official journal of aluminium extruders' council alex ...alexindia.co.in/alex-journal...

Issu

e 10

AUGUST 2

011Official Journal of Aluminium Extruders' Council

ALEXALEXALEX

INDEX

Editor

[email protected]

Editorial CommitteeN. S. Parulekar

[email protected]

Rajeev Sherry

[email protected]

R. Haridass Menon

[email protected]

PublisherR. T. Kulkarni

[email protected]

Hon. Secretary

Aluminium Extruders' Council

Anand Joshi

37/4/A, 6th Lane, Prabhat Road, Pune 411 004. India, Tel.: 25670808, 25674455, E-mail : [email protected]

Issue 10, AUGUST 2011

Aluminium Extruders' Council (ALEX)

www.alexindia.co.in

ALEXOfficial Journal of Aluminium Extruders' Council

Creative World of Light Metal

TRUSTEES

R. K. Sharma

Gopal M. Pai

R. T. Kulkarni

R. Haridass Menon

Anand Joshi

H. T. Makhijani

T. M. Malkani

S. K. Mongia

Dr. M. Nilmani

International Aluminium Institute - Life cycle 02

Inventory of the Worldwide Aluminium Industry

With regard to Energy Consumption and

Emissions of Greenhouse Gases

Automotive

Aluminium Extrusions in Solar Lighting 03

Finishing Of Aluminium Profiles - Present & 05

Future

Preventive Maintenance 12

The substitution of aluminium for higher density traditional International Aluminium Institutematerials saves 2.5 metric tons of CO2 equivalent (878

litres of gasoline ) over lifetime of today's average north Life cycle Inventory of the Worldwide Americans passenger car or light truck. If the use of

Aluminium Industry With regard to aluminium to replace traditional materials continues to

grow from president average of 130 KGs to 277 KGs the Energy Consumption and Emissions of potential saving per vehicle would increase to 5 metric tons

of CO2, the equivalent of 1,756 litres of gasoline. Greenhouse GasesThe data on primary aluminium was derived from

independent and comprehensive studies of bauxite mining Automotive,refining, smelting, and ingot casting from the European

This report's findings show that aluminium products help to Aluminium Association (AA), and the Australian reduce greenhouse gas emissions from transport. Every Aluminium council (AAC). The EAA and AA provide data kilogram of aluminium that replaces traditional higher on recycled aluminium. Each of these studies, and the density materials in a vehicle today saves the equivalent of report itself, were reviewed by external life cycle experts 20 grams of carbon-di-oxide emissions over the life time of and are in agreement with current emerging international the vehicle. The average aluminium content in the organisation for standardisation (ISO) standards for life automotive market has increased over the past 15 years. cycle inventory assessments.For example, aluminium use has increased from 64

The full report can be found on the IAI's website while on kilograms to about 113 kilograms per vehicle in the 1999

expanded summary and a brochure detailing the results north American fleet and is anticipated that the use of

can be obtained from the IAI secretariat.aluminium in automobiles will continue to grow. Aluminium

www.world-aluminium.org shipments to the transport sector have increased the

worldwide by over one million tonnes per year during the (compiled by R. H. Menon)past decade. In addition to striving to improve its own

performance, the industry is also helping its car ,truck, and

railcar-manufacturing customers to fulfil their objectives of

improving fuel efficiency and reducing GHG emission.

The report concluded that;

Each kilogram of automotive aluminium replacing

traditional higher density materials can save a net 20

kilograms of CO2 equivalents due mainly to the efficiencies

of lightweighting. The magnitude of this saving is

influenced by a critical set of factors such as the average

distance a vehicle is driven over its lifetime, fuel saving that

results from lightweighting , and the substitution rate of

aluminium for other heavier materials. The impact of these

factor was evaluated using a multi-parameter sensitivity

analysis and the CO2 savings were positive under all sets

of assumptions.

Recovering and re melting aluminium scrap saves more

than 95% of the greenhouse gas emissions associated

with primary aluminium ingot production. The aluminium

industry is working closely with the automobile

manufacturers to enable the easier dismantling of

aluminium components from cars in order to improve the

recovery of aluminium recycling rates for transport

application range from 60-90 percent in various countries.

In 1997 over 4.4 million tonnes of scrap were used in the

transport sector and the use of aluminium in automobiles is

increasing year upon year.

ADVERTISE IN ALEX JOURNALTariff for ALEX Journal

For Advertisements in Colour

Back Cover Page

Front Inner Page

Back Inner Page

Inside Pages

Six Issues

75,000/-

60,000/-

50,000/-

25,000/-

1650

1350

1100

555

Rupees US $Single Issue

15,000/-

12,000/-

10,000/-

5,000/-

300

250

220

110

Rupees US $

Full Page

Half Page

Quarter Page

Six Issues

15,000/-

12,500/-

7,000/-

350

275

225

Rupees US $Single Issue

3500/-

2500/-

1250/-

75

55

30

Rupees US $

For Advertisements in Black & White

Payment in the name of

Aluminium Extruders' Council (ALEX)payable at Pune

+ 10.30 Service Tax

Advertisement size as follows For Full page - 17 (W) x 24 (H) cms.For Half page - 17 (W) x 11 (H) cms.

02 ALEX JOURNAL - AUGUST 2011

of the lantern is small light bulbs LED (Light Emitting Aluminium Extrusions in Solar LightingDiodes). These provide sufficient light and consume

Dr M.Nilmani, small amount of power thus continuously alight up to 12

- 16 hours on a fully charged battery. Good quality Recently the author was director of a conference on

lanterns use High Brightness LED. To increase the life "Rural Energy Security" held by Indian Merchant

of these LEDs it's important that the heat generated by Chamber in conjunction with the Ministry of New &

the HB LED is dissipated efficiently. Since the heat Renewable Energy. It was attended by world experts to

transfer coefficient of extruded aluminium alloys such formulate a policy paper on distributed energy for rural

as LM 24 is almost twice that of die cast alloys, extruded sectors. As per August 2010 data 89,808 villages in

aluminium is preferred as heat sink in quality lanterns India have never seen a light bulb glowing in their

(Fig1 b). The PV solar panels use extruded aluminium hutments. They have been forced to live through the

frames. If 35 million such lanterns with aluminium pitch dark nights, no street lights, not even a single light

framed panels are to be provided, consumption of indoors, no fans thus leading a tough & unsafe life.

extruded aluminium heat sink & frames will be In India over 35 million people lack access to electricity. enormous.These communities mainly living in rural settings are

not grid connected, or grid does not have supply due to

power deficit. They are forced to light up their homes in

the evenings with kerosene or other fossil fuels.

Kerosene not only gives poor lighting but at the same

time acts as an impediment for over all development as

well as hazard for human and environmental health.

The open flame, smoke and soot from kerosene lamps

endanger lives by reducing indoor air quality and

increasing the likelihood of fire. Kerosene is expensive

for the poor villager's monthly budget. If the kerosene

lamp is replaced with a clean solar light, at no running

cost, it would make a major difference to their economy

& health. Each solar lantern in its useful life of ten years

displaces the use of about 400-500 liters of kerosene

thereby mitigating about 1.45 tonnes of CO2, assuming

4-6 liters of kerosene consumption per family per

month. It's estimated that for 1000 families of the village

1,450 tonnes of CO2 will be saved from the atmosphere

helping to mitigate global warming. The author through

his NGO is installing solar lights in villages with no

access to electricity. This gave author an excellent

opportunity to understand the major solar power

projects that are proposed for the distributed power

sector where aluminium extrusions will play a For the larger setup of solar panels on roof tops, significant role. aluminium extrusion is finding increasing use in the

fixtures to hold the panels especially on the roof top. Aluminium Extrusions in Photovoltaic (PV) Aluminium in PV systems is used predominantly in Systemsconstruction/mounting structutres (72% of total

Solar lanterns are the most basic PV system (see Fig1). aluminium input), panel frames (22%), inverters (6%). Besides the PV solar panel, one of the key components High strength to low weight ratio and ease of mounting,

Figure 1 (a) Solar Lantern and a PV Panel with extruded aluminium Frame

Figure 1 (b) Use of aluminium extruded heat sink for high brightness LED

03ALEX JOURNAL - AUGUST 2011

fitting and corrosion resistance all these factors are specific aluminium use could be as high as 131 Kg/kW.

driving the use of aluminium extrusions in solar Out of that 100 Kg/kW would be extruded aluminium.

systems. A recent review shows that between 23kg/kW Hydro is supplying extruded aluminum solar collector

to 59kg/kW of aluminium is used in the PV systems.assemblies for a new 75 megawatt CSP in Florida, the

versatility of extruded aluminum and its advantages in Aluminium Extrusions in Concentrated Solar solar structures based on its ability to minimize Power (CSP) Systems transportation, assembly costs, fewer parts and full

CSP is a parabolic trough system to create steam for recyclability are the reasons for its use.

power generation. As shown in Fig 2 each of the long Since India lies at the tropic of cancer we get abundant parallel rows of trough reflectors pivots on an axis to sunshine to make full use of solar energy. Solar energy track the daily trajectory of the Sun and focus the Sun's has become an attractive source of renewable energy energy on a tubular receiver in the focal line of the because of reduction in the cost of manufacturing of parabolic trough.

solar panel these days. Till September 2010,

off grid installed capacity of solar PV power

plants including street lighting was 100 MW.

"Jawaharlal Nehru National Solar Mission"

was launched in January 2010, which

promises to generate 1,000 MW by 2013 and

by 2022 generate 20GW, to deploy 20 million

solar lighting systems and to achieve 20

million sq. meters solar thermal collector area.

Looking to these figures demand for

aluminium extrusions in solar energy has a The Use of aluminum support structures in

bright future.concentrated solar power energy generating facilities is

About the authorgrowing. Large mirror surface reflect heat from the sun.

Extruded aluminium components eg trusses, frames,

arches, etc are used in the support structure to ensure

correct alignment of the mirrors and provides the

strength needed to withstand common forces,

stresses, movements and wind loads. The maximum

aluminium consumption is when both elevation and

collectors are made of aluminium. In that case the

Dr Nilmani is managing Director of NCS Associates

(Australia) Pty Ltd. He is also the Chief Trustee of KNCT

& Centre for Human Hope, currently working on

providing Solar Lighting to Villages as part of social

work.

n

Fig 2. FRAMES: Extrusions and connectors in aluminium form the frames on which the mirrors were mounted at Nevada Solar One.

Fig 3. On right is Reflector Trough made of glass in segments and can not withstand high force winds. On left is a mirror film laminated

to aluminium.


Italtechno, Italy has introduced a special mechanical Finishing Of Aluminium Profiles treatment. This machine is known as "SATMAC".

Treatment is carried out by means of a machinery, which - Present & Future carries out a shot blasting on the aluminium profiles. The

Aluminium by virtue of its silvery colored appearance, its finish obtained is a completely uniform mechanical etch strength to weight ratio, its excellent reflectivity and surface appearance. An immersion time of 3 to 5 minutes corrosion resistance, its availability in all types of is sufficient to obtain a finish superior to the "matt" standard mill product and complicated extruded shapes surfaces' demanded by many European countries. The and excellent finishing potential has always attracted· the process claims a saving of 75% of caustic soda attention of designers and architects. Inspite of all these consumption. versatile properties the use of aluminium in various fields,

(1) A smooth and bright surface is obtained by the especially in building and architecture would not have

following two treatments: increased to the extent it has, but for the various finishing

(a) Chemical brightening processes developed from time to time which not only

improved the abrasion and corrosion resistance of (b) Electro-chemical brighteningaluminium, but also provided the metal with various (2) attractive shades that would last for years.

(a) The chemical brightening is achieved by Almost all aluminium used in building and architecture

dipping the material in a solution containing are finished by one of the following processes:

phosphoric, sulphuric and nitric acid at 85-95°(,

The main problem of this treatment is the

orange fumes of nitrous gas and a strong fumes

suction device is essential.

(b) The electro-chemical brightening is carried out

in a solution containing phosphoric acid,

chromic acid and sulphuric acid at 75-85°C and

at a current density 5-15 ampjdm2o This

requires a high-capacity rectifier and a

substantial capital investment. ANODIZING

Anodizing of aluminium extruded profiles, treated with Anodizing is a process for producing a protective and mechanical or chemical treatment stated above or direct decorative film of aluminium oxide on aluminium and its from extruders in mill finish, is carried out in a series of in-alloys. The structure of the film formed is porous which line process tanks. enables it to absorb colors and electrolytic coloring

The sequence of operation in anodizing is as follows: produces a number of attractive shades. These colors As shown in the layout the anodizing process starts with are fast to light and weathering. jigging. Here full-length aluminium extruded sections are Major portion of aluminium profiles .are anodized in mill suspended from a specially designed flight bar suitable to finish as received from extruders and produce a good carry the necessary current required for the anodizing attractive finish. But sometimes in order to provide a process. special aesthetic appeal to the metal, these are provided

with a special mechanical or chemical treatment prior to

anodizing process.

The standard finishing on aluminium are:

(1) Mechanical Treatment;

(2) Chemical polishing or Electro-chemical brightening.

Mechanical Treatment - Mechanical Treatment are

applied to aluminium profiles by special machines fitted

with wheels that brush the aluminium surface producing

a characteristic scratched surface. Presently the brushes The sections after loading on work bars are carried to used are made of harmonic stainless steel. various tanks by an overhead transport system. If a smooth or lustrous finish is required, the wheels of the Degreasing - the process removes soils like oils, grease, machines are made of soft cotton fabrics and low lubricant etc. that are present on the profiles and make it abrasive paste is used. neat and clean for the next operation.

Finishes for Architectural Aluminium

Wet Painting Powder CoatingAnodizing

OrganicInorganic

Jigging ® DEGREASING ® Rinsing ® ETCHING

Rinsing ¬ DE SMUTIING ¬ Rinsing ¬ Rinsing

Rinsing ® ANODIZING ® Rinsing ® Rinsing

Rinsing ¬ Rinsing ¬ ELECTRO COLORING

SEALING ® Rinsing

¯

¯

¯

¯


Etching - this provides an attractive silvery satin finish on The quality of the anodized aluminium from the aspects

aluminium. This is carried out in caustic base solution. of its performance can be largely ensured by adequate

control of the following three characteristics of the film: Desmutting - this process removes the thin surface layer

of inter metallics which remain on the surface after (a) Thickness of the film;

etching. The process provides a clean passive surface (b) Completeness of sealing; for further processing.

(c) Compactness of density, which is sometimes defined Anodizing - it is generally carried out in sulphuric acid. as abrasion resistance. The parameter that governs the formation of the film are

For architectural use, the minimum anodic coating as under:

suggested is 15 microns. This may go upto 25 microns (1) The composition of electrolyte; depending on the environmental conditions. (2) Temperature;

Consistency in the quality of finish depends on (3) Current density;

(a) A process sequence that is the optimum for the (4) Air agitation; finishes being produced and the material

processed; (5) Time.

(b) A good house keeping and plant operation; Depending on the control exercised on the parameter

stated above, the oxide film produced may be thick or (c) A regular analytical control of all processes in the thin, hard, soft, coherent or powdery. line.

Next operation is sealing or electro coloring depending The working parameters of all the processing baths, on whether_ the materials are to be supplied in natural or which includes the composition of the bath, the in colored finish. temperature and processing time should be

documented, implemented and recorded. These records Electro coloring - the process is carried out generally in should be analyzed at regular interval and deficiencies tin sulphate solution, with a suitable additive. A.C. current noted and rectified. at low voltage is passed between the work and a suitable

electrode. Tin or tin oxide particles are deposited at the All production equipments in the anodizing plant should bottom of the pores of the anodic oxide coating. The color be subject to check and controls to ensure precision and depth of shades produced depend on the metal operation. An elaborate preventive maintenance plan being deposited and the coloring conditions used. The should be prepared, documented and implemented at colors range from champagne to light bronze, deep scheduled interval. Records should be maintained bronze to black. showing details when such routine tasks are carried out.

Sealing - sealing is the last operation in anodizing. It is Analytical Control essentially a process of blocking the pores in the anodic

Analytical control is required for: film. The sealing used to be carried out in the past by

(a) Optimum bath performance; immersion of the profiles in the boiling water. Majority of

the anodizers now have changed to cold sealing with (b) Optimum process time; proprietary chemicals at room temperature.

(c) Lower rejection/higher productivity; Sealing gives surface resistance to staining, abrasion,

(d) Reduced cost of production due to reduced and crazing and color degradation. Efficient sealing is

dumping of spent baths. ABSOLUTELY ESSENTIAL where long life under

The analysis of baths should be carried out at regular outdoor exposure is required. interval depending on quantum of work done.

Rinsing - Rinsing operations throughout the line are very Consistency in quality is possible only by regular analysis important m ensuring satisfactory appearance and of process bath. quality of the final product.

Development in Anodizing Proper and adequate rinsing is critically important for

anodizing. Counter flow and double rinsing systems can The developments are dealt with in the sequence the reduce water consumption considerably. Plants for anodizing process is carried out. recycling some or all of the rinse water are now available Etchingand are installed. Air agitation in most rinse is desirable

Etching is the first critical operation in anodizing. Etching and helps to prevent stagnant areas and concentration of gives an attractive silvery satin finish to the aluminium pH gradients in the rines.


profiles. It is carried out in caustic base solution. The anodic coating for outside exposure. All these processes

etchants have limited life due to the precipitation of are based generally on the following:

aluminium hydroxide in the bath and have to be (1) Anodizing by the conventional sulphuric acid frequently dumped or discarded. process.

Additives are now available in the market and provide (2) Modification of the anodic coating in a special long life non-fuming etching operation. Specific electrolyte with a power unit providing a advantages are: sophisticated power output at a low voltage.

(1) No occasional dumping or discarding of etching (3) Subsequently, coloring in the conventional way in solution an electrolyte usually based on tin sulphate.

(2) No formation and deposition of hard rock like (1) "SPECTRa COLOR 2000", by Novamax hydrate which are difficult to remove Technologies (US).

(3) No evolution of obnoxious caustic fumes during (2) "Reflex" by Indalex Aluminium Solution. etching process

(3) "Multi Color" by Italtechno, Italy. (4) Consistent etching rate and attractive finish.

All the above processes offer an almost unlimited range Anodizing of colors in anodizing aluminium as greens, blues, golds,

Conventional anodizing is carried out a sulphuric acid burgundies and more. The colors produced fulfill all the

concentration of 165±10 gms/ltr., 21 ± 1°C temperature quality requirements for outside exposure as light bronze 2 to black produced by two-step electrolytic process. and a current density of 1.3-1.7 amp/dm

The latest development in electrocoloring is new (1) Anodizing additives are now available that protect stainless steel "F ASHTON' color developed by the newly formed anodic coating from the Italtechno, Italy. This color is obtained with a standard electrolyte during the anodizing process, thereby electrocoloring solution normally used for bronze electro increasing the efficiency of the coating formation. coloring. A special power supply called "TECNO 7S" is (2) These additives permit the anodizing to be carried required for this technology. This special power supply out at high temperature and high concentration of can also be used for standard bronze to black color. sulphuric acid. ELECTRO DEPOSITION COATING ON ANODISED (3) High concentration and high temperature reduce ALUMINIUM the voltage to get the desired current density In Japan, aluminium profiles after anodizing resulting in electrical saving upto 25%. electrocoloring are not sealed by hot sealing or cold (4) Additives reduce the speed of "build up" of sealing. Instead, electro deposition of anodic coating with aluminium concentration, glvmg increased life to acrylic or fluoro carbon resins are standard methods of the anodizing solution. surface treatment. Presently clear and bright film, clear

Vertical Anodizing and matt film and white film are applied on anodized In Japan, many modern anodizing lines carry extruded aluminium. According to Japanese standard, an oxide profiles vertically rather than horizontally through the line. film of 9 microns and ED coating film of 12 microns The extruded sections (6 m in length) are jigged on a thickness are provided on "A" class coating while "B" horizontal table and are then raised to vertical position for class coating is provided with an oxide film of 9 microns transfer through the line. Only one worker per shift is said and ED coating film of 7 microns. to be required to jig works for a line with a capacity of Presently 60 lac tons of anodized aluminum products are 2000 tons/month. Automatic jigging and dejigging are annually coated with acrylic and fluoro carbon resin in also possible in this system. The process sequence in Japan. such line is similar to that in the horizontal line.

WET PAINTING Electro coloring

The use of painted aluminium started in USA in 1950. A Electro coloring produces colors that fulfill all the quality two-coat paint system was regarded as the norm of requirements for outside exposure. But the color range is painting of aluminium. very limited, champagne, light bronze, deep bronze to

ALKYD based paints, Vinyl paints, epoxy based paints, black. Polyesters and Acrylics were developed and are used for

A number of innovative processes have been developed various specific purposes. during the last two decades to widen the color range of


A substantial quantity of aluminium profiles is painted in (b) Powder Coating Process-The actual application of

the U. S. with liquid paints in vertical spray systems. The the powder on the profiles in booths with

solvents used in liquid paint systems pose a serious electrostatic guns. pollution problem on account of volatile organic contents

(c) Curing of the powder paints is usually carried out in (VOC), which are released during coating application.

convection or infrared radiation ovens. The Solvent insinuators are used in meeting air pollution

operation implies the formation of a regular regulations.

homogenous film and its subsequent hardening. POLYVINYL / POL YVINYLIDENE FLUORIDE, PVF /

Quality Control In Powder CoatingPVDF coatings are extensively used in USA. This is

Proper and thorough cleaning is the most important because a large portion of the US is located at latitudes requirement in the pre-treatment process for powder further south than Europe with heavy sunlight exposure. coating. Without complete cleaning conversion coating AAMA specification 605.2-90 is very stringent and a will not perform and the powder coating may tend to cure majority of the other coating processes do not meet these

on top of soil/dirt and subsequently loose adhesion to the standards. These coats offer the ultimate in exterior

weathering available from coating industry. The PVDF metal and may pee) off.

coats have outstanding chemical and UV resistance and Work instructions showing details of working parameter provide maximum resistance to exposed surface of of the entire processing bath and the associate rinses coating.

should be prepared, documented and implemented. Recently, a high performance liquid system "SILOXANE" Analytical control at regular interval is essential to based coating system, which has a .permissible limit of achieve the consistency and reproductivity of the results 3.0 ib. of solvent per gallon" has been developed and this required. meets the AAMA specification 605.2-90. This coating

Hot Drying system has excellent viscosity characteristics. Cure

The materials are wet after conversion coating. temperatures are also significantly lower than. that Conversion coating formed is amorphous and initially commonly required fort PVDF. contain 98% of water. This water has to be removed and A new air-drying field applied Fluoropolymer finish the material has to be hot dried before powder names DURANAR ADS has been developed for application. Higher temperature drying will give to "MUD restoration of many surfaces including weathered CRACKING" and the coating may "flake off". The general anodizing. This has been successfully used to refinish a practice in Europe is that the drying temperature should number of buildings in Europe and USA. One of the be at 65°C. largest projects finished in America is a 54storied building

covering an area of 1.6 million square feet. Powder Coating Process

POWDER COATING The quality of the finished powder coating material is the

result of both coating powder and the powder coating Powder coatings are "solid paint" ground into a fine process. As such the first essential requirement of quality powder. No solvents are present and therefore no solvent assurance in powder coating is the quality of the coating induced health hazards are present. The finely ground powder. The coating powder should have the requisite solid paint is electrostatically applied on the surface to be properties so that the film resulting from the application of coated. It is then subjected to heat, which melts the

powder layer, allow it to flow and fuse into a continuous the powder should be able to produce the desired

coating. surface, physical and environmental characteristics as

per requirement of the end user. (a) Pretreatment- the operation includes leaning of the

materials from oil and grease from the previous The application of coating powder to the materials is operations, removing the surface layer of inter- carried out in a powder booth. A well-designed powder metallics and natural oxide film from the surface of booth is necessary for a successful powder coating the metal and providing a corrosion resistant system. The booth should be dust free and pressurized to coating on the surface to help adhesion of the prevent the air borne contaminants from entering the powder to the material. room and depositing on the powder sprayed.

Adequate and through rinsing after every operation A well-designed powder booth is essential for economy, and final rinse in DM water is generally provided high powder .transfer efficiency, quick colour changing, prior to drying. productivity and safety.


Curing of the Powder Paint WORLD SCENARIO - WHERE DO WE STAND!

Primary Metal Production 2003The purpose of the curing is to obtain the desired

decorative and functional properties for which the World 21.93 million tons. powder material was formulated. Europe 3.87 million tons.

Quality control requires continuous measurement and China 5.4 million tons. recording of temperature at critical points in the oven.

India 0.7 million tons. The oven temperature is controlled and maintained at a

CONSUMPTION IN BUILDING central panel housed at a central location.

World 36% of production It also desires that oven profiling should be carried out Europe 51 % of production periodically. The oven profile graph called "road map to

success" shows information about oven performance. India 7% of production Incorrect curing affects the appearance of the product FINISHING OF ALUMINIUM and may result in chipping of the coating.

In 2000: Anodized Powder Coated Final Inspection

Europe 6.36 lac tons 10.90 lac tons Quality control will not be complete without final

Italy 2.7 lac tons 4.40 Lac tons inspection of the finished powder coating material. The

In India, the total production of extrusion during 2003 was final checklist includes the following:

about 1.20 lac tons. Out of this 50,000 tons were (1) Surface Appearance; architectural sections. Major portion of these are either

powder coated or anodized. (2) Color;

PRESENT STATUS(3) Coating Thickness;

Anodizing(4) Adhesion; Anodizing is still one of the most popular and high

(5) Solvent Resistant Test. performance finishes for aluminium profiles used in

The tests should be carried out regularly as per building and architecture. It has durability, stability, documented work instructions and recorded. aesthetic appeal, ease of maintenance and low cost that

makes it the most outstanding choice of architects and A good housekeeping, plant management and plant builders. In our country, major portion of aluminium used

maintenance are a part of quality control in powder in building and architecture is anodized.

coating. A good house keeping requires that the working Anodizing is mostly carried out in our country by job and storage areas should be kept clean and tidy. It also anodizers who have very small plants having capacity of requires application of safety measures for day to day 200-300 tons per year. Majority of the extruders abroad running of the plant. The workers employed in the have their own anodizing facility. In our country, only

powder application should be provided with protective about half a dozen extruders have their own anodizing

clothing and respiratory protection to protect them from plants having an installed capacity of about 1000 tons per

respiratory and skin contact. year.

Work instructions for the efficient operations of the Unfortunately, the quality of anodizing in our country is plants and a detailed preventive maintenance plan still not up to the mark. Except for a few anodizers who should be prepared, documented and implemented. anodize as per international standards, majority of

anodizing plants are run without any technical NEW DEVELOPMENTS IN FINISHINGbackground. Lack of technical competence and

New Developments have taken place in finishing expertise are the main reasons for poor quality of finished

whereby woodgrain, marble and fancy effects can be anodized materials produced in our country. produced on aluminium sheets and profiles. Pressure,

Aluminium extruded profiles anodized to a film thickness temperature and timing combine to print inks on film,

of 4-5 microns and sometimes only cleanly washed in penetrating the coating layer producing wood and

caustic soda solution and neutralized in nitric acid are marble effects suitable for outside exposure. Decoral

sold in the market as anodized material. As per 8.1.5. and System,' Italy, specialize in the manufacture and supply international standard aluminium for architectural use, of the plant for the purpose.


minimum anodic thickness should be 15 microns. of aluminium will be 1.5 million tons. A 67% growth is

Sealing of anodized coating, which is an essential expected in building and construction.

operation in anodizing from the performance point of With the increase in the production of primary metal and view, is generally unknown to these anodizers who work use of aluminium in building and construction the to a price than to a quality. When such aluminium finishing industries, both anodizing and powder coating anodized materials are fabricated and used in building will also· grow and there is tremendous scope for the construction and are exposed to outside atmosphere, growth and development of these industries if only the they become patchy and ugly looking. following actions are taken for the purpose.

Wet Painting The first important step to be taken is to create

Wet Painting generally called PVDF coating has not awareness about the process to consumers, architects,

become popular in our country due to health hazard and builders and promoters. They should be advised that

high cost of production and also because the finishes when they select the vendors for procuring

produced by anodizing and powder coating are sufficient anodized/powder coated aluminium profiles they should

to meet the environmental and weathering conditions ascertain that the supplier has the requisite

prevailing in our country. infrastructure; technical competence and the required

testing facility to produce the material as per international Powder Coating standard. They should insist for a test certificate,

Powder Coating was introduced in our country during the certifying that the materials are as per B.L.s. /

last decade. It is, however, slowly gaining ground due to International Standard. These steps if carried out, would

its outstanding stiffness and durability and infinite variety compel the anodizers and powder coaters to upgrade

of attractive shades it offers. their quality to international standard.

Just like anodizing majority of powder- coating plants are There is no certification and quality-labeling scheme of

also run without any technical background and the type of "Qualanod and Qualital" which is now in

competence. These powder-coating units have no operation in UK and most of the countries in Europe. The

quality assurance plans for the three distinct stages of scheme if introduced and properly implemented will

powder coating process. infuse confidence in the quality of anodized and powder

A suitable surface treatment, which includes a clean coated material among architects and consumers. It may oil/grease free surface, a suitable conversion coating that be difficult to introduce and implement these types of would promote adhesion of the coating powder to the schemes in our country, as the number of quality metal surface is either not carried out at all or is anodizers and powder coaters is quite few. It is, inadequately done. therefore, suggested that the B.1.s. should be entrusted

to do this job. B.1.s are the only quality-certifying agency The required quality of powder is not used; little attention in our country. However, they certify only products and is paid to the curing of the powder-coated material. All not the process. these results in chalky and dirty looking appearance of

the finished materials and even chipping of the coating Concluding, it is emphasized that the extruders, genuine within a couple of months of its outside exposure. anodizers and powder coaters must chalk up a strategy

to upgrade the quality of anodizing and powder coating Majority of the powder coating units are small scale, and to prevent the unscrupulous anodizers and powder having a capacity of 300-500 tons per year. coaters to tarnish the good name of aluminium and

FUTURE OF FINISHINGfinishing process.

The production of aluminium in our country is about 0.7 Reference:

million tons. 7% only is used for building and (1) "The Technology of Anodizing Aluminium"- Arthur W. construction. Our per capita consumption is only 0.68 kgs

Brace while it is 26 kgs in USA. There are about 3000

applications of aluminium while we are using only 300. (2) "Alu-Asia 95"- International Aluminium Publication India is the fifth largest resource of bauxite in the world.

(3) "International Aluminium Today" - December, 2001 Taking all these facts into consideration, it can be safely

(4) "International Aluminium Institute." - Statistical predicted that production of aluminium and per capita

Report June, 2004.consumption is bound to increase. It has beep estimated

that after the tenth five-year plan per capita consumption

is likely to grow up from 0.68 kg to 1 kg and the production


Contribution of Late Mr. T. N. Pathak,

Courtesy - Mr. P. K. Pathak

preventive maintenance will result in savings due to Preventive Maintenance

an increase in service life of effective system.

There are long-term benefits of preventive

maintenance:

Decreased cost of replacement.

Decreased system downtime.

Improved system reliability.

Improved spares inventory management.

Preventive maintenance is a logical choice if, and

What is Preventive maintenance? It is a schedule of only if, the following conditions are met:

planned maintenance actions aimed at the The component in question has an increasing failure

prevention of breakdowns and failures. The primary rate. In other words, the failure rate of the component

goal of preventive maintenance is to prevent the increases with time, thus implying wear-out.

failure of equipment before it actually occurs. It is Preventive maintenance of a component that is

designed to preserve and enhance equipment assumed to have an exponential distribution (which

reliability by replacing worn components before they implies a constant failure rate) does not make sense!

actually fail. Preventive maintenance activities The overall cost of the preventive maintenance include equipment checks, partial or complete action must be less than the overall cost of a overhauls at specified periods, oil changes, corrective action. (Note: In the overall cost for a lubrication and so on. In addition, workers can corrective action, one should include ancillary

record equipment deterioration so they know to tangible and/or intangible costs, such as downtime

replace or repair worn parts before they cause costs, loss of production costs, lawsuits over the

system failure. Recent technological advances in failure of a safety-critical item, loss of goodwill, etc.)

tools for inspection and diagnosis have enabled

Preventive maintenance is preferred because of even more accurate and effective equipment

long-term effects and cost savings. Doing maintenance. The ideal preventive maintenance

maintenance actions only when the system fails is prevents all equipment failure before it happens.

now outdated. Unfortunately, there are multiple misconceptions

nabout preventive maintenance. One such

misconception is that PM is unduly costly. This logic Mr Vishwas Kale is Managing Director, Vijayesh dictates that it would cost more for regularly Instruments Pvt Ltd, Pune and has more than thirty

scheduled downtime and maintenance than it would years experience in instrumentation. He was twice

normally cost to operate equipment until repair is President, ISA in India, is currently Member,

absolutely necessary. This may be true for some Industrial Process Measurement And Control

components; however, one should compare not Committee of Bureau of Indian Standards, New

only the costs but the long-term benefits and Delhi,Senior Life Member, ISA ( USA ) , Member,

Experts Panel of NCTS-Indian Institute of savings associated with preventive maintenance.

Foundrymen, Member ALUCAST, amongst many Without preventive maintenance, for example, costs

positions he holds with various organizations. He has for lost production time from unscheduled

received awards for innovative products. equipment breakdown will be incurred. Also,

Vishwas KaleManaging Director

Vijayesh Instruments Pvt Ltd, Pune


Disclaimer - The editor and the Aluminium Extruders' Council (ALEX) do not accept any responsibility for the statements, contents, opinions and point of views expressed by the authors.

official journal of aluminium extruders' council alex ...alexindia.co.in/alex-journal...

Documents