Automotive World 2018: Joining of dissimilar materials, high function plastics exhibition

Multi-materialization, resin molding processing for EVs and autonomous driving

2018/02/22

Summary

 At the Automotive World 2018 exhibition (January 17-19, 2018, Tokyo Big Sight), material manufacturers, processing manufacturers, processing machinery makers, parts manufacturers, and trading companies showcased a rich variety of products and technologies, including many electrification and automated driving related exhibits.

 As electric vehicles (EVs) grow in number, the need for weight reduction (lightweighting) is increasing due to the increasing weight of secondary batteries used as a power source. Moreover, as electrification and automated driving continue to be promulgated, components that consume more power will also come into increasing use, and this will result in the need for lightweighting as a countermeasure for energy conservation. To respond to these demands, the use of plastics that have low specific gravity and light metals is increasing, and among these, multi-materials created through dissimilar metals bonding are attracting attention recently as a lightweighting solution. At this year’s Automotive World, an exhibition zone was set up for dissimilar material joining and bonding, and companies showcased lightweight materials that combine the workability properties of plastics and mechanical strength properties of metals.

 

 

 Following the previous report on CFRP components/plastic molding technologies exhibition, and with support from Mr. Takeo Yasuda, head of the Yasuda Polymer Research Institute, this report will cover the exhibition of technologies for dissimilar materials joining, plastics for electrification, automated driving, and various uses of high performance plastics.

 

Related Reports:
Automotive World 2018: CFRP components and plastic molding technology (Feb. 2018)
Tokyo Motor Show 2017: Plastics utilized for autonomous driving and electric vehicle components (Dec. 2017)
JSAE Exposition 2017: Leading resin material makers (Aug. 2017)
JSAE Exposition 2017: Exhibitions of resin molding processing technologies (Aug. 2017)



Dissimilar materials joining: Structural adhesives, resin/metal joining technologies

 Recently, multi-materialization by joining of dissimilar materials has been adopted as a countermeasure (solution) in vehicle lightweighting designs. Particularly in the joining of plastics and metals, the ability to provide parts with combined properties of metals like strength and thermal conductivity, and properties of plastics such as reduced weight and workability is gaining attention.

 In this exhibition, many manufacturers exhibited various joining and adhesive technologies. Some of the latest joining technologies are introduced in this report.

 

Structural Adhesives

 Daicel Evonic exhibited front-end modules made by dissimilar materials joining at the front booth. 
 The product’s features/characteristics are as follows:

  • Significant increase in mechanical strength achieved by using PA type adhesive on composite parts made with metals/resins
  • More than 25% reduction in material usage to achieve weight reduction
  • Ability to reduce warp common in conventional composite parts
  • Ability to compensate for a known disadvantage of adhesive strength deterioration due to difference in shrinkage ratio common to composite materials
Front end module (Daicel-Evonik)
Degreased metal (e.g., Al) coated with special adhesive is molded with other resin materials (such as glass fiber reinforced PA6, PA66, PPA, PP).
*GF: Glass fiber, PA: Polyamide, PPA: Polyphthalamide
Copolymer nylon “VESTAMELT”
Mitsubishi Outlander PHEV rear body  (JFE Steel)
JFE Steel introduces "Topology Optimization Technique" for structural adhesive dispensing positioning design. The joint locations of spot weld, adhesives and bolt joints in the vehicle body are optimized within the design space, improving stiffness of thin steel sheets and reducing the quantity of adhesives used.
Display panel:Topology Optimization Technology

 

Resin/Metal Joining Technology

Yamashita Electric introduced a plastic/metal joining technology using Daicel Polymer’s DLAMP, and uses its original heat and cool system during molding. The joining is done by molding a special shape with laser irradiation on the surface of the metal, which is then placed in the mold and the thermoplastic resin is injection molded (by insert molding). This method is also applicable to different kinds of metal parts like stainless steel and aluminum. Furthermore, by combining with filament fiber reinforced resin having a coefficient of linear expansion close to a metal, a higher adhesive strength and excellent joint durability becomes possible.

Joining technology used on Daicel Polymer DLAMP (Yamashita Electric) 
In the resin/metal joining technology, samples of aluminum joined with various resins are introduced. The exhibit shows tensile/shear adhesive strength, tensile strength, indicating sufficient joining strength for the products.

Features of DLAMP
  • Applicable to different metals depending on laser treatment conditions
  • Partial treatment (half side treatment, patterning) is possible
  • Low running cost (only electricity cost)
  • Does not generate waste fluids or scrap materials
AMALPHA (MEC)
The picture shows an integrated molded sealing plate and electrode of a lithium-ion battery (LiB). The metal cover is made of aluminum (Al), the electrode of Al/Cu, and the resin of PPS. By direct bonding of metal and resin, thin design with improved durability, parts reduction, and cost reduction was realized for can-type LiB.
*PPS: Polyphenylenesulfide

AMALPHA Bonding Mechanism
  • AMALPHA is a proprietary metal surface treatment technology designed for direct metal and resin bonding
  • This technology bonds metals and resins at a micro-interfacial level to enable integral molding of metals and resins
  • AMALPHA treatment is a chemical etching treatment technology used to form microscopically rough surfaces in the order of microns, on metal. When resin is forced into the roughened surface and solidifies, a strong bond is achieved due to the “anchor effect”.
AMALPHA Process / AMALPHA Performance

 

Automotive parts using dissimilar materials bonding

Break pedal (F-Tech)
Brake pedal made by dissimilar material joining through press forming and injection molding of metal (Al) and heat-and-cool CFRTP(PA). Although not officially adopted yet, good results have been obtained from mechanical strength tests.
*CFRTP: Carbon fiber reinforced thermo plastics, PA: Polyamide
Display panel
Lightweight composite beam (Asano)
The exhibit showed a composite beam built by adhesive bonding of aluminum and CFRTP. Weight reduction and strength mechanical improvement becomes possible.
Display panel
Air duct (Toyobo)
The exhibit shows a molded part by bonding PBT and high temperature TPC. These two materials have a good compatibility and an example of joined product using good adhesive properties of both materials is shown.
*PBT: Polybutylene terephthalate, TPC: Thermoplastic copolyester

 

Front subframe for Honda Accord (F-Tech)
The exhibited product achieves high rigidity and low weight with a composite structure of iron and aluminum. It adopts dissimilar material joining technology based on FSW (Friction Stir Welding). From now on, aluminum frames are expected to meet the needs of contactless charging for EVs and magnetic field compatibility.
Display panel
Magnetic pulse forming technology (IHI)
IHI introduces forming by electromagnetic force. The processing technology used is based on high velocity impact of the material to the die. The process also produces atomic bonding between the materials which achieves higher bonding strength.
Rear Door Panel Forming (Image)
Magnetic Pulse Technology: Forming / Welding
Display panel
Dissimilar materials bonding (EJOT)
EJOT is a German maker specializing in fastening technology, and introduces bonding technology of composite materials using friction welding. Other than metals and CFRP, the technology also applies to materials with different thickness and combination of new materials. The welding technology was used on the Audi TT tonneau cover (Luggage room cover).
EJOT TSSD bonding technology / EJOWELD bonding technology


Plastic molding products and materials for EV

Modified PPE applied to lithium ion battery (Asahi Kasei)
Modified PPE adopted for use on spacers, busbars, and frame of lithium Ion batteries.
*PPE: Polyphenyleneether
Proposals for EV related devices EV (Sekisui Chemical)
Sekisui Chemical exhibited its proposals on how its products can be used on ECU, battery packs, motors and inverters, DC-DC converters, battery module components.

 

Asahi Kasei compounded a low specific gravity/non-halogen flame retardant modified PPA, and developed a grade with flame retardant properties and excellent flowability that is able to be molded into products with complex shapes. The product features are as follows:

  • Uses non-halogen flame retardant material injection molded and achieving UL94 V0 rating
  • Excellent fluidity for thin wall designs
  • Low specific gravity product contributing to weight reduction

 

PTC heater (BorgWarner)
Engineering plastic type resins like PBT are used on insulating materials like housings.
Positive Temperature Coefficient (PTC) heater is one type of hot wire heater that self-regulates the heat amount with respect to the ambient temperature. Initially, it was used as auxiliary heater on vehicles specified for cold regions, recently it is being used as heater for EVs that do not have heat source from conventional engines.
Connectors for EV bus (GLOBETECH)
Black insulating material using machined POM. There are very few examples of usage of POM on connectors, however its voltage resistance is found to be sufficient for this application.
*POM: Polyoxymethylene  (polyacetal)
Globetech also exhibited high current connectors and heat resistant connectors among various types of connectors and sockets.
Motor controller (Mitsuba)
Controller for in-wheel type compact/flat motor appropriate for compact electric vehicle drives. Engineering plastic-based materials (assumed to be PC) is used in the housing
*PC: Polycarbonate


Plastics for use on HMI system, sensing

Electronic rearview mirror (Nippon Seiki)
This is an electronic mirror that can switch between mirror mode and camera monitor mode, with improved visibility compared to conventional systems. It appears that PC/ABS based materials are used.
*PC: Polycarbonate, ABS: Acrylonitrile, Butadiene, Styrene copolymer resin

Heater control switch (Kawabe)
A switch showing a Copper terminal insert molded on PA66.
Kawabe operates on an integrated production system for insert molding of high precision, high quality metal pressed parts into engineering plastic-based plastics
*PA: Polyamide

Silicon resin made audio switch (Sekisui Chemical)
This is a product utilizing characteristics of silicon resin such as softness and electrical insulating properties, and are used on instrument panel peripheral components.

 

Infrared-transparent insulation transparent resin sheet (polyolefin based) (Asahi Kasei)
The infrared-transparent insulation protection cover (GAT) is the world’s first special resin transparent cover that simultaneously passes “visible” radiation” and infrared radiation. As a result of making a normally opaque polyolefin transparent, transmission of infrared radiation (8-14μm) and visible radiation was obtained. This protection cover is adopted for use on switchboards that requires both visual observation and infrared thermography inspection.
Electromagnetic wave shield element (JXTG Nippon Oil & Energy)
The inductive paste layer and plating layer are molded into a resin base material. The electromagnetic wave shield coating on the plastic parts shows a high EMC performance. It is applied on ECU, PCU and other automotive sensing devices. Main features are as follows:
・Low weight resin molded parts realizing EMC performance equivalent to that of metals
・High adhesiveness with proprietary conductive paste
・Proposes materials matched to requirements (base material, electromagnetic wave layer)
*EMC: Electromagnetic compatibility
High transparency COP for lenses (ZEON)
Zeon`s proprietary COP (cycloolefin polymer) is the optimum material for camera lenses which are increasing in use on automobiles. Main features are as follows:
・Low water absorption: water absorption <0.01% with excellent dimensional stability
・High light transmittance: total light transmittance at 92% with excellent transparency
・Low specific gravity: specific gravity at 1 lower weight compared to other transparent plastics


High performance plastics: Compact/lightweight, high strength/high elasticity, heat/radiation resistance, mechanical characteristics

Foam molded engine cover (Toyobo)
By crystallization and rheology control, high quality micro cellular foam is realized from hard materials (PA, PBT) to soft materials (TPC). 30~50% weight reduction, high quality high magnification foaming, stable foam cell forming, low warpage, heat insulation becomes possible, and compatible with mucell molding and chemical foaming. While Toyobo exhibited mainly hard materials like PA and PBT and soft materials like TPC, it also exhibited secondary processing (decorative, bonding, etc) technologies and examples of their application.
*PA: Polyamide, PBT: Polybutylene terephthalate, TPC: Thermoplastic copolyester
PC/PET alloy for exterior components (Kaneka)
With PC/PET alloy exhibiting excellent high flowability, it is able to address thin-walled design. High heat resistance, high rigidity, low linear expansion, contributes to weight reduction of exterior components. By resinification and thinning, a maximum of 56% weight reduction can be expected.
*PC: Polycarbonate, PET: Polyethylene terephthalate

 

Fuel tube (Ube Industries)
Various tubes and their different applications (like fuel tubes, cooling pipes, etc) made from PA like PA12, PA6, PA9T, and EVOH, ETFE, PP, and laminated adhesive resins
*PA: Polyamide, EVOH: Ethylene-vinylalcohol copolymer, ETFE: Ethylene tetrafluoro ethylene, PP: Polypropylene
Various types of tubes using PA12 based materials
Drive unit for power slide door (Mitsui Kinzoku Act)
Integrated ECU, compact lightweight electric sliding door unit. In addition to high performance of the mechanical parts, safety and convenience are both achieved by advanced control. PBT with excellent balance between mechanical and electrical characteristics is used.
On many of the exhibited high performance mechanical parts like side door latch, sliding door parts, trunk latch, engineering plastics like POM, PBT are used.
*PBT: Polybutylene terephthalate, POM: Polyoxymethylene (polyacetal)
PF-based pulley with high mechanical strength and excellent tribological properties (Sumitomo Bakelite)
A pulley made from phenolic resin (PF) as a substitute for metals, lightweight with excellent wear resistance. With reinforced fiber glass as a base material, in addition to high mechanical strength and high elasticity, and being insoluble and infusible as characteristic of PF resins, it also shows high tribological properties under high speed conditions. The following are the features of the material:
・Adhesion due to friction heat on the sliding surface unlikely to occur
・Low frictional coefficient and excellent tribological properties.
*PF: Polyfluorene

 

Heat dissipative grade LED lamp socket (Unitika)
Uses heat dissipative nylon to control excessive temperature increase on LED lamps. The company’s dissipative grade uses PA6, PA66, and PA 10T as base resin, and can be used over a wide temperature range. In the dissipative PA line up, both heat conductive type and insulation type are provided, achieving both high heat conductivity and process-ability.
*PA: Polyamide
Transparent polyamide polarized film  (Daicel-Evonik)
Microcrystalline polyamide (PA) film with polarization characteristics. By having the presence of microcrystals inside the unique aliphatic PA, it is able to possess both characteristics of crystalline resins and non-crystalline resin. Features high transparency (light transmittance above 90%), high chemical resistance and shock resistance and low specific gravity (1.02)
Direct molded sensor module (Sumitomo Bakelite)
Having an equivalent of better reliability than conventional products, uses materials that contribute to size/weight and parts reduction. A diverse type of molding is possible, and applicable to each type of structural base materials. Product features are as follows:
・Bulk molding for connector shapes is possible
・Possible adaptation to low temperature curing


Various plastic materials and molded parts for automotive use: Interior materials/decorative materials

3D embossed decorative sheet (Tatsuta Chemical)
Vehicle interior sheets based on ABS resin that could be molded while maintaining texture. Compatible with various molding process methods, making painting unnecessary. Consisting of separator, adhesive layer, decorative layer, and topcoat, it achieves both high designability and process-ability. By overlay molding, it is used on interior panels
Piano black non-paint weld-less moldings (Yamashita Electric)
Molded ABS+PMMA parts with piano black tone. Piano black tone resin parts are typically realized by painting and are high cost components. By heat and cool system molding, molded parts are formed without weld lines, flow marks and with high gloss appearance, eliminating the need for decorative painting, thereby reducing parts cost.
*ABS: Acrylonitrile, Butadiene, Styrene copolymer resin, PMMA: Polymethyl methacrylate
New polysiloxane frame resin (Kaneka)
Temperature-cured resin based on a new polysiloxane frame. It is used as base polymer for painting and coating materials, and possesses characteristics as long-term durability, surface hardness, glossiness. Flexible selection between thermal curing, UV curing with excellent coating properties (scratch resistance, wear resistance, chemical resistance). Expected use on interior materials coating.

 

NANOCON METALLIC molding products (Unitika)
High-gloss metallic colored molded parts from nanocomposite nylon resin (NANOCON) developed by Unitika. The material is applied to various kinds of interior parts. Below are the characteristics of the material.
・Paint-less:NANOCON based color
・Realizes both appearance and rigidity
・Chemical resistance because of its nanocomposite structure

Electroplating on resin (Okuno Chemical Industries)
Next generation electroplating process that will not use environmentally hazardous substances like chromic acid and expensive palladium is exhibited. Furthermore, Okuno introduces excellent decorative electroplating process for resins

 

Aside from the products introduced above, many plastics related exhibitions were also displayed at the show.

  • Somar: Epoxy type insulating resins, adhesives, high performance films
  • DNP: Decorative films, curved resin glass for automotive applications
  • Denka: Various types of heat dissipating materials, heat dissipating sheets, and application examples for automotive field
  • Hitachi Kasei: High temperature resistant sealant for case molding
  • Fuji Polymer Industries: Various kinds of heat dissipative materials, thermally conductive electrically insulating adhesive sheets
  • Mitsubishi Paper Mills: Cellulose fiber compounds
  • Teraoka Seisakusho: Automotive-grade high temperature resistant insulation tapes, and various kinds of adhesive tapes for automotive applications and examples of their usage
  • Keihin: Resin materials used on automotive power control units and air conditioning unit
  • Furuya Industrial Co: Unique molding technology for DSI molded products
  • Mino Group: 3D decorative products
  • Plastic automotive components from Chinese and Korean companies
Thermal solution (Denka)
Introduced heat dissipation materials, thermally conductive sheets for automotive applications.
Display panel: 1 / 2
Power control unit (Keihin)
It appears that PPS material with better heat resistance is being used.
*PPS: Polyphenylenesulfide
Twin turbo charger inlet T joint (SEJI)
Resin molding from a Korean manufacturer that received an Innovation Award from SPE (Society of Plastics Engineers)
Installed models: Hyundai Genesis G70, Kia Stinger
Display panel

 

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Keyword
lightweight, multimaterial, dissimilar material, resin, plastic, bonding, adhesive, molding

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