ARRANGEMENT COMPRISING PLASTIC INGREDIENTS AND REINFORCEMENT

Abstract: An arrangement or a semi-manufactured item comprises plastic ingredients (6) and reinforcement contained inside a tightly sealed plastic film cover (5). Said ingredients consist of a based material contained inside the cover in a moisture-proof fashion together with the appropriate initiator and activator for polymerization to nylon-6 or nylon-6 copolymers. Polymerization is capable of being initiated at a temperature considerably above the temperature or the temperatures achieved during the manufacture and storage of the arrangement.

Description: TITLE OF THE INVENTION - - - Arrangement comprising plastic ingredients and reinforcement. TECHNICAL FIELD '* The present invention relates to an arrangement comprising 5 plastic ingredients and reinforcement enclosed inside a tightly sealed plastic film cover in which the ingredients are intended to assume a de-activated condition, in which a chemical process for the transformation of the ingredients into a finished plastic material is not initiated, and an activated condition, in 10 which the process is initiated. DESCRIPTION OF THE PRIOR ART Previously disclosed, for instance in European Patent Application 17^52, is the method of enclosing plastic material containing a cure system which will commence to function as soon as initiation 15 takes place via suitable initiation organs, whereby the intended curing process will be achieved. DESCRIPTION OF THE PRESENT INVENTION TECHNICAL PROBLEM A number of advantages are achieved by enclosing plastic 20 _ ingredients inside a tightly sealed plastic film cover. This will permit a centralized production of the environmentally harmful factors, more simple handling procedures than are required, for example, with SMC materials Sheet Moulding Compounds) due, aroπgst other things, to the fact that the - t 25 ingredients are packed in individual portions. The accurate weighing-out of the relative proportions of the plastic ingredients and minimal waste, etc. can be achieved. The need exists, however, in the case of this type of sem -manufactured item which is capable of being initiated into the activated condition with the help of heat, to be able to achieve a bettep distinction between the de-activated and the activated conditions of the arrangement so as to avoid the p isk of accidental activation taking place. There is also a requirement fop semi-manufactured items which remain stable du p ing ' storage and which contain a high level of p einfopcement in ordep to ppoduce strong and durable finished products. • SOLUTION The principal object of the present invention is to propose an " arpangement which, amongst othep things, will solve the ppoblem outlined in the fopegoing. What may essentially be regapded as the cha p acte p istic feature of the novel arrangement is that the plastic iπgpedients consist of a base material contained inside the plastic film covep in a moistupe-ppoof fashion together with the apppoppiate initiator and activator fop polymepization to nylon-6 OP nylon-6 copolyme p s, whereby polyme p ization is capable of being initiated only at a tempe p atuPβ, fo p instance of about 150 C, which is considerably highep than the te pβPatupe OP the tempe p atu p es achieved du p ing the manufactu p e and storage of the appangement. In fupthe p developments of the idea of invention it is proposed that the reinforcement, ppefe p ably being glass fibre reinforcement, shall comprise long fibres and/or one or more continuous and possibly braided fibre mats (roving). The reinforcement should then preferably account for about 30 per cent by weight of the total wβϊght of the arrangement. The arrangement should preferably also be of relatively thin execution, for example 1-3 mm in thickness. In one preferred embodiment the plastic film cover is made of nylon. In a second preferred embodiment the cover is made of OMPI polyolefine, polyester or fluorinated vinyl polymer. The plastic film is comparatively thin, preferably between 0.02 and 0.2 mm in thickness. The base material is also metered in order to compensate for shpinkage due to polymepization. Othep fu p the p developments of the idea of invention ape concerned more with the st p uctupe of the a p pangement. Thus, in a p p efep p ed embodiment, the composition of the ingredients of the unit, the geo et p ical position of the ingredients inside the unit and the external fo p m of the unit must be determined with great accuracy in the cou p se of the manufactupe of the unit, which may be achieved by the use of a computep-cont olled production ppocess. The plastic covep may be papt of OP may be separated fpom the unit when it is activated OP transformed into a finished ppoduct. The unit may be executed with intepnal walls OP with internal pockets and/o p may be provided with an inner unit which, fo p the purpose of separation, encloses those ingredients which ape to fo p papt of said chemical ppocess when the unit is activated. ADVANTAGES The proposed a p pangement provides advantages, amongst other things in the area of manufactupe. The base material is liquid at temperatures in excess of 69 C, and polymerization will only occur at a temperature of about 140 C. The base material may be brought during manufacture to a temperature, for instance of about 70-75 C, which is not critical from the point of view of polymerization. At said temperature a glass fibre mat, for example, may be dipped into or sprayed with the base material , containing an initiator and an activator. At ambient temperature C20-25°C) the material will have solidified, and an essentially dry and rigid filling can then be enclosed by the thin plastic film cover. Transport and storage are simplified in this way. "BUREA OMPI The proposed arrangement also enables a finished product to be produced in nylon-6 or nylon-6 copolymers with long fibres (glass fibre) or continuous and possibly braided fibre mats (in glass). Until now it has been possible to execute the reinforcement in nylon-6 products only in the form of m llimetre-thick glass fibres. Moisture-proof enclosure can be provided with the help of a vacuum chamber inside which the humidity level is kept down by the use of low pressure, for example 0.1-0.3 bar. Enclosure can also make use of an inert gas (nitrogen gas), if necessary in combination with the use of a vacuum chamber. The finished product is then conditioned in order to produce increased tenacity (toughness) in -the material. If so desired, a very advantageous external structure can be achieved which does not require any further processing, for example in the form of grinding, washing and/or cleaning, but which may be painted or finished in some other way directly. The characteristics built into the unit in the course of its manufacture mean that it can be stored for lengthy periods (in some cases for a number of months). In. the event of manufacture taking place inside a vacuum chamber a very high degree of freedom from air bubbles will be achieved in the finished product, which offers particular advantages in the area of, amongst other things, the manufacture of components which will subsequently be subjected to surface treatment, for example painting at high temperature, when air bubbles would otherwise appear and cause local porosity in the material. The foregoing also means that components which previously had to be produced from sheet and metal, for example within the automobile and marine industries, can now be produced either entirely or in part from plastics. This also means that much 'BU EA OMPI W of the rust problem encountered, for instance, within the automobile industry can now be resolved, and that the noise level associated with the production of such components can be reduced. DESCRIPTION OF THE DRAWINGS Preferred embodiments of an arrangement in accordance with the invention are described below with reference to the accompanying drawings, in which: Figure 1 shows a perspective view seen from above and from the right of a first arrangement or a semi-manufactured item, and of an identical arrangement joined to said first arrangement and illustrated in part only; Figures 2a-2b * show respectively a horizontal and a side view of a second arrangement; Figure 3 shows in vertical longitudinal section a low-pressure chamber inside which the production of a semi-manufactured item can take place; and Figures 4a-4b show in diagrammatic form the underlying principle of a production line for a third arrangement. DESCRIPTION OF THE PREFERRED EMBODIMENT Figure 1 shows two arrangements or units 1 and 2 applied to a base U , said arrangements or units being joined together by means of a connecting piece 3 and 4 along one edge of each.unit. The units may also be separate or connected to other units. Each unit is represented as a polygon, in particular as a square or rectangular unit having a length L , a width 8 and a thickness H . The thickness is selected so as to permit thin finished products to be produced having a thickness preferably of between 0.5 and 5.0 mm, and in particular of between 1 and 3 mm. The unit may, however, be tailor-made (p p e-moulded) fop each particular application and may accordingly exhibit othep shapes depending on the intended application. Each unit comppises a thin (e.g. 0.02 - 0.2 mm) covep of plastic material, pefepped to here as a plastic film cover 5 , and ingredients 6 contained inside the plastic covep and so a p panged that, with the unit in its storage OP tpanspopt position, they do not take part in a mutual chemical reaction fop the purpose of producing a finished plastic material, and that, with the unit in an activation and utilization position initiated by means of an activation process, they take part in said chemical reaction. When viewed from the outside, each unit may be executed in a mope OP less p igid form depending, amongst othep things, on the viscosity of the enclosed ingredients and on any peinfopcement. The plastic covep 5 encloses the ingredients 6 in an essentially aip-tight condition and, in the embodiment shown hepe, in an aip-evacuated condition. The type of the plastic cove p may vary depending on whethep the covep is to be included as part of the finished plastics matepial OP is to be used as a means of protection in, amongst othep things, moulds which will possibly be used fo p the final moulding of and/op fop combination with some othe p part of the unit. The covep which, as a general rule, will be wished to be flexible, may be selected from amongst the following groups of materials, for example: the polyolefins, the polyamides, the polyesters or the fluorinated vinyl- polymers. The plastic cover is welded or is joined in some other fashion (e.g. by glueing) around its outside edges, of.. which 3, 3a and 3b are shown here. The plastic film must be capable of being glued or welded and must as a rule be capable of being stretched- and must exhibit low permeability by liquid ingredients. The plastic covep may in a typical embodiment be executed with bappiep walls and pockets fop the purpose of forming various spaces inside the unit. This will enable different ingredients to be kept separate inside the various spaces. On the aforementioned activation taking place, which may involve activation by compression, thesH walls will rupture, causing the ingredients to mix, and the chemical reaction can then be initiated by the supply of external heat. A barrier wall of this kind is indicated as a broken line by the reference designation 7 . The plastic cover itself may also be double, whereby the first (outer) plastic cover is given a first characteristic and the second (inner) plastic cover is given a second characteristic. Each unit is a geometrical fit with, or can be made to fit the shape of the object or the addition to said object which the unit is to form. Figures 2a and 2b illustrate typical examples of the unit E which has been pre-moulded during manufacture so as to provide a good fit with the final shape of, for example, a chair. The edge E* may be welded or gl ed.together in a previously disclosed manner using previously disclosed welding or glueing organs S . The quantity of material which the unit represents or includes is in itself sufficient to form the object OP the addition. It will be necessary to waste only a small amount of matepial. The distribution of the ingredients inside the unit is provided (controlled) ppefepably at an optimum level in the course of manufactupe, which is also true of the composition of the ingredients. It is possible in this way, for example, to place reinforcements A in their precise positions inside the unit, which is thus able to exhibit first parts (A') with a first ingredient composition and second parts D with a second ingredient composition. This is true both in the horizontal .. and in the vertical plane. Figure 3 illustrates a more detailed example of the construction and manufacture of the unit. The unit should be produced in an essentially moisture-free environment preferably inside a " ' BUKEΛT/' OMPI " chamber 8 at a pressure well below atmospheric pressure, e.g. about 10-30 kpa (0.1 - 0.3 bar) or below. The entrapment of moisture and air is eliminated to a very great extent in this way. The unit in accordance with the invention will form a reinforced (glass fibre-reinforced) semi-manufactured product in nylon-6 or r' in a nylon-6 copolymer Onto a film 9 of nylon-6 or a similar material are Laid one or more thin glass fibre mats prepared beforehand in an appropriate manner. Said mat or mats are impregnated with monomer/monomers, an initiator and an activator for the polymerization reaction. Sefore impregnation takes place, the materials are heated to bring them to a suitable viscosity, for example to a temperature of 70-75 C. Impregnation may then take place by spraying, for example by means of the sprayer organ 12 , or by dipping. Once the glass fibre mat has been coated with the aforementioned ingredients it is cooled, causing the coated material to soHdffy, thereby, producing a- relatively dry and rigid, impregnated glass fibre mat. It is, of course, possible to build up in accordance with the above several layers of the impregnated glass fibre mat. Similarly, the impregnation of the fibre-glass fabric or the glass fibre mat may take place before the preparation operation. Once the desired number of glass fibre mats has been laid-up and impregnated, a film 13 of nylon-6 (in accordance with the above) is laid on top. Said upper and lower sheets 9, 13 are then joined together, either by welding or by glueing, so as to form a tightly sealed cover. The welding organs and/or the glueing organs 14a, 14b and 15a, 15b may be executed from previously disclosed elements and are so arranged as to be capable of being moved around the peripheral-- edge of each semi-manufactured item. The organs 14a, 14b and 15a, 15b are also capable of being moved in other directions towards and away from each other. A base for the film 9 is indicated by the reference designation 16 and clamping organs for the films are indicated by the reference designations 17a, 17b and 18a, 18b . The film - 13 is capable of being unrolled over the finished laminate by means of an organ 19 , fop example an unpolling opgan capable of being moved ovep the laminate. The flow of matepial leaving the application opgan 12 is indicated by the pefepence designation 20 . The end 13 of the film is shown by means of a broken line. The chambep is provided with aip evacuation equipment 21 and 22 • which also incorporates aip de-humidification organs 21a, 22a and tempepatupe-contpolliπg equipment 21b and 22b of a previously disclosed kind. The parts of the equipment 21 and 22 ape joined togethep via a line 23 which extends through the wall of the chambep 8 . Material containers 24 fop the base material and fop the initiator and the activatop a p e connected via the line 25 . The * opgan 12 can be controlled by a robot 26 in a previously disclosed fashion in various directions 27a, 27b . Fibre mats 10, 11 and film 9, 13 can be introduced via a doop 8a in the chambep. By appanging fop the enclosupe operation to take place uπdep high negative ppessupe, the finished material can be made to contain only vepy small quantities of entrapped gas, fop example not mope than of the o p dep of 0.5 pep cent by volume, and fop example 0.2-0.3 pe p cent by volume of the total volume of the unit. The chamber is able, as an alternative to the moistupe-fpee enclosure environment, to fopm by means of negative pressure and the aip evacuation organ an enclosure environment containing an inert gas, for example nitrogen gas, which eliminates the problems associated with entrapped moisture. The equipment 21,22 may, either as an alternative or in addition, incorporate organs 21c, 22c to guarantee the supply of the nitrogen environment into the chamber. Since the selected materials are not subjected at any stage during manufacture to a temperature sufficiently high to initiate the polymerization reaction, the risk of the premature polymerization or activation of the unit is eliminated. The initial temperature at which said polymerization will usually begin is about 1 0-150°C. Polymerization will start, therefore, when the unit and its "BUREA OMPI Λ ια contents are heated to the temperature referred to above. The unit is easily moulded into a product, since all the materials apart from the glass fibre mat become liquid at temperatures in excess of 69°C. The expression monomer used in connection with nylon-6 shall be understood to denote ε -caprolactam in this context. The expression initiator denotes a compound from one of the following groups: the alkali metals; the alkali earth metals; the oxides, hydrides or alcolates of the last-mentioned metals; or their compounds with the lactams, in this case sodium caprolactamate. The expression activator is used in this context to dunote an acylatiπg compound, in this case a prepolymer isocyanate. When metering the quantities of said ingredients supplied to the unit (impregnation of the glass fibre mat) allowance must be made for the shrinkage which occurs during the polymerization reaction. The pre-forming of the unit into a finished product or an addition may take place at low pressure in a simple mould. One requirement associated with this is that the mould shall be capable of being heated to the temperature at which the polymerization reaction will start and will continue in a satisfactory manner, in this case about 140 C. Heatable moulds of this kind have already been disclosed and do not, therefore, require to- be discussed in any more detail here. When using nylon-6 copolymers, use may be made of the complete systems which are generally available on the market, for example a system marketed by Monsanto under the name Nyrim 2025 MG. The unit may, in accordance with Figures 4a-4d, also be used in the production of a semi-manufactured item, for example for a door with windows. A sheet 28 of nylon-6 (Cappan ER 20) is vacuum-fo p med to the appropriate initial dimensions of a semi-manufactuped blank fo p a doop 29 , the outline fop the window of which is indicated by the reference designation -30 . O PI . , This operation may be pepfop ed at a fipst station. The peinfopcement matepial 31 which has been given a shape corresponding to the shape of the door is applied to the vacuum-formed sheet at a second station. The pre-forming of the reinforcements 31 may be done separately by means of stamping or by layer cutting or by some other previously disclosed method. Hoses 32, 33 or similar are applied to the components in question at a third station. A covering sheet 48* of the same nature as the bottom sheet is then positioned over the components and the hoses 32, 33 . The top and bottom sheets are then welded or glued along their edges 39 . The sheets are then stamped or cut in such a way that the unit in accordance with Figure 4c is produced. The hose 33 is then connected to a vacuum pump 34 and the hose 32 is connected to a connector unit 35 for a nylon monomer containing an initiator and an activator. Once the unit 36 has been filled with the monomer/monomers in question, the hoses 32, 33 are sealed, for example by welding, so that the cover formed by the top and the - bottom sheets encloses the ingredients contained therein under essentially moisture-proof and, if necessary, air-evacuated conditions. The sheet may simply be caused to weTd together with the laminate contained inside it by raising the temperature during hardening to 200-220 C. In order to prevent adhesion in the mould in this case, double sheets may be used, whereby the outer sheet shall exhibit a melting temperature in excess of the last-mentioned temperature. The proportion of the reinforcement present may assume values of up to about 30 per cent by weight. As an alternative to or in addition to said continuous fibre mats, use may be made of long fibres, for example of glass, of about 25 cm in length or longer. The arrangement or the semi-manufactured item may be given a lengthy storage capacity, for example several months, enabling the arrangement or the semi-manufactured item to be stored and handled under ordinary ambient temperature conditions. Finish-formed plastic material is conditioned so as to produce a certain amount of toughness i-n the material. The present invention is not restricted to the embodiments specified above by way of example, but may undergo modifications within the context of the following Patent Claims and the idea of invention. "BU AU OMPI

Claims: PATENT CLAIMS 1. Arrangement comprising plastic ingredients (6) and reinforcement (10, 11) contained inside a tightly sealed plastic film cover (9, 13) in which the ingredients are intended to adopt a de-activated condition, in which a chemical process for transforming the ingredients into a finished plastic material is not initiated, and an activated condition, in which the process is initiated, c h a r a c t e r i z e d in that the plastic ingredients consist of a base material (20) contained inside the plastic film cover in a moisture-proof fashion together with the appropriate initiator and activator for the polymerization of nyloπ-6 or nylon-6 copolymers, whereby polymerization is capable of being initiated only at a temperature, for instance of about 130-150 C, which is considerably higher than the temperature or the temperatures achieved during the manufacture and storage of the arrangement. 2. Arrangement in accordance with Patent Claim 1, c h a r a c t e r i z e d in that the reinforcement, preferably being of glass, comprises long fibres, for instance fibres of at least 25 mm in length. 3. Arrangement in accordance with Patent Claim 1 or 2, c h a r a c t e r i z e d in that the reinforcement, preferably being of glass, comprises one or more continuous and possibly braided fibre-glass mats. 4. . Arrangement in accordance with Patent Claim 1, 2 or 3, c h a r a c t e r i z e d in that the reinforcement accounts for about 30 per cent by weight of the .total weight of the arrangement. 5. Arrangement in accordance with any of the preceeding Patent Claims, c h a r a c t e r z e d in that together with its reinforcement it is sufficiently thin to permit a material thickness for a finished product which is between 0.5 and 5.0 mm in thickness, and preferably 1-3 mm in thickness. 6. Arrangement in accordance with Patent Claim 1, c h a r a c t e r i z e d in that the plastic film cover is executed in nylon and is preferably between 0.02 and 0.2 mm in thickness. 7. Arrangement in accordance with Patent Claim 1, c h a r a c t e r i z e d in that the plastic film cover is executed in polyolefine, polyester and/or fluoriπated vinyl polymer and is preferably between 0.02 and 0.2 mm in thickness. 8. Arrangement in accordance with any of the preceeding Patent Claims, c h a r a c t e r i z e d in that the base material is metered in order to compensate for shrinkage due to polymerization.

Inventors: CHRISTENSEN JAN, CHRISTENSEN, JAN
Applicants: ROVAC AB, AB ROVAC
Application year: 1983
Main classification: B29G7
IPC codes: B29B11, B29B15, B29C37, B29C70, B29K77, B29L31, C08J5