performance. Properties of Carbon graphite and silicon carbide were used in the Simulation and simulation was performed using ANSYS Mechanical Module 14.5 and CFD FLUENT. Simulated values for the mating ring made of single material and the composite ring was observed and compared. The interface temperature of the mating ring is effectively decreased, due to increase in heat dissipation. Keywords – Frictional heat, Interface temperature, Leakage, Mating ring, Mechanical seal, Thermal conductivity and Thermal effects.
Study of sliding wear rate of hot rolled steel specimen subjected to Zirconia...IJERA Editor
Wear is nothing but loss of material by usage. In a mechanical industry mechanical components will operate
under severe load, temperature and high speeds. Under such a type of situation, when metal to metal contact take
place the surfaces that comes in contact is subjected to wear. These should be considered as a serious affair in an
industry because if the process of wear continues it can reduce service life of the component and also to the
entire mechanical system to which the component has been used. In the light of the above the present work
mainly deals with the study of wear behavior of hot rolled steel with and without zirconia coating on the contact
surface and the effect of zirconia coating with varying thickness.
A Good Alternative: Press Fitting vs. Welding in Pipe SystemsJoseph_Tivey
Welding has long been a staple in pipe production, particularly in tube joining. The use of welding, however, presents a constant risk of fire and electrocution, among others. As an alternative to welding in the process of tube joining, more industries are adopting press fitting tools to avoid health and safety hazards as well as reduce installation time.
The desired to reach higher efficiencies, lower specific fuel consumption and reduced emission in modern engines has becomes the primary focus of engine researches and manufactures over the past three decades. Ceramic coating is a solution to such problem as they provide good thermal barrier properties for designers. In the design of adiabatic engines, reducing in cylinder heat rejection requires very special thermal barrier coatings on the engine combustion chamber. Partial Thermal barrier coatings (TBC) on the top surface of the piston is considered as a solution for reduction of unburned Hydrocarbon (HC) emission produce by incomplete combustion with respect to crevice volume when engines start. The TBC on the top piston surface decreases the thermal conductivity and increases the unburned charged oxidation, so that the metallic substrates will be exposed to lower peak temperature thereby reducing the thermal stress in engines components. Also thermal barrier coatings on other elements of combustion chamber of internal combustion engine offer advantages including fuel efficiency, multi fuel capacity and high power density. Therefore, thermal barrier coating (TBC) technology is successfully applied to the internal combustion engines, in particular to the combustion chamber.
The Indian economy is classified into different sectors to simplify the analysis and understanding of economic activities. For Class 10, it's essential to grasp the sectors of the Indian economy, understand their characteristics, and recognize their importance. This guide will provide detailed notes on the Sectors of the Indian Economy Class 10, using specific long-tail keywords to enhance comprehension.
For more information, visit-www.vavaclasses.com
The Art Pastor's Guide to Sabbath | Steve ThomasonSteve Thomason
What is the purpose of the Sabbath Law in the Torah. It is interesting to compare how the context of the law shifts from Exodus to Deuteronomy. Who gets to rest, and why?
This is a presentation by Dada Robert in a Your Skill Boost masterclass organised by the Excellence Foundation for South Sudan (EFSS) on Saturday, the 25th and Sunday, the 26th of May 2024.
He discussed the concept of quality improvement, emphasizing its applicability to various aspects of life, including personal, project, and program improvements. He defined quality as doing the right thing at the right time in the right way to achieve the best possible results and discussed the concept of the "gap" between what we know and what we do, and how this gap represents the areas we need to improve. He explained the scientific approach to quality improvement, which involves systematic performance analysis, testing and learning, and implementing change ideas. He also highlighted the importance of client focus and a team approach to quality improvement.
Instructions for Submissions thorugh G- Classroom.pptxJheel Barad
This presentation provides a briefing on how to upload submissions and documents in Google Classroom. It was prepared as part of an orientation for new Sainik School in-service teacher trainees. As a training officer, my goal is to ensure that you are comfortable and proficient with this essential tool for managing assignments and fostering student engagement.
Read| The latest issue of The Challenger is here! We are thrilled to announce that our school paper has qualified for the NATIONAL SCHOOLS PRESS CONFERENCE (NSPC) 2024. Thank you for your unwavering support and trust. Dive into the stories that made us stand out!
How to Split Bills in the Odoo 17 POS ModuleCeline George
Bills have a main role in point of sale procedure. It will help to track sales, handling payments and giving receipts to customers. Bill splitting also has an important role in POS. For example, If some friends come together for dinner and if they want to divide the bill then it is possible by POS bill splitting. This slide will show how to split bills in odoo 17 POS.
Welcome to TechSoup New Member Orientation and Q&A (May 2024).pdfTechSoup
In this webinar you will learn how your organization can access TechSoup's wide variety of product discount and donation programs. From hardware to software, we'll give you a tour of the tools available to help your nonprofit with productivity, collaboration, financial management, donor tracking, security, and more.
Students, digital devices and success - Andreas Schleicher - 27 May 2024..pptxEduSkills OECD
Andreas Schleicher presents at the OECD webinar ‘Digital devices in schools: detrimental distraction or secret to success?’ on 27 May 2024. The presentation was based on findings from PISA 2022 results and the webinar helped launch the PISA in Focus ‘Managing screen time: How to protect and equip students against distraction’ https://www.oecd-ilibrary.org/education/managing-screen-time_7c225af4-en and the OECD Education Policy Perspective ‘Students, digital devices and success’ can be found here - https://oe.cd/il/5yV
The French Revolution, which began in 1789, was a period of radical social and political upheaval in France. It marked the decline of absolute monarchies, the rise of secular and democratic republics, and the eventual rise of Napoleon Bonaparte. This revolutionary period is crucial in understanding the transition from feudalism to modernity in Europe.
For more information, visit-www.vavaclasses.com
The French Revolution Class 9 Study Material pdf free download
Welding plastics
1. Welding of Plastics
Amit Mukund Joshi
(B.E Mechanical, A.M.I.Prod.E)
Introduction
Mechanical fasteners, adhesives, and welding processes can all be employed to form joints between
engineering plastics. Mechanical fasteners can join two components quickly, but they do not provide leak
tight joint, and the localized stresses may cause them to pull free of the polymeric material.
Adhesives can provide good properties and fully sound joints, but they are difficult to handle and slow to
cure. Also joint preparation & surface cleanliness need to be given importance in adhesive bonding.
Welding can be used to produce bonded joints with mechanical properties that approach those of parent
material. The plastic welding is confined to thermoplastic polymers because these materials can be
softened by heat. Thermosetting polymers once hardened cannot be softened again on heating. The heat
required for welding thermoplastic polymers is less than that required for metals.
Plastic welding processes can be divide into two groups: -
a) Processes involving mechanical movement – ultrasonic welding, friction welding, vibration welding.
b) Processes involving external heating – hot plate welding, hot gas welding and resistive and implant
welding.
Processes
1) Ultrasonic welding
This method uses mechanical vibrations to form the joint. The vibrations are of high frequency. The parts
to be assembled are held together under pressure between the oscillating horn and an immobile anvil and
are subjected to ultrasonic vibrations of frequency 20 to 40 KHz at right angles to the contact area.
Alternating high frequency stresses generate heat at joint interface to produce a good quality weld. The
tools for this process are quite expensive so that large volume production runs are preferred.
The welding is limited to small components with weld lengths not exceeding few centimeters.
Applications range from valves and filters used in medical equipment, to cassette bodies, automotive
components and vacuum cleaner bodies welded on multi-head machines.
2. Ultrasonic Welding Device
2) Friction Welding
The friction welding of thermoplastic (also called spin welding) is based on the same principle as that
employed for welding metals. In this process one of the substrates is fixed, while the other is rotated with
a controlled angular velocity. When the parts are pressed together, frictional heat causes the polymer to
melt and a weld is created on cooling. Major welding parameters include rotational speed, friction
pressure, forge pressure, weld time and burn off length.
The advantages of friction welding are high weld quality and the simplicity and reproducibility of
the process. The drawback of this process is that, in its simplest form it is suitable only for
applications in which at least one of the components is circular and requires no angular alignment.
3. (a) (b)
(c) (d)
Arrangement for rotary friction welding
(a) Rotary member brought up to speed (b) Rotary member advanced into contact under axial load
(c) Rotary contact pressure maintained for specified period.
(d) Rotation stopped and pressure maintained or increased for specified period to produce weld.
3) Vibration Welding
This process is also called linear friction welding. Two thermoplastic parts are rubbed together under
pressure and at a suitable frequency and amplitude, until enough heat is generated to melt the polymer.
After vibration is stopped, the parts are aligned and the molten polymer is allowed to solidify creating the
weld. The process is similar to spin welding, except the motion is linear rather than rotational. The
process is rapid; the vibrations applied typically of 100 – 240 Hz, 1-5 mm amplitude.
The main advantage of this process is its ability to weld large complex linear joints at high
production rates. Other advantages are the ability to weld a number of components simultaneously,
simplicity of tooling and suitability for welding almost all thermoplastic materials. Vibration welding
has found its principal applications in the automobile and domestic appliance industry.
Vibration welding can be applied to almost all thermoplastic materials, whether injected molded,
extruded , blow moulded, thermoformed, foamed or stamped.
4) Hot Plate Welding
It is the simplest of the mass production techniques to join plastics. A heated plate is clamped between the
surfaces to be joined until they soften. The plate is then withdrawn and the surfaces are brought together
again under controlled pressure for a specific period. The fused surfaces are allowed to cool, forming a
joint. The welding tool or heating element has built in electric heaters to prevent the plastics sticking to it.
4. Temperatures are generally between 1800
C and 2300
C depending on the thickness and type of the
material to be welded. This process is commonly used to weld together the butt ends of plastic pipes used
in gas and water distribution, sewage and effluent disposal and in chemical industries; attachment of filler
tubes and connectors onto blow molded fuel tanks for automotive applications.
Many items of daily use are produced by this process – vacuum cleaner housings, components
for washing machines and dishwashers, automotive parts such as brake fluid reservoirs, rear lights,
indicator lights, etc. The drawback of this process is that it is relatively slow. Weld times range from 10 to
20 seconds for small items and to as much as 30 minutes for very large pipes. Hot plates for conventional
type of welding (using temperature up to 3000
C) are made mainly of aluminium. Hot plates for high
temperature welding mainly consist of aluminium copper alloy. The temperature of hot plates is
controlled by electronic regulators, with the thermosensor located as close as possible to the working
surface.
5) Hot Gas Welding
This is similar to oxy-acetylene welding of metals. The only difference is that the open flame of oxy-
acetylene welding is replaced by a stream of hot gas. Compressed air, nitrogen, hydrogen, oxygen or
carbon dioxide is heated by an electric coil as it passes through a welding gun.
Hot gas welding is a fabrication process for thermoplastic materials. The process, invented in the mid 20th
century, uses a stream of heated gas, usually air, to heat and melt both the thermoplastic substrate material
and the thermoplastic welding rod. The substrate and the rod fuse to produce a weld. To ensure welding
takes place, adequate temperature and pressure must be applied to the rod, along with the use of the
correct welding speed and gun position.
Typical applications include chemical storage vessels, ventilation ducting and repair of plastic
moldings such as car bumpers. Nitrogen is used for oxygen sensitive plastics such as polyethylene while
oxygen results in higher weld strengths. Compressed air is popular since it gives satisfactory results for
many purposes and is cheap.
Hot Gas Welding
5. Plastics, which can be welded, are PVC, polyethylene, polycarbonates and nylons. The main advantage
of this process is that large, complex fabrications can be constructed. This process is slow
and the weld quality is entirely dependent on the skill of the welder.
6) Implant Welding
In this process, metal inserts are placed between the parts to be joined and are then heated by means of
induction or resistance heating. The resistance method requires that wires be placed along the joint to
carry current to the implants; this is not required for induction welding. The thermoplastic material melts
around the implants and flows to form a joint. Implant welding has been applied to complicated joints in
large components such as vehicle bumpers, electrically driven vehicles and sailing dinghy hulls.
New Methods
Laser welding is suitable for joining both sheet film and molded thermoplastics. It uses a laser beam to
melt the plastic in the joint region. The laser generates an intense beam of radiation (usually in the infra
red area of the electromagnetic spectrum) which is focussed onto the material to be joined. This excites a
resonant frequency in the molecule, resulting in heating of the surrounding material.
Laser welding is a high volume production process with the advantage of creating no vibrations
and generating minimum weld flash. The benefits of a laser system include; a controllable beam power,
reducing the risk of distortion or damage to components; precise focussing of the laser beam allowing
accurate joints to be formed; and a non contact process which is both clean and hygienic. Laser welding
may be performed in a single-shot or continuous manner, but the materials to be joined require clamping.
Weld speeds depend on polymer absorption.
References
1) E.Paul Degarmo, J.T Black, Ronald A Kohser, Materials and processes in manufacturing, Prentice
Hall, India.
2) Robert A Grimm, Welding processes for plastics, Advance materials and processes, vol 147, 1995.
3) Joining plastics in production, The welding institute.
Amit M Joshi
amitmech@hotmail.com
amitmechindia@yahoo.com