Method of forming automotive headliners from composite foamed resin blanks

An automotive vehicle headliner is formed from a flat strip having laminated layers of resilient, cellular, foamed plastic and a finish textile material. The strip is cut to form a flat blank which is heated to a temperature at which the foamed plastic loses its resilience. While in its heated state the blank is compressively deformed and simultaneously trimmed in a mold to the desired size and contour and the cells adjacent the marginal edge of the blank are reduced in size to reduce the wall thickness of the blank. The deformed and trimmed blank is cooled while the compressive air force is maintained.

BACKGROUND OF THE INVENTION 
It is common practice at the present time to manufacture automotive 
headliners from multi-layered laminates including one or more layers of 
thermoplastic materials and a finish layer of fabric or fabric-like 
textile material. Examples of such headliners, and the processes of 
producing them, are illustrated in U.S. Pat. Nos. 3,252,732; 3,265,530; 
3,620,906; 4,020,207; 4,042,751; 4,119,749; and 4,131,702. Some of these 
prior constructions are formed as panels from laminated sheets which are 
cut and then formed or shaped, whereas others are formed by various kinds 
of molding techniques. In all instances, however, various trimming 
operations appear to be necessary following the formation of the panels 
that ultimately are to become headliners. 
Another disadvantage of processes used heretofore in the production of 
automotive headliners is that, in many instances, the edges of the liners 
are of such thickness that special trim strips or moldings are necessary 
to secure the edges of the liners and to avoid exposure of the edges when 
the liners are fitted to automotive vehicles. 
SUMMARY OF THE INVENTION 
An article formed according to the invention utilizes a blank composed of 
laminated layers of material. The blank initially is of substantially 
uniform thickness and comprises a form stable, relatively stiff or dense 
backing layer of foamed, cellular thermoplastic material, an intermediate 
layer of relatively soft, or less dense foamed cellular material and a 
thin layer of synthetic textile material. The blank is sheared from an 
elongate strip or sheet and subsequently heated to a temperature at which 
the backing and intermediate layers become plastic or tacky and lose their 
resilience. The heated blank is placed between relatively movable mold 
halves having complementary, confronting mold surfaces defining a cavity 
which is configured to impart to the blank the desired contour. 
While in a heated state, the blank is subjected to compressive force 
between the relatively movable mold halves. The size of the cavity 
diminishes in a direction toward the periphery of the mold, thereby 
enabling the confronting surfaces of the mold halves adjacent the marginal 
edges of the blank to compress the blank and collapse or reduce the size 
of the cells of the backing and intermediate layers. As the mold halves 
move toward one another to apply the compressive force, cutting edges 
provided on the mold halves react with one another to cut the blank to the 
exact size of the headliner to be produced, following which the mold 
halves move to their fully closed positions. 
While maintaining the mold halves in their fully closed positions, cooling 
fluid is circulated through the mold halves to conduct heat from the blank 
and cool the latter. Following cooling of the blank, the mold halves are 
moved away from one another to enable the finished liner to be removed 
from the mold. 
A liner produced in accordance with the invention has the desired contour 
and marginal edges which taper to thin, cleanly cut edges. The contouring, 
trimming, and tapering of the blank are formed in a single operation.

DETAILED DESCRIPTION 
The objective of the invention is to produce a molded article, such as an 
automotive headliner, designated generally by the reference character 1 in 
FIG. 7. In a preferred embodiment the headliner comprises a multilayer 
laminate having a form stable relatively stiff backing member 2 formed of 
cellular, thermoplastic material, such as foamed polystyrene; an 
intermediate relatively soft layer 3 formed of cellular, foamed 
thermoplastic material such as polyurethane; and a finish layer 4 formed 
of thin textile material such as nylon. The layer 2 has a crown portion 5 
of substantially uniform thickness from which extends a marginal, 
upstanding sidewall 6 that terminates in an outwardly turned lip 7. The 
thickness of the sidewall 6 varies over its length so as to taper 
outwardly from the crown portion 5, and the taper preferably is linear 
over the width of the side and lip. The layer 3 has a corresponding crown 
portion 8 of substantially uniform thickness, a corresponding sidewall 9, 
and a corresponding lip 10, and again the portions 9 and 10 taper 
substantially linearly toward the marginal edge. 
Apparatus for producing the article 1 comprises a mold 11 composed of a 
first or lower half 12 and a second or upper half 13. The lower half 
comprises a rectangular frame 14 secured in any suitable manner to a base 
15. Fitted within the frame 14 is a die 16 having a cavity 17 configured 
to correspond to the contour of the article to be formed. For ease of 
illustration the base of the cavity is disclosed as being flat and 
horizontal, but it will be understood that this surface could be contoured 
differently. 
The cavity 17 has at its outer region an upstanding, outwardly inclined 
side surface 18. At its upper end the surface 18 merges with a flat, 
horizontal surface or rim 19. 
The die 16 is vertically reciprocable relative to the base 15 and normally 
is maintained in an elevated position relative thereto by a plurality of 
compression springs, one of which is shown at 20. Upward movement of the 
die 16 is limited by bolts 21 threaded into openings in the base of the 
die and having enlarged heads 22 slidably accommodated in a counterbore 23 
formed in the base 15. When the die is in its elevated position, the flat 
surfaces 19 project above the level of the frame members 14. However, the 
member 16 is capable of downward movement a distance sufficient to locate 
the peripheral surfaces 19 at level lower than that of the frame members 
14, as is shown in FIG. 6. 
The upper mold half 13 has a peripheral flange 24 which is bolted or 
otherwise suitably fixed to a platen 25 that is movable vertically toward 
and away from the base 13 by conventional power means (not shown). The 
mold member 13 has a convex die 26 having a bottom surface which 
complements the cavity 17 and merges with side surfaces 27 that converge 
downwardly along lines inclined to a vertical plane of reference. Each 
surface 27 terminates in a step 28 which, in turn, terminates in a smooth, 
vertical shearing edge 29 which is adapted to be accommodated snugly 
within the frame members 14 of the lower mold half. 
The inclination of the side surfaces 27 is different from that of the side 
surfaces 18 of the lower mold half. The angle of inclination of the 
surfaces 27 to the vertical plane is greater than that of the surfaces 18 
for a purpose presently to be explained. 
The die 26 has a number of small bore vent openings 30, as is customary, to 
permit air to escape from the cavity 17. Similar vents (not shown) may be 
provided in the die 16. 
The platen 25 is guided in its movements by guide pins 31 fixed to the bed 
15 and extending through bushing-lined openings 32 in the platen. Movement 
of the platen 25 toward the bed 15 is limited by stop blocks 33 fixed to 
the bed 15 and projecting upwardly therefrom. 
The die members 16 and 26 are provided with a plurality of passages 34 and 
35, respectively, connected by suitable tubing (not shown) in a 
conventional manner to a source of coolant fluid, such as water, which may 
be circulated through the passages for cooling the dies and an article 
therebetween. 
OPERATION 
The disclosed apparatus is adapted for use in connection with flat blanks 
36 of multi-layered materials such as those referred to earlier. The 
blanks are cut from elongate, flat laminated strips of substantially 
uniform thickness and so arranged that the backing layer 2 is lowermost, 
the finish textile layer 4 is uppermost, and the intermediate layer 3 is 
sandwiched therebetween. 
The strips from which the blanks 36 are cut may be produced in any one of a 
number of known ways and may be cut into blanks by any suitable transverse 
cutting apparatus. 
Prior to introduction between the separated mold halves 12 and 13, a blank 
is heated by any one of a number of known heating devices. The temperature 
to which the blank is heated should be sufficient to cause the materials 
forming the layers 2 and 3 to lose their resilience, but should be 
insufficient to enable the materials of the layers to melt, flow, or to 
char or otherwise adversely affect the finish layer 4. The temperature to 
which the blank is heated thus may vary in accordance with the materials 
from which the blank is composed, but if the layer 2 is formed of foamed 
polystyrene, the layer 3 is composed of foamed polyurethane, and the layer 
4 is composed of nylon, satisfactory results may be obtained by heating 
the blank to a temperature of about 230.degree. F. 
Following heating of the blank 36 it is introduced between the separated 
mold halves 12 and 13. As is indicated in FIGS. 4 and 5, the width of the 
blank is sufficient to enable it to span the width of the mold halves and, 
of course, the length of the blank will be sufficient to enable it to span 
the length of the mold halves. 
Promptly after the blank is introduced between the mold halves, and while 
the temperature of the blank is substantially that to which it was heated, 
the mold halves are closed so as to enable the die 26 to enter the cavity 
17 and deform the blank 36. As the mold halves close, the different 
inclinations of the surfaces 18 and 27 will result in those portions of 
the blank therebetween to be subjected to a compressive force greater than 
elsewhere. The cells of the foamed materials 2 and 3 at these portions of 
the blank thus will be reduced in size or collapsed so as to provide at 
the periphery of the blank a wall thickness which tapers from the central 
portion thereof toward the marginal edge. As the mold halves continue to 
move toward one another, the die 16 will be displaced downwardly against 
the bias of the springs 20, but eventually the step 28 will reach the 
level of the frame members 14. The confronting surfaces of the frame 
members 14 and of the step 28 are sharp so as to provide cutting edges 
which will shear the blank as the surface 29 telescopes within the frame 
members 14 to provide coplanar edges for each layer. 
The maximum distance that the mold halves may move toward one another is 
limited by the stop blocks 33, thereby resulting in an article 1 having a 
predetermined thickness at its marginal edge. 
Following complete closure of the mold halves, the compressive force is 
maintained and coolant fluid is circulated through the passages 34 and 35 
so as to chill the molded article and reduce its temperature to about 
100.degree. F. The time required to effect chilling of the molded article 
depends upon several factors, such as the temperature of the coolant, the 
number of passages, and the rate of circulation, but suitable chilling can 
be effected within ten to twenty seconds. 
Following chilling of the molded article, the mold halves are separated, 
whereupon the springs 20 expand and lift the molded article out of the 
cavity 17 for easy removal. 
Since the blank is heated before compression to a temperature level at 
which the foamed materials lose their resilience, and since the blank is 
subjected to the compressive force while the temperature of the blank is 
at such level, the cells of the foamed materials will be collapsed or 
reduced in size while the foamed materials are tacky. Such reduction is 
accomplished by expelling air from the cells, such air being exhausted 
through the vents in the dies. The foamed materials will regain their 
resilience following cooling, but since the compressive force is 
maintained during chilling, the compressed materials will not regain their 
original thickness. As a consequence, the sidewalls of the molded article 
will have a varying thickness and will taper toward the marginal edge. 
The disclosure is representative of presently preferred embodiments of the 
invention, but is intended to be illustrative rather than definitive 
thereof. The invention is defined in the claims.