Every year in China, around 1.4 billion m2 new building projects will be finished and more than 20 million m2 curtain-wall works will be completed. Building construction output are increasing at 13% annually, this development are creating a great demand for materials of curtain-wall works。
　　According to curtain-wall installation ways, this constructions are devided into two sorts of system, framework construction system and panel-unit inlay construction system. For raw material sources, they are sorted for glass, metal and stone. In metal curtain-wall materials, they have Aluminium alloy panel,aluminium honeycomb panel, color steel panel, stone-grain panel,aluminium panel with alu-electrophoresis porcelain quality, composite aluminium panel, composite alu-plastic panel etc.
　　Aluminum panel are coated by two main ways of spray-coating and pre-roll-print-coating. Composite aluminum panels have two sorts, they are bi-layer and tri-layer composite.
　　Alu-plastic composite panel, as a primary building curtain-wall materials depend on its advantages of light weight and easy installation at competitive price, has been in the market over a decade since its application accepted and it was widely produced in China. Recent years however, it has been in a problem of disorder market because of their inferior materials abused, even the cases of outer materials replaced by inner ones. They caused larger difference between their appearance and inner quality.Exceeded lower price caused inferior product. After a few years installation, this sort of panel has become to be color faded, warp or out of shape, chalking, etc.This destroyed the image of alu-plastic composite panel in curtain-wall market under the furious market competition.
　　Most of the curtain-wall contractors are selecting Aluminum alloy panel instead of composite panel, that is the main reason above. In order to avoid the terrible influence of inferior alu-plastic composite panel, most name brand manufacturer are promoting their new innovative products, some of them set up the aluminum panel production line with spray-coating, some invested line of alu-alu composite panel. What a surprising news is that there is a manufacturer producing the roll-coating aluminum alloy panel in China are going to start production this year.These two kinds of innovative curtain-wall products will gear up the competition market and impact furtherly alu-plastic panel sales.

　　Alu-alu composite panel is a new product developed abroad in recent years, it is seldom in domestic market.Alu-alu panel is sorted by bi-layer and tri-layer, some makers in China are trying to research and develop this product, which will be introduced to test the market in coming years. With the properties of aluminum alloy panel and its advantages of easier processing and installation like alu-plastic panel, it will be satisfied to contractors in building field if the price is reasonable when touch the market.
　　Pre-roll-coating aluminum alloy panel has been used abroad over a decade, yet at home since 1990’s. It has not been widely used in China because its higher price and incomplete recognized. Recently, the image of alu-plastic panel has been damaged by the market of unorderly grade alu-plastic panel with interior materials abused, aluminum alloy panel has been keening on concerned by curtain-wall designers, contractors and owners of the buildings, who select the aluminum alloy panel increasingly. However,SPRAY-COATING panel has shortcomings of color difference, uneven thickness coating, higher cost of paint waste ect,while the new technology of PRE-ROLL-COATING and its products have been recognized by users.Some representative buildings or projects have even been specified pre-roll-coating alu alloy panel as the material for curtain-wall decoration. Hence, it is rather confident that pre-roll-coating panel will have a promising market in future.
　　Pre-roll-coating technology guaranteen even-coating without color difference since adopting continuous roll-coating method which is a primary technological process. Solid color panel is roll-coated by double coating and bake, metal color is usually done either triple or quadruple, that is why its color is permanent with original sheen with little fading.

　　Selecting higher strength aluminum alloy being the raw mterials,pre-roll-coating panel has pretty surface decoration,long period weather resisting property, self-cleaning, and properties of light in weight,higher strength,easier processing,impact resistance,fire-retardant,water proof, better flat,friendly environment,even coating thickness without color difference. These advantages above are attracting more building owners, designers and contractors.