DK152566B

DK152566B - PROCEDURE FOR THE MANUFACTURING OF AN ARTICLE CONSISTING OF A THERMOFORM SHOULD BE REINFORCED BY A GLASS FIBER REINFORCED PLASTIC LAYER AND APPARATUS FOR PRACTICE

Info

Publication number: DK152566B
Application number: DK257977A
Authority: DK
Inventors: Paul Evrard; Michel-Claude Terroy
Original assignee: Altulor
Priority date: 1977-06-10
Filing date: 1977-06-10
Publication date: 1988-03-21
Also published as: DK257977A; DK152566C

Description

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Opfindelsen angår en fremgangsmåde til fremstilling af en genstand bestående af en termoformet skal forstærket ved hjælp af et glasfiberarmeret plastlag.BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a method of manufacturing an article consisting of a thermoformed shell reinforced by a glass fiber reinforced plastic layer.

Det er f.eks. fra det franske patentskrift 75 29 312 kendt af forstærke en af en termoformet skal dannet genstand ved hjælp af lamineret, glasfiberforstærket plast enten ved manuel påføring af et vævet stof og påsmøring af plasten eller ved påsprøjtning af glasfibre og polyesterplast samtidig eller efter hinanden.It is e.g. from French Patent 75 29 312 known by reinforcing one of a thermoformed article formed by laminated, glass fiber reinforced plastic either by manually applying a woven fabric and applying the plastic or by spraying glass fibers and polyester plastic simultaneously or in succession.

Den første af disse fremgangsmåder er meget tidskrævende og derfor uegnet til massefremstilling, og den anden fremgangsmåde er vanskeligt anvendelig ved forholdsvis små genstande, navnlig når disse er udformet med f.eks. halsformede indsnævringer eller lignende.The first of these processes is very time consuming and therefore unsuitable for mass production, and the second method is difficult to use for relatively small objects, especially when designed with e.g. neck-shaped constrictions or the like.

Opfindelsen har derfor til formål at anvise en fremgangsmåde til massefremstilling af genstande, der i hovedsagen består af en termoformet skal, der er forstærket med glasfiberarmeret plast. Som et eksempel på en sådan genstand kan nævnes en motorcykelhjelm, som skal have et tiltalende udseende og en styrke, der effektivt beskytter brugerens hoved i tilfælde af en ulykke. Fremgangsmåden ifølge opfindelsen er ejendommelig ved, at skallens ene yderflade anbringes i anlæg mod en elastisk deformerbar understøtning, der er således udformet, at den slutter nøje mod skallens nævnte flade, at et tilpasset glasfiber-armeringslag anbringes i skallen, at en formpart med en arbejdsflade modsvarende skallens anden yderflade indsættes i skallen således, at der findes et frit mellemrum mellem arbejdsfladen og skallens nævnte anden flade, at der på i og for sig kendt måde tilføres plast med forhøjet tryk til dette mellemrum, at plasten hærdes og at den forstærkede skal frigøres fra understøtningen og formparten.It is therefore an object of the invention to provide a method of mass-making of articles consisting essentially of a thermoformed shell reinforced with fiberglass-reinforced plastics. An example of such an item is a motorcycle helmet which must have an attractive appearance and a strength that effectively protects the wearer's head in the event of an accident. The method according to the invention is characterized in that one outer surface of the shell is arranged against an elastically deformable support, which is formed so that it ends precisely against said shell, that an adapted fiberglass reinforcing layer is placed in the shell, that a mold part with a working surface correspondingly, the second outer surface of the shell is inserted into the shell such that there is a free space between the working surface and the second surface of said shell, that in a known manner, high-pressure plastic is applied to this space, that the plastic is hardened and that the reinforced material must be released. from the support and the mold part.

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flpfindolcon angår sndi/idgrø et apparat til udauelae af denne fremgangsmåde, og som er ejendommeligt ved, at det omfatter en elastisk deformerbar understøtning, der er indrettet til at kunne understøtte den ene yder-flade på en termoformet skal, der skal forstærkes, med tæt anlæg mod denne yderflade, en formpart med en arbejds-flade som er komplementær med skallens anden yderflade og som eventuelt har en elastisk deformerbar del, og organer til indsprøjtning af plast under tryk i det af formpartens arbejdsflade og skallens nævnte anden yderflade afgrænsede mellemrum.flpfindolcon relates to a sand-grout an apparatus for extending this method, which is characterized in that it comprises an elastically deformable support adapted to support one outer surface of a thermoformed shell to be reinforced with abutment against this outer surface, a mold part having a working surface which is complementary to the second outer surface of the shell and which optionally has an elastically deformable part, and means for injecting plastic under pressure in the space defined by the mold part's working surface and the second outer surface defined by the shell.

Fremgangsmåden og apparatet ifølge opfindelsen muliggør massefremstilling af harpiksforstærkede termoformede og i hovedsagen af en skal dannede genstande, selvom disse genstande er forholdsvis små, idet indsprøjtning af forstærkende harpiks under tryk er mulig på grund af den elastisk deformerbare understøtning, der bevirker, at spændinger fordeles over skallen, således at man undgår risiko for dannelse af krakelering og fine revner i skallen.The method and apparatus according to the invention enable mass production of resin-reinforced thermoformed and substantially shell-shaped articles, although these articles are relatively small, since injection of reinforcing resin under pressure is possible due to the elastically deformable support which causes tension to be distributed over the shell so as to avoid the risk of formation of crackling and fine cracks in the shell.

Når formpartens arbejdsflade er elastisk deformerbar, er det muligt at forstærke skålformede genstande med f.eks. halsformede indsnævringer, og det er endvidere nemt at frigøre skallen fra formen.When the work surface of the mold part is resiliently deformable, it is possible to reinforce bowl-shaped objects with e.g. neck-shaped constrictions, and it is also easy to release the shell from the mold.

Opfindelsen forklares nærmere i det følgende under henvisning til tegningen, hvor fig. 1 i snit viser et apparat ifølge opfindelsen med en deri anbragt skålformet genstand, og fig. 2 viser i snit et apparat til fiksering af en deformerbar del af formparten i apparatet.The invention will be explained in more detail below with reference to the drawing, in which fig. 1 is a sectional view of an apparatus according to the invention with a bowl-shaped object disposed therein; and FIG. 2 shows in section an apparatus for fixing a deformable part of the mold part of the apparatus.

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1 det følgende er som et eksempel valgt fremstilling af en styrthjelm for motorcyklister, idet en sådan hjelm har forholdsvis små dimensioner og omfatter en forstærket, termoformet skal med en halslignende indsnævring, der er temmelig vanskelig at fremstille ved hjælp af den hidtil kendte teknik.In the following, as an example, a crash helmet for motorcyclists is chosen, such a helmet having relatively small dimensions and comprising an reinforced thermoformed shell with a neck-like narrowing which is rather difficult to manufacture by the prior art.

Til forstærkning af skallen anvendes det i fig. 1 viste apparat, der i hovedsagen består af en understøtning 2 for den termoformede skal 1 og en formpart 3, hvoraf den største del er skudt ind i skallen i brugsstillingen. Understøtningens 2 og formpartens 3 form modsvarer formen af skallens inderside og yderside, således at understøtningen 2 vil slutte tæt mod skallens yderside, medens formparten 3 sammen med skallens inderside afgrænser et mellemliggende, frit rum.For reinforcing the shell, it is used in FIG. 1, consisting essentially of a support 2 for the thermoformed shell 1 and a molding part 3, the greater part of which is pushed into the shell in the operating position. The shape of the support 2 and the mold part 3 corresponds to the shape of the inside and outside of the shell, so that the support 2 will close tightly against the outside of the shell, while the mold part 3 together with the inside of the shell delimits an intermediate free space.

Understøtningen og formparten omfatter hver en stiv, bærende del og en elastisk deformerbar del, der danner en beklædning på den bærende del.The support and the molding portion each comprise a rigid, supportive member and an elastically deformable member forming a lining on the support member.

Understøtningen 2 omfatter således en stiv bærende del 5, der er skålformet med svagt udad skrånende sidevæg, og en elastisk deformerbar del 6, der er udformet således, at den vil slutte tæt mod ydersiden af skallen 1. Den stive, bærende del 3 kan f.eks. bestå af lamineret polyester, medens den elastisk deformerbare del fortrinsvis består af en gummi af polynorbornen, der sælges under varemærket "Norsorex". Den bærende del 5 kan bestå af ethvert andet stift materiale, metallisk eller ikke-metallisk, og den elastisk deformerbare del kan bestå af andre elastomerer, der er tilstrækkelig faste til at kunne understøtte skallen effektivt, og som samtidig er tilstrækkelig elastisk deformerbar til at kunne tilpasse sig nøje til skallens form. Formparten 3 består ligeledes af en stiv, bærende del 7 med en konisk midter-væg, der er beklædt med en elastisk deformerbar delThe support 2 thus comprises a rigid support member 5, which is cup-shaped with a slightly outwardly inclined side wall, and an elastically deformable member 6, which is designed to close tightly to the outside of the shell 1. The rigid, support member 3 .g. consist of laminated polyester, while the elastically deformable portion preferably consists of a rubber of the polynorborn, sold under the trademark "Norsorex". The support member 5 may consist of any other rigid material, metallic or non-metallic, and the resiliently deformable member may consist of other elastomers which are sufficiently firm to support the shell and which are at the same time sufficiently elastically deformable to accommodate adapt closely to the shape of the shell. The mold part 3 also consists of a rigid, supporting part 7 with a tapered middle wall covered with an elastically deformable part

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4 8, fortrinsvis af polymeriseret siliconeplast, der sælges under varemærket "Silastene", medens den bærende del 7 f.eks. består af lamineret polyester. For at formindske apparatets vægt er formpartens 3 bærende del 7 udformet med et centralt hulrum 9, der er tilsluttet en indsprøjtningskanal 10, der strækker sig gennem den del af den deformerbare del 8, der danner hulrummets 9 bund. Indsprøjtningskanalen 10 er let tilspidset med henblik på, at der kan opnås tæt tilslutning af en ikke vist ledning for tilførsel af forstærkende plast.4, preferably of polymerized silicone plastic sold under the trademark "Silastene", while the supporting portion 7 e.g. consists of laminated polyester. In order to reduce the weight of the apparatus, the supporting part 7 of the mold part 3 is formed with a central cavity 9 which is connected to an injection channel 10 which extends through the part of the deformable part 8 forming the bottom of the cavity 9. The injection channel 10 is slightly tapered so that a tight connection of a non-shown conduit for supply of reinforcing plastic can be obtained.

Understøtningens 2 stive, bærende del 3 har mindst én åbning 11, der tjener til at lette løsgørelse af den deformerbare del 6 fra den bærende del 5.The rigid, supporting part 3 of the support 2 has at least one opening 11 which serves to facilitate the release of the deformable part 6 from the supporting part 5.

Både understøtningens og formpartens deformerbare del 6 henholdsvis 8 har tapformede fremspring 12 henholdsvis 13 til deres fiksering på den bærende del 5 henholdsvis 7, idet fremspringene optages i modsvarende udsparinger i den pågældende bærende del.Both the deformable portion 6 and 8 of the support and the molding portion have tapered projections 12 and 13, respectively, for their fixation on the support portion 5 and 7, respectively, the projections being received in corresponding recesses in the respective supporting portion.

Understøtningens og formpartens bærende dele 5 og 7 er fikseret i forhold til hinanden ved hjælp af bolte 14, der er ført igennem et hul i en flange 15 på understøtningens bærende del og gennem et tilsvarende hul 16 i en flange 17 på formpartens bærende del. Under indsprøjtningen af forstærkende harpiks er de to bærende dele fastgjort til hinanden ved hjælp af f.eks. bolte eller spændestykker.The supporting parts 5 and 7 of the support and the molding part are fixed relative to each other by bolts 14 which are passed through a hole in a flange 15 on the supporting part of the support and through a corresponding hole 16 in a flange 17 on the supporting part of the molding part. During the injection of reinforcing resin, the two supporting parts are attached to each other by means of e.g. bolts or clamps.

Under indsprøjtningen af forstærkende plast i rummet mellem formparten 3 og den termoformede skal 1, udsættes denne for forholdsvis store trykkræfter, der bevirker betydelige spændinger. Da skallen fortrinsvis består af methyl polymethacrylat, er den temmelig skør og derfor udsat for brud eller revnedannelser i områder, hvorDuring the injection of reinforcing plastics into the space between the mold part 3 and the thermoformed shell 1, this is subjected to relatively large compressive forces which cause considerable stresses. Since the shell is preferably composed of methyl polymethacrylate, it is rather brittle and therefore subject to rupture or cracking in areas where

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5 den er utilstrækkeligt understøttet, og hvor spændingerne er kritiske. Det er derfor vigtigt, at skallen understøttes fuldstændigt og ensartet på alle steder, hvilket kun sker, når understøtningen 2 slutter tæt mod ydersiden af skallen, der har en halslignende indsnævring.5 it is inadequately supported and where tensions are critical. It is therefore important that the shell is completely and uniformly supported at all locations, which only happens when the support 2 ends close to the exterior of the shell having a neck-like constriction.

Endvidere er det, for at rummet mellem formparten og skallen kontinuerligt kan have tilnærmelsesvis konstant højde, vigtigt, at formpartens yderflade har en form modsvarende skallens indvendige flade, også for så vidt angår området med den halslignende indsnævring.Furthermore, in order for the space between the mold part and the shell to have a substantially constant height, it is important that the outer surface of the mold part has a shape corresponding to the inner surface of the shell, also with regard to the area of the neck-like narrowing.

Af disse grunde er understøtningen og formparten udstyret med de elastisk deformerbare dele 6 og 8, der bevirker, at de vil tilpasse sig fuldstændigt til skallens form og understøtte skallen ensartet, således at opståede spændinger fordeles ensartet.For these reasons, the support and the molding part are equipped with the elastically deformable parts 6 and 8, which cause them to fully conform to the shape of the shell and support the shell uniformly so that the resulting stresses are distributed evenly.

For at bibringe understøtningens elastisk deformerbare del 6 en form, der slutter nøje til skallen, støbes det elastisk deformerbare materiale på skallens yderside, således at denne dækkes fuldstændigt af et lag gummi af polynorbornen, der er tilstrækkeligt til at udfylde de indsnævrede områder i en tykkelse på mindst 5 mm, og som efter at være stivnet forstærkes med et polyester laminat, der danner den stive bærende del 5, og da det ikke er muligt at forbinde disse to materialer, udformes fremspringene og udsparingerne 12 til indbyrdes fiksering af den elastisk deformerbare del og den stive bærende del.In order to give the elastically deformable part 6 of the support a mold which adheres closely to the shell, the elastically deformable material is molded on the outside of the shell so as to be completely covered by a layer of rubber of the polynorborn sufficient to fill the narrowed areas in a thickness of at least 5 mm, and which, after being stiffened, is reinforced with a polyester laminate forming the rigid support member 5, and since it is not possible to connect these two materials, the projections and recesses 12 are formed for fixing the elastically deformable member to one another. and the rigid bearing portion.

Når dette er sket, beklædes skallens inderside med et kalibrerende lag af voks, hvis tykkelse svarer til tykkelsen af det glasfiberarmerede plastlaminat, hvormed skallen skal forstærkes.When this is done, the inside of the shell is coated with a calibrating layer of wax, the thickness of which corresponds to the thickness of the glass fiber reinforced plastic laminate with which the shell is to be reinforced.

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Endvidere påses det, at der ved fremstillingen af den stive, bærende del 7 af lamineret polyester ikke dannes udsparinger eller halslignende indsnævringer. Silicone harpiks eller et lignende materiale tilføres aggregatet bestående af den skålformede, stive bærende del 5, den elastisk deformerbare del 6 og skallen, der er beklædt med laget af kalibrerende voks. Den stive bærende del 7 trykkes på plads, idet silicone harpiksen tvinges til at flyde langs skallens væg op til det punkt, hvor den flyder ud gennem huller, der findes i den stive bærende del 7, og den fastgøres ved hjælp af boltene 14, der føres gennem hullerne 16 i flangerne 15 og 17.Furthermore, it is ensured that no recesses or neck-like constrictions are formed in the manufacture of the rigid, supportive portion 7 of laminated polyester. Silicone resin or a similar material is supplied to the assembly consisting of the bowl-shaped, rigid support member 5, the resiliently deformable member 6 and the shell coated with the layer of calibrating wax. The rigid support member 7 is pressed into place, forcing the silicone resin to flow along the shell wall up to the point where it flows out through holes found in the rigid support member 7 and is secured by the bolts 14 which is passed through holes 16 in flanges 15 and 17.

Efter polymerisationen skilles apparatet ad, vokslaget fjernes, og hullerne 10 og 11 udformes i formpartens elastisk deformerbare del 8 og i understøtningens stive bærende del 5.After polymerization, the apparatus is separated, the wax layer removed, and the holes 10 and 11 formed in the elastically deformable part 8 of the mold part and in the rigid supporting part 5 of the support.

Den "form", der således er dannet, består af skallen 1 der hviler på den elastisk deformerbare del 6 af poly-norbornen, der igen understøttes af den stive bærende del 5, samt af formparten 3, omfattende den stive bærende del 7, og den elastisk deformerbare del 8, der først føres alene ind i og deformeres i skallen og derefter formes af af den stive bærende del 7.The "mold" thus formed consists of the shell 1 which rests on the elastically deformable portion 6 of the poly-norbornene, which in turn is supported by the rigid support portion 5, and of the mold portion 3, including the rigid support portion 7, and the resiliently deformable portion 8 which is first inserted into and deformed in the shell only and then formed by the rigid bearing portion 7.

Formpartens elastisk deformerbare del 8 indsættes i og udtages fra apparatet ved hjælp af det i fig. 2 viste organ, der blot består af en plade 20, som et centralt rør 22 er ført igennem, og som langs kanten har udsparinger 21 til optagelse af tappe 13 på den elastisk deformerbare del 8 til fiksering af denne på pladen 10. Rørets 22 ene ende er udformet med en keglestubfor-met, lukket spids 23, der passer ind i tilførselskanalen 10 i formpartens deformerbare del 8, og endvidere har røret et hul 24 i dets sidevæg i nærheden af spidsen 23. Den anden ende af røret er tilsluttet en ikke vistThe elastically deformable portion 8 of the molding member is inserted into and removed from the apparatus by means of the device shown in FIG. 2, consisting merely of a plate 20 through which a central tube 22 is passed, and which along the edge has recesses 21 for receiving pins 13 on the elastically deformable part 8 for fixing it to the plate 10. The tube 22 end is formed with a cone-shaped, closed tip 23 which fits into the feed duct 10 in the deformable portion 8 of the mold part, and furthermore the tube has a hole 24 in its side wall near the tip 23. The other end of the tube is connected to a non- shown

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7 vakuumpumpe, og endelig findes der et tætningsorgan 25 til sikring .af, at røret er ført væsketæt gennem pladen 20. Når .apparatet skal lukkes, anbringes form-partens deformerbare del 8 på pladen 20 med tappene 13 indsat i udsparingerne 21 og med rørets ende 23 indsat i indsprøjtningjslkanalen 10, således at denne lukkes, hvorefter rummet 26 mellem pladen og den deformerbare del 8 bringes under delvis vakuum, hvorved den deformerbare del falder sammen, således at dens halslignende indsnævring forsvinder, og at den nemt kan føres ind i skallen. Når dæn således er bragt på plads, er rummet 26 under den omgivende lufts tryk, således at den deformerbare del 8 genindtager sin oprindelige form med den halslignende indsnævring, hvorefter pladen 20 fjernes, og formpartens stive bærende del 7 bringes på plads til vedligeholdelse af den deformerbare dels ønskede f orm.7 a vacuum pump, and finally there is a sealing means 25 for ensuring that the tube is fluid-tight through the plate 20. When the apparatus is to be closed, the deformable portion 8 of the mold member 20 is placed on the plate 20 with the tabs 13 inserted into the recesses 21 and with the tube. end 23 inserted into the injection channel 10 so that it is closed, whereupon the space 26 between the plate and the deformable portion 8 is brought under partial vacuum, whereby the deformable portion collapses so that its throat-like constriction disappears and can easily be inserted into the shell. . Thus, when pads are brought into place, the space 26 is under the pressure of ambient air so that the deformable portion 8 resumes its original shape with the neck-like constriction, after which the plate 20 is removed and the rigid supporting portion 7 of the mold portion is placed in place to maintain the deformable partly desired shape.

Forstærkningen af skallen sker på følgende måde.The shell is reinforced as follows.

Efter at skallen er påført den elastisk deformerbare del 6 af "Norsorex" og sammen med denne er anbragt i den stive, bærende del 5, anbringes der i skallen glasfibermåtter og/eller glasfibre, der er omhyggeligt tilskåret således, at der opnås en beklædning af skallen, hvorefter apparatet lukkes, idet formpartens elastisk deformerbare del 8 og dens stive bærende del 7 anbringes som anført foran, og de to stive bærende dele 5 og 7 fastgøres til hinanden. Det er vigtigt, at apparatet ikke lukkes hermetisk, hvilket kan sikres enten ved, at der fastklemmes fibre mellem formpartens stive bærende del 7 og skallen, eller ved at der dannes fine radiale furer i den flade på den nævnte bærende del 7, der ligger an mod skallen.After the shell is applied to the resiliently deformable portion 6 of "Norsorex" and disposed therewith in the rigid, supporting portion 5, fiberglass mats and / or glass fibers, which are carefully cut so as to obtain a coating of the shell, after which the apparatus is closed, the elastically deformable portion 8 of the molding portion and its rigid support portion 7 being positioned as above, and the two rigid supporting portions 5 and 7 secured to each other. It is important that the apparatus is not hermetically sealed, which can be ensured either by clamping fibers between the rigid supporting part 7 of the mold part and the shell, or by forming fine radial grooves in the surface of said supporting part 7 towards the skull.

Ved hjælp af en sprøjtestøbemaskine indsprøjtes plast under et tryk på mellem 1 og 10 bar gennem kanalen 10 8By means of an injection molding machine, plastic is injected under a pressure of between 1 and 10 bar through the duct 10 8

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i formpartens elastisk derformerbare del 8, idet det påses, at dette sker så langsomt som muligt for at undgå bobler eller blærer og tomrum i glasfibrene samt dannelse af luftlommer, og denne indsprøjtning fortsættes, indtil plasten flyder ud f.eks. gennem de radiale furer i form-partens stive bærende del 7.in the elastically deformable portion 8 of the mold member, ensuring that this occurs as slowly as possible to avoid bubbles or blisters and voids in the glass fibers as well as the formation of air pockets, and this injection is continued until the plastic flows out e.g. through the radial grooves in the rigid bearing portion 7 of the molding member.

Det elastisk deformerbare materiale, hvoraf delene 6 og 8 består, bevirker, at trykpåvirkningen adsorberes, og spændingerne fordeles over skallen, der er ensartet understøttet, således at man undgår dannelse af krakelering og fine revner.The elastically deformable material, of which the parts 6 and 8 are made, causes the pressure effect to be adsorbed and the stresses distributed over the shell, which is uniformly supported, so as to avoid cracking and fine cracking.

Når polymerisationen af plasten er afsluttet, udtages skallen fra apparatet, idet dette åbnes, og formpartens stive bærende del 7 fjernes, hvilket nemt kan ske på grund af delens tilspidsede form. Derefter udtages form-partens elastisk deformerbare del 8 ved hjælp af det i fig* 2 viste organ, og den plastforstærkede skal udtages sammen med understøtningens elastisk deformerbare del 6 fra den skålformede bærende del 5, og sluttelig afkrænges understøtningens elastisk deformerbare del 6 fra skallen.When the polymerization of the plastic is completed, the shell is removed from the apparatus as it is opened and the rigid supporting part 7 of the mold part is removed, which can easily be done due to the tapered shape of the part. Thereafter, the resiliently deformable portion 8 of the mold member is removed by means of the member shown in Fig. 2, and the plastic reinforced portion is removed along with the elastically deformable portion 6 of the support from the cup-shaped support portion 5 and finally the resiliently deformable portion 6 of the support is peeled from the shell.

Fremgangsmåden ifølge opfindelsen gør det muligt at forstærke skålformede genstande, selvom disse er udformet med f.eks. halslignende indsnævringer, og således at man undgår dannelse af krakelering eller fine revner.The method according to the invention makes it possible to reinforce cup-shaped objects, although these are designed with e.g. neck-like constrictions, and thus avoiding the formation of crackling or fine cracks.

Claims

A method of manufacturing an article consisting of a thermoformed shell reinforced by a glass-fiber reinforced plastic layer, characterized in that one outer surface of the shell (1) is placed against an elastically deformable support (6) so designed that it closely adjoins said surface of said shell that an adapted fiberglass reinforcing layer is placed in said shell, so that a mold part (3) having a work surface corresponding to the second outer surface of the shell is inserted into the shell such that there is a free space (4) between the working surface and said second outer surface; that, in a manner known per se, high-pressure plastics are added to this gap, that the plastic is hardened and that the reinforced shell must be released from the support and mold part.

Method according to claim 1, characterized in that the plastic is injected slowly into the space between the mold part and the shell in order to avoid the formation of bubbles, blisters or voids in the fiber layer.

Method according to claim 1 or 2 for reinforcing an article with a recess or a neck-like narrowing, wherein the working surface of the mold part has an elastically deformable part, characterized in that the deformable part collapses when the mold is assembled and separated. ad.

Apparatus for carrying out the method according to the preceding claim, characterized in that it comprises an elastically deformable support (6) adapted to support one outer surface of a thermoformed shell to be reinforced, with a tight abutment against said outer surface. , a mold part having a work surface which is complementary to the shell second outer surface, DK 152566B and which optionally has an elastically deformable part (8), and means (10) for injection of plastic under pressure in the boundary of the mold part and the other outer surface defined by the shell spaces (4).

Apparatus according to claim 4, characterized in that the mold part (3) consists essentially of a rigid supporting part (7) with a downwardly tapered central side wall covered by a removable deformable part (8).

Apparatus according to claims 4 and 5, characterized in that the elastically deformable part (6) of the support consists of polynorbornene rubber.

Apparatus according to claims 5 and 6, characterized in that the elastically deformable part (8) of the mold part consists of polymerized silicone resin.