Light weight, low cost, high impact strength, moldability, and customization are rapidly driving the demand for thermoplastics, which help keep electronics, lighting, and car engines cool. #Polyolefin
PolyOne’s thermally conductive compounds are used in automotive and E/E applications, such as LED lighting, heat sinks and electronic enclosures.
Covestro’s Makrolon thermal PC products include grades for LED lamps and heat sinks.
RTP’s thermally conductive compounds can be used in housings such as battery boxes, as well as radiators and more integrated heat dissipation components.
OEMs in the electrical/electronics, automotive, lighting, medical equipment, and industrial machinery industries have been keen on thermally conductive thermoplastics for many years because they are seeking new solutions for applications including radiators and other heat dissipation devices, LEDs. Case and battery case.
Industry research shows that these materials are growing at a double-digit rate, driven by new applications such as all-electric vehicles, complex cars and large commercial LED lighting components. Thermally conductive plastics are challenging more traditional materials, such as metals (especially aluminum) and ceramics, because they have many advantages: plastic compounds are lighter in weight, lower in cost, easy to form, customizable, and can provide more advantages in thermal stability , Impact strength and scratch resistance and abrasion resistance.
Additives that improve thermal conductivity include graphite, graphene, and ceramic fillers such as boron nitride and alumina. The technology to use them is also advancing and becoming more cost-effective. Another trend is the introduction of low-cost engineering resins (such as nylon 6 and 66 and PC) into thermally conductive compounds, which puts more commonly used high-priced materials such as PPS, PSU, and PEI into competition.
What’s all the fuss about? A source at RTP said: “The ability to form net parts, reduce the number of parts and assembly steps, and reduce weight and cost are all driving forces for the adoption of these materials.” “For certain applications, such as electrical enclosures and component overmolding , The ability to transfer heat when becoming an electrical isolator is the focus of attention.”
Dalia Naamani-Goldman, Manager of Electronic and Electrical Transportation Marketing of BASF’s Functional Materials Business, added: “Thermal conductivity is rapidly becoming an issue of increasing concern for electronic component manufacturers and automotive OEMs. Due to technological advancements and space constraints, applications are miniaturized and therefore thermal The accumulation and dissemination of power has become the focus of attention. If the footprint of the component is limited, it is difficult to add a metal heat sink or insert a metal component.”
Naamani-Goldman explained that higher voltage applications are penetrating automobiles, and the demand for processing power is also growing. In electric vehicle battery packs, the use of metal to disperse and dissipate heat increases weight, which is an unpopular choice. In addition, metal parts operating at high power may cause dangerous electric shocks. Thermally conductive but non-conductive plastic resin allows higher voltages while maintaining electrical safety.
Celanese’s field development engineer James Miller (predecessor of Cool Polymers acquired by Celanese in 2014) said that electrical and electronic components, especially electrical and electronic components in electric vehicles, have grown with the component space It becomes more and more crowded and continues to shrink. “One factor limiting the size reduction of these components is their thermal management capabilities. Improvements in thermally conductive packaging options make devices smaller and more efficient.”
Miller pointed out that in power electronic equipment, thermally conductive plastics can be overmolded or packaged, which is a design choice not available in metals or ceramics. For heat-generating medical devices (such as medical devices with cameras or cauterization components), the design flexibility of thermally conductive plastics allows for lighter weight functional packaging.
Jean-Paul Scheepens, general manager of PolyOne’s specialty engineering materials business, pointed out that the automotive and E/E industries have the greatest demand for thermally conductive compounds. He said that these products can meet a variety of customer and industry needs, including expanded design freedom, enabling design The increased surface area can improve thermal stability. Thermally conductive polymers also provide more lightweight options and part consolidation, such as integrating heat sinks and housings into the same component, and the ability to create a more unified thermal management system. The good economic efficiency of the injection molding process is another positive factor. ”
Joel Matsco, senior marketing manager for polycarbonate at Covestro, believes that thermally conductive plastics are mainly focused on automotive applications. “With a density advantage of about 50%, they can significantly reduce weight. This can also be extended to electric vehicles. Many battery modules still use metal for thermal management, and because most modules use many repetitive structures inside, they use thermal conductivity The weight saved by replacing metals with polymers quickly increased.”
Covestro also sees a trend towards lightweighting of large commercial lighting components. Matsco points out: “35-pound instead of 70-pound high bay lights require less structure and are easier for installers to carry on scaffolding.” Covestro also has electronic enclosure projects such as routers, in which plastic parts act as Container and provide heat management. Matsco said: “In all markets, depending on the design, we can also reduce costs by up to 20%.”
PolyOne’s Sheepens’s stated that key applications of its thermal conductivity technology in automotive and E/E include LED lighting, heat sinks and electronic chassis, such as motherboards, inverter boxes, and power management/security applications. Similarly, RTP sources see its thermally conductive compounds being used in housings and heat sinks, as well as more integrated heat dissipation components in industrial, medical or electronic equipment.
Matsco of Covestro said that the main application of commercial lighting is the replacement of metal radiators. Similarly, thermal management of high-end network applications is also growing in routers and base stations. BASF’s Naamani-Goldman specifically pointed out that the electronic components include bus bars, high-voltage junction boxes and connectors, motor insulators, and front and rear view cameras.
Celanese’s Miller said that thermally conductive plastics have made great strides in providing 3D design flexibility to meet higher thermal management requirements for LED lighting. He added: “In automotive lighting, our CoolPoly Thermally Conductive Polymer (TCP) enables the use of thin-profile overhead lighting housings and aluminum replacement radiators for external headlights.”
Celanese’s Miller said CoolPoly TCP provides a solution for the growing automotive head-up display (HUD)-due to limited dashboard space, airflow and heat, this application requires higher heat dissipation than uniform lighting . Sunlight shines on this position of the car. “The weight of thermally conductive plastic is lighter than aluminum, which can reduce the impact of shock and vibration on this part of the vehicle, which may cause image distortion.”
In the battery case, Celanese has found an innovative solution through the CoolPoly TCP D series, which can provide thermal conductivity without electrical conductivity, thereby meeting relatively strict application quality requirements. Sometimes, the reinforcing material in the thermally conductive plastic limits its elongation, so Celanese materials experts have developed a nylon-based grade CoolPoly TCP, which is tougher than the typical grade (100 MPa flexural strength, 14 GPa flexural modulus, 9 kJ / m2 Charpy notch impact) without sacrificing thermal conductivity or density.
CoolPoly TCP provides flexibility in convection design and can meet the heat transfer requirements of many applications that have historically used aluminum. The advantage of its injection molding is that aluminum die castings consume one-third of the energy of aluminum, and the service life is extended by six Times.
According to Matsco of Covestro, in the automotive sector, the main application is to replace radiators in headlamp modules, fog lamp modules and taillight modules. Heat sinks for LED high beam and low beam functions, LED light pipes and light guides, daytime running lights (DRL) and turn signal lights are all potential applications.
Matsco pointed out: “One of the main driving forces of Makrolon thermal PC is the ability to directly integrate the heat sink function into the lighting components (such as reflectors, bezels, and housings), which is achieved by multiple injection molding or two-component methods. “Through the reflector and frame usually made of PC, the improved adhesion can be seen when the thermally conductive PC is re-molded onto it to control heat, thereby reducing the need for fixing screws or adhesives. Demand. This reduces the number of parts, auxiliary operations and overall system-level costs. In addition, in the field of electric vehicles, we see opportunities in the thermal management and support structure of battery modules.”
BASF’s Naamani-Goldman (Naamani-Goldman) also stated in electric vehicles that battery pack components such as battery separators are very promising. “Lithium-ion batteries generate a lot of heat, but they need to be in a constant environment of about 65°C, otherwise they will degrade or fail.”
Initially, thermally conductive plastic compounds were based on high-end engineering resins. But in recent years, batch engineering resins such as nylon 6 and 66, PC and PBT have played a big role. Covestro’s Matsco said: “All of this has been found in the wild. However, due to cost reasons, the market seems to be mainly concentrated on nylon and polycarbonate.”
Scheepens said that although PPS is still very often used, PolyOne’s nylon 6 and 66 and PBT have increased.
RTP stated that nylon, PPS, PBT, PC and PP are the most popular resins, but depending on the application challenge, many higher performance thermoplastics such as PEI, PEEK and PPSU can be used. An RTP source said: “For example, the heat sink of an LED lamp can be made of nylon 66 composite material to provide a thermal conductivity of up to 35 W/mK. For surgical batteries that must withstand frequent sterilization, PPSU is required. Electrical insulation properties and reduce moisture accumulation.”
Naamani-Goldman said that BASF has several commercial thermally conductive compounds, including nylon 6 and 66 grades. “The use of our materials has been put into production in a variety of applications such as motor housings and electrical infrastructure. As we continue to determine customer needs for thermal conductivity, this is an active area of ​​development. Many customers do not know what level they need Conductivity, so materials must be tailored for specific applications to be effective.”
DSM Engineering Plastics recently launched Xytron G4080HR, a 40% glass fiber reinforced PPS that optimizes the performance of electric vehicle thermal management systems. It is designed with thermal aging properties, hydrolysis resistance, dimensional stability, chemical resistance at high temperatures and inherent flame retardancy.
According to reports, this material can maintain a strength of 6000 to 10,000 hours at a continuous working temperature exceeding 130°C. In the most recent 3000-hour 135°C water/glycol liquid test, the tensile strength of Xytron G4080HR increased by 114% and the elongation at break increased by 63% compared with the equivalent product.
RTP stated that according to application requirements, any of a variety of additives can be used to improve thermal conductivity, and pointed out: “The most popular additives continue to be additives such as graphite, but we have been exploring new options such as graphene or new ceramic additives. .system.”
An example of the latter was initiated last year by Martinswerk Div ​​of Huber Engineered Polymers. According to reports, based on alumina, and for new migration trends (such as electrification), the performance of Martoxid series additives is better than other alumina and other conductive fillers. Martoxid is enhanced by controlling particle size distribution and morphology to provide improved packing and density and unique surface treatment. According to reports, it can be used with a filling amount exceeding 60% without affecting mechanical or rheological properties. It shows excellent potential in PP, TPO, nylon 6 and 66, ABS, PC and LSR.
Covestro’s Matsco said that both graphite and graphene have been widely used, and pointed out that graphite has a relatively low cost and moderate thermal conductivity, while graphene usually costs more, but has obvious thermal conductivity advantages. He added: “There is often a need for thermally conductive, electrically insulating (TC/EI) materials, and this is where additives such as boron nitride are common. Unfortunately, you get nothing. In this case, boron nitride provides The electrical insulation is improved, but the thermal conductivity is reduced. Moreover, the cost of boron nitride may be very high, so TC/EI must become a material performance that urgently needs to prove cost increase.
BASF’s Naamani-Goldman puts it this way: “The challenge is to strike a balance between thermal conductivity and other requirements; to ensure that materials can be processed efficiently in large quantities and that the mechanical properties do not drop too much. Another challenge is to create a system that can be widely adopted. Cost-effective solution.”
PolyOne’s Scheepens believes that both carbon-based fillers (graphite) and ceramic fillers are promising additives that are expected to achieve the required thermal conductivity and balance other electrical and mechanical properties.
Celanese’s Miller said the company has explored a variety of additives that combine the industry’s widest selection of vertically integrated base resins to provide proprietary ingredients that make thermal conductivity The range is 0.4-40 W/mK.
The demand for multifunctional conductive compounds such as thermal and electrical conductivity or thermal and flame retardant also seems to increase.
Covestro’s Matsco pointed out that when the company launched its thermally conductive Makrolon TC8030 and TC8060 PC, customers immediately started asking whether they could be made into electrical insulating materials. “The solution is not so simple. Everything we do to improve EI will have a negative impact on TC. Now, we offer Makrolon TC110 polycarbonate and are developing other solutions to meet these requirements.”
BASF’s Naamani-Goldman said that different applications require thermal conductivity and other characteristics, such as battery packs and high-voltage connectors, which all need heat dissipation and must meet strict flame retardant standards when using lithium-ion batteries.
PolyOne, RTP and Celanese have all seen huge demand for multifunctional compounds from all market segments, and provide thermal conductivity and EMI shielding, higher impact, flame retardancy, electrical insulation, and Compounds with functions such as UV resistance and thermal stability.
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