Thermal conductive plastic: Use thermal conductive fillers to uniformly fill the polymer matrix material to improve its thermal conductivity. The thermal conductivity is mainly measured by the thermal conductivity coefficient (unit: W/mk).

Main classification

Thermal conductive plastic are divided into two categories: thermal conductive and electrically conductive plastic and thermal conductive insulating plastic.

Component structure

The main components of thermal conductive plastic include matrix materials and fillers. Matrix materials include PPS, PA6/PA66, LCP, TPE, PC, PP, PPA, PEEK, etc.; fillers include AlN, SiC, Al2O3, graphite, fibrous high thermal conductivity carbon powder, flaky high thermal conductivity carbon powder, etc.

Product Features

(1) Uniform heat dissipation, avoiding hot spots and reducing local deformation of parts caused by high temperature

(2) Light weight, 40-50% lighter than aluminum

(3) Convenient molding and processing, no secondary processing

(4) High degree of freedom in product design

(5) Since the molding method is mainly mold injection molding, the rubber is pressurized after heating and then cooled to form. The characteristics of the processing technology make the thermal conductivity of the material after molding present anisotropy, that is, the direction of rubber flow during injection molding (in-plane) and the direction perpendicular to the rubber flow (through-plane). Generally, the thermal conductivity in the direction of rubber flow is 5 to 10 times that in the direction perpendicular to the rubber flow. This difference is caused by the fact that the rubber is easy to form continuous molecular chains in the flow direction during injection molding.

Application Fields

These fields include LED lighting, automobiles, heating/cooling/refrigeration.

Processing parameters

PA substrate:

Pre-drying: 4~6H @ 100C

Mold temperature: 80~100C

Back pressure: 1~3MPa

Barrel temperature: Nozzle temperature 270C (recommended), front section 260C (recommended), middle section 250C (recommended), rear section 240C (recommended).

Advantages

Although aluminum materials are relatively mature in terms of heat dissipation system technology, they still have some shortcomings. Similarly, plastic thermal conductive materials are not completely without disadvantages. The following is a comparison of the advantages and disadvantages of the two. First of all, plastic thermal conductive materials have advantages over aluminum:

(1) Light weight In indoor lighting, the weight of lamps has an impact on many aspects. For example, the increase in weight will increase the difficulty of installation and transportation of lamps, and will also cause hidden dangers to personal safety. The density of pure aluminum is 2700kg/m3, and the density of aluminum alloy will be even higher. The density of thermal conductive plastic is about 1420 kg/m3, which is about half of that of aluminum alloy. Therefore, under the same appearance, the weight is only about half of that of aluminum alloy.

(2) Safety: Plastic is an insulating material, so there is no need to worry about the safety hazards caused by the electrical conductivity of the lamp shell. In terms of high voltage resistance testing, plastic has an absolute advantage.

(3) Improve design freedom: Plastic has good fluidity, so it can produce very thin parts and design more complex shapes. The main production methods of aluminum shells are die casting or stretch molding, and it is impossible to process more complex shapes during the production process. In addition, in terms of appearance, injection molding products will be easier to produce, and you can also add your own logo that is different from other companies.

(4) Convenient processing and higher efficiency: Plastic thermal conductive materials, like other plastic parts, can be molded in one go without post-processing, and during injection molding, the mold can be designed as one out of four, so the work efficiency is very high. After extrusion molding, aluminum materials often need to undergo a deburring process. If the requirements for the appearance are relatively high, the aluminum materials must also undergo nickel plating and other processes, and the processing cycle will increase.

(5) Simplified starting system When the shell is made of aluminum alloy, since the shell is conductive, an isolated starting system must be used inside. The plastic itself is insulated, so when it is used as a heat dissipation system, a non-isolated starting system can be used. Since the non-isolated system is not only lower in cost but also smaller in size than the isolated system, this can not only reduce costs but also occupy less space.

(6) Reduce system costs In terms of unit price, the price of thermal conductive plastic per unit mass is bound to be higher than that of aluminum, but the system cost is the same or lower, and the larger the quantity, the more obvious the cost advantage of plastic. In addition, plastic thermal conductive materials are currently in an early stage, and their future prices will definitely decrease with the development of the industry and the increase in product volume, while the price of aluminum as a non-ferrous metal is unlikely to decrease significantly. The cost reduction of plastic is mainly reflected in processing costs.

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