Axolotl has joined Smartfix Industries to develop a new building façade system that offers the possibility of personalising a façade with over 200 metal effects - embossed or debossed.

Comprising a variety of aluminium extrusions, the panels create flexible joining solutions without exposed fixings. The panels are then bonded with any of Axolotl’s metals and effects, including embossing or debossing. There are no limitations imposed by height, so even the tallest skyscraper can be individualised to stunning effect.

Vista System International / Fen Systems, a fast growing pioneer in signage solutions and a leader in Modular Curved Frame Technology, along with their Australian exclusive distribution centre in Sydney N.S.W., has published a new video on the Vista Light sign system– its’ versatile yet affordable illuminated signs.
Vista Light sign system is used to create freestanding, convex, double sided signs that can be backlit with the addition of interior illumination, or used with standard sign substrates without illumination and as a single sided wall mounted frame. This illuminated sign system is suitable for show rooms, lobbies, displays, parking garages, advertising, and for signage at point of purchase, shopping centres and trade shows, etc.

This cost effective illuminated signage system, designed to accept standard sign substrates, is constructed from two special aluminium extrusions, an end cap, face inserts and a base. These illuminated signs are also suitable for either portable or permanent installation. The only tool needed for this sign system’s assembly is a screwdriver and the unique design of the illuminated sign system allows the use of two panels for inserting temporary artwork that needs to be changed often, such as posters.

The model is coated with fluoride and carbon that provide a smooth surface. It is lightweight and has even edges. The tube has a diameter of T5 or T6, with an inner wall thickness of at least 0.8mm. Versions with electrophoresis, powder-spray and fluoride-carbon coating, and anodic oxidation, are offered.

Buyers' size and shape specifications are accepted.

FOB Suzhou price and minimum order are given on direct inquiry. Delivery is within 30 days after receipt of an L/C or TT.

The company has received ISO 9002 certification. It markets its in-house Huadong brand and exports mainly to Western Europe and North America.

The rising cost of aluminum is driving suppliers to implement price increases to shore up shrinking margins.

Suppliers of aluminum extrusion profiles in mainland China and Taiwan are warning of more price increases in coming months unless material costs drop, or at least stabilize, soon.

Prices have already risen by as much as 20 percent in both the mainland and Taiwan after the cost of aluminum alloy soared to about $2,500 per ton. Suppliers in the mainland said this is the highest that costs have been in 17 years.

Material costs have been inflating incessantly for the past two years primarily because of a shortage in supply. Several small suppliers of the material in the mainland have been forced to stop operations because of environment-protection regulations. This is a crucial development that is forecast to impact heavily on the aluminum alloy supply for the next three to five years.

The plans of some large aluminum alloy producers in the US and Europe to close certain processing plants is compounding this problem, threatening to cut supply and drive costs up further.

Mainland makers of aluminum extrusion profiles source about 80 percent of their material requirement from the provinces of Guangxi, Qinghai and Henan, purchasing the rest from the US, Russia and Australia.

Most makers in Taiwan source aluminum ingots from local suppliers. The ingots are usually imported from Australia, then reprocessed in Dubai, Bahrain and South Africa. Only a few makers in Taiwan, however, have the capability to import the ingots directly.

Components made from aluminium extrusion are some of the commonest parts used in the manufacturing industry. Infinitely flexible in their variety, their light weight and cost-effectiveness give them a vast range of structural and finishing uses, whether in their naturally bright unfinished form or powder coated, electroplated or anodised to a myriad of rich colours and tough finishes.

In today's highly competitive marketplace you would expect there to be any number of companies vying to supply endless varieties of extrusions in any quantity you require, offering realistic prices and minimum delivery times.

Wrong!... Surprisingly the vast majority of aluminium extruders insist on minimum orders of 250kg and typically offer a lead time of six to eight weeks!

This is fine when all you need is a constant supply of standard aluminium extrusions. However, if you are involved in design, research and development, prototyping and one-off projects that many extrusion producers either can't or don't meet, then Capalex should be your first choice.

The forcing of solid metal through a suitably shaped orifice under compressive forces. Extrusion is somewhat analogous to squeezing toothpaste through a tube, although some cold extrusion processes more nearly resemble forging, which also deforms metals by application of compressive forces. Most metals can be extruded, although the process may not be economically feasible for high-strength alloys.

The most widely used method for producing extruded shapes is the direct, hot extrusion process. In this process, a heated billet of metal is placed in a cylindrical chamber and then compressed by a hydraulically operated ram (see illustration). The opposite end of the cylinder contains a die having an orifice of the desired shape; as this die opening is the path of least resistance for the billet under pressure, the metal, in effect, squirts out of the opening as a continuous bar having the same cross-sectional shape as the die opening. By using two sets of dies, stepped extrusions can be made.

The extrusion of cold metal is variously termed cold pressing, cold forging, cold extrusion forging, extrusion pressing, and impact extrusion. The term cold extrusion has become popular in the steel fabrication industry, while impact extrusion is more widely used in the nonferrous field.

Schematic of the direct, hot extrusion process.
Schematic of the direct, hot extrusion process.

The original process (identified as impact extrusion) consists of a punch (generally moving at high velocity) striking a blank (or slug) of the metal to be extruded, which has been placed in the cavity of a die. Clearance is left between the punch and die walls; as the punch comes in contact with the blank, the metal has nowhere to go except through the annular opening between punch and die. The punch moves a distance that is controlled by a press setting. This distance determines the base thickness of the finished part. The process is particularly adaptable to the production of thin-walled, tubular-shaped parts having thick bottoms, such as toothpaste tubes.

Advantages of cold extrusion are higher strength because of severe strain-hardening, good finish and dimensional accuracy, and economy due to fewer operations and minimum of machining required

Aluminium plate and extrusions are used extensively in the superstructures of ships where the designers wish to increase the above waterline size of the vessel without creating stability problems. In hovercraft and in the various types of surface skimming vessels, such as fast mulithulled catamarans, (figure 1), the weight advantage of aluminium has enabled marine architects to obtain more from the available power.

Figure 1. The use of large aluminium extrusions gives quality and cost benefits in fast multihulled catamarans.

On offshore oil platforms, aluminium has become the established material for helidecks and helideck support structures because of weight and through life maintenance advantages. For the same reasons it has found frequent use in stair towers and telescopic personnel bridges. Aluminium accommodation modules have been installed on the Snorre and on the Statfjord C platforms in the Norwegian sector of the North Sea. These modules have provided a range of benefits. An overall weight saving of the order of 40% compared to steel has been achieved in the case of the Snorre accommodation module. Cost advantages were obtained in the case of Statfjord C as a result of using only 60 tonne maximum load capacity platform crane for erection and assembly purposes.
Market Influences

In world ship building, certain types of vessels are increasing in popularity. The interest in cruise holidays has surged and whereas it was once simply a matter of converting former ocean liners, purpose built vessels are one of the fastest growing sectors of the industry. New fast ferries which can dramatically shorten journey times are entering service around the world.

The oil industry is seriously affected by the fall in world oil prices. If more marginal fields, for example some of the more difficult North Sea finds, are to be exploited then the costs of oil production hardware will have to be lowered. These market conditioned are pressurising designers, for a variety of technical reasons, to lower effective weight of structures, to cut construction costs and to reduce through life maintenance requirements.

If composite construction is adopted and very high strength fibres are used, fibre reinforced plastics can sometimes be an option to reduce weight, but problems can occur because of high material costs, high moulding costs and difficulties with fire ratings. Often the only feasible way of lowering weight is to adopt or change to aluminium.

Construction costs are very dependant on joining/assembly techniques. If joining can be reduced or made more simple by, for example, using the largest available extrusions or/and, where acceptable, using mechanical joints as opposed to welds, then construction times and hence costs can be lowered. The proven corrosion resistance of unprotected aluminium alloys in marine conditions, for example, the plate alloy AA5083 or the extrusion alloy AA6082, is well documented. This advantage over constructional steel has a considerable influence on through life maintenance costs.

Following the 1988 North Sea Piper Alpha oil and gas platform disaster, which claimed 167 lives, the new approach to safety has meant that accommodation modules are now installed on offshore structures as far away as possible from the more dangerous operations. This frequently means that the weight of the living quarters module is a factor which has a major influence on new build project costs.

Since the first offshore platforms were built, considerable advances have been made in the techniques for recovering ever higher proportions of hydrocarbons from the layered geological structures below the sea bed. These improved techniques have often meant that additional heavy pieces of equipment have had to be installed on the existing offshore facilities. Many of these ageing platforms are approaching their maximum designed topside weight. It is usually much cheaper to replace parts of an existing installation with new light weight modules than to install a completely new structure.
Properties Of Large Extrusions

The mechanical properties of extrusions are influenced by grain size. This in turn is largely determined by recrystalisation characteristics of the alloy, extrusion ratio, extrusion temperature and final heat treatment. The flow of material in the extrusion process causes a directionality of mechanical properties. Transverse proof stress and UTS are 85-90% of the longitudinal values.

One of the main advantages of the aluminium extrusion process is its ability to provide complex hollow shapes. Most hollow profiles are produced from die tooling which forms welds during the extrusion process. Judged by the criteria appropriate for the more familiar fusion welds, there would seem to be no problems with extrusion welds. Composition is constant, there is no filler metal and there is no liquid to solid phase change. Nevertheless, properties across the weld can differ from those of the parent metal because of differences in grain size and variations in the distribution of intermetallic phase particles.

The term extrusion weld covers two types of weld: seam welds formed when two streams of metal flow together in the die, and charge welds formed at the die ports between successive billets. Both types are solid state welds formed under deformation and pressure. From a correctly designed die it is very difficult to form a low quality seam weld. Quality problems from charge welds are unfortunately far more frequent if correct operating procedures at the press are not followed.

It is most important that the correct length of extruded material is scrapped at the start and end of each billet in order to ensure that the low property material is removed. Proportionally large billets are required for large extrusions to provide a sufficient length of material to allow the potentially defective front and back ends to be removed. This means, particularly for extrusions with high cross-sectional areas, that high extrusion pressures and not just large diameter press containers are essential.

Table 1 shows minimum property values for extruded AA6082 T6 material in the longitudinal and transverse directions and includes minimum transverse values taken across extrusion welds. The table also shows values of mechanical properties of AA6082 butt welds for comparison purposes.The longitudinal fatigue strength of AA6082 T6 after 107 cycles at stress ratio(R) = 0, is quoted typically as 130MPa. Fatigue tests made transverse to the extrusion direction give results of approximately 80% of this longitudinal value. Extensive testing of fusion welded flooring sections containing extrusion welds has shown that failures usually occur at the fusion welds or in the heat affected zone on either side of the weld seam.

Fatigue characteristics of samples taken transverse to the extrusion direction containing extrusion welds are similar to transverse values from the base material, always with the proviso that sufficient front end extrusion scrap has been removed to provide satisfactory extrusion weld quality. Large extrusions have better fatigue characteristics than similarly dimensioned assemblies of small extrusions fusion welded together.
Joining Methods

MIG and TIG welding have been in use for many years and have established themselves as reliable techniques when the correct procedures are employed. The various problems which can arise have also been studied in detail. Typical defects are shown in figure 2. The four fusion weld defects represented in the diagram affect different aspects of the mechanical properties of the base material. Whereas the local heating, over ageing and consequent softening of the heat affected zone on either side of the weld bead lowers proof stress and UTS, the micro and macro porosity and shrinkage defects can act as sites for fatigue initiation and as a result can lower fatigue properties.

Figure 2. Possible quality problems in fusion welds

In addition to problems caused by weld flaws, fatigue strength is affected by mechanical factors such as holes, threads and grooves and also by the positioning of flaw free welds. However, extrusion technology can be used to position fusion welds in non critical areas or to enlarge the section close to a weld in order to compensate for the loss in properties caused by the welding process.

The design rules for fatigue of aluminium structures are covered by a number of standards including British code BS8118 Structural use of aluminium and the European code ECCS - paper, Doc 68 European recommendations for aluminium alloy structures fatigue design. Of the two codes the British Standard is in general the more conservative. An efficient quality assurance system is needed to monitor and guarantee both performance of welding equipment and workmanship.

Often the most convenient and technically optimum way of joining two or more aluminium extrusions is to use a specially designed mechanical fixing arrangement. The combination of relatively few welds with a high proportion of mechanical joints has become standard for helidecks. In the latest designs for offshore accommodation modules, the outer skin is a welded structure and selected parts of the interior have been designed to incorporate mechanical joints with sealants between the individual flooring sections.
Fast Catamaran Deck Design

By making use of large extrusion technology simply to reduce the amount of welding, considerable quality and cost benefits can be obtained. Benefits from use of large extrusions in more complex parts of a structure than the deck are more difficult to quantify but nevertheless real. The advantage of being able to free more parts of the design from the potential difficulties created by the need to thoroughly inspect the fusion weld joining two standard extrusions can easily be appreciated.
Offshore Module Design

The Snorre accommodation module was built using more than 20 different profiles, some of which were relatively difficult hollow sections. The welded design needed some 780 tonnes of aluminium making it the largest all aluminium structure ever built. The total finished weight of the Snorre accommodation module was 2100 tonnes. The Statfjord `C' accommodation module was based on the same basic components as were used for Snorre.

It was considered that a design change should make possible a lower weight, lower cost module. The design change has involved reducing and simplifying the number and type of extruded sections and moving to a combination of welded and mechanical joints to lower construction costs. Since the new design requires relatively few profiles it is intended that these be held in stock to make virtual off the shelf delivery a possibility. This will make modules available in the very short delivery times, important for the offshore refurbishment market. The primary and secondary beams and ternary decking have been so designed to allow flexibility inside the module so that heavy items can be supported in the structure with relatively little design input.

The aluminium sector, from the mining of bauxite to the production of the final products, is one of the most dynamic Greek industries. In 1999 it contributed more than 1.5% of GDP to the Greek economy and employed 40,000 people directly or indirectly, while aluminium exports accounted for approximately 5.5% of overall exports of the country. On the basis of data from the Greek Aluminium Association, the turnover of the aluminium sector in 1999 is estimated at approximately 660 billion drachmas, up by 6% in relation to the previous year.

Processed aluminium products can be divided into lamination and extrusion products, cables and foundry products depending on how they are processed.

The term extrusion means the process for working aluminium from which elongated products arise such as pipes or rods with differing cross sections, so - called profiles. The production of extrusion products accounted for 43% of overall production figures of initial processed aluminium in 1999. Lamination means the process of working aluminium from which flat or level products are produced. The lamination sector accounted for 51% of overall production of primary processing products in 1999.

The extrusion sector consists of large-scale production units which are mainly engaged in the production of aluminium profiles. The items produced by the specific enterprises are then used as raw material by secondary processing units which transform them into final products.

Domestic production of aluminium extrusion products has been rising steadily during the period 1991 - 1999, with the exception of the 1993/1992 period. The annual average rate of growth in production during the period 1994 - 1999 was approximately 14.5%. Greek production stood at 110,000 tons in 1999 from 99,000 tons in 1998, an increase of approximately 11%. The corresponding increase for the period 1998/1997 was in the order of 21%. Exports accounted for between 35% and 38% of overall production figures over the last two-year period.

The largest part of extrusion products are destined for use in construction, accounting for 81% (89,300 tons) of overall production figures for 1999. Household equipment absorbed 7% (8,000 tons) of overall production while smaller quantities were used in mechanical and electrical applications (3,100 tons) and transport (2,500 tons).

Future trends in the aluminium extrusion sector will depend, to a significant degree, on demand for final products and in particular for aluminium frames. Moreover, the increase in building activity in view of the 2004 Olympic Games is expected to promote demand for the products being examined to higher levels.

Based on prevailing conditions and trends in the market, the size of the domestic market in aluminium extrusion products is expected to reach the level of 78,500 tons approximately this year, up some 5% compared to 1999. In the year 2001, domestic ostensible consumption is expected to increase further to 82,500 tons (an increase of 5% in relation to 2000) while in 2002 an increase in the size of the extrusion products market by 5% - 6% compared to the previous year is expected.

The main aluminium lamination product initial processing industry is ELVAL HELLENIC ALUMINIUM INDUSTRY S.A. while ALOUMAN S.A. is also involved in the sector producing aluminium disks and final products. It should be noted that the aluminium lamination secondary product processing sector consists of a range of enterprises while a small number of companies control a large share of the market.

Domestic production of lamination products followed an upward trend during the period 1993 - 1999 with an annual rate of growth of approximately 9.5%. Production figures for the aforementioned products stood at 130,000 tons in 1999 compared to 125,500 tons in 1988, up some 4%. Exports account for the largest part of production during the period under examination, while over the last two years, the degree of export performance for the sector ranged from 72% to 74%.

Packaging accounted for 76% (98,500 tons) of overall production of the sector during 1999 while lamination products intended for construction activity accounted for 17% (22,300 tons) of the total. The production shares of other activity are at quite lower levels.

Domestic ostensible consumption of lamination products fluctuated during the period 1993 - 1999. Over the last two years there has been an upward trend with production standing at 49,800 tons in 1999 compared to 48,258 tons during the previous year (an increase of 3%). Imports accounted for 32% in 1999 compared to 28.5% in 1998.

The largest part of the market (76%) in 1999 was absorbed by products intended for packaging (37,700 tons) while products for construction uses had a 17% market share (8,600 tons) during the same year.

The development of the domestic market in aluminium lamination products is related to the trends in demand for secondary production products and in particular to packaging items as well as to a possible expansion of the use of aluminium in new markets/products.

The size of the domestic market in lamination products is expected to be in the order of 51,500 tons in 2000, up some 3.4% in relation to 1999. During the year 2001, domestic ostensible consumption is expected to stand at 53,000 tons up by 3% compared to 2000, while during the period 2002/2001, a further increase in the size of the market in the order of 3% - 4% (in terms of quantity) is expected.