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`SOCIETY OF AUTOMOTIVE ENGINEERS, INC.
`400 Commonwealth Drive, Warrendale, Pa. 15096
`
`New Solutions for the
`Trim of Automotive Vehicles
`
`Heinz-Gerd Reinkemeyer
`Dynamit Nobel Aktiengesellschaft (Germany)
`
`Automotive Engineering Congress and Exposition
`Detroit, Michigan
`February 23-27, 1976
`
`760177
`
`0001
`
`EX1058
`Yita v. MacNeil
`IPR2020-01139
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`Downloaded from SAE International by UCLA Library - CDL, Wednesday, July 21, 2021
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`Copyright © Society of Automotive Engineers, Inc. 1976
`All rights reserved.
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`0002
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`Downloaded from SAE International by UCLA Library - CDL, Wednesday, July 21, 2021
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`760177
`
`New Solutions for the
`Trim of Automotive Vehicles
`
`Heinz-Gerd Reinkemeyer
`Dynamit Nobel Aktiengesellschaft (Germany)
`
`1.3 Seats
`1.4 Partition between Interior and
`Trunk
`2.Trunk k
`3.
`Hood
`INTERIOR TRIM
`
`1.
`
`In addition to minor applications of PE
`foam such as profiles, stamped gaskets,
`seals, and insulations which are already
`mass produced,
`there are a number of appli
`cations in interior trim which will be
`described below.
`1.1 ROOF LINING - The conventional
`types of roof lining made of artificial
`leather insulating material and metal sup
`ports require a considerable amount of labor
`at the assembly line.
`Motor car manufacturers are looking for
`ways to reduce assembly time.
`Two approaches
`are under discussion or even partly in prac
`tical use:
`Snap-in roof lining
`Prefabricated lining glued to the roof.
`The conventional snap-in linings in use
`are made of resin bonded fibers and are com
`paratively heavy.
`We have developed two distinct types of
`lining:
`
`DYNAMIT NOBEL was the first European company
`to manufacture cross linked polyethylene foam
`by the Furukawa method as of the end of 1972.
`Market research showed the motor car indus
`try to be the best potential market for this
`type of material. Dynamit Nobel therefore
`concentrated its research activities particu
`larly in this sector. Since mid 1973,
`specific subjects have been developed in
`cooperation with leading European motor car
`manufacturers.
`The aim of these developments was to ar
`rive at new components which would have the
`advantage of being inexpensive, lighter and
`more comfortable than conventional parts.
`The favorable characteristics of this
`new foam are its thermoformability, resis
`tance to chemical agents and rotting, and
`its variability in regard to density and
`hardness when laminated to textiles, other
`plastics and metal. These features have
`permitted the development of new components,
`some of which have already gone into pro
`duction, while others are still in the
`testing stage.
`The following areas of interest will be
`discussed in this paper:
`1.
`Interior Trim
`l.1 Roof Lining
`1.2 Floor Coverings
`
`ABSTRACT
`
`Based on the merits of cross linked
`polyethylene foam, i.e. good thermoform
`ability, low weight, strength, and lamin
`ability to other materials, Dynamit Nobel
`has developed new techniques and components
`for the trim in automotive vehicles.
`
`We have described trim parts such as
`roof linings, floor coverings, seats, trunk
`lining, and hood lining which are either being
`tested or already installed on standard
`models. They offer advantages over tradi
`tional components with regard to weight,
`comfort and price.
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`facilitate its gluing to the roof. On the
`assembly line one man can adapt it to the
`shape of the roof and make the installation.
`Suitable glues are already on the market.
`About 1,500 test cars equipped with such roof
`linings are on the roads at the moment. This
`type of roof lining, including installation
`labor is less expensive than the conventional
`type and weighs about 50% less, i.e. about
`
`710 g instead of 1520 g, and it givesabout
`20 mm more head clearance.
`an optically improved version of this
`lining using a polyamide fiber jersey finish
`is being developed.
`It is a thermoformed PE
`sheet glued in with the same type of adhesive.
`The advantages are lower weight and more
`head room.
`It will cost about the same as
`traditional types, but improve the appearance
`of the interior.
`1.2 FLOOR COVERINGS - The majority of
`European motor car manufacturers use thermo
`formed carpets or rubber mats for the car
`floors. Wadding and bituminous layers are
`used for sound proofing. The carpets are
`impregnated with polyethylene on the reverse
`side. That impregnation is rigid and often
`causes the carpet to bulge.
`Rubber mats provide very little foot
`comfort.
`Waddings easily absorb water.
`The pre
`cut sound proofing material is not easy to
`apply and frequently extra time is needed to
`remedy faulty fitting.
`The development of new methods comprised
`several stages:
`The first step consisted of a combina
`tion of the traditional tufted carpet with PE
`foam, using a reduced amount of PE impregna
`tion. The reasons for this were better adap
`tation to the contours of the car floor,
`better appearance, more comfort, a lesser
`risk of rotting than with wadding, good
`thermal and - to some extent - sound insula
`tion.
`
`Today, fully or partly PE foam backed
`carpets are used by Ford, British Leyland,
`Jaguar and others. Daimler Benz and VW have
`adopted PE foam insulation which is separately
`inserted under carpet (Fig. 3).
`In addition,
`two new approaches were
`made:
`Low priced, lightweight floor coverings
`for the standard models,
`More comfortable floor coverings as a
`complete package of carpet and sound proofing.
`Both versions are undergoing field tests.
`The Lightweight Type will replace rubber
`mats and tufted carpets in the standard
`models.
`Thermoformed floor coverings of about
`6 mm PE foam, density 50 kg/m3, with a film
`finish are being field tested, the laboratory
`tests having been positive. These new cover
`ings have a mat finish and offer practically
`
`1.1A Snap-In Lining - already installed
`in test vehicles (Fig. 1).
`It is a sandwich
`consisting of:
`A support material (e.g. metal or rigid
`PE foam),
`A cushioning (PE foam),
`A surface finish (PVC film or textile).
`The polyethylene is used to give the
`compound its shape and enables motor car
`manufacturers to design roof linings with in
`tegral sun visors or hardware which can be
`adapted quickly and economically to a deluxe
`model using relatively inexpensive tooling.
`This type of lining is more expensive than
`the conventional type of artificial leather
`and metal frame but lighter than linings made
`of resin bonded fibers.
`1.1B Adhesive Roof Lining made of PE
`foam with decorative finish (film or textile)
`Fig. 2).
`
`In its simplest form, it consists of a
`flat PE foam sheet with an ornamental PVC
`film finish. The lining is perforated to
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`the complete seat. Such seats have success
`fully passed the laboratory tests of motor
`car manufacturers.
`The development of this type is not yet
`completed as a few problems are yet to be
`overcome: air permeability,
`the correct
`grade of harness, etc.
`l.4 PARTITION BETWEEN INTERIOR AND
`TRUNK - Some car models do not have a steel
`partition between passenger compartment and
`trunk but a combination of cardboard or lamin
`ates, wadding and leatherette covers. In
`stallation entails a great amount of labor.
`A PE foam sheet, 6 mm thick and of 30
`kg/m3 density,
`thermoformed on a vacuum press
`can replace all these components (Fig. 4).
`Proposals for such parts have been submitted
`to a number of motor car manufacturers. At
`this time, price comparison is not yet com
`pleted.
`
`unlimited variations. The sheets are thermo
`formed in a vacuum press and result in a
`weight saving of 60 to 70% (the weight is 2
`to 3 kg compared to about 8 kg for a con
`ventional rubber mat).
`Floor coverings made from non-woven type
`carpets flame laminated to PE foam and thermo
`formed in special presses not only provide
`appealing designs but also better comfort.
`Depending on the type of non-woven material
`used, they are lighter than conventional
`tufted carpets.
`The More Comfortable Floor Covering con
`sists of PE foam (sometimes combined with PU
`foam), a heavy layer and the carpet. The
`heavy course is either extruded and then
`laminated to the carpet or directly applied
`to the carpet. The PE foam is laminated to
`the heavy layer. The latter weighs about 5
`to 8 kg/m2.
`The entire compound is thermo
`formed in one operation on a special press.
`The floor covering is fitted in either one or
`two parts (front and rear part of car).
`Installation and storage costs are lower
`than for conventional materials. They can be
`fitted easier and more efficiently than the
`conventional carpetings. Although the cost
`of the material may be about equal,
`the lower
`handling cost is bound to reduce the total
`cost of the floor covering.
`1.3 SEATS - The manufacture of seat
`covers still requires a considerable amount
`of labor (sewing, welding, fitting). New
`techniques make it possible to reduce these
`costs to a minimum.
`The textile industry has developed fab
`rics which stretch easily and are thus suit
`able for thermoforming extreme shapes.
`On
`vacuum presses,
`these fabrics, flame laminated
`to about 3 mm thick PE foam, can be thermo
`formed into seat covers. Depending on the
`shape of these covers,
`the cushioning can be
`formed during the same operation to produce
`
`2.
`
`TRUNK
`
`floor covering,
`Trunk trim comprises :
`trimming of the sides.
`Dynamit Nobel started by concentrating
`its efforts on the trunk mat.
`In view of PE
`foam's excellent thermoformability, it is
`highly suitable for trunk mats of cars with
`intricately shaped trunks (Fig. 5).
`So far,
`such trunks are equipped mainly with rubber
`mats. After extensive laboratory and field
`tests with trunk mats of PE foam, 4 mm thick,
`100 kg/m3 density, produced on a new vacuum
`press, Ford Europe has decided to adopt these
`mats on standard models beginning in 1976.
`These were the decisive factors:
`Weight saving compared with the tradi
`tional rubber mat, about 3 kg per car (a PE
`foam mat weighs about 0.5 kg),
`Better styling,
`Odorless,
`Lower cost.
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`structure and is about 12 mm thick. The sur
`face has a partial skin. The foam sheets are
`glued to the hood. The purpose of this
`lining is sound proofing and the suppression
`of vibrations. Water absorption and adhesion
`are still unsatisfactory.
`Cut to size or stamped components of PE
`foam are being tested by some motor car manu
`facturers. The problem of the glue has been
`solved. Water absorption is non-existent.
`Tests are still in progress with regard to
`sound proofing and heat resistance. At this
`stage, it is difficult to assess the poten
`tial of this development.
`An interesting field is the use of PE
`foam for the lining of ventilation ducts to
`insulate them against heat radiation. Thermo
`formed components of PE foam of about 90
`kg/m3 density can compete with varnished
`cardboard and represent weight savings.
`
`CONCLUSION
`
`In addition to the techniques and com
`ponents described above, other parts to be
`made of PE foam will contribute to a reduc
`tion of weight and cost and to an increase
`in comfort, e.g. door and side panels, parcel
`tray, crash pad.
`We believe that the field described
`above offers good opportunities to the auto
`mobile industry and its suppliers.
`
`Other motor car manufacturers are cur
`rently testing PE foam trunk mats.
`The next step in this direction will be
`an integral trunk trim, i.e. a large thermo
`formed part integrating mat and side lining.
`Work is currently in the experimental stage.
`3.
`HOOD
`
`Many European car models have PUR foam
`lined hoods. The foam layer has an open cell
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`his responsibility, not the Society's; however, the paper has
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`cussion will be printed with the paper if it is published
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`0007
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