Aluminum has always been a favorite material for LED lamp products — so why is thermally conductive plastic gaining favor in the market? A comparison between thermally conductive materials and aluminum makes it clear. RenJie Plastics has launched a thermally conductive plastic for heat-dissipation fins that cuts cost by 20%–30% compared with conventional aluminum heat-sink fins; the emissivity of this thermally conductive plastic is 7–8 times higher than that of aluminum.

The advantages of thermally conductive plastic materials over aluminum:

(1) Light weight

In indoor lighting, the weight of a luminaire affects many aspects — for example, greater weight makes installation and transport more difficult and also poses a safety hazard. The density of pure aluminum is 2700 kg/m³; aluminum alloys are even denser, whereas the density of thermally conductive plastics is around 1420 kg/m³, roughly half that of aluminum alloys. So for the same shape, the weight is only about half that of an aluminum alloy part. What are the advantages of thermally conductive plastics over aluminum for heat dissipation?

(2) More environmentally friendly and safer

In the production of plastic housings, virtually no toxic pollution is generated, whereas aluminum housings often involve an electroplating step in production, and the metals in the waste liquid from electroplating cause serious pollution of water sources and soil. In terms of safety, plastic is an insulating material, so there is no need to worry about the safety hazards caused by a conductive lamp housing. In high-voltage withstand testing, plastic has an absolute advantage.

(3) Greater design freedom

Plastics flow very well, so very thin parts can be produced and more complex shapes designed. The main production methods for aluminum housings are die casting or stretch forming, which cannot handle the machining of relatively complex shapes. In addition, in terms of appearance, injection-molded products look more attractive, and a company's own distinctive logo can also be added.

What are the advantages of thermally conductive plastics over aluminum for heat dissipation?

(4) Easier processing and higher efficiency

Like other plastic parts, thermally conductive plastic materials can be formed in a single step with no post-processing, and the mold can be designed as a four-cavity tool during injection molding, so work efficiency is very high. After extrusion forming, aluminum materials usually still require a deburring step, and if the appearance requirements are high, aluminum must also undergo processes such as nickel plating, which further lengthens the processing cycle.

(5) Simplified driver system

When the housing is made of aluminum alloy, the housing is conductive, so an isolated driver system must be used inside; plastic itself is insulating, so a non-isolated driver system can be used for the heat-dissipation system. Because a non-isolated system is not only lower in cost but also smaller in size than an isolated system, this both reduces cost and takes up less space.

What are the advantages of thermally conductive plastics over aluminum for heat dissipation?

(6) Lower system cost

In terms of unit price, thermally conductive plastic per unit mass is inevitably more expensive than aluminum, but the system cost is equal or lower, and the larger the quantity, the more obvious the cost advantage of plastic. In addition, thermally conductive plastic materials are currently at an early stage; their price will certainly fall as the industry develops and volumes increase, whereas the price of aluminum as a non-ferrous metal is unlikely to drop significantly. The cost reduction from plastics is mainly reflected in processing costs.