Reinforced Blow Moulded Vehicle Running Board and Method of Making Same

Abstract

A structurally reinforced blow moulded assembly includes an overmould body bonded to one or more preformed internal stiffening ribs. The reinforcing r ribs are partially encapsulated by o the overmould body in an orientation selected to carry load a forces thereon. The resin mixture used to form the overmould body comprises 10% to 40% by weight short glass having a length less about 15 cm, and 60% to 90% by weight thermoplastic resin. To facilitate recycling the reinforcing ribs comprise 30 to 60% by weight long glass fibers and 40% to 70% of thermoplastic bonding resin.

Claims

1. A method of manufacturing a structurally reinforced blow moulded assembly, the blow moulded assembly comprising, an overmould member having a sidewall, the overmould member comprising between 10% by weight to 30% by weight short glass fibers having a longitudinal length of less than 10 cm, and 70% by weight to 90% by weight of a thermoplastic base resin, and a longitudinally elongated reinforcing rib insert at least partially encapsulated within said sidewall, said reinforcing rib insert having at least one flange member comprising 40% by weight to 70% by weight long glass fibers having a length of greater than 25 cm up to a length corresponding to a longitudinal length of said reinforcing rib insert, and 30% by weight to about 60% by weight of a bonding resin, said method comprising the steps of, drawing said long glass fibers co-mingled with said bonding resin through a pultrusion mould to at least partially heat fuse the co-mingled fibers to form a reinforced rib blank having at least one reinforced core, cutting the reinforced rib blank to a desired longitudinal length of the reinforcing rib insert, positioning the reinforcing rib insert at least partially in an overmould mould, and blow moulding the overmould member over the reinforcing rib insert.

2. The method as claimed in claim 1, wherein the reinforcing rib insert includes a forward said flange member, a rearward said flange member and a longitudinally extending connecting web joining the forward flange member and the rearward flange member, and wherein during said drawing step, melt injection moulding additional bonding resin about the melt fused co-mingled fibers to form the connecting web.

3. The method as claimed in claim 2, wherein at least one of the forward flange member, the rearward flange member and the reinforcing web includes a bonding layer and/or one or more longitudinally extending melt fingers, and wherein said step of injecting additional said bonding resin comprises melt injection moulding said additional bonding resin about the at least one reinforced core to form said bonding layer and/or melt fingers.

4. The method of claim 1, wherein the step of drawing the long glass fibers comprises drawing spooled polypropylene glass threads through the pultrusion mould.

5. The method as claimed in claim 1, wherein the step of at least partially heat fusing the co-mingled fibers comprises compacting and heating the co-mingled fibers to a temperature about a decomposition temperature of the bonding resin to heat fuse the fibers in a generally parallel arrangement.

6. The method of claim 5, wherein said long glass fibers are twisted, pre-wound and/or braided prior to compacting and heating.

7. The method as claimed in claim 1, wherein the blow moulded assembly comprises a vehicle part selected from the group consisting of a vehicle running board, a vehicle seat back, a vehicle load floor and a vehicle bumper beam, the overmould mould comprising a blow mould having a plurality of mould platens, and said step of positioning the reinforcing rib insert comprises positioning the reinforcing rib insert in a first said mould platen, and after positioning the reinforcing rib insert, blow moulding the overmould member.

8. The method of claim 7, wherein said step of blow moulding the overmould member includes, melt extruding a parison into the blow mould comprising a short fiber/base resin mixture comprising 10% to 30% by weight said short glass fibers and 70% to 90% by weight said thermoplastic resin, and blow moulding the parison over the reinforcing rib insert to form the overmould member at least partially melt bonded to the reinforcing rib insert.

9. The method as claimed in claim 8 wherein said step of positioning said reinforcing rib insert further comprises securing said reinforcing rib insert in said first mould platen by vacuum suction.

10. The method as claimed in claim 8, wherein the short glass fibers have a longitudinal length selected at less than about 1 cm.

11. The method as claimed in claim 8, wherein the thermoplastic resin comprises polyethylene, polypropylene or ABS.

12. A method of manufacturing a structurally reinforced blow moulded vehicle part, the vehicle part comprising, an overmould body having a sidewall defining a hollow interior, a forward surface and rear surface spaced from the forward surface, the overmould body further comprising between about 10% by weight to 30% by weight short glass fibers, and about 70% by weight to 90% by weight of a thermoplastic resin, wherein said short glass fibers have a longitudinal length of less than about 10 cm, and a longitudinally elongated reinforcing rib reinforcing said forward surface against a rearward load force, the reinforcing rib having a longitudinally extending forward portion, a longitudinally extending rearward flange member having a rearward bearing surface, and a connecting web joining the forward portion to the rearward flange, said method comprising, drawing long glass fibers having a length greater than about 25 cm co-mingled with a bonding resin through a pultrusion mould to melt bond said co-mingled fibers as part of a reinforced rib blank, the reinforced rib blank comprising 40% by weight to 70% by weight of said long glass fibers, and 30% by weight to about 60% by weight of said bonding resin, cutting said reinforcing rib from said reinforcing rib blank, positioning the reinforcing rib at least partially in a blow mould, and blow moulding the overmould member over the reinforcing rib in the blow mould, whereby said reinforcing rib is at least partially encapsulated by said sidewall with the longitudinally extending forward position in substantially bearing contact with at least a portion of said sidewall defining the forward surface, and the rearward bearing surface disposed in a generally coplanar orientation with said rear surface.

13. The method of claim 12, wherein during said drawing step, melt injecting additional bonding resin about said melt bonded co-mingled fibers.

14. The method as claimed in claim 12, wherein at least one of the forward portion, the rearward flange member and the connecting web includes a bonding layer and/or one or more longitudinally extending melt fingers, and wherein said step of injecting additional bonding resin comprises melt injection moulding said additional bonding resins about bonded generally parallel arranged co-mingled fibers to form said bonding layer and/or melt fingers.

15. The method of claim 13, wherein the step of drawing the long glass fibers comprises drawing spooled polypropylene glass threads impregnated with said bonding resin through the pultrusion mould.

16. The method as claimed in claim 12, wherein the blow mould comprises a plurality of mould platens, and said step of positioning the reinforcing rib comprises securing the reinforcing rib in a first said mould platen under vacuum, and thereafter blow moulding the overmould member over the reinforcing rib to at least partially melt bond to the reinforcing rib insert.

17. The method as claimed in claim 16, wherein vehicle part is selected from the group consisting of a vehicle running board, a vehicle seat back, a vehicle load floor and a vehicle bumper beam, and said thermoplastic and said bonding resin are each selected from the group consisting of polypropylene, ABS and polyethylene.

18. A method of manufacturing a structurally reinforced moulded assembly, the moulded assembly comprising, an overmould member having a sidewall defining a hollow interior, a forward support surface and a rear surface spaced from the support surface, the overmould member comprising between 10% by weight to 30% by weight short glass fiber having a longitudinal length of less than 10 cm, and 70% by weight to 90% by weight of a thermoplastic base resin, a longitudinally elongated reinforcing rib insert at least partially encapsulated within said sidewall, said reinforcing rib insert having a forward flange member, a rearward flange member spaced from the forward flange member, and a longitudinal connecting web joining the forward flange member to the rearward flange member, said method comprising the steps of, drawing said long glass fibers co-mingled with a bonding resin through a pultrusion mould to effect melt fusing of the co-mingled fibers to form a reinforced rib blank, said rib blank including said forward flange member, said rearward flange member and said connecting web, wherein at least one of said forward flange member and said rearward flange member comprises 40% by weight to 70% by weight of said long glass fibers, and 30% by weight to 60% by weight of said bonding resin, having at least one reinforced core, cutting the reinforced rib blank to a finished longitudinal length of the reinforcing rib insert, whereby the long glass fibers of the reinforcing rib insert have a longitudinal length of great than 25 cm up to the finished longitudinal length of the reinforcing rib insert, positioning the reinforcing rib insert at least partially in an overmould mould, and blow moulding the overmould member over the reinforcing rib insert, with an interior side of the forward support surface in bearing contact with at least a portion of the forward flange surface.

19. The method as claimed in claim 18, wherein during said drawing step, melt injection moulding an additional amount of bonding resin about the melt fused co-mingled fibers to form the connecting web.

20. The method as claimed in claim 19, wherein the moulded assembly comprises a blow moulded vehicle part selected from the group consisting of a vehicle running board, a vehicle seat back, a vehicle load floor, and a vehicle bumper beam, at least one of the forward flange member, the rearward flange member and the reinforcing web includes a bonding layer and/or one or more longitudinally extending melt fingers, and wherein said step of injecting additional said bonding resin comprises melt injection moulding said additional bonding resin about the at least one reinforced core to form said bonding layer and/or melt fingers.

21. The method of claim 20, wherein the step of drawing the long glass fibers comprises drawing spooled polypropylene glass threads through the pultrusion mould.

22. The method of claim 19, wherein said step of moulding the overmould member comprises, positioning the reinforcing rib insert in a blow mould, melt extruding a parison into the blow mould comprising a short fiber/base resin mixture comprising 10% to 30% by weight said short glass fibers and 70% to 90% by weight said thermoplastic resin, and blow moulding the parison over the reinforcing rib insert to form the overmould member at least partially over and melt bonded to the reinforcing rib insert, with the rearward flange member generally coplanar with the rear surface.

23. The method as claimed in claim 22, further comprises securing said reinforcing rib insert in said blow mould by vacuum suction.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Reference may be had to the enclosed drawings together with the following detailed description, in which:

[0022] FIG. 1 shows a partial cutaway perspective bottom view of a conventional blow moulded vehicle running board in accordance with the prior art;

[0023] FIG. 2 illustrates a perspective view of a blow moulded vehicle running board in accordance with a first aspect of the invention;

[0024] FIG. 3 shows a partially cut-away perspective bottom view of the running board of FIG. 2 taken along lines 3-3, showing the positioning of a reinforcing rib therein;

[0025] FIG. 4 shows a partial perspective view of the reinforcing rib used in the running board of FIG. 2 in accordance with a first embodiment of the invention;

[0026] FIG. 5 shows a cross-sectional view of a reinforcing rib for use in the running board of FIG. 2 in accordance with a second embodiment of the invention;

[0027] FIG. 6 shows schematically a moulding die used in the pultrusion moulding of the reinforcing rib shown in FIG. 5;

[0028] FIGS. 7 to 9 illustrate schematically the positioning of the reinforcing rib of FIG. 5 in a blow moulding die during blow moulding encapsulation and fusion of the overmould running board sidewall thereabout;

[0029] FIG. 10 provides a partial cross-sectional view of the moulding die platen used in the blow moulding die shown in FIG. 7, illustrating the securement of the reinforcing rib therein, prior to the formation of the overmould sidewall; and

[0030] FIG. 11 shows a cross-sectional view of the blow mould running board illustrating the partial and encapsulation of the reinforcing rib by the overmould sidewall, immediately following blow moulding operation.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0031] Reference may be had to FIG. 2 which illustrates a thermoplastic glass fiber composite vehicle running board 50 which is manufactured in accordance with a most preferred aspect of the invention. The vehicle running board 50 is provided for mounting against a pair of conventional L-shaped steel mounting brackets 28a,28b for securement along the side of a vehicle (not shown). Depending on the application, the running board 50 has a typical longitudinal length selected at between about 1 and 2 meters, and a lateral step width of between about 10 and 20 cm. As will be described, the vehicle running board 50 is formed having internal structural reinforcement which provides the running board 50 with sufficient structural integrity to enable its securement to the vehicle using only the single pair of mounting brackets 28a,28b in supporting the running board 50 towards each respective longitudinal end, thereby reducing the running board installation time.

[0032] As shown best in FIG. 3 the running board 50 has a generally hollow open interior 100 and is formed having a binary construction consisting of a fiber reinforced thermoplastic sidewall 52 which is reinforced by a longitudinally extending fiber reinforced thermoplastic reinforcing rib 54. As will be described to manufacture the running board 50, the sidewall 52 is formed as a blow moulded overmould which partially encapsulates, and is melt bonded to the reinforcing rib 54 for enhanced structural rigidity. As shown best in FIG. 3, the sidewall 52 defines the overall running board profile. In this regard, the sidewall 52 delineates an upper surface 60 which includes the running board upper tread surface 62 for supporting a user thereon, a generally planar bottom surface 64 which is spaced from the tread surface 62, and forward and rearward connecting webs, 66,68 which merge with to join the upper and bottom surfaces 60,64. As shown best in FIGS. 3 and 4, the bottom surface 64 is formed having a pair of moulded recesses 72a,72b which are each spaced towards a respective running board end 74a,74b. The recesses 72a,72b are sized to receive therein the associated mounting bracket 28 in the securement of the running board 50 along the side of the vehicle.

[0033] FIG. 3 shows best the stiffening rib 54 as positioned to carry and transmit load forces on the sidewall 52 to the mounting brackets 28a,28b. As will be described, the rib 54 is moulded directly into the running board 50 itself, so as to extend in a generally vertical orientation along its longitudinal mid-axis.

[0034] The sidewall 52 and reinforcing rib 54 are both formed from complimentary fiber/resin compositions which are selected to enable waste flash, defective reinforcing ribs 52 and/or the entirety of any blemished or defective running boards 50 to be recycled for subsequent use in the manufacture of other thermoplastic blow moulded articles.

[0035] Most preferably, the sidewall 52 is formed from a fiber reinforced thermoplastic base resin mixture which contains from about 10% by weight to about 30% by weight short glass fibers, and about 70% by weight to about 90% by weight of a base resin of ABS, polyethylene polypropylene or mixtures thereof. To facilitate blow moulding, the short glass graphite andlor polycarbonate fibers having a length of less than 1 cm, and more preferably less than about 0.5 cm.

[0036] The reinforcing rib 54 is formed having an overall composition which includes upto 50% by weight long glass graphite and/or polycarbonate fibers, and at least 50% by weight of a thermoplastic bonding resin. Although not essential, the long glass fibers are preferably selected from glass fibers which are comingled with a bonding resin, such as ABS, polyethylene, polypropylene or mixtures thereof, and which are heat fused in a generally parallel orientation. The long glass fibers 122 have a longitudinal length of preferably at least about 25 cm, and more preferably extend substantially the entire longitudinal length of the rib 54. For maximum recyclability, the bonding resin is most preferably is chosen the same as the base resin used in the formation of the sidewall 52 The applicant has appreciated that providing the reinforcing rib 54 having the aforementioned composition advantageously allows for simplified recycling and repurposing of defective or blemished ribs 54 and running boards 50. In particular, blemished or defective running boards 50 may be reground, and the reground material thereafter re-mixed into the base resin mixture for use in the blow moulding of sidewalls in the manufacture of a subsequent running board 50, and/or in the manufacture of further articles and parts.

[0037] FIG. 4 illustrates a partial perspective view of the reinforcing rib 54 in accordance with a first embodiment of the invention. The reinforcing rib 54 is provided with an elongated longitudinal length which extends substantially the longitudinal length of the running board 50. The rib 54 is provided with a pair of laterally extending spaced upper and lower flanges 76,78. The flanges 76 extend the longitudinal length of the rib 54 and are joined by a connecting web 80. The vertical height between the flanges 76,78 is selected such that following the encapsulation of the rib 54 by the sidewall 52, any load forces on the upper tread surface 62 along the entire length of the running board 50 are transmitted to and carried by the rib 54 onto the mounting brackets 28.

[0038] In the embodiment shown, the upper and lower flanges 76,78 are provided with a partially rounded cross-sectional profile. The applicant has appreciated that the rounded flange shape of the flanges 76,78 advantageously facilitate pultrusion moulding of the reinforcing rib 54. Most preferably, the upper flange 76 has a generally round cross-sectional profile having an approximate radially diameter selected at between about 1 and 2 cm. The lower flange 78 is formed having a flattened triangular cross-sectional profile. The lower flange 78 provides the rib 54 with a generally planar bottom 84 having a lateral width selected at between about 2 and 4 cm for dispensing load forces thereon, and which tapers upwardly to merge with the connecting web 80.

[0039] In the construction shown, the connecting web 80 has a lateral thickness selected at less than about 5 mm, preferably less than about 3 mm, and most preferably about 1 mm. Depending upon the size of the running board 50, the web 80 is formed having the vertical dimension between the flanges 76,78 selected at between about 0.3 and 1.5 cm. It is to be appreciated, however, that connecting webs of different dimensions may be used, depending upon the article of manufacture.

[0040] Although not essential, in a most preferred construction the reinforcing rib 54 is provided having a compound construction in which the upper and lower flanges 76,78 are provided respectively with a long fiber reinforced core, 86,88 which are each in turn further encapsulated by an outermost bonding layer 90. Preferably, each of the long fiber reinforced cores 86,88 are themselves composed of 40% by weight to about 70% by weight of the long glass fibers, and about 30% by weight to about 60% by weight of the bonding resin, and wherein the bonding resin is used to effect the melt fusion of the long glass fibers to each other in a generally parallel strand orientation. Although not essential, preferably the connecting web 80 is formed so as to consist entirely of bonding resin. The bonding layer 90 most preferably is also formed entirely of the bonding resin, to better facilitate the partial melt bonding and fusion with the sidewall 52 during overmoulding.

[0041] As shown best in FIG. 7, the reinforcing rib 54 is provided with a pair of cutouts 94a,94b. Each cutout 94 is sized and spaced for alignment with a corresponding recess 72a,72b. The cutouts 94 have a dimension selected such that in final assembly, the upper flange 76 of the rib 54 locates immediately adjacent to the underside of the upper tread surface 62 and the bottom 84 of the lower flange 78 in a substantially coplanar alignment with the adjacent portions of the bottom surface 64. So positioned, the upper flange 76 and connecting web 80 provides reinforcement to the running board 50 at each of the recesses 72a,72b. The extension of the cutout portions of the rib 54 over the recesses 72a,72b thus minimizes any points of weakness along the longitudinal length of the running board 50. Once vertically positioned, the stiffening rib 54 thus provides added structural support by transmitting load forces placed on the tread surface 62 directly and evenly through the running board 54, to the bottom surface 84.

[0042] Reference may be had to FIG. 5 which illustrates a pultrusion formed connecting rib 54 for use with the running board 50 in accordance with a further embodiment of the invention, and wherein like numerals are used to identify like components. In the rib 54 shown in FIG. 5, the portion of the bonding layer 90 in which defines the outermost perimeter of the upper flange 76 and connecting web 80 is further provided with a series of longitudinally extending melt fingers 96. The melt fingers 96 extend radially outwardly a distance of between about 0.5 and 1 mm, and have a thickness selected to preferentially melt and heat fuse with the sidewall 52 during overmoulding operation. The applicant has appreciated that the provision of the melt fingers 96 advantageously provide enhanced melt bonding between the reinforcing rib 54 and sidewall 52, to more securely fix the rib 54 against movement relative thereto.

[0043] FIG. 6 shows schematically the manufacture of the reinforcing rib 54 shown in FIG. 5 by pultrusion moulding in accordance with a preferred method. FIG. 6 illustrates a pultrusion mould 110 which includes a pair of primary mould cavities 112,114 which are used to preform the long fiber reinforced cores 86,88 respectively, and a capstock feed inlet 116 which provides fluid communication with the secondary mould cavity 120 which is downstream from the primary cavities 112,114, and which is used from the finished rib profile. The capstock feed inlet 116 is used for the melt injection of bonding resin to form the outer bonding layer 90 and connecting web 80 about the heat bonded glass fiber cores 86,88.

[0044] As shown in FIG. 6, with the pultrusion mould 110, initially long glass fibers which have been co-mingled with the bonding resin are drawn into the primary mould cavities 112,114. Initially, parallel strands of thermoplastic co-mingled glass fibers are compacted and heated in each mould cavity 112,114 the mould at a temperature slightly above the resin decomposition temperature, to fuse the fibers and form reinforced cores 86,88 having the desired profile.

[0045] After partial melt fusing of the co-mingled fibers as the reinforced cores 86,88, the formed cores 86,88 drawn into the secondary mould cavity 120 where the bonding resin is melt injected via the capstock feed inlet 116 to form the bonding layer 90, connecting web 80 and melt fingers 96.

[0046] In one simplified form of manufacture, the stiffening rib 54 is formed by pultrusion by drawing polypropylene glass spooled threads through the pultrusion mould 110, while impregnating with a structural plastic bonding resin to form a finished rib blank 54. The blank 54 is then cut to the desired longitudinal rib length, having regard to the length of the finished running board 50, and the cutouts 94a,94b are formed in a single stamping. The resulting formed , rib 54 is provided with melt fused glass fibers which have an axially length which extend the entire length of the rib 54, and which have a continuous length selected at between about 200 cm to 250 cm.

[0047] While in a preferred method of manufacture, the elongated glass fibers are drawn through the mould 110 so as to heat fuse to each other in a generally parallel arrangement, it is to be appreciated that in other constructions, the long glass fibers 122 may be pre-wound, braided, and/or twisted prior to being drawn into the mould 110. Similarly, while pultrusion provides various advantages in manufacture, it is to be appreciated that in alternate modes of manufacture, the rib 54 could also be formed by compression or injection moulding.

[0048] In a most preferred sidewall construction, the upper surface 60, bottom surface 64 and side webs 66,68 are integrally formed from a plastic/short fiber base resin parison mixture, consisting of polypropylene or ABS, and 10 to 30% glass fibers which have an average length of between about 0.1 cm and 0.5 cm. It is envisioned that the base resin mixture used to form the running board sidewall 52 includes both virgin and re-ground components including waste flash, as well as reground rejected pieces. The sidewall 52 is formed as an overmould body which is blow moulded over a preformed reinforcing rib 54 to substantially encapsulate and bond therewith.

[0049] FIGS. 7 to 9 show best a two-part mould 130 used in the final manufacture of the running board 50 shown in FIG. 2. The mould 130 includes bottom and top mould platens 132,134. The bottom platen 132 is used to form the running board bottom surface 64, recesses 72a,72b and part of the connecting webs 66,68. The top platen 134 is used to form the upper surface 60 including the upper tread surface 62, as well as part of the connecting webs 66,68.

[0050] FIGS. 7 and 11 show best, the bottom platen 132 as being provided with a longitudinally elongated vacuum channel 136. The channel 136 is formed having a flat bottom sized to receive therein in juxtaposed contact the bottom 84 of the reinforcing rib 54. The vacuum channel 136 is further provided with a series of longitudinally spaced vacuum manifold apertures 140 which are fluidically coupled by associated vacuum lines 142 (FIG. 10) to a negative pressure source (not shown). The apertures 140 are spaced along the bottom of the channel 136 at locations selected whereby the activation of the vacuum source effects a sufficient negative pressure to releasably secure a reinforcing rib 54 to the bottom platen 132, with the bottom 84 of the lower flange 78 in juxtaposition within the vacuum channel 136.

[0051] To form the running board 50, a preformed reinforcing rib 54 is initially positioned in the platen 132 in a generally vertical orientation with its bottom 84 positioned in the vacuum channel 136. The vacuum source is actuated, drawing air through the apertures 140 via the associated vacuum lines 142, maintaining the rib 54 in the desired orientation during blow moulding operations. With the rib 54 so secured, the mould 130 is activated to hot extrude a parison 144 of melted base resin between the top and bottom platens 132,134. With the parison 144 hot extruded therebetween, the platens 132,134 are thereafter move together in the direction of arrows 200 closing the mould cavity. The heated parison 144 is thereafter stretched into the desired shape to form the sidewall 52 by blow moulding, encapsulating the stiffening rib 54 in the manner shown in FIG. 11. During stretching of the parison 144, the melt fingers 96 are contacted and partially melted and fuse bonded to the blown moulded plastic sidewall 52. The heat fusing of the blown plastic sidewall 52 with the melt fingers 96 further anchors the rib 54 in the desired vertical orientation within the interior of the running board 50.

[0052] Because the exposed rib bottom 84 and bottom surface 64 of the formed running board 50 is substantially flat, the formed part may be easily removed from the lower mould bottom platen 132 with minimum concern of die lock.

[0053] Because the formed running board 50 is made entirely with a glass reinforced plastic structure, any excess flash produced in moulding operations, as well as waste rib material or even entire rejected parts may be re-ground and re-melted for use in subsequent part manufacture. The current invention thus advantageously provides a more economical, waste-resistant manufacturing process.

[0054] In another possible construction, the rib 54 may be provided with one or more through-bores (not shown) in addition to or in place of the melt fingers 96. Such through-bores are sized to allow for the penetration of the blow moulded plastic therethrough, to facilitate stabilization and anchoring of the rib 54 within the running board interior 100.

[0055] Although the foregoing description describes the manufacture of a reinforced blow moulded running board 50 having a single stiffening rib 54, the invention is not so limited. It is to be appreciated that the running board 50 could be provided with multiple stiffening ribs 54 at lateral and/or longitudinally arranged orientations. In addition, the process of the present invention may be used in the manufacture of a variety of other types of blow moulded components and article for both vehicle and non-vehicle applications, with the result that the foregoing detailed description should not be viewed as limiting.

[0056] While the detailed description describes the rib 54 as having an upper flange 76 with a rounded-cross section profile, and a lower flange 78 having a generally triangular profile, the invention is not so limited. It is to be appreciated that depending upon the application and the load forces to be carried, the reinforcing rib 54 may be provided with a number of different profiles. In one alternate, non-limiting embodiment, both the upper and lower flanges 76,78 could be provided as generally planar lateral projections. In an alternate possible design, the reinforcing rib 54 may be formed having an L-shaped profile. Other rib profile designs are also possible will now become apparent.

[0057] While the detailed description describes and illustrates various preferred embodiments, the invention is not so limited. Many modifications and variations will now occur to a person skilled in the art. For a definition of the invention, reference may be had to the appended claims.