METHOD AND DEVICE FOR SUCTION OF DELETERIOUS SUBSTANCES AT MANUFACTURE OF LARGE PLASTIC DETAILS

Abstract: Method for production harmless to the environment of large objects of plastic by conventional plastic material application, and where around the application area is placed in adjustable proportion sealing cover (5, 6), and with the area under the cover connected exhaust air terminal devices (4), whereby the plastic application is carried out through an opening (B) in the cover during simultaneous moderate air flow through the exhaust air terminal devices (4), whereby the smallest required opening (B) in the cover for performing of the work is set and during the plastic application work this opening (B) is moved in correspondence to a change of the position of the present application location, and a device comprising a cassette (2) provided with an exhaust air terminal device (4) ending in its interior, and with a cover sealing against the upper edges of the cassette (2) said cover consisting of at least two cover units (5, 6), which are individually movable on the upper side of the cassette (2) between a completely covering and sealing position on the top side of the cassette and to size and position freely settable opening (B).

Description: Method and Device for Suction of Deleterious Substances at Manufacture of Large Plastic Details. The present invention refers to a method and a device for production harmless to the environment of large details of plastic by conventional plastic material application, and where around the application area is placed a sealing cover which is adjustable to its extent, and with to the area connected exhaust air terminal devices, whereby the plastic application is carried out through an opening in the cover, during simultaneous moderate air flow through the exhaust air terminal devices. Background of the invention The industry producing products in reinforced plastic today have great demands of improving both the internal and ex- ternal environment, and for this to be possible the emis¬ sions of styrene have to be reduced. One way to achieve this is to improve previously used pro¬ duction methods or offer new such methods. The application of plastic material traditionally is carried out by spraying and rolling or by manual application, and by filling and inlay of reinforcement fabric or mats and distance material. Production by spraying and laying up is carried out prefe¬ rably in conventional spray boxes, which demand large air flows. This in turn results in a large heating demand, which leads to high heating costs and problems to find sufficient¬ ly low cost gas purifier plants. The object of the invention and most essential features The object of the present invention is to provide a method according to the introductory part of the specification by means of which these drawbacks are eliminated, and which gives a possibility in a simple and reliable way achieve a production harmless to the environment of large details of plastic, with low costs for air transport and heating and this is achieved by setting the smallest required opening in the cover for performing of the work and during the the plastic application work moves this opening in correspon- dence to a change of the position for the present applica¬ tion location. The invention also comprises a device for carrying out the method and the characterizing features of this are apparent from the patent claim 3. Description of the drawings In the following the invention will be described in closer detail with reference to diagrammatically shown embodiments in the accompanying drawings. Fig. 1 shows in perspective view a device according to the invention for the production of a ship body with the method according to the invention. Fig. 2 is a longitudinal section through a variant of the device according to Fig. 1 intended for the production of smaller objects. Fig. 3 shows a view from the end of a modified design of the device according to the invention. Fig. 4 is a lateral view of the device according to Fig. 3. Fig. 5 shows a view from the above of the device according to Fig. 3. Fig. 6 is a perspective view of the device according to Fig. 3. Fig. 7 and 8 show in perspective view two different designs of a supply air terminal device contained in the device according to the invention. Fig. 9 shows in perspective view an alternative embodiment of the device according to the invention. Fig. 10 shows a further alternative of covering for the device according to the invention. Fig. 11 shows in a diagrammatic sectional view of still an embodiment of the cover for the device according to the invention. Fig. 12 shows diagrammatically the device according to the invention connected to an air circulation system. Fig. 13 shows diagrammatically in a view from the above a device according to the invention with circular basic form, and Fig. 14 in a diagrammatical sectional view a further modification where the device is designed in the shape of a hangar. Description of preferred embodiments The invention is illustrated in Fig. 1 in connection with production of a ship body by means of a body form 1, around the open side of which is arranged a frame formed casette 2, which in the example shown is rectangular and completely encloses the open side of the form. At the opposite short sides 3 of the casette 2 are provided exhaust terminal devices 4 connected to a plant not shown by means of which the exhaust air is cleaned and out of which heat can be retrieved. The upper open side of the casette 2 in the example shown is provided with two covering units 5, 6, e.g. in the form of flexible webs, e.g. cloths of polytetrafluorethene or the like which are individually windable on rolls provided in parallelepipedical housings 7, 8, which extend over the opening of the casette in the cross direction, and which can be driven in the longitudinal direction of the casette on the longitudinal edges driven by separate electric motors 9, 10. The housings 7, 8 are preferable provided with illumina¬ tion 11. When the device is used, the housings 7, 8 by means of the motors 9,10 are placed at a mutual distance, which is adap¬ ted after least possible space which is needed in order to reach the inside of the form 1 by passing the free opening between the houses 7, 8 to put in reinforcenent, distance material and the like and to apply plastic material by means of spraying or a wetting roll (not shown). Thereby the size of the opening between the housings 7, 8 can be varied between maximum opening, where each housing is located at the opposite short sides 3 of the casette 2, and a complete¬ ly closed opening where the housings 7, 8 are placed against each other, and where the covers 5,6 thereby cover the whole opening. This position (not shown) preferably can be used when the object is going to cure after terminated material application, whereby also the flow velocity in the exhaust terminal devices preferably can be reduced. Since the both housings are individually movable on the upper side of the casette, it is not only possible to vary the size of the opening, but also to vary the position of the opening such that the mininum necessary work opening can be moved from a short side of the plastc application area, that is the inside of the form, to the other short side under maintai¬ ning of the size of the opening, or if required with a change of the size of the opening. The size of the opening B preferably can be controlled automatically to an empiri¬ cally appropriate value and the position of the opening along the length of the casette preferably is controlled by photo cells not shown or similar sensors in relation to the movements of an operator or the movements of a working tool. By practical tests it has shown that at manual work such as spraying it is sufficient with a work opening of about 3m length, and it has also shown, that the concentration of styrene just outside the casette at such a large opening is about a tenth of the corresponding concentration if the work is carried out in a completely open form, an this with an air flow in the exhaust air, which corresponds 10 - 20 % of the air flow in an equivalent spray box. In Fig. 1 is illu¬ strated with the the arrows A how the air in the room where the device is placed is sucked in through the opening, which is designated B and thereby gives as laminar air flow as possible, which to a great extent prevents the styrene vapor to leave the casette 2 and the form 1 through the opening B between the cover units 5, 6. Through the lighting 11 ar¬ ranged on one or on both housings 7,8, a satisfactory ligh¬ ting of the working area is obtained irrespective of the movement of the same in the longitudinal direction of the body form. In Fig. 2 is shown a longitudinal cross section of a modifi¬ ed design of the device according to the invention, whereby the casette 2 cooperates with a box-shaped space 12, which corresponds the body form 1 in the embodiment according to Fig. 1 and in which space is indicated the objects 13,14,15 produced which are fixed in the space. In this case the form itself does not constitute part of the closed space, such as in the case according to Fig. 1, but for the rest the corre¬ sponding details with corresponding reference designations are of similar design. As can be seen from this view, the covering units 5a,6a, are located at a distance above the air terminal exhaust devices 4, which has shown to be impor- tant not only in this embodiment, since in the exhaust air there will be turbulence caused by the spraying if the cover is close to the air terminal exhaust devices. However, by locating the cover at a distance above the air terminal exhaust devices a disturbance free laminar flow is obtained. The cover units 5a, 6a in this case are designed differently from those in Fig. 1 and here is of a type, which will be described in closer detail in connection with Fig. 10. In fig.3,4 and 5 is shown an end view, a side view and a view from the above of a device suspended in a rack 16 according to the invention, whereby the rack 16 in the example shown extends between floor and ceiling and compri¬ ses U-formed beams (see Fig. 5). The rack as well be free¬ standing which means that the device can be placed freely. On the short sides of the device, which comprises the caset¬ te 2 and the body form 1, turn discs 17 are fixedly provided thereto, with shaft pivots extending therefrom, which are guided in the space between the shanks of the U-formed beam 16. The turn discs 17 are suspended in wires 19, which are guided over rolls 20 on longitudinal shafts 21, of which at least one is driven by a motor 22, by means of which the unit consisting of the body form 1 and the casette 2, with components connected thereto is vertically adjustable and moreover turnable about the shaft pivots 18 to give the operator an ergonomically correct working posture. The covering units 5 and 6 correspond to those shown in Fig. 1, however their winding mechanism is modified with respect to the embodiment according to Fig. 1, in that the housings 7a and 8a only contain lighting and air supply terminal devices, while the winding mechanisms 23 instead are placed at the short sides of the casette. In these figures is also illustrated the arrangement of flexible sealings 24 provided to seal between the casette 2 and the body form 1, which reduces the risk of leakage of an atmosphere abundant of solvent. In Fig. 6 is illustrated in perspective view and diagram¬ matically how the device according to the invention compri¬ sing the body form 1 and the casette 2 can turned in the rack 16 about the longitudinal mid axis, by means of the control system 17-22 according to Fig. 4, such that the opening B through which the working area is reached, can be located in a position which makes that the person, which is going to do the work can work in a normal and comfortable posture. Fig. 7 and 8 diagrammatically illustrate how the housing 25, which houses rolls for the windable covering units in accor¬ dance to Fig. 1 or lighting as well are designed as air supply terminal devices in accordance to Fig. 3, whereby in the case according to Fig. 7 nozzles 26 are directed inwards against the opening B between the housings 25 while in the case according to Fig. 8 slots 27 are directed in the same way, whereby in both cases at one side of the housings are provided each a ducted fan 28, which gives a suitable supply air velocity. By using such supply air terminal devices it can be achieved that a reflection of styrene vapor is block- ed, simultaneously reducing the wake space that results behind an operator, who stands in or just outside outside the opening, to a minimum. Fig. 9 in a perspective view obliquely from the above illu- strates a device according to the invention with a modified design of the covering units 29, 30, which in the figure are shown as foldable doors, but which can also be of roll-front door type. Fig. 10 diagrammatically illustrates a part of a covering unit 32 of the type which is diagrammatically indicated in Fig. 2 and which consists of a number into each other tele- scopically displaceable and along the upper side of a caset¬ te movable partial sleeve formed elements 33, 34, 35. In connection to the front element 35 there is provided a beam 36 running in the cross direction which may be attached to the front element or be individually movable on the upper longitudinal edges of the casette not shown in this figure and constitute a running path for a robot not shown in the figure, which robot thus can be moved together with the beam 36 in the longitudinal direction and be drivable on the beam 36 in the transversal direction, so that the robot easily can reach and operate over the whole temporary opening area. In Fig. 11 is illustrated in a cross section through the cover diagrammatically an alternative design of an easily robotizable device according to the invention. In this case the cover is divided by two longitudinal beams 37, which extend centrally in the longitudinal direction over the whole casette 2 and between themselves form a slot. Hereby the cover is divided, which can be of the same type as that shown in Fig. 10 in a number of L-shaped, telescopi- cally into each other sliding elements 38, which each extend over half the width of the casette, whereby every single element 38 is individually settable, so that the openings at each sides of the beams 37 can have different positions and /or size according to present requirements and desiderata. The top side of the beams 37 are made as a running path for a carriage 39 which can be driven in the longitudinal direc¬ tion of the beams, which carriage supports a robot 40, which extends through the slot between the beams 37, down into the space under the cover 38. The robot 40 thereby can be driven along the whole extension of the device and thereby serve the whole working area irrespective of the position of the opening or the degree of opening settable by the covers 38. The under side of the beams 37 preferably can be provided with lighting ramps 41, which preferably can be mounted with UV-lamps for setting of UV-setting plastic material. In Fig. 12 is diagrammatically illustrated how a device according to the invention comprising a form 1, and a caset¬ te 2 with cover elements 5,6, which in the position shown are completely closed, is connected to a closed cycle in that one of the exhaust terminal devices 4 is connected to a hose 42 with a pump 44 or the like, which transports the exhaust air through the hose and with a heat exchanger 43, by means of which the air can be supplied with heat or cooled according to requirements, and which hose returns the air through the other exhaust terminal device 4a, which in this position serves as an air intake. This function can be used when the product is going to be cured, whereby e.g. plastic materials can be used which cure only at elevated temperature, e.g. at + 30°C, whereby during the plastic applying process at room temperature there is no risk of premature and uneven curing, and thus after finished ap- plying work the cover units can be closed, and 30°C preheated air kan be fed in a closed cycle, whereby the curing starts. In Fig. 13 is shown diagramatically in a view from the above how the device instead of the rectangular base form, which has been shown in previous designs, can have a circular base form where the cover elements are constituted by sector formed elements 45, which are individually turnable movable around the center of the device to over or under lapping of adjacent elements, so that one or several openings B can be provided in an optional position around the periphery of the device, and there optionally the underlying construction can be rotated so that different parts thereof come just in front of an opening or the person which carries out the plastic application can walk around the device concurrently with the advance of the application work. Finally Fig. 14 illustrates in cross section a further embodiment of the device, where the cover provided on the casette 2 has a shape of a hangar and consists of two quar¬ ter circular elements 46, 47, of which at least one and preferably both are pivotable and slidable towards the other in a way that is illustrated by arrows, so that an opening through which the inside of the casette can be reached, can be provided on optional side oft the device. The invention is not limited to the embodiments shown in the accompanying drawings and in connection thereto described embodiments but modifications are possible within the scope of the following patent claims.

Claims: CLAIMS 1. Method for production harmless to the environment of large objects of plastic by conventional plastic material application, and where around the application area is placed in adjustable proportion sealing cover (5,6; 5a,6a; 29,30, 30;32 ;38), and with the area under the cover connected exhaust air terminal devices (4), whereby the plastic application is carried out through an opening (B) in the cover during simultaneous moderate air flow through the exhaust air terminal devices (4), c h a r a c t e r i z e d t h e r e i n that the smallest required opening (B) in the cover for performing of the work is set and during the the plastic application work this opening (B) is moved in correspondence to a change of the position of the present application loca¬ tion. 2. Method according to patent claim 1, c h a r a c t e r i z e d t h e r e i n, that about the application side is provided a casette (2) with a number of movable arranged cover units (5,6;5a, 6a;29,30;33,34,35;38) thereon and that these cover units are individually moved to simultaneously set the size of and the position of the opening (B) along the entire length of the casette (2). 3. Device for production of large objects of reinforced plastic, whereby an object in a conventional way is built up by application of plastic material, in accordance to the method according to the patent claim 1, c h a r a c t e r i z e d t h e r e i n, that the device comprises a casette (2) provided with an exhaust air terminal device (4) ending in its interior, and with a cover sealing against the upper edges of the casette (2) said cover consisting of at least two cover units (5,6;5a, 6a;29,30;33,34,35;38), which are individually movable on the upper side of the casette (2) between a completely covering and sealing position on the top side of the casette and to size and position freely settable opening (B). 4. Device according to patent claim 3, c h a r a c t e r i z e d t h e r e i n, that the covering units each are provided with flexible material paths, which are windable from the opposite short sides (3) of the casettes to individual extent, in order to form said opening (B) between its opposite edges. 5. Device according to patent claim 4, c h a r a c t e r i z e d t h e r e i n, that each cover unit (5 respectively 6) is provided with an accompanying housing (7 respectively 8) provided in the cross direction of the casette, which housings each support a roll for winding on and unwinding from the roll of web of the cover unit during its movement in the longitudinal direction of the casette. 6. Device according to patent claim 5, c h a r a c t e r i z e d t h e r e i n, that the housings (7,8) of the cover units are provided with individual motors (9 respectively 10) for movement of the housings along the casette (2) for winding and unwinding respectively of the cover units (5,6). 7. Device according to patent claim 3, c h a r a c t e r i z e d t h e r e i n, that the cover units are constituted by a number of stiff material discs (5a,6a;33,34,35;38) arranged during covering of the top side of the casette (2) moved overlapping each other or telescopically slidable in the longitudinal, cross or in the rotational direction for setting and movement of said opening (B). 8. Device according to patent claim 7, c h a r a c t e r i z e d t h e r e i n, that the top side of the casette (2) shows a path (36;37) for supporting a processing robot (40) drivable along the path. 9. Device according to patent claim 8, c h a r a c t e r i z e d t h e r e i n, that the path is constituited by a beam (36) running in the cross direction of the device. 10. Device according to patent claim 8, c h a r a c t e r i z e d t h e r e i n, that the path is constituted by centrally positioned beams (37) running longitudinally in the upper part of the casette (2), which divides the upper part of the casette (2) into two parallel covers (38). 11. Device according any of the patent claims 5 to 10, c h a r a c t e r i z e d t h e r e i n, that at the cover elements (5,6;5a,6a;30,31;35,38) limiting the opening (B) there is provided supply air nozzles (26,27) provided to direct supply air flow in an optimal way towards the opening (B). 12. Device according any of the patent claims 3 to 11, c h a r a c t e r i z e d t h e r e i n, that the casette (2) with its side turned away from the covers is connected to a closed space (1, 12) containing the plastic application area. 13. Device according to the patent claim 12, c h a r a c t e r i z e d t h e r e i n, that the closed space (1) is constituted by a form which internally is going to be covered by plastic material, e.g. a ship body form. 14. Device according to any of patent claims 3-13, c h a r a c t e r i z e d t h e r e i n, that the device is provided with sensors, such as photo cells, arranged to control the positions of the covering units. 15. Device according to any of patent claims 3-14, c h a r a c t e r i z e d t h e r e i n, that in connection to the side of the casette facing plastic application area there is provided lamps (11,41) intended for lighting and/or curing purposes. 16. Device according to any of patent claims 3-15, c h a r a c t e r i z e d t h e r e i n, that the device via an outlet acting as an exhaust terminal device (4) and via an inlety acting as a supply air terminal device (4a), is connectable to a closed air cycle (42), with means (43)for temperature control of the supply air during the complete closed position of the cover (5,6).

Inventors: MAUPOIX MAX, PALMERS GOERAN, MAUPOIX, MAX, PALMERS, GOERAN
Applicants: INST VERKSTADSTEK FORSK IVF, INSTITUTET FOER VERKSTADSTEKNISK FORSKNING
Application year: 1991
Main classification: B29C41
IPC codes: B05B15, B29C35, B29C37, B29C41, B29L31