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Long fibre reinforced thermoplastics continue growth in automotive
Long fibre reinforced thermoplastics continue growth in automotive Reducing costs and vehicle weight are two of the major driving forces behind the increased use of long fibre reinforced thermoplastics in the automotive sector. Jennifer Markarian reports on some of the latest developments in this market. Long fibre reinforced thermoplastics (LFT), used primarily in automotive applications, continue to show strong growth as they replace metal, short fibre reinforced thermoplastics, and thermoset plastics such as SMC and BMC. Most LFT uses long glass fibres, although other long fibres such as carbon, aramids, and natural fibres are used in speciality applications (see article in January/ February 2007 issue of Plastics Additives & Compounding). Global LFT consumption was 160,000-190,000 metric tons in 2006, estimates Ron Babinsky, consultant at Townsend, which has launched a global study covering the LFT market, expected to be published in June 2007. In North America and Europe, about 80% of the regional volume goes into automotive applications, adds Mr. Babinsky. LFT has seen growth of 10-11% AAGR globally for the last few years, with slightly higher growth rates predicted for the next five years. Europe is the largest LFT user with about 55-60% of the global market, followed by North America and Japan, with smaller amounts used in the rest of the world such as Brazil, Korea and China, says Mr. Babinsky. “The European market is a leading indicator – LFT has taken root and is growing in Europe, and can be expected to grow in North America and then the rest of the world,” predicts Tom Shafer, market manager for plastics and foams at Dow Automotive.
The automotive industry is increasingly turning to LFT to reduce both costs and vehicle weight. LFT significantly reduces weight compared to metal, improving fuel efficiency and reducing emissions. Using LFT to replace metal allows suppliers to integrate parts, thus greatly reducing assembly costs in parts such as door modules. The trend toward smaller vehicles increases opportunities for LFT to replace metal in applications such as front end modules, because LFT stiffness is adequate for smaller spans, notes Mike
Design flexibility LFT injection and compression moulding offer design flexibility. In addition to displacing complex, multiple piece metal assemblies, LFT are replacing thermoformed glass-mat thermoplastics
The Dodge Nitro front-end carrier - an application where long glass fibre reinforced polypropylene was part of the steel replacement solution. (Photo: Dow Automotive)
Plastics Additives & Compounding March/April 2007
Automotive_layout 20
Shoemaker, market development manager at Dow Automotive. On the other hand, increasing use of common platform architectures at OEMs makes metal more cost competitive, he adds.
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ISSN1464-391X/07 © 2007 Elsevier Ltd. All rights reserved.
01/03/2007 16:07:48
Automotive and thermosets, which are more limited in design due to constraints in the thermoforming process. Processors are reviewing conventional LFT press technologies and considering switching to injection moulding, says Franziska Strümpel, technology manager for Krauss Maffei’s IMC (Injection Moulding Compounder). Injection moulding offers design flexibility and cost savings by allowing addition of functional elements and eliminating post processing. Another attraction is the possibility of using specialized processes, such as multicomponent moulding, decor moulding, or foam processes, adds Mrs. Strümpel. “As you integrate more pieces, the part becomes increasingly complex. Complex LFT parts can be produced with injection moulding, compression, or injection/compression moulding,” explains Darin Grinsteinner, engineering manager with D-LFT automotive moulder Composite Products Incorporated (CPI).
Trends in D-LFT compounding LFT parts can be moulded using either pre-compounded pellets or by compounding the glass fibre and other additives directly in-line with final part production (D-LFT). Townsend estimates that in North America and Europe, 40-45% of LFT automotive part production uses D-LFT, with the balance using pellets or concentrates. Industry experts are divided on whether D-LFT or pre-compounded pellets will have stronger future growth, but both will certainly continue to have a place in the market. D-LFT use is largest in Europe, with lesser volumes in North America but no significant capacity in Japan, adds Mr. Babinsky. China is experiencing a build up of pre-compounded pellet capacity as North American suppliers gear up for this rapidly growing market. Initially DLFT was used mostly with compression moulding, but is now growing more in injection moulding, which is the dominant fabrication process in overall LFT use. D-LFT’s main advantage is the potential for lowering material cost. Typically,
moulders using more than 450,000900,000 kg (1-2 million pounds) of LFT precompounded pellets per year can gain an economic advantage with D-LFT, say sources at Husky. The ability to reprocess some LFT regrind in-house is another, more minor area for cost savings. DLFT can be used to obtain longer fibre lengths, and puts the resin through one less heat history. D-LFT also gives moulders formulation flexibility. “Almost anything is feasible – different types of fibre, different percentages of fibre – because processors are no longer limited by the formulation of readycompounded material,” says Krauss Maffei’s Strümpel. Disadvantages of DLFT include high capital equipment cost and the responsibility for formulation, which requires more product quality control testing and increases the moulder’s liability in the automotive parts supply chain. Dow Automotive’s functional masterbatch for D-LFT has been well received by OEMs and DLFT users as a way to alleviate some formulation concerns. “In partnership with Dow, we provide the functional masterbatch and resin, and help the moulder go through the OEM approval process,” explains Mr. Shafer. Krauss-Maffei’s IMC (injection molding compounder) D-LFT system has been
The Krauss-Maffei IMC 2000-14000MX.
21 Automotive_layout 21
used in commercial operations for several years. The IMC uses continuous compounding and extrusion to a melt buffer, from which the melt goes into the discontinuous injection process. “Continuous compounding is key to achieving constant conditions, avoiding fluctuations in formulation and quality,” says Mrs. Strümpel. For natural fibres, the constant melt temperature and material degassing in a continuously running extruder offer gentle processing, she adds. Krauss Maffei’s patented mixing elements allow thorough wetting and the uniform distribution of natural fibres in the matrix. The IMC has a built-in quality control monitoring and logging capability to assist moulders with these increased responsibilities. The control software logs material formulation for every injection cycle. Husky Injection Molding Systems introduced its next-generation in-line compounding and injection moulding system (ILC) in June 2006, developed in partnership with Coperion Werner & Pfleiderer. The two companies first demonstrated an ILC machine at K 2001. The next-generation ILC system maximizes fibre length in the moulded part, which results in improved mechanical properties. Key to this is an optimized melt path connecting the twin screw extruder to shooting pot and machine nozzle, as well
Plastics Additives & Compounding March/April 2007
01/03/2007 16:07:57
Automotive as a Husky hot runner system designed specifically for long fibres. The Husky ILC uses a discontinuous operation that allows the extruder to stop and start during the injection moulding cycle. “Eliminating the buffer simplifies machine operation and maintenance, and reduces shear to help maximize fibre length,” says Ali Mortazavi, Husky’s market manager for Automotive. The material feeding system and extruder are synchronized at the factory to ensure consistent formulation over the entire moulding cycle. PlastiComp’s Pushtrusion™ technology for direct compounding was originally designed as a discontinuous process for injection moulding that could be easily retrofit to existing injection moulding machines. A new version of Pushtrusion was recently developed to compound and compression mould continuously very long (25-50 mm) fibre reinforced plastics that are being evaluated as potential alternatives to GMT. PlastiComp also supplies LFT pellets, and recently began moulding parts, focusing on sub-contracting for moulders interested in Pushtrusion. “This is a low risk approach to actual production experience
for the moulder, without a large initial investment in new Pushtrusion moulding equipment,” explains Steve Bowen, president of PlastiComp LLC.
Growing use of LFT concentrates Interest in long glass fibre pellet concentrates has been growing. Concentrates contain 60-75% fibres, which the moulder blends with unreinforced resin to achieve the desired glass fibre level. Concentrates are appealing because they offer a compromise between the high capital cost of D-LFT and the comparatively high material cost of precompounded pellets, notes Mr. Babinsky. They also offer greater flexibility than pellets with specific fibre levels, but keep some responsibility for formulation with the concentrate producer. Both resin producers and large independent compounders offer LFT pellet concentrates. Concentrate use is growing most in Europe, but growth in the U.S. market will follow, predicts Mr. Shoemaker. Most European customers using amounts more than 1000 metric tons
per year are using concentrates rather than pre-compounded fibre levels, primarily for the cost advantage, says Dr. Tapio Harmia, responsible for business development at FACT (Future Advanced Composites & Technology GmbH). Whether the customer or FACT sources the neat resin, FACT takes the responsibility for formulation and will work with customers to solve problems that could be due to the concentrate or base resin, he explains.
Growing applications for LFT Key growth applications for LFT have been functional parts such as seats, instrument panel retainers, front end modules and door modules. More recently LFT are being used in visible, exterior parts such as front ends, grill guards and roof racks. The largest single application for D-LFT in North America is running boards, notes Mr. Babinsky. CPI sees high growth potential in LFT for integrated front ends and grill wrapping systems. These parts would need higher temperature resistance because of their proximity to the engine, notes Mr. Grinsteinner. Exterior parts, including after market parts, are using LFT because of the process versatility available, agrees Mr. Shafer. Interior automotive applications have strict requirements for odour and emissions, which is a real challenge, particularly for PP compounds, says Dr. Harmia. Additives such as coupling agents, processing stabilizers, and heat stabilizers are needed to meet physical property requirements, but have potential volatile components, sometimes as a result of interactions in the final formulation. FACT has introduced compounds with low odour and emissions, and continues to work on this area, notes Dr. Harmia.
Aesthetics of LFT parts
Husky's Q2350 ILC system developed in partnership with Coperion Werner & Pfleiderer. Plastics Additives & Compounding March/April 2007
Automotive_layout 22
Using LFT in exterior parts brings the need for improved surface finishes, which are difficult to obtain in parts with high fibre content. “LFT has traditionally been concerned with only structural integrity and dimensional stability. In visible applications, these properties must be balanced with aesthetics,” says Mr. Grinsteinner. Glass
22 01/03/2007 16:08:00
Automotive fibres tend to give a poor painted surface, making the painted market difficult for LFT to penetrate. In-mould paint films can be used but have had limited success, say industry sources. Obtaining a glossy part surface involves both the mould surface finish and low viscosity in the material. Since long fibres increase viscosity, flow is adjusted through the base resin and lubricants. A key benefit of long fibres, compared to other reinforcements, is that they provide the backbone of mechanical strength without requiring a high molecular weight resin to improve physical properties. Lower molecular weight, high-flow resin grades offer improved surface characteristics, as well as improved process efficiency and reduced cycle times. FACT recently introduced a LF-polyamide with improved surface characteristics and flow behaviour, obtained through base resin properties, flow additives, and surface modifying additives, says Dr. Harmia. Compounders see a need for improved lubricants for LFT beyond the available waxes and silicones. For interior parts, use of these additives should be balanced with the requirement for low emissions, adds Dr. Harmia. Processors continue to search for methods of improving gloss. Since part of the appearance problem is that fibres at the part surface reduce
gloss by making the surface rough, CPI is experimenting with maximizing the amount of fibre in a part while suppressing the fibres at the surface through a combination of material selection and mould set-up. While to date most LFT parts are in basic black or grey, moulded-in-colour is the way of the future, say industry experts. “Areas like heavy trucks, ATVs, and lawn and garden are likely to pick up on this first, followed by use in automotive,” predicts Mr. Grinsteinner. Colouring LFT is challenging because pigments cause fibre breakage and affect the coupling chemistry between the resin and fibre, causing decrease in mechanical properties. Special effects offer similar challenges to LF formulations, because metal flakes are extremely abrasive and damaging to fibres. Fibres also act as a whitener, which must be considered in choosing the pigment loading. Optimizing the compounding process for colour helps minimize negative effects, says Mr. Grinsteinner. Residence time, shear levels, and colour addition point should be considered. Adding colour further upstream creates more mixing but increases the opportunity for fibre breakage, he explains. With the trend to mouldedin-colour for automotive parts, there is an increasing need for cost-effective light
stabilizers and weatherable pigments. “It is a challenge for moulded-in-colour LFT parts to meet automotive requirements designed for clear-coated paint,” notes Mr. Grinsteinner. Contacts: Composite Products Incorporated Tel: +1 507 452 2881 Website: www.compositeproducts.com Coperion Werner & Pfleiderer Tel: +41 61 825 66 00 or +1 201 327 6300 Website: www.coperion.com Dow Automotive Tel: +1 248 391 6300 Website: www.dowautomotive.com FACT Tel: +49 6301 320 20 0 Website: www.fact-kunststoffe.de Husky Tel: +1 905 951 5000 Website: www.husky.ca Krauss-Maffei Tel: +49 89 8899 0 Website: www.krauss-maffei.com PlastiComp LLC Tel: +1 507 454 4334 Website: www.plasticomp.com Townsend Tel: +1 281 873 8733 Website: www.townsendpolymer.com
Long fibre reinforced thermoplastics can now be used in a great many automotive parts (Diagram: Husky). Plastics Additives & Compounding March/April 2007
Automotive_layout 24
24 01/03/2007 16:08:09
The automotive industry is increasingly turning to LFT to reduce both costs and vehicle weight. LFT significantly reduces weight compared to metal, improving fuel efficiency and reducing emissions. Using LFT to replace metal allows suppliers to integrate parts, thus greatly reducing assembly costs in parts such as door modules. The trend toward smaller vehicles increases opportunities for LFT to replace metal in applications such as front end modules, because LFT stiffness is adequate for smaller spans, notes Mike
Design flexibility LFT injection and compression moulding offer design flexibility. In addition to displacing complex, multiple piece metal assemblies, LFT are replacing thermoformed glass-mat thermoplastics
The Dodge Nitro front-end carrier - an application where long glass fibre reinforced polypropylene was part of the steel replacement solution. (Photo: Dow Automotive)
Plastics Additives & Compounding March/April 2007
Automotive_layout 20
Shoemaker, market development manager at Dow Automotive. On the other hand, increasing use of common platform architectures at OEMs makes metal more cost competitive, he adds.
20
ISSN1464-391X/07 © 2007 Elsevier Ltd. All rights reserved.
01/03/2007 16:07:48
Automotive and thermosets, which are more limited in design due to constraints in the thermoforming process. Processors are reviewing conventional LFT press technologies and considering switching to injection moulding, says Franziska Strümpel, technology manager for Krauss Maffei’s IMC (Injection Moulding Compounder). Injection moulding offers design flexibility and cost savings by allowing addition of functional elements and eliminating post processing. Another attraction is the possibility of using specialized processes, such as multicomponent moulding, decor moulding, or foam processes, adds Mrs. Strümpel. “As you integrate more pieces, the part becomes increasingly complex. Complex LFT parts can be produced with injection moulding, compression, or injection/compression moulding,” explains Darin Grinsteinner, engineering manager with D-LFT automotive moulder Composite Products Incorporated (CPI).
Trends in D-LFT compounding LFT parts can be moulded using either pre-compounded pellets or by compounding the glass fibre and other additives directly in-line with final part production (D-LFT). Townsend estimates that in North America and Europe, 40-45% of LFT automotive part production uses D-LFT, with the balance using pellets or concentrates. Industry experts are divided on whether D-LFT or pre-compounded pellets will have stronger future growth, but both will certainly continue to have a place in the market. D-LFT use is largest in Europe, with lesser volumes in North America but no significant capacity in Japan, adds Mr. Babinsky. China is experiencing a build up of pre-compounded pellet capacity as North American suppliers gear up for this rapidly growing market. Initially DLFT was used mostly with compression moulding, but is now growing more in injection moulding, which is the dominant fabrication process in overall LFT use. D-LFT’s main advantage is the potential for lowering material cost. Typically,
moulders using more than 450,000900,000 kg (1-2 million pounds) of LFT precompounded pellets per year can gain an economic advantage with D-LFT, say sources at Husky. The ability to reprocess some LFT regrind in-house is another, more minor area for cost savings. DLFT can be used to obtain longer fibre lengths, and puts the resin through one less heat history. D-LFT also gives moulders formulation flexibility. “Almost anything is feasible – different types of fibre, different percentages of fibre – because processors are no longer limited by the formulation of readycompounded material,” says Krauss Maffei’s Strümpel. Disadvantages of DLFT include high capital equipment cost and the responsibility for formulation, which requires more product quality control testing and increases the moulder’s liability in the automotive parts supply chain. Dow Automotive’s functional masterbatch for D-LFT has been well received by OEMs and DLFT users as a way to alleviate some formulation concerns. “In partnership with Dow, we provide the functional masterbatch and resin, and help the moulder go through the OEM approval process,” explains Mr. Shafer. Krauss-Maffei’s IMC (injection molding compounder) D-LFT system has been
The Krauss-Maffei IMC 2000-14000MX.
21 Automotive_layout 21
used in commercial operations for several years. The IMC uses continuous compounding and extrusion to a melt buffer, from which the melt goes into the discontinuous injection process. “Continuous compounding is key to achieving constant conditions, avoiding fluctuations in formulation and quality,” says Mrs. Strümpel. For natural fibres, the constant melt temperature and material degassing in a continuously running extruder offer gentle processing, she adds. Krauss Maffei’s patented mixing elements allow thorough wetting and the uniform distribution of natural fibres in the matrix. The IMC has a built-in quality control monitoring and logging capability to assist moulders with these increased responsibilities. The control software logs material formulation for every injection cycle. Husky Injection Molding Systems introduced its next-generation in-line compounding and injection moulding system (ILC) in June 2006, developed in partnership with Coperion Werner & Pfleiderer. The two companies first demonstrated an ILC machine at K 2001. The next-generation ILC system maximizes fibre length in the moulded part, which results in improved mechanical properties. Key to this is an optimized melt path connecting the twin screw extruder to shooting pot and machine nozzle, as well
Plastics Additives & Compounding March/April 2007
01/03/2007 16:07:57
Automotive as a Husky hot runner system designed specifically for long fibres. The Husky ILC uses a discontinuous operation that allows the extruder to stop and start during the injection moulding cycle. “Eliminating the buffer simplifies machine operation and maintenance, and reduces shear to help maximize fibre length,” says Ali Mortazavi, Husky’s market manager for Automotive. The material feeding system and extruder are synchronized at the factory to ensure consistent formulation over the entire moulding cycle. PlastiComp’s Pushtrusion™ technology for direct compounding was originally designed as a discontinuous process for injection moulding that could be easily retrofit to existing injection moulding machines. A new version of Pushtrusion was recently developed to compound and compression mould continuously very long (25-50 mm) fibre reinforced plastics that are being evaluated as potential alternatives to GMT. PlastiComp also supplies LFT pellets, and recently began moulding parts, focusing on sub-contracting for moulders interested in Pushtrusion. “This is a low risk approach to actual production experience
for the moulder, without a large initial investment in new Pushtrusion moulding equipment,” explains Steve Bowen, president of PlastiComp LLC.
Growing use of LFT concentrates Interest in long glass fibre pellet concentrates has been growing. Concentrates contain 60-75% fibres, which the moulder blends with unreinforced resin to achieve the desired glass fibre level. Concentrates are appealing because they offer a compromise between the high capital cost of D-LFT and the comparatively high material cost of precompounded pellets, notes Mr. Babinsky. They also offer greater flexibility than pellets with specific fibre levels, but keep some responsibility for formulation with the concentrate producer. Both resin producers and large independent compounders offer LFT pellet concentrates. Concentrate use is growing most in Europe, but growth in the U.S. market will follow, predicts Mr. Shoemaker. Most European customers using amounts more than 1000 metric tons
per year are using concentrates rather than pre-compounded fibre levels, primarily for the cost advantage, says Dr. Tapio Harmia, responsible for business development at FACT (Future Advanced Composites & Technology GmbH). Whether the customer or FACT sources the neat resin, FACT takes the responsibility for formulation and will work with customers to solve problems that could be due to the concentrate or base resin, he explains.
Growing applications for LFT Key growth applications for LFT have been functional parts such as seats, instrument panel retainers, front end modules and door modules. More recently LFT are being used in visible, exterior parts such as front ends, grill guards and roof racks. The largest single application for D-LFT in North America is running boards, notes Mr. Babinsky. CPI sees high growth potential in LFT for integrated front ends and grill wrapping systems. These parts would need higher temperature resistance because of their proximity to the engine, notes Mr. Grinsteinner. Exterior parts, including after market parts, are using LFT because of the process versatility available, agrees Mr. Shafer. Interior automotive applications have strict requirements for odour and emissions, which is a real challenge, particularly for PP compounds, says Dr. Harmia. Additives such as coupling agents, processing stabilizers, and heat stabilizers are needed to meet physical property requirements, but have potential volatile components, sometimes as a result of interactions in the final formulation. FACT has introduced compounds with low odour and emissions, and continues to work on this area, notes Dr. Harmia.
Aesthetics of LFT parts
Husky's Q2350 ILC system developed in partnership with Coperion Werner & Pfleiderer. Plastics Additives & Compounding March/April 2007
Automotive_layout 22
Using LFT in exterior parts brings the need for improved surface finishes, which are difficult to obtain in parts with high fibre content. “LFT has traditionally been concerned with only structural integrity and dimensional stability. In visible applications, these properties must be balanced with aesthetics,” says Mr. Grinsteinner. Glass
22 01/03/2007 16:08:00
Automotive fibres tend to give a poor painted surface, making the painted market difficult for LFT to penetrate. In-mould paint films can be used but have had limited success, say industry sources. Obtaining a glossy part surface involves both the mould surface finish and low viscosity in the material. Since long fibres increase viscosity, flow is adjusted through the base resin and lubricants. A key benefit of long fibres, compared to other reinforcements, is that they provide the backbone of mechanical strength without requiring a high molecular weight resin to improve physical properties. Lower molecular weight, high-flow resin grades offer improved surface characteristics, as well as improved process efficiency and reduced cycle times. FACT recently introduced a LF-polyamide with improved surface characteristics and flow behaviour, obtained through base resin properties, flow additives, and surface modifying additives, says Dr. Harmia. Compounders see a need for improved lubricants for LFT beyond the available waxes and silicones. For interior parts, use of these additives should be balanced with the requirement for low emissions, adds Dr. Harmia. Processors continue to search for methods of improving gloss. Since part of the appearance problem is that fibres at the part surface reduce
gloss by making the surface rough, CPI is experimenting with maximizing the amount of fibre in a part while suppressing the fibres at the surface through a combination of material selection and mould set-up. While to date most LFT parts are in basic black or grey, moulded-in-colour is the way of the future, say industry experts. “Areas like heavy trucks, ATVs, and lawn and garden are likely to pick up on this first, followed by use in automotive,” predicts Mr. Grinsteinner. Colouring LFT is challenging because pigments cause fibre breakage and affect the coupling chemistry between the resin and fibre, causing decrease in mechanical properties. Special effects offer similar challenges to LF formulations, because metal flakes are extremely abrasive and damaging to fibres. Fibres also act as a whitener, which must be considered in choosing the pigment loading. Optimizing the compounding process for colour helps minimize negative effects, says Mr. Grinsteinner. Residence time, shear levels, and colour addition point should be considered. Adding colour further upstream creates more mixing but increases the opportunity for fibre breakage, he explains. With the trend to mouldedin-colour for automotive parts, there is an increasing need for cost-effective light
stabilizers and weatherable pigments. “It is a challenge for moulded-in-colour LFT parts to meet automotive requirements designed for clear-coated paint,” notes Mr. Grinsteinner. Contacts: Composite Products Incorporated Tel: +1 507 452 2881 Website: www.compositeproducts.com Coperion Werner & Pfleiderer Tel: +41 61 825 66 00 or +1 201 327 6300 Website: www.coperion.com Dow Automotive Tel: +1 248 391 6300 Website: www.dowautomotive.com FACT Tel: +49 6301 320 20 0 Website: www.fact-kunststoffe.de Husky Tel: +1 905 951 5000 Website: www.husky.ca Krauss-Maffei Tel: +49 89 8899 0 Website: www.krauss-maffei.com PlastiComp LLC Tel: +1 507 454 4334 Website: www.plasticomp.com Townsend Tel: +1 281 873 8733 Website: www.townsendpolymer.com
Long fibre reinforced thermoplastics can now be used in a great many automotive parts (Diagram: Husky). Plastics Additives & Compounding March/April 2007
Automotive_layout 24
24 01/03/2007 16:08:09