January 2018 Bakelite® Molding Compounds Design Guide General Design, Processing & Troubleshooting Guide 1 Introduction 2 Material Selection 2.1 Material Type and Grade Selection 2.2 Why Consider Engineering Thermosets vs. Metals 2.3 Why Consider Engineering Thermosets vs. Engineering Thermoplastics 2.4 Hexion’s Product Portfolio for Automotive Solutions 3 Design Guide 3.1 Design Software 3.2 Best Practices 3.3 Part Design Recommendations 3.4 Mold Design Recommendations 4 Processing Guide 4.1 Process Selection 4.2 Process Parameters 5 Secondary Operations 5.1 Deflashing 5.2 Machining 5.3 Assembly 5.4 Decorating 6 Troubleshooting Guide 6.1 Injection Molding 6.2 Compression Molding 6.3 Examples of Common Defect Types Title: Ford 1.0 I3 MMLV EcoBoost Cam Carrier Automotive Under-the-Hood 7 Disclaimer / Resources Manufacturer: Ford Motor Company Material: Bakelite® PF 1110 Engineering Thermoset- based composition containing carbon fiber 8 Product Overview 1 Introduction 4 5 Now you can have the premium features of a cutting edge Bakelite® phenolic molding compounds, when they were invented over a century ago, revolu- material without the cutting edge price or risk tionized the manufacture of household goods such as radios and lamp cases. Today, molding compounds based on epoxy [EP], unsaturated polyester [UP], melamine phenolic [MP] and phenolic [PF] resins allow products to be mass produced in an infinite variety of contours and Bakelite® engineering thermosets make it possible to design lightweight complex parts that forms. Dimensional stability, surface hardness and heat resistance, coupled with inherently low require precision and performance. Usable as molded, they can be a lower cost solution than flammability and superb electrical features, are hallmarks of these materials. Bakelite® molding die-cast metal. compounds continue to be used in household appliances but are increasingly found in tight toler- ance high performance parts in automotive under-the-hood applications such as pistons, pulleys, Bakelite® engineering thermosets are readily processed in thermoset injection molding equip- valve blocks and pump parts and in a variety of electrical components. ment. They have a proven track record in demanding applications where their ability to maintain dimensions and mechanical performance during temperature spikes provide additional design safety. Figure 1. Tight Tolerance High Performance Parts Low Risk Design Flexibility Phenolic molding compounds have Grades with inherently low shrinkage and been used in demanding applications for low coefficient of thermal expansion make decades. a range of tight tolerance parts possible. § Inherent properties make them ideal § Complex net shape parts for high-stress as well as high-heat § High precision parts environments § Tight tolerances over large spans § Phenolic resins have been used for § Special grades available with isotropic many years in electrical, automotive CTEs close to aluminum & steel under-the-hood and transmission ap- § Inherently flame resistant plications § Reliable supply chain trusted by mul- tiple tier 1 manufacturers § Fast, low cost functional prototypes of Figure 2. Automotive Underhood Parts large parts possible Easy to Process Cost Effective Cost effective parts vs. machined die-cast § Can be injection molded aluminum and high temperature enginee- § Possible to mold net shape parts with- ring thermoplastics. out secondary machining § Possible to screw mechanical fasteners § Complex net shape parts save machin- directly into molded material–no inserts ing costs over metal equivalents § Recyclable 1 Ready to get started? Contact us today at [email protected] 1 Conforms to EU End-of-Life of Vehicles Directive (2000/53/EC) and Waste Framework Directive (2008/98/EC) 6 7 Figure 3. Automotive Underhood Parts Table 1. Resin System Advantages & Strengths Molding Compounds Advantages Strengths Phenolic § Good thermo-mechanical § Mechanical stability behavior & creep resistance § Tolerant of temperature spikes in use § Inherently flame retardant Melamine-phenolic § Tougher than straight § Commutator applications phenolic resin § Electrical properties for small motors § Good electrical insulating § Copper adhesive properties Unsaturated polyester § Free radical cure – no off-gas § Exceptional high voltage tracking generated resistance Epoxy § High strength & rigidity § Cure by polyaddition – no off-gas § Good thermal & electrical generated ideal for overmolding insulating properties § Low viscosity possible, fill tight dimensions Modern processing techniques coupled with next-generation formulations are expanding the universe of applications where Bakelite® molding compounds are being used. 1.1.2 Types of Bakelite® Molding Compounds Available General purpose and specialty molding compounds § Organic or mineral fillers 1.1.1 Engineering Thermosets § Graphite-extended for tribological performance § Specialty grade capable of being galvanically chrome-plated § Modified grades with enhanced dimensional stability and flame resistance Bakelite® molding compounds are engineering thermosets (ETS) not engineering thermoplastics Glass-fiber reinforced molding compounds (ETP). Once processed and cured, they are infusible and cannot be re-melted or dissolved. This § High modulus, low creep is the key to their strength, toughness and durability. § Mechanical strength at elevated temperatures Bakelite® molding compounds are formulated from one of four heat-cured, crosslinkable resin § Resistant to automotive fluids systems, which are combined with reinforcements, fillers and modifiers, to produce materials that § Dimensionally stable, capable of complex high precision tight tolerance parts meet or exceed a wide range of end use application requirements. The original and still predomi- nant resin system used is phenolic: the other three are: melamine-phenolic, epoxy and unsatu- rated polyester. Advantages and strengths of each resin system are summarized in Table 1. 8 9 ® 1.1.3 Advantages of Bakelite Molding Compounds 1.1.6 Engineering Thermosets can be Recycled § High strength, rigidity and surface hardness Material recyclability is increasingly important to automotive manufacturers. It is possible to recy- § Exceptional dimensional stability cle engineering thermosets in several ways: mechanical, chemical, or as a filler in making cement. § Low coefficient of thermal expansion Mechanical recycling involves grinding cured thermoset scrap and reintroducing it as a filler in § Good thermomechanical properties, virtually no cold flow (low creep) fresh molding compounds. Chemical recycling involves pyrolysis or solvolysis whereby the matrix § High dynamic stress resistance (high fatigue stress) material is separated from the fiber reinforcement and is digested to basic components that can § High resistance to media, no environmental stress cracking be reused. A third approach, promoted in Europe and Japan, involves the use of thermoset scrap § High thermal resistance, tolerant of temperature spikes in end use environment in the cement making process. Inorganic components are reduced to ash and bond with the § Inherently flame retardant: incandescent wire resistance of 960 °C, cement clinker, while the organic component serves as a thermal energy source in the calcination special grades full fill UL 94 V-0 in thin walls process. Finally, incineration is considered a suitable method for disposing of thermoset waste, § Good thermal and electrical insulating properties extracting thermal energy from the organic component. Figure 4 diagrams a typical life-cycle for § Improved NVH (damping) vs aluminum thermoset automotive under-the-hood parts. (See EPCD-HXN-682) § Tribological grades resistant to abrasion and wear Thermoset parts may have lower environmental impact, eg. GWP (global warming potential), than aluminum over the lifecycle. 2 1.1.4 Bakelite® Engineering Thermosets Meet the Needs Figure 4. Life-Cycle Supply Chain for Under-The-Hood Parts of Today’s Demanding Automotive Market As engines are downsized to meet increased fuel efficiency standards and reduced CO2 Production Consumer emission requirements, and under-the-hood temperatures rise, demand for cost-effective, light- of Energy weight, heat tolerant material solutions rises. Bakelite® engineering thermosets deliver perfor- mance benefits for a variety of under-the-hood components from pulleys to electrical compo- nents and light weight solutions for E-Mobility: Waste Disposer Plastics Dump Disassembling Usage Sorting § Up to 40 percent weight savings versus aluminum § Inherently corrosion resistant Raw Processing § Stable in automotive fuel and fluids Material Waste § Heat stability beyond most engineering thermoplastics Recycling § Inherent vibration dampening and low noise versus metal § Lower environmental impact over lifecycle than aluminum Preparation Cleaning Molder Crushing Extraction Plastics 1.1.5 Bakelite® Engineering Thermosets Meet the Needs Manu- facturer of Today's Electrical Market Because of their excellent heat resistance, mechanical strength, and electrical insulating proper- ties, Bakelite® thermosets have been used for decades in a wide variety of electrical applica- tions such as motor parts and switches. A broad product selection is available including organic and inorganically filled grades with properties optimized for specific applications and UL listing requirements. 2 Based on a case study, comparative peer-reviewed LCA (life cycle analysis) of a water pump housing made of injection molded