Design Overview in Automotive Industry: PART 2

REPORT 2

OBJECTIVE: TO PROVIDE AN OVERVIEW OF THE MATERIAL SELECTION PROCESS, IDENTIFYING AND UNDERSTANDING THE CHARACTERISTICS OF VARIOUS KINDS OF PLASTICS USED IN THE AUTOMOTIVE INDUSTRY, UNDERSTANDING VARIOUS AUTOMOTIVE COMPONENTS AND MANUFACTURING PROCESSES. 

 

MAIN REPORT: 

1. FACTORS TO BE CONSIDERED WHILE SELECTING MATERIALS FOR ANY COMPONENT:

• Identification and Optimization of Design Requirements
• Understanding the Material Selection Criteria
• Identifying and Evaluating candidate materials.
• Performance Requirements
• Reliability Requirements
• Optimizing Size, Shape and Mass to reduce overall weight
• Economic Effectiveness
• Manufacturing Requirements
• Optimization of Production Process
• Industry Standards
• Validation under Governmental Regulation
• Analyzing Intellectual Property Requirements
• Sustainability & Recyclability Requirements

 

2. UNDERSTANDING THERMOSETS AND THERMOPLASTICS WITH EXAMPLES:

A) THERMOSET PLASTICS: Thermoset Plastic is a polymer that is irreversibly hardened by heat. They have also known as ‘Thermosetting Polymers’ or ‘Thermosetting Resins’. The initial material for a thermoset plastic is liquid or pseudo-solid. Heat provides energy for covalent bond formation, cross-linking the polymer’s subunits, and results in hardening the plastic. At times, the heat is applied externally but it may also come from the chemical reactions when ingredients are mixed as well. Eventually, upon applying pressure, a catalyst, or a hardener can increase the curing or hardening rate. Once hardened, a thermosetting plastic cannot be remelted, so it is formed into its final shape by injection moulding, extrusion moulding, compression moulding, or spin casting. The two thermoset moulding compound processes are ‘Reaction Injection Moulding(RIM)’ & ‘Resin Transfer Moulding(RTM)’

 

 

Examples of Thermosetting Plastics:

• Polyurethane
• Vulcanized Rubber
• Epoxy Resin
• Fiberglass(A fiber-reinforced Thermoset)
• Bakelite(Phenolic)
• Cyanate Esters
• Duroplast
• Melamine
• Polyester Resin
• Silicon Resin
• Vinyl esters

 

B) THERMOPLASTICS: Thermoplastics are made by joining small molecules, called ‘monomers’, together to form long chains by using a process called ‘Polymerisation’. A single polymer chain can be made from thousands of monomers. Atoms in a polymer chain are joined by strong covalent bonds, whereas the forces between chains are weak. Depending on the type of monomer, a polymer chain can have branches. If a polymer chain has only a few short branches then chains can form ordered, crystalline regions, called ‘Spherulites’. However, if the chain has many side branches, then it is not possible for ordered regions to be formed and the polymer is amorphous. Examples of amorphous polymers are polystyrene(PS), Polyvinyl Chloride,(PVC), Acrylonitrile-butadiene-styrene(ABS), etc. Even for polymers with crystalline regions, there are always some amorphous regions existing in-between the crystallites, hence these polymers are called ‘Semi-crystalline’ Examples of semi-crystalline polymers are Polyethylene(PE), Polyamide(PA), Polypropylene(PP). For semi-crystalline polymers, as the temperature increases, the bonds between the polymer chain weaken to create a pliable solid and then viscous liquid that allows the material to be shaped to produce parts. Amorphous plastics are used for applications where optical clarity is required since light is scattered by crystallites. These amorphous plastics are less resistant to chemical attacks though and environmental stress cracking due to the lack of crystalline structure. Before actually using a thermoplastic polymer, normally, they’re mixed with additives, such as stabilisers, plasticisers, lubricants, flame retardants, and colorants, to improve the polymer’s functionality, stability, or appearance. For example, stabilizers are added to reduce degradations due to sunlight or heat, and plasticisers are added to increase the mobility of amorphous chain segments, lowering the glass temperature, and decreasing brittleness.

 

 

Examples of Thermoplastics:

• Polypropylene(PP)
• Thermoplastic Polyurethane(TPU)
• Polyethylene(PE)
• Polyamide(PA)
• Acrylonitrile-Butadiene-Styrene(ABS)
• Polyvinyl Chloride(PVC)
• Polycarbonate(PC)
• Polymethyl methacrylate(PMMA)
• Polybutylene Terephthalate(PBT)

 

3. PROS & CONS OF THERMOSET PLASTIC MATERIALS:

PROS:

• More resistant against High-Temperatures
• Hard & Rigid
• Thick to thin Wall capabilities
• Excellent Aesthetic finishes
• High Mechanical Property
• Cost-Effective
• Excellent Dimensional Stability

CONS:

• Cannot be Recycled
• Surface-finish is achieved with much more difficulty
• Cannot be remoulded or reshaped
• Poor thermal conductivity for housing replacements
• Rigidity to the material can result in product failure when used in high vibration applications

 

4. PROS & CONS OF THERMOPLASTIC MATERIALS:

PROS:

• Extremely adhesive to metal
• Highly-Recyclable
• Superb Impact Resistance
• Can be remoulded & reshaped
• Slip-Enhancement
• High Chemical Resistance
• Hard crystalline or rubber surface options
• Higher Flexibility
• Higher Electrical Insulation
• Chip resistance
• Eco-frinedly manufacturing options
• Aesthetically-Superior finishes
• Super corrosion resistant

CONS:

• Degrade more easily in direct sunlight or under UV exposure
• Not all thermoplastics resist hydrocarbons, organic solvents, or polar solvents
• Some types experience creep under long-term loading
• Can fracture rather than deform under high stress
• May soften when reheated
• Can be more expensive than thermoset plastics
• Rigidity to the material can result in product failure when used in high vibration applications

 

5. TYPES OF MANUFACTURING PROCESSES FOR THERMOSET & THERMOPLASTIC MATERIALS:

A) TYPES OF MANUFACTURING PROCESS FOR THERMOSET PLASTICS:

• Thermoset Injection Molding
• Reaction Injection Molding
• Resin Transfer Molding
• Bulk Molding Compound
• Sheet Molding Compound
• Compression Molding
• Filament Winding Process
• Pultrusion Process

 

Thermoset Plastics are mostly made through liquid molding processes. Here, the polymers and other agents are fed together into tanks or barrels, where they’re heated until they reach a liquid state and are mixed. The liquid polymers and other agents are then injected into a mold cavity. As the material cools down and hardens to the specified shape of the cavity, it goes through a curing/hardening process where the polymers are cross-linked together. This process forms numerous irreversible chemical bonds that eventually prevent the risk of melting, softening, or wrapping when if the final products are subjected to higher temperatures or are placed inside any corrosive environment. This property makes thermoset plastics a favorable choice to be used in high-temperature environments and better suited to be used outdoors.

 

• Thermoset Injection Molding: In case, cold materials are injected into an extremely hot mold to create a part. This process hardens or cures to such a degree that it can never be melted ever again to be reused.

      

 

• Reaction Injection Molding: The RIM process begins when two liquid agents ‘Polyol’ & ‘Isocyanate’ are placed in separate tanks and heated to an elevated temperature. They are then fed at high pressure into a mix-head. Once combined, the mixed liquid flows into a mold where the chemical reaction takes place, forming a polymer in the mold.

        

 

• Resin Transfer Molding: RTM is a closed-molding process also known as liquid molding. Resin formulations are mixed with hardener, or catalyst, and injected into a mold that contains dry fibers such as fiberglass, where the part is allowed to harden and form.

        

 

• Bulk Molding Compound: Bulk molding compound(BMC) is a bulky mixture of chopped glass fibers; resin paste and fillers. Even though other fibers such as sisal, asbestos, carbon, aramid, chopped nylon rag, and wood are used, the most common reinforcing fiber in BMC is E-glass fiber. As BMC is usually mixed in a dough-like form rather than as a sheet, it is also called dough molding compound(DMC) and is sold in log or rope form. Chopped glass fibers are compounded with the resin paste in an intensive mixer and extruded in the form of a continuous log. The extruded log is cut to the desired length by a pneumatic cutter located outside the extruder. The impact strength is highly dependent on the fiber length.

        

 

• Sheet Molding Compound: Sheet Molding Compound(SMC) is a compression molding compound often used for larger parts where higher mechanical strength is needed. SMC is a fiber-reinforced thermoset material. The method by which SMC is produced ensures complete integration of fibers and resin. The resin is applied in the form of a paste to a film. Next, the fibers are cut and added to the paste. The substance is then squeezed between two films, it is compacted until it reaches the desired thickness and texture.

        

 

• Compression Molding: In this process of molding, compressive forces with heat are used to shape a raw material utilizing a mold. Matched metal dies are mounted in a molding press. The material charge is placed in the mold, heated mold halves are closed, and pressure is applied. Cycle time ranges according to the part size and thickness. Compression molding is ideal for larger parts that require high dimensional stability. Tooling costs will vary depending on the size and complexity of the part, along with overall cavitation.

        

 

• Filament Winding Process: Filament winding is the process of winding resin-impregnated glass or advanced fiber around a rotating mandrel to create a composite structure. By using different fibers and resins and incorporating various winding techniques, filament winding creates high fiber loading with directional strength characteristics. It results in high fiber volume, accurate and optimized fiber orientation, and robust composite products.

         

• Pultrusion Process: The Pultrusion process is a highly automated continuous fiber laminating process producing a high fiber volume profile with a constant cross-section.

        

 

 B) TYPES OF MANUFACTURING PROCESS FOR THERMOPLASTICS:

• Plastic Extrusion
• Injection Molding
• Rotational Molding
• Plastic extrusion & Injection Blow Molding
• Vacuum Casting
• Thermoforming & Vacuum Forming
• Compression Molding

 

Thermoplastic’s polymer bonds allow them to be heated and remolded indefinitely, making them highly recyclable depending on their chemical makeup. Thermoplastics can come from both natural and synthetic sources. For example, some thermoplastics are made from cellulosic, or cellulose fibers found in wood and cotton. Nylon, acrylic, and polyester come from petrochemicals, including petroleum and plant-based materials. Granules are created when the base material is heated, desired additives like dyes are mixed in, and the mixture is cooled and separated into small particles that are easy to package and transport. From there, manufacturers can reheat granules, add desired chemicals, and mold them in different ways to create a wide range of products.

 

• Plastic Extrusion: In the plastic extrusion process, plastic powder or pellets are fed into the extrusion machine via a hopper. The polymer is heated inside a barrel at a controlled temperature and a screw pushes molten plastic through a metal die, which is then cooled to give the plastic a fixed, continuous shape while being continuously pulled and formed into the final shape. The product can be cut or trimmed to the desired length. This is one of the most common ways to manufacture plastic products. The plastic extrusion process works well for high-volume production of a wide range of products including pipes construction products such as ventilation doors and windows frames and seals.

        

 

• Injection Molding: A hopper feeds the plastic polymer into a heated barrel and screw. The screw melts the plastic and injects the liquid polymer into a temperature-controlled split mold tool that creates the shape of the product. Injection molding is used for high-volume manufacturing and many components can be manufactured in a short space of time, from tiny parts to large components such as vehicle bumpers and bins. Unlike the extrusion process, molten plastic is forced into a die to form its final shape.

        

 

• Rotational Molding: In this process, the plastic polymer is placed into the mold before heating. The closed mold enters a furnace and rotates, which allows the plastic polymer to coat the entire inside of the mold evenly. The heat melts the plastic into a single layer that conforms to the shape of the mold cavity while leaving the interior of the final product hollow. A water spray cools the mold while still rotating which solidifies the polymer. Rotation is stopped, the mold is opened, and the plastic part is removed. Suitable for short, economical production runs and is not suited for precision forming due to the finish of the part. It is ideal for making large, complex shapes with a uniform wall thickness, e.g., large storage tanks for water, chemicals, and fuel, crates, cooler boxes, bins, bollards, canoes, toys, and playground equipment.

        

 

• Plastic extrusion & Injection Blow Molding: Similar to the extrusion and injection molding process, air pressure forces the hollow plastic to expand into the mold or extrusion shape, leaving the interior of the object hollow. This process is used for the mass production of inexpensive containers such as bottles, cups, beakers, etc.

        

 

• Vacuum Casting: This is a method of developing small functional plastic parts especially high-quality prototypes, and suitable for low-volume production. Vacuum casting is a highly versatile technology for elastomers that uses a vacuum to pull the liquid raw material into the mold. This process is used when air entrapment is a problem, if there are elaborate details or recessed surfaces, or if the material is reinforced with fiber or wire. The raw material is poured into the two-piece silicon mold and the vacuum is released. The mold is removed from the chamber and the casting is cured/hardened in the oven. Mold is then removed to release the casting. Mold can be reused.

         

 

• Thermoforming: The process involves heating a previously extruded plastic sheet at a pliable temperature which is then stretched into a specific shape over a mold, then trimmed to create the required product. Machines can make thousands of components quickly. Examples of products are disposable cups, containers, lids, trays, blisters, and various products for the food, medical, and general retail industries. A simplified version of thermoforming is plastic vacuum forming.

        

 

• Compression Molding: This method is generally used in the manufacturing of thermoset plastics where the polymers become irreversibly rigid when heated. The raw material is pre-heated and placed into an open mold cavity. The mold is closed from the top and then pressure is applied which forces the material to spread out completely into all the areas of the mold. Heat and pressure are maintained until the material had hardened. Once cured, the formed product can be removed. This method of plastic molding is used regularly in the manufacture of automotive parts such as hoods, fenders, spoilers, as well as smaller more complex parts. It is also widely used to produce sandwich structures such as honeycomb or polymer foam.

        

 

6. MATERIALS THAT ARE CLASSIFIED AS THERMOPLASTIC:

 A) POLYCARBONATE(PC):

•  Highly Transparent: The Light Transmission Rate for Polycarbonate is 88% which is pretty good. It is a naturally transparent amorphous thermoplastic. Polycarbonate is used in parts such as Headlamp Bezels, Headlamp Lenses, Light-Housing, Instrumental-Panel’s transparent components, etc.
• Highly Weather Resistant: Amongst its many beneficial use-cases, one is panels that are made out of PC that is resistant to temperatures both hot and cold, sunlight, snow, rain, etc although after prolonged exposure to UV, overtime the clarity gets diminished and it’ll adopt a yellowish hue eventually.
• High Strength: Polycarbonate can withstand an impact of over 900psi, and is about 200 times stronger than steel. As a thermoplastic, polycarbonate will flex and return to its original shape while components made out of metals can get dented upon impact. Its ultimate tensile strength is about 9500psi and its yield tensile strength is about 9000psi which means it would be able to withstand the pressure of being approximately 2000ft underwater before suffering permanent deformation. It can maintain rigidity up to 140˚C and toughness down to -20˚C or even lower in cases of some special grades.
• Good Electrical Properties: Polycarbonate is mainly used for electronic applications that capitalize on its collective safety features as it has very good insulating characteristics. Also, it has a high heat resistance and flame-resistant properties.
• Remains flexible down to -150˚
• Non-flammable & Self-extinguishable
• Good Dimensional Stability
• Resistant to weak acids, hydrocarbons, and oils.
• Hygroscopic: PC is hygroscopic which means if not properly dried, it releases water vapor during molding. This normally results in the formation of tiny bubbles that get excreted out of the surface often described as ‘Silver Streaks’.

       

 

 B) ACRYLONITRILE BUTADIENE STYRENE(ABS):

• High Rigidity: ABS has high rigidity and impact resistance. Even in low-temperature conditions or over long periods, ABS plastics will retain these characteristics. Its tensile strength is around 35-44 Mpa and because of its plastic yield at high strain rates, the impact failure of ABS is ductile rather than brittle. It is used in Instrument-Panel, Door-trims, etc. As it has good impact resistance, it is used in creating bumpers as well.
• Excellent Insulation: It has very good insulating properties, both acoustic and thermal.
• Highly Weldable: It is a good weldable material as it is an amorphous material and has a Tg(Glass Transition Temperature) of around 110˚-125˚ The glass transition temperature is the temperature range where the polymer substrate changes from a rigid glassy material to a soft(not molten) material, and is usually measured in terms of stiffness or modulus.
• High Dimensional Stability: It remains mechanically strong over time.
• Good Surface Characteristics: High Surface brightness and excellent surface finish. ABS is an ideal material whenever superlative surface quality, color fastness, and luster are required. ABS is a two-phase polymer blend. A continuous phase of ‘Styrene-Acrylonitrile’ co-polymer(SAN) gives the material rigidity. Hardness and heat resistance. The toughness of ABS is the result of microscopically fine polybutadiene rubber particles uniformly distributed in the SAN matrix. Hence, ABS is also used in Wheel-covers, IP substrate, etc
• Good Abrasion & Strain Resistance

        

 

 C) POLYAMIDES(PA)/NYLON:

• High Rigidity & Hardness: Polyamides have an Ultimate Tensile-Strength of around 85Mpa and Tensile Modulus(Degree of Stiffness) of around 2.6Gpa.
• Good Dynamic Fatigue Resistance
• High Impact Strength, even at low temperatures.
• Heat Resistant
• Exhibits Excellent Electrical Properties & Chemical Resistance
• Virtually no Stress-Cracking(Stress Resistance)
• Good Abrasion and wear resistance.
• Good sound and vibration damping.
• Easy processability.
• When reinforced with glass fibers, their stiffness can compete with metals.

        

 

D) POLYETHYLENE TEREPHTHALATE(PET):

• Outstanding Chemical Resistance
• Water-Repellent and are used in Wiper-Arms
• Superior strength & stiffness. Used in Gear-Housing and Delrin Bushing.
• Excellent dimensional stability.
• Good Impact Strength
• High heat resistance and hence used in the engine cover.
• Flame retardant.
• Outstanding Clarity
• High Gloss and hence used in Wiper-covers
• Very low moisture absorption
• Good Creep Resistance
• Low Sliding friction and Sliding wear
• Resistant to Hydrolysis (Up to +70˚C)
• Good Adhesion and Welding Ability

        

 

E) POLYPROPYLENE(PP):

• Made by polymerization of propene monomer. There are two main syntheses to produce polypropylene one of which is ‘Ziegler-Natta Polymerization’ and another one is ‘Metallocene Catalysis Polymerization’
• Polypropylene Homopolymer is the most widely utilized general purpose grade. It contains only propylene monomer in a semi-crystalline solid form. Main applications include packaging, textiles, healthcare, pipes, automotive and electrical applications.
• Another kind of Polypropylene is Polypropylene Copolymer which is further divided into random copolymers and block copolymers produced by polymerizing propane and ethane. These are Polypropylene Random Copolymer and Polypropylene Block Copolymer.
• There’s also Polypropylene Impact Copolymer which is a Polypropylene Homopolymer containing a co-mixed Polypropylene Random Copolymer which has an ethylene content of 45-65% referred to as PP impact copolymer. It is useful in parts that require good impact resistance.
• Melting Point: Melting Point of Polypropylene- For Homopolymer, it is around 160-165˚C & for Copolymer, the Melting point is around 135-159˚
• Lightweight: One of the Lightest Polymers among all commodity plastics. This feature makes it a suitable option for lightweight applications.
• Semi-Rigid
• Translucent
• Good Chemical Resistance
• Good Fatigue Resistance
• Integral hinge property
• Good Heat Resistant
• Excellent Electrical and Chemical Properties even at High Temperatures
• No Stress Cracking Problems
• Poor resistance to UV
• Used in Bumpers, Wheel-covers, Chemical-tanks, Cable insulation, and Carpet fibers. Instrumental panels, Door-trims. Etc.

       

 

 F) POLYURETHANE(PUR):

• Versatile: Polyurethane is an extremely versatile elastomer. Its mechanical properties can be isolated and manipulated through creative chemistry which creates several unique opportunities to solve problems with performance characteristics unequaled in any other material.
• Hardness: Wide range of Hardness. Shore Hardness is a measure of the resistance of a material to indentation. Polyurethane relies on the prepolymer’s molecular structure and can be manufactured from 20 Shore to 85 Shore.
• Load-Capacity: Polyurethane has a high load-bearing capacity in both tension and compression. Polyurethane can change its shape under a heavy load but will return to its original shape once the load is removed with little compression set in the material when designed properly for a given application.
• Flexible: Polyurethane performs very well when used in high flex fatigue applications. Flexural properties can be isolated allowing for very good elongation and recovery properties.
• Abrasion & Impact Resistant: For applications where severe wear proves challenging, Polyurethane is an ideal solution even at low temperatures.
• Tear Resistant: Polyurethane possesses high tear resistance along with high tensile properties.
• Resistance to Water, Oil & Grease: Polyurethane’s material properties will remain stable(with minimal swelling) in water, oil and grease. Polymer compounds have the potential to last many years in subsea applications.
• Wide Resiliency Range: Resilience is generally a function of hardness. For shock-absorbing elastomer applications, low rebound compounds are usually used(Resilience range- 10-40%). For high-frequency vibrations or where quick recovery is required, compounds in the 40-65% resilience are used. In general, toughness is enhanced by high resilience.
• Strong Bonding Properties: Polyurethane bonds to a wide range of materials during the manufacturing process. These materials include other plastics, metals, and wood as well. This property makes polyurethane an ideal material for wheels, rollers, and inserts.
• Performance in Harsh Environments: Polyurethane is very resistant to extreme temperatures, meaning harsh environmental conditions and many chemicals rarely cause material degradation.
• Economical Manufacturing Process: Polyurethane is often used to manufacture one-off parts, prototypes, or high volume, repeat production runs. Size ranges vary from a couple of grams to 2000lb parts.
• Uses: PUR is used in Car-seats, Door-trims, B-Pillars, High resilience foam seating, rigid foam insulation panels, headliners, suspension insulators, etc.

        

 

G) POLYVINYL CHLORIDE(PVC):

• Versatility: PVC can be used to create a multitude of rigid or flexible plastic materials. It allows for precise adjustments to its material properties so that one can give the exact performance and quality requirements for specific end-use applications.
• Makes vehicle last longer: The average life of a modern road car is around 15-17 years which was 10-12 years in the 90s. PVC is used to contribute to this as the principal protector of the underbody (in the form of wear-resistant coating), as a sealant against humidity, and in other protective profiles. The durability of PVC has also made it a first choice for the cladding of interior parts such s dashboards and door panels. Longer-lasting vehicles also mean saving on natural resources.
• Conserves fossil fuels: PVC itself is a material with comparatively low energy consumption in its manufacture, thereby cutting down the depletion of natural resources compared to alternative materials that might be used. When used in vehicles this natural low carbon footprint advantage is enhanced further by the lightness of PVC components in comparison to traditional materials. Reduced vehicle weight = reduced fuel consumption.
• Helps save lives. PVC is important in shock-absorbing vehicle components such as 'soft' dashboards, reducing injury in the case of impact. Fabrics coated with PVC are often used in life-saving vehicle airbags, whilst the fire-retardant properties of the material contribute to the overall safety of a vehicle.
• Increases design freedom. The freedom given by PVC in vehicle interiors allows for even the most challenging designs to enhance the comfort of vehicle interiors. PVC can be made to give many attractive qualities of appearance and leather-like softness.
• High Flexibility
• Flame Retardant
• Greater Thermal Stability
• Extremely low lead-content
• Uses Underbody Coating, Sealants, Floor Modules, Wire Harnesses, Passenger Compartment Parts such as Dashboard and Door Panel seating and Armrest, Exterior Parts such as body side protection ships, weather strips, and window sealing profiles.

       

 

 H) POLYMETHYL METHACRYLATE (PMMA):

• Transparency: PMMA allows 90% of light to pass through it which is more than glass or any other plastic.
• Weather Resistant: PMMA shows high resistance to UV light and weathering. PMMA is also unaffected by moisture and offers a high strength-to-weight ratio.
• Lustrous: Used for window glazing in many automobiles. Used to make windshields to provide clean and tinted. 40-50% lighter than conventional glass materials which attracts manufacturers to work with it because of its transparency, Pleasant acoustic properties, and outstanding formability.
• Strength: They are much lighter than glass and yet offer almost double impact resistance, uniform thickness tolerance, and low internal stress levels for consistent performance.
• Uses Window glazing, Number Plates, Windshields, Rear & Indicator lights, Interior light covers, light guides, fascia, Interior and Exterior Panels, Trims, Bumpers, Fenders, and other molded components.

       

 

 I) POLYBUTYLENE TEREPHTHALATE(PBT):

• PBT is a polymer that gives good durability under thermal stress or harsh environments, particularly in automotive under-the-hood applications.
• Superior Chemical Resistance with High Mechanical and Electrical properties.
• PBT’s extremely high electrical resistance and high dielectric strength help protect electronic components by providing a guard against leakage and breakdown in power circuitry. They designed many grades for electronic parts that have enabled innumerable applications in both signal and power uses.
• Uses Switches, Circuit Breaker, Power Sockets, Cable Liner, Windshield Wiper Cover, Mirror housing, Cowl Vents, Handles and Fans, Fuel System Components, Connectors, Sensor housing, and fuse boxes. Motor components and ignition system components.

       

 

7. MATERIALS WHICH ARE CLASSIFIED AS THERMOSETS:

 A) VULCANIZED RUBBER:

• Vulcanized rubber is a type of thermoset plastic as once it is molded, it retains its shape and can’t be recycled again. The untreated rubber is converted into vulcanized rubber through a process called vulcanization. In this process, the natural rubber is treated with Sulphur and various activators like Zinc fatty acid esters at the temperature of 140-160°C.
• Vulcanized rubber is more hardened than natural rubber. It is used in the manufacturing of various goods as it has both electrical and thermal insulation properties. Moreover, it has good abrasion properties and is inexpensive. It is used in manufacturing tires for vehicles because it has high tensile strength, hence it reduces the chances of tire punctures. Other uses of vulcanized rubber include seat belts, toys, conveyor belts, rubber hoses, and shoe hoses.
• It has excellent elasticity and a lower water absorption tendency.
• It is resistant to the action of organic solvents and oxidizing agents.
• It also has a high degree of cross-linking, resulting in the high rigidity of the polymer.
• Has high tensile strength and high abrasion resistance.

       

 

B) BAKELITE:

• Bakelite was the first thermoset plastic that was synthesized from synthetic components. The chemical name of Bakelite is ‘Polyoxybenzyl Methylene Glycol Anhydride. Commercially, it is also known as phenol-formaldehyde resin as it is synthesized by the condensation process between phenol and formaldehyde, under high pressure with HCl as a catalyst.
• Other catalysts like ammonia and zinc chloride are also used sometimes, as per the requirement of the reaction. The product obtained from this reaction is further heated slowly till a hard substance called Bakelite is obtained. Bakelite is easily moldable in its liquifiable state; hence it is used in the manufacturing of various products.
• To increase the strength of the Bakelite, various fillers like gypsum, mica, and asbestos are also used. Bakelite has a wide application in the electrical industries for making switches, boards, sockets, and wire insulation because of its electrical insulation properties.
• The unique property of Bakelite is that it can be produced in different colours which is why it is widely used in the manufacturing of colourful bangles, bracelets, and artificial jewellery. The application of Bakelite is also found in various kitchenware products.
• It can be quickly molded.
• Very smooth molding can be obtained from this polymer.
• Bakelite moldings are heat-resistant and scratch-resistant.
• They are also resistant to several destructive solvents.
• Owing to its low electrical conductivity, bakelite is resistant to electric current.

         

 

C) DUROPLAST:

• Duroplast is a composite thermoset material that is similar to Bakelite except for the fact that it is reinforced with cotton or wool fibers.
• One of the most significant properties of Duroplast is that it is lightweight and strong. Due to this property, Duroplast is used in making car bodies, which reduces the cost of using steel for making various car parts.
• It has a major disadvantage, which is its difficulty to decompose. If we burn them, they release highly toxic fumes that are harmful to the environment.
• Duroplast material has high mechanical strength and surface hardness. Their elasticity is low, however. The curing process is irreversible. Duroplast cannot be melted because it is rigid up to degradation temperature. Phenolic resins are among the most commonly used Duroplast materials.
• The molecular crosslinking of Duroplast creates good chemical stability. The colorings and dyeing options of components made of Duroplast are limited.

        

 

D) UREA-FORMALDEHYDE RESINS:

• Urea-Formaldehyde is also known as Amino plastic or carbamide-methanol.
• They are synthesized by the reaction between the Urea and Formaldehyde in the presence of water and at a PH value higher than 7.
• These Thermosets are highly cross-linked and have a semi-crystalline structure. They become rigid very rapidly if the temperature is elevated.
• They have wide applications in wood product industries and are used as an adhesive for particleboard.
• Other applications include laminating decorative items, coating, air filtration, and fiberglass mats.
• High tensile strength – The maximum stress that a material can withstand while being stretched or pulled before breaking.
• High flexural modulus – The ratio of stress to strain that a material can endure while bending before it yields.
• High heat-distortion temperatures – At what temperature the material will begin to “soften” when exposed to a fixed load at elevated temperatures?
• Low water absorption
• Mold shrinkage – When the volume of the molten plastic filled inside the cavity of a mold shrinks during the process of cooling and solidifying.
• High surface hardness
• Elongation at break – The ratio between changed length and initial length after the material breaks.
• Volume resistance – The electrical resistance of a body to current passing through its bodily substance.

        

 

E) MELAMINE-FORMALDEHYDE RESINS:

• It is an amino resin and has various material advantages, such as transparency, better hardness, thermal stability, excellent boil resistance, scratch resistance, abrasion resistance, flame retardant, moisture resistance, and surface smoothness, which lead MF to large industrial applications.
• Melamine-based polymers have also been extensively employed as cross-linking agents in baked-on surface-coating systems. As such, they have had many industrial applications—for instance, in automobile topcoats and finishes for appliances and metal furniture. However, their use in coatings is decreasing because of restrictions on the emission of formaldehyde, a major component of these coatings.

        

 

F) EPOXY RESINS:

• Resistance to chemicals, particularly in alkaline environments
• Heat resistance
• Adhesion to a variety of substrates
• High tensile, compression, and bend strengths
• Low shrinkage during curing
• High electrical insulation and retention properties
• Corrosion resistance
• Cures under a wide range of temperatures
• Resistance to fatigue
• Applications: Outdoor coatings, sealers, heavy-duty protective coatings, industrial and automotive paints, primers, and sealers. Also used in Motors, generators, transformers, gear switches, bushings, insulators, printed wiring boards (PWBs), potting, and semiconductor encapsulants.

        

 

G) POLYIMIDES:

• Polyimide resins are produced by the condensation reaction of aromatic primary diamines with aromatic tetracarboxylic dianhydrides.
• Because of the presence of aromatic rings in them, they have excellent thermal and chemical properties, and they can withstand high temperatures.
• Widely used in the production of sockets, bushings, and bearings as they exhibit high mechanical strength and are water-resistant.
• Also a great replacement for high-performance materials like metals and ceramics. However, their one shortcoming is that they are quite expensive.

        

 

H) POLYURETHANE:

• Polyurethanes are produced by the reaction between the organic diisocyanate and a diol compound.
• They can also be produced in the foamed structure if water is used in their manufacturing process. This foamed structure is used in the manufacturing of cushions, carpets, armrests, and mattresses.
• Polyurethane has a rigid foam structure, and they are used as insulation for various buildings.
• Their elastomeric structure finds applications in making car bumpers, steering wheels, windshields, gaskets, door panels, and other automotive and electrical components.
• The main disadvantage is that they are prone to microbial attacks and often get yellow underexposure to UV light.

        

 

8. MATERIAL USED FOR ITS TRANSPARENT PROPERTY- POLYCARBONATE: 

Polycarbonate Plastics are naturally transparent amorphous thermoplastics. They're available in the market in a variety of colors. Polycarbonate allows for about 88% transmissibility of light through it which is very close to what glass is capable of.

• Polycarbonate has an extremely strong chemical structure. Its molecules possess tremendously strong bonds in high numbers, giving it its unique levels of resistance.
• High Impact Strength and excellent strength retention up to 140˚
• High Modulus of Elasticity
• Low Coefficient of Thermal Expansion
• Good Electrical Insulation Properties
• Non-flammable & Self-extinguishable
• Resistant to Weak acids, Hydrocarbons, and Oils.
• Low Deformation under load.
• Easy to fabricate & machine.

       

                                            AUTOMOTIVE POLYCARBONATE GLAZING 

 

       

                                                    POLYCARBONATE HEADLIGHTS

 

9. PROPERTIES OF ABS BECAUSE OF WHICH IT IS USED IN THE AUTOMOTIVE INDUSTRY:

Acrylonitrile Butadiene Styrene(ABS) is an opaque thermoplastic that consists of three monomers which are ‘Acrylonitrile’, ‘Butadiene’ & ‘Styrene’. ABS is made by emulsion or by polymerizing styrene and acrylonitrile in the presence of polybutadiene. This process produces a long chain of polybutadiene that crisscrosses with shorter chains of polystyrene-co-acrylonitrile, creating very strong bonds.

Properties due to which ABS is preferred to be used in the Automotive Industry:

• High Rigidity
• Good Impact Resistant Properties even at Low-Temperatures
• Good Insulating Properties
• Good Weldability
• Good Abrasion and Strain Resistance
• High Dimensional Stability
• High Surface Brightness and Excellent Surface Finish

Also, Various Blends of ABS are even more suitable to be used in the Automotive Industry.

ABS-PC Blend:

• High Impact Hardness and Strength.
• Improved Heat Deflection Temperature(HDT)
• Improved Dimensional Stability
• Electrical Properties become independent of Moisture & Temperature.

ABS-PC blend combines the strength and heat resistant property of PC and flexibility of ABS. This blend is 50-60% more than standard ABS.

Applications: Rear-Lamp housing, Glove-Boxes, Overhead and Middle Consoles. IP retainers, Wheel covers, etc.

       

ABS-TPU Blend:

• High Impact Strength
• TPU contributes toughness, lubricity, and wear resistance.
• ABS provides increased stiffness and improved processability.

ABS-TPU are non-toxic, and well suited for deep-drawing and thermoforming.  They also have high elasticity and resistance to weathering, and high resistance to oils, grease, lubricants, and various other solvents. TPU is widely used as an additive for strengthing other materials, Composites of TPU and ABS have improved flexural modulus up to 15000psi whereas pure TPU’s tensile strength is around 5076psi.

ABS-PVC Blend:

• High Impact Strength
• Better Thermal Properties
• High Rigidity
• Improved Chemical Resistance
• Improved Electrical Properties
• Overall low cost

 

10. PROPERTIES OF NYLON(POLYAMIDE) AND ITS USES IN AUTOMOTIVE COMPONENTS:

• High Rigidity and Hardness
• Good Dynamic Fatigue Resistance
• High Mechanical Damping Characteristics
• High Impact Strength, even at Low-Temperatures
• Highly Heat Resistant
• Good Sliding Properties
• Excellent Electrical Characteristics
• Virtually no Stress-Cracking(Stress-Relaxation)
• Good Abrasion & Wear Resistance
• Good sound and vibration damping
• Easy processability
• Good Chemical Resistance

Nylon/Polyamide has different types of grades depending upon the way they are polymerized with various monomers. Names of those different grades are- Polyamide 6 (Nylon 6), Polyamide 11 (Nylon 11), Polyamide 12 (Nylon 12), Polyamide 66 (Nylon 66), Polyamide 610 (Nylon 610), Polyamide 66/610 (Nylon 66/610), Polyamide 6/12 (Nylon 6/12), Polyamide 666 (Nylon 666 or 6/66), Polyamide 6/69 (Nylon 6/6.9), Nylon 1010, Nylon 1012.

INTAKE MANIFOLDS: Automobile intake manifolds were once used to be made out of metals but nowadays are often fabricated from 30-35% glass reinforced PA6. Grade 6,6 and 4,6 are also used in Intake-Manifolds. Substituting metal in the manifold with nylon reduces the production costs significantly by up to 30%, It also reduces the overall weight of the part by up to 50% which proves to be very beneficial for the automotive system by cutting costs and improving fuel efficiency.

AIRBAG CONTAINERS: Also, in airbag containers, PA6 offers parts integration and reduces weight compared to metal containers. Containers made out of PA6 do not splinter at low temperatures like some other polymers. It comprises sufficient stiffness and strength to withstand high temperatures without failure.

POWERTRAIN: For a car’s powertrain, manufacturers are promoting plastic chain tensioner guides made out of PA6 as it offers better wear resistance, enhance safety, and reduce noise generation.

COOLING SYSTEM: PA6 is being used in cooling systems as well where it allows consolidation of various components previously made out of aluminum.

EXTERIOR: PA6 is being used in exterior parts too which includes door, tailgate handles, exterior mirrors, front-end grilles, fuel caps, lids, wheel covers, trims, etc.

It is also used in the engine compartment’s stator, armature, rotor components, gasoline motors, exhaust systems, fenders, brake systems, etc.

 

11. MATERIAL BLENDS & TYPES OF BLENDS USED IN THE AUTOMOTIVE INDUSTRY:

When talking Material Blends in Plastics usually refers to Polymer blends that are combinations of two or more polymers, which are physically mixed to obtain a single phase. That means, that rather than obtaining the properties of each polymer separately, one set of properties is obtained by blending a few polymers. Therefore, each polymer may not show its own desired property. Blends are usually obtained in a molten state or by dissolving in solvents. Polymer blends can be in various forms such as miscible one phase, miscible separated phase, alloys, compatible, incompatible, interpenetrating, and semi-interpenetration polymer network. Polymer blends are mainly classified as compatible and incompatible polymer blends. Compatible polymer blends are miscible blends, where there are no separate phases, but a single phase. These types of blends provide superior mechanical properties. Incompatible polymer blends are the blends that form two well-defined separate phases after mixing. These types of blends generally have poor mechanical properties. However, incompatible blends are more common than compatible blends.

Various Polymers Blending Methods:

• Mechanical Mixing- Cheapest Method
• Dissolution in Co-Solvent, then Film Casting, Freeze or Spray drying
• Latex-Blending
• Fine Powder-Mixing
• Use of Monomer as a solvent for another component, then Polymerization

Various Blends used in Automotive Industry: 

• ABS Blends
• ABS/PC Blend
• ABS/TPU Blend
• ABS/PVC Blend
• PPO/PS Blend
• AES/PC Blend

 

12. FILLERS & ADDITIVES WITH THEIR PROPERTIES: 

• FILLERS: Fillers are generally made out of fine glass, quartz, or silica and are added to enhance the elastic modulus, increase tensile strength, hardness, and wear resistance, as well as decrease polymerization shrinkage of the restoration. Fillers are added to a polymer formulation to reduce the costs and improve the properties. Fillers can be solid, liquid, or gas. They occupy space and replace the expensive resin with less expensive compounds without modifying other characteristics.
• The minerals commonly used as fillers in plastic molding compounds include Calcium-Carbonate, Talc, Silica, Wollastonite, Clay, Calcium Sulphate Fibers(Franklin Fibers), Glass-Beads, and Alumina-Trihydrate. 
• Glass: Glass Fibers are used to increase the mechanical properties of the thermoplastic or thermoset such as flexural modulus and tensile strength.
• Calcium Carbonate(CaCO3): It is used as a filler for the final plastic product to increase its brightness and make its surface glossier.
• Wollastonite(CaSiO3): This filler can improve moisture content, wear resistance, thermal stability, and high dielectric strength.
• Silica: It is used to improve the physical and mechanical values(tensile strength, elongation, etc) of silicone rubber vulcanisates.
• Talc: It is an all-purpose inexpensive filler powder for all resin types for creating a cheap but heavy gap filler. Also used in resin casting to reduce cost, shrinkage & heat generated by resin.

        

• ADDITIVES: Additives are chemicals added to the base polymer to improve processability, prolong the life span, and achieve the desired physical or chemical properties in the final product. While the content of additives is typically only a few percent, their impact on polymer performance and stability is significant. These additives can be both organic and inorganic compounds. While Plastics in their original form are impact resistant and long-lasting, they're often brittle, hard, combustible, or too heavy for the intended use and hence additives are added to them to improve their characteristics.
• The most commonly used additives in different types of polymeric packaging materials are Plasticizers, Flame-Retardants, Antioxidants, Acid-Scavengers, Light and Heat Stabilizers, Lubricants, Pigments, Antistatic agents, Slip compounds, and Thermal-Stabilizers.   
• Stabilizers: These are added to prolong the useful life of a polymer formulation by protecting it from thermal and light-assisted oxidation.
• Plasticizers: These are additives used in the production of plastics to reduce the attraction between polymer chains, thereby increasing the flexibility and durability of the resulting plastic. The most common plasticizers are ‘phthalate esters’, which are used primarily in the manufacturing of products made from PVC, including shower curtains, upholstery, and food containers.
• Flame Retardants: These are chemicals that are applied to materials so that they can prevent or slow down the growth of any inflammable activity.
• Lubricants: These are the substances that work between surfaces in relative motion to prevent friction and wear.

        

 

13. 10 AUTOMOTIVE INTERIOR COMPONENTS, MATERIALS THEY'RE MADE OUT OF & PROPERTIES OF THOSE MATERIALS:

INTERIOR COMPONENTS	MATERIALS	PROPERTIES
STEERING WHEEL	POLYURETHANE/Faux-Leather	HIGH IMPACT STRENGTH WIDE RESILIENCY RANGE ABRASION RESISTANT CHEMICAL RESISTANT
SPEEDOMETER	POLYCARBONATE	EXCELLENT TRANSPERANCY WEATHERING RESISTANT DIMENSIONAL STABILITY HIGH IMPACT STRENGTH
INTERIOR DOOR HANDLE	ACRYLONITRILE                    BUTADIENE STYRENE	HIGH IMPACT RESISTANT HIGH RIGIDITY GOOD SURFACE FINISH GOOD WELDABLE MATERIAL
DOOR PANEL	POLYVINYL CHLORIDE	HIGHLY FLEXIBLE  FLAME RETARDANT GOOD THERMAL STABILITY EASE OF MANUFACTURING
SUN VISOR	POLYPROPYLENE	GOOD FATIGUE RESISTANCE INTEGRAL HINGE PROPERTY SEMI-RIGID GOOD HEAT RESISTANCE
GLOVE-BOX	PC-ABS	HIGH IMPACT RESISTANCE DIMENSIONAL STABILITY  IMPROVED HEAT DEFLECTION TEMPERATURE  GOOD ELECTRICAL PROPERTIES
HEADLINER	POLYURETHANE	WIDE RESILIENCY FLEXIBILITY TEAR RESISTANCE STRONG BONDING PROPERTY
BRAKE PEDAL	POLYAMIDE	HIGH RIGIDITY HIGH IMPACT STRENGTH GOOD FATIGUE RESISTANCE EASY PROCESSABILITY
DASH PANEL	ABS	GOOD SURFACE FINISH ABRASION RESISTANT EXCELLENT INSULATION DIMENSIONAL STABILITY

 

 14. 10 AUTOMOTIVE EXTERIOR COMPONENTS, MATERIALS THEY'RE MADE OUT OF & PROPERTIES OF THOSE MATERIALS:

COMPONENTS	MATERIALS	PROPERTIES
DOOR	POLYBUTYLENE TEREPHTHALATE	CHEMICAL RESISTANT HIGH STRENGTH HIGH STIFFNESS GOOD ELECTRICAL PROPERTIES
BUMPERS	ACRYLONITRILE              BUTADIENE STYRENE	HIGH RIGIDITY IMPACT RESISTANT STRAIN RESISTANCE DIMENSIONAL STABILITY
HEADLIGHTS	POLYCARBONATE	HIGHLY TRANSPARENT HIGH IMPACT STRENGTH  DIMENSIONAL STABILITY WEATHERING RESISTANCE
FENDERS	ACRYLONITRILE               BUTADIENE STYRENE	HIGH RIGIDITY IMPACT RESISTANT GOOD WELDABILITY DIMENSIONAL STABILITY
SPOILERS	ACRYLONITRILE              BUTADIENE STYRENE	ABRASION RESISTANT HIGH SURFACE BRITGHTNESS AND EXCELLENT SURFACE ASPECT 70 - 80 N/mm² NOTCHED IMPACT STRENGTH 60 - 80 Kj/m² Thermal COEFFICIENT OF EXPANSION
ROOF	POLYCARBONATE	HIGHLY TRANSPARENT HIGH IMPACT STRENGTH  DIMENSIONAL STABILITY WEATHERING RESISTANCE
HOOD	POLYPROPYLENE	Semi-rigid. Good fatigue resistance. Integral hinge property. Good heat resistance.
GRILLES	ACRYLONITRILE              BUTADIENE STYRENE	DIMENSIONAL STABILITY GOOD WELDABILITY 70 - 80 N/mm² NOTCHED IMPACT STRENGTH 60 - 80 Kj/m² Thermal COEFFICIENT OF EXPANSION
DOOR HANDLE	POLYAMIDE/NYLON	High wear resistance. High thermal stability. Very good strength and hardness. High mechanical damping characteristics
TAILGATE	POLYCARBONATE	HIGHLY TRANSPARENT HIGH IMPACT STRENGTH  DIMENSIONAL STABILITY WEATHERING RESISTANCE

 

15. 5 TYPES OF THERMOPLASTIC MOLDING WITH AN AUTOMOTIVE EXAMPLE: 

A) INJECTION MOLDING : 

Injection molding is a manufacturing process that allows for parts to be produced in large volumes. It works by injecting molten materials into a mold. It is typically used as a mass production process to manufacture thousands of identical items. Injection moulding materials include metals, glasses, elastomers, and confections, although it is most commonly used with thermoplastic and thermosetting polymers.

        

• Firstly a mold is made. The mold comprises two halves, a fixed part, and a moving part. The mold design must allow for the easy ejection of the parts.
• Install the mold in a specific machine: the Injection Molding Machine. The two parts of the mold are strongly pressed against each other. The material (in the form of pellets) is poured into a plasticizing screw (or endless screw) which is heated. The rotation of the screw, combined with the temperature, softens the pellets, which are transformed into molten plastic material. The molten and deformable material is stored at the front of the screw before injection.
• Inject the softened plastic materials under high pressure under the effect of heat in the mold. In this phase, it must be ensured that the mold is filled before the material solidifies. This is why we continue to send the material under pressure to compensate for the withdrawal that occurs when the material cools.
• Cooling of the whole through cooling channels within the mold. Following this operation, the object is ejected from the mold.
• Eject the part.

Automotive Parts that are manufactured using this process:

Fenders, Grilles, Bumpers, Door-Panels, Floor-Rails, Light-Housings, etc

 

B) THERMOFORMING: 

Thermoforming is the process of heating a thermoplastic sheet to its softening point. The sheet is stretched across a single-sided mold and then manipulated. Then, it cools into the desired shape. The most common methods to get the sheet to conform to its final shape are vacuum-forming, pressure-forming, and mechanical forming.

• Vacuum Forming: The specific process that involves forming a part by heating and stretching the plastic across a mold using a vacuum. Normally the mold is open and the force involved in forming the sheet is limited to about 15 psi.

                   

• Pressure Forming: This process adds a pressure box to the tooling package. It utilizes both vacuum and positive air pressure. This process generates as much as three to four times the forming pressure as vacuum forming does. Therefore, fine details such as surface textures can be formed on the mold without incurring excessive extra costs.

                    

• Twin Sheet Forming: As the term suggests, there are two molds for this process: one on the top and one on the bottom. Therefore, two sheets of plastic must be heated and formed at the same time. A fused joint must be placed around the perimeter of the mold while air pressure is injected between the sheets. This process is ideal for forming hollow parts that require a distinct upper and lower shape.

                      

Automotive Parts that are manufactured using these processes : 

Dashboards, Center Consoles, Interior Door Panels, Truck Bed Liners, Shaped tub for trunks, Bumper fascias.

 

C) COMPRESSION MOLDING: 

The compression molding process begins when a precise amount of rubber is placed into the bottom mold cavity. Next, the rubber is secured when the top half of the mold is fastened in place. Then, forceful pressure anchors the mold while heated cavities stimulate rubber to flow into position. After the cure time is met, the top and bottom mold parts are separated, and the rubber compression mold is removed.

It’s helpful to first understand the three main aspects of a successful compression molding process:

1. Time: Time is taken to heat and cure the rubber.
2. Temperature: The appropriate temperature is required to heat the rubber.
3. Pressure: Amount of force needed to give mold proper shape. 

                    

Automotive Parts that are manufactured using this process: 

Seat backs and Headrests, Backseat load-through components, Airbag housing, B-Pillars, Door crossbeams, Bumper beams, and Large floor components.

 

D) EXTRUSION MOLDING: 

Extrusion Molding: In the plastic extrusion process, plastic powder or pellets are fed into the extrusion machine via a hopper. The polymer is heated inside a barrel at a controlled temperature and a screw pushes molten plastic through a metal die, which is then cooled to give the plastic a fixed, continuous shape while being continuously pulled and formed into the final shape. The product can be cut or trimmed to the desired length. This is one of the most common ways to manufacture plastic products. The plastic extrusion process works well for high-volume production of a wide range of products including pipes construction products such as ventilation doors and windows frames and seals.

               

Automotive Parts that are manufactured using this process: 

Paneling and Railing, Bumper support, Fender, Mud Guards, Door looking systems.

 

E) Rotational Molding: In this process, the plastic polymer is placed into the mold before heating. The closed mold enters a furnace and rotates, which allows the plastic polymer to coat the entire inside of the mold evenly. The heat melts the plastic into a single layer that conforms to the shape of the mold cavity while leaving the interior of the final product hollow. A water spray cools the mold while still rotating which solidifies the polymer. Rotation is stopped, the mold is opened, and the plastic part is removed. Suitable for short, economical production runs and is not suited for precision forming due to the finish of the part. It is ideal for making large, complex shapes with a uniform wall thickness, e.g., large storage tanks for water, chemicals, and fuel, crates, cooler boxes, bins, bollards, canoes, toys, and playground equipment.

                         

Automotive Parts that are manufactured using this process: 

Bins & Containers, Automotive parts, Road cones and Barriers, etc.

 

16. AUTOMOTIVE FREEHAND SKETCH OF KOENIGSEGG GEMERA: