COLOSIO, Livio (Via Ugo la Malfa 4, Provaglio D'iseo, I-25050, IT)
| Claims 1. A method for realising products made of plastic material comprising a step of applying, to at least a portion (2a) of a product (2) made of a plastic material, at least a layer of protective coating (5) comprising a nano-ceramic material. 2. The method of claim 1, comprising a step of entirely coating the product (2) made of a plastic material with the layer of protective coating (5). 3. The method of any one of the preceding claims, wherein the step of applying at least a layer of protective coating (5) comprises a step of spraying the nano- ceramic material on the portion (2a) of the product (2) and/or a step of dipping the portion (2a) of the product (2) into the nano-ceramic material and/or a step of painting the portion (2a) of the product (2) with a paint comprising nano- ceramic material. 4. The method of any one of the preceding claims further comprising a step of heating at least the portion (2a) of the product (2) of plastic material with the layer of a protective coating applied in order to sinter the protective coating (5) made of nano-ceramic material. 5. The method of the preceding claim wherein the step of heating is performed at a temperature comprised between 180°C and 400°C or at a temperature comprised between 190°C and 300°C, or at a temperature of between 200°C and 250°C and/or is performed for a duration comprised between 5 minutes and 60 minutes, for a duration comprised between 10 minutes and 40 minutes or for a duration comprised between 15 and 30 minutes. 6. The method of any one of the preceding claims, wherein the step of applying is performed by applying, to the portion (2a) of the product (2) made of a plastic material, a layer of the protective coating (5) having a thickness comprised between 5 and 500 micrometres, or a thickness comprised between 10 and 100 micrometres, or a thickness comprised between 15 and 50 micrometres. 7. The method of any one of the preceding claims, wherein the layer of protective coating (5) is realised in such a way as to protect the portion (2a) of the product (2) made of a plastic material at least from an ultraviolet radiation i5 and/or in such a way as to increase a resistance to high temperatures of the portion (2a) of the product (2) made of plastic material, and/or such as to increase the mechanical resistance of the portion (2a) of the product (2) made of plastic material. 8. The method of any one of the preceding claims, further comprising a step of applying an intermediate layer of a bonding material on the portion (2a) of the product (2) made of plastic material, or a step of performing a preparation step of the portion (2a) of the product (2) made of plastic material, destined to increase adhesion of the layer of protective coating (5) to the portion (2a) of the product (2) made of plastic material before the step of applying at least a layer of protective coating (5). 9. The method of any one of the preceding claims, wherein the product (2) is made of a thermoplastic material such as PBT, PET, PA, PPS or LCP, or of a heat-hardening material such as phenol resin (Bakelite®) or of polyester, or of plastic materials having working temperatures which are above about 180°C. 10. A product made of a plastic material, characterised in that it comprises at least a portion (2a) having at least a layer of a protective coating (5) made of a nano-ceramic material applied on the portion (2a). |
Field of the Invention.
The invention relates to a method for realising products made of a plastic material.
The invention is applicable in all sectors where products made of a plastic material are used which products must exhibit high qualities of resistance to high temperatures and/or high resistance to other stresses such as ultraviolet radiations or others.
The invention can also be applied for realising various products which in the present art cannot be realised in plastic materials due to some restrictive requisites of heat or mechanical resistance or with respect to other stresses such as ultraviolet radiation or radiation of another type.
For example, the invention is advantageously applicable in the sector of lamp- holders for lamps of halogen type and lamp-holders for discharge lamps (for example metal iodide lamps, metal halide lamps, mercury vapour lamps, sodium vapour lamps), for realising parts in a plastic material such as lamp-holders or components of lighting devices of various types.
Prior Art
Purely by way of reference to the lamp-holder sector, the prior art comprises various types of lamp-holder, usually realised specifically for corresponding types of lamp. The known-type lampholders are generally made of a ceramic material (for example porcelain or steatite), plastic or metal (in general metal materials are used only for the external casings of lamp-holders and not for the main body, for reasons of electrical insulation).
Lamp-holders thus generally comprise a body provided with a housing seating for the end of a lamp, which body is made of a ceramic or plastic material. Ceramic lamp-holders offer some advantages, among which a low cost of the raw material and a high resistance to high temperatures (ceramic material can resist temperatures of higher than 1000°C), but exhibit some drawbacks, the main of which is a greater difficulty in realising complete shapes provided for example with undercuts, due to the poor fluidity of the material in the production process.
An important drawback is the greater dimensional tolerance in the end product, as for ceramic products the tolerances, as stated in the regulations defined in standard DIN40680, are very high, leading indeed to problems of irregular shapes, especially in the case of products having considerable dimensions. Among the drawbacks there are also: the small number of combinations possible in the dies for realising the ceramic body, a long duration of the production cycle, the need for a sintering treatment in a kiln at a high temperature (about 1300°C) for various hours, with a consequently high level of energy consumption, and further a weight and transport costs of significant entity.
Plastic lamp-holders are generally made using special plastics able to resist high temperatures (even up to 260°C/280°C). These lamp-holders exhibit some important advantages with respect to the lamp-holder made of ceramic material, in particular as they offer the possibility of realising more complex shapes, provided with undercuts too, thanks to the greater fluidity of the material during the production step.
Other advantages are constituted by the lower dimensional tolerance of the end product, the possibility of using a large number of combinations in the dies for realising the plastic body, a shorter duration and a lower energy consumption in the production cycle, a weight and a transport cost of lower entity.
Plastic lamp-holders exhibit some drawbacks, such as high costs for raw materials (in the case of special plastics able to resist very high temperatures) and a lower overall resistance to high temperatures with respect to ceramic lamp-holders.
As is known, lamps exhibit a characteristic emission of ultraviolet rays (UV). It is also known that some lamps, in particular halogen lamps and in particular discharge lamps (metal iodide lamps, metal halide lamps, mercury vapour lamps, sodium vapour lamps), exhibit considerable UV emission, which can lead to problems in terms of personal safety in use, and can also cause problems, for example, of deterioration of colouring of some products irradiated by the lamps.
To obviate this drawback, in the prior art a filter has been applied to the lamps, which filter is more or less transparent and able to reduce the emission of UV rays and thus reduce the above-cited drawbacks.
Also known is that some types of lamps are provided with a parabola, i.e. an element placed in the posterior part of the lamp and destined to reflect the greater quantity of light radiation towards a preferred emission direction. The prior art also contains lamp-holders made of phenolic resins (for example Bakelite ® ), typically being black in colour, which are painted with conventional paints suitable for the purpose for giving a different colour from the original colour.
The prior art also comprises lamp-holders made of thermoplastic materials which can be realised from the outset with various colorations, by adding a pigment to the material they are made of, or alternatively the lamp-holders can be painted to change their colour with conventional paints suitable for the purpose.
The applicant has found that the known lamps and the lamp-holders made of plastic material exhibit a further and not known drawback. In particular, lamp- holders of plastic material of known type, when used with lamps having a UV ray emission that is very high, exhibit a significant deterioration in the portion irradiated by the lamp, which leads not only to a reduction in the surface qualities of the lamp-holder (for example deterioration of the colour) but also to an erosion and therefore to a progressive wearing-out of the material of the lamp-holder.
The applicant has found that surprisingly the problem of deterioration due to UV rays becomes extremely significant beyond a certain limit of UV radiation emission, and that at the same time the emissions become very relevant beyond a predetermined power of the lamp. Further, the effect of the UV rays is very much stronger on the lamp-holder than on the other illuminated objects due to the very close proximity of the lamp to the lamp-holder.
Further, the lamp-holder is contemporaneously subjected to high use temperatures and the emission of UV rays.
All the cited factors add up to make the lamp-holders made of plastic material substantially inadequate for use with high-power lamps having high UV radiation levels (for example halogen type lamps, and in particular discharge lamps, but also other types), as their use in these cases can lead to potentially dangerous situations, with loss of grip of the lamp in the lamp mounting of the lamp-holder, or loss of the requisites of electric insulation of the lamp-holder. It is worthy of note that conventional UV filters applied to high-UV emitting laps do not resolve the cited problems, both because of an unsuitable positioning for protecting the lamp-holder, and especially because they are in themselves not sufficient for protecting the lamp-holder given the proximity thereof to the lamp, the high emission of the most recent-generation lamps and the poor resistance of the plastic to the UV rays in use conditions.
Other lamps are also known, provided with a reflector element or parabola incorporated in the lamp such as to direct the light radiations in a preferential direction. The known-type parabolas integrated in the lamps can be of three main types: aluminium parabolas assembled adjacent to the glass of the lamp; reflector parabolas realised by metal-coating (mirror-coating) of the glass of the lamp (dichroic lamps); or a combination between the first and the second solution, in which instead of the metallisation of the glass an actual aluminium parabola of low thickness is inserted.
In the second and third cases, typically the metallisation is performed starting from a certain distance with respect to the cathodes of the lamp such as not to create short-circuits.
Known parabolas integrated in lamps are however not always capable of protecting the relative lamp-holder on which the lamp is mounted from the UV rays as the parabola part or the mirroring normal starts from a little beyond the glass zone of the lamp, close to the coupling zone with the lamp-holder.
It is also known that in some cases the parabolas are not integrated in the lamps but are mounted on the lighting devices. In these cases the problem of deterioration of the lamp-holders by the UV rays remains, as these parabolas are mounted posteriorly to the lamp-holder, or they exhibit, for reasons connected with mounting, a hole or a conformation which does not enable the lamp-holder to be protected.
The above-cited problems with respect to the lamp-holder made of plastic, in particular with respect to the limitations in resistance to high temperatures and/or behaviours in the presence of ultraviolet radiation, are found in similar measure in other products made of plastic, both in the same sector, lighting, for example further components of lighting devices, or belonging to other sectors even quite removed from that of illumination.
The main aim of the present invention is to resolve one or more of the problems encountered in the prior art.
An aim of the present invention is to make available a method for realising a product made of a plastic material which exhibits high resistance to high temperatures, i.e. to temperatures close to or above the maximum working temperature of each material. The maximum working temperature is in general the maximum continuous working temperature for that particular material, which can be defined from technical specifications and standards or can be defined by the response (or not) of the material to a determined test at that temperature. The temperature is in general lower than that to which each plastic material begins to undergo significant deterioration.
A further aim of the present invention is to make available a method for realising a product in plastic material which exhibits a high resistance to ultraviolet rays.
It is a further aim of the present invention to increase considerably the field of application of plastic materials to the include products of various types.
It is a further aim of the present invention to provide a product made of plastic material, for example a lamp-holder, which offers all the advantages of a lamp- holder of plastic material (among which for example high dimensional precision, low tolerance, the possibility of obtaining complex forms) and which further exhibits a high resistance to ultraviolet rays emitted by a relative lamp, apart from good resistance to heat and/or good mechanical resistance.
A further aim of the invention is to realise a lamp-holder having a body made of a plastic material which is able to resist higher temperatures, for example by 20- 40°C higher, with respect to a conventional lamp-holder made using a traditional method of the same plastic material.
These aims and others besides, which will emerge more fully from the following description, are substantially attained by a method for realising products in plastic material according to what is set out in one or more of the appended claims, taken singly or in combination with one another.
The invention further relates to a method of any one or more of the appended claims, wherein the coating further comprises, at least during the application stage thereof, one or more additives destined at least to enable application on the product.
The invention further relates to a method as in one or more of the appended method claims, wherein the layer of protective coating is realised entirely in a non-ceramic material.
The invention further relates to a method according to one or more of the appended method claims, comprising a step of applying to the portion of the product made of plastic material a plurality of layers of protective coating comprising nano-ceramic material. The invention further relates to a method as in one or more of the appended method claims, wherein a plurality of layers of protective coating each comprises different types and/or quantities of additives.
The invention further relates to a method as in one or more of the appended method claims, further comprising a step of producing the product in plastic material before the step of applying the layer of protective coating.
The invention further relates to a method or a product according to one of more of the appended claims, wherein a layer of protective coating is applied on the portion of the product in plastic material which coating exhibits a thickness of less than 100 micrometres (or microns), or less than 50 micrometers or less than 35 micrometres.
The invention further relates to a method of one or more of the appended method claims, wherein the step of heating is performed by firing at least the portion of the product made of plastic material in a sintering kiln.
The invention further relates to a method of one or more of the appended method claims, wherein the preparation treatment of the portion of the product made of a plastic material is performed by a sand-blasting surface treatment of the product made of plastic material and/or by a sand-blasting treatment with corundum.
The invention further relates to a method or a product as in any one of the appended claims, wherein the product made of a plastic material is different from a lamp-holder and/or a lamp.
The invention further relates to a product made according to a method according to any one of the preceding claims.
The invention further relates to a product as in one or more of the appended method claims, wherein the layer of protective coating is realised in such a way as to protect the portion of the product made of plastic at least from an ultraviolet radiation and/or in which the layer of protective coating is realised in such a way as to increase resistance to high-temperatures of the portion of the product made of plastic material, and/or in which the layer of protective coating is realised such as to increase the mechanical resistance of the portion of product in plastic material.
The invention further relates to a product of one or more of the appended method claims, wherein the layer of protective coating is applied by spraying or by dipping or painting, and by subsequent heating of the portion. The invention further relates to a product of one or more of the appended claims, further comprising an intermediate layer of gripping material, or a preparation treatment, between the body and the layer of protective coating, destined to increase adhesion of the layer of protective coating to the body.
The invention further relates to a lamp-holder comprising a body made of a plastic material provided with a housing seating for an end of a lamp, further comprising at least a layer of protective coating applied to at least a portion of the body, the protective coating being destined to protect the portion of the body at least from the heat emitted by the lamp, in order to increase the resistance of the body to the high temperatures, or from the UV radiations emitted by the lamp.
Brief Description of the Drawings.
There now follows a detailed description, by way of non-limiting example, of some preferred embodiments of a method for realising products in plastic material, and a product made of plastic material made using the method, wherein:
figure 1 is a perspective view of a body of a lamp-holder of the prior art;
figure 2 is a perspective view of a body of a lamp-holder of the present invention;
figure 3 is a perspective view of the body of a lamp-holder of figure 2 mounted in a respective casing and connected to respective electric wires;
figure 4 is a perspective view of a lamp of known type mounted on the lamp- holder of figure 3;
figure 5 is a flow chart illustrating some steps of a method of an embodiment of the present invention.
Disclosure of Invention.
The invention relates to a method for realising products in a plastic material comprising a step (denoted by B in figure 5) of applying to at least a portion of a product made of plastic material at least a layer of a protective coating comprising nano-ceramic material.
The method can further comprise a step (denoted by A in figure 5) of producing the product in plastic material before the step of applying the layer of protective coating.
The method can comprise a step of entirely coating the product made of plastic material with the layer of protective coating The step of applying at least a layer of protective coating can comprise a step of spraying the nano-ceramic material on the portion of the product and/or a step of dipping the portion of the product in the nano-ceramic material and/or a step of painting the portion of the product with a paint comprising nano-ceramic material. Note that the single processes of spraying, painting or dipping products different from those which are the object of the present invention, in order to apply a coating with a nano-ceramic material, are of known type and therefore will not be described in greater detail in the present description.
The method further comprises a step (denoted by C in figure 5) of heating at least the portion of the product made of plastic material with the layer of a protective coating applied in order to sinter the protective coating made of nano- ceramic material. The step of heating can be performed, for example, at a temperature comprised between 180°C and 400°C or at a temperature of between 190°C and 300°C or at a temperature of between 200°C and 250°C. The step of heating can have a duration comprised between 5 minutes and 60 minutes or a duration of between 10 and 40 minutes or a duration of between 15 and 30 minutes. The temperature and the heating time can however vary, even beyond the above-indicated limits, according to the type of plastic material used, the thicknesses of the layer or the protective coating layers, etc.
The layer of the protective coating applied to the product can have for example a thickness comprised between 5 and 500 micrometres, or a thickness comprised between 10 and 100 micrometres, or a thickness comprised between 15 and 50 micrometres. The thickness could even be greater or lower than the above-cited limits in the case of special applications which require such values. The thickness can be selected on the basis of type of plastic used, protection requirements needed in the particular case, or other factors.
The layer of protective coating is realised in such a way as to protect the portion of the product made of plastic material at least from an ultraviolet radiation and/or in such a way as to increase the resistance to high temperatures of the portion of the product made of plastic material, and/or such as to increase the mechanical resistance of the portion of the product made of plastic material. In the present text, the term "high temperatures" relates to temperatures close to or above the upper resistance limits of each plastic material used, and/or close to or above the maximum continuous working temperatures which are standard for each plastic material, as usually defined in the technical sector by respective technical norms and specifications. For example, in the case of plastics for realising lamp-holders, the "high temperatures" can be for example in the order of 240°C-300°C.
The method can further comprise a step (denoted by Dl in figure 5) of applying an intermediate layer of gripping material (in itself of known type) on the portion of the product in plastic material, or a step (denoted by D2 in figure 5) of performing a preparative treatment of the portion of the product made of plastic material, for example a sand-blasting treatment (also of known type), destined to increase adhesion of the layer of protective coating to the portion of the product made of plastic material, before the step of applying at least a layer of protective coating.
The sand-blasting process can comprise some steps of known type among which an initial degreasing of the product made of plastic material, a sand-blasting with a determined measure and roughness of the grains and an appropriate sandblasting pressure, a step of cleaning the product of the residues of sand-blasting and a step of drying and preliminary heating before painting or spraying with the protective coating.
The following detailed description relates mainly to a lamp-holder, but the invention is applicable substantially similarly also to numerous other products made of plastic material belonging to other sectors, in which the above specifications are required or there are other requirements in which the invention can be applied.
The figures illustrate, by way of non-limiting example, an example of a lamp- holder, produced by the present applicant, and an example of a lamp, marketed under the Philips ® mark, but the invention is applicable also to lamp-holders and lamps that are different from the ones illustrated.
With reference to the appended figures, 1 denotes in its entirety a lamp-holder of the present invention. The lamp-holder 1 comprises at least a body 2 made of a plastic material provided with a seating 3 for housing an end 8 of a lamp 4. In the present description, the term "plastic material" is taken to mean plastic materials used for realising lamp-holders, such as, for example, thermoplastic materials of the type of PBT, PET, PA, PPS and LCP, or heat-hardening materials such as phenolic resins, (Bakelite ® ) or polyester etc., or even other plastic materials in a case of other products used in other sectors.
The lamp-holder 1 comprises at least a layer of a protective coating 5 applied to at least a portion 2a of the body. In the present text, the term "protective coating" is taken to mean one or more coatings of a protective material applied on a support (for example a body of the lamp-holder or a lamp or another product made of a plastic material), for example by spraying, painting, dipping or the like, such as to stably cover the support. In other words, the protective coating is constituted by a material which is in the liquid, fluid or powder phase, before application thereof to the body.
The protective coating takes on its definitive conformation, complementarity shaped and solidly constrained to the portion of body, only following application thereof to the portion of body. The term "protective coating" does not comprise mechanical elements that are structurally distinct from the support and rested on the support or mechanically interposed between the support and a further element (such as for example between a lamp and a body of a lamp- holder). In particular, by "protective coating", no reference is made to an element which is structurally independent interposed removably between the elements, or even unremovably between the elements.
The protective coating 5 is destined to provide a heat protection for the portion of the body or product made of plastic material, and therefore to increase the maximum working temperature to which the body or product can be subjected. The protective coating 5 can further be destined to protect the portion of body at least from an ultraviolet radiation emitted by the lamp 4. It should be remembered that plastic materials at same working temperatures have heat resistance i.e. maximum working temperatures which are different and lower if irradiated by UV rays, due to the combined effect of temperature and UV irradiation.
The coating 5 can be further destined to guarantee a mechanical protection and/or a heat protection to the body 2. The coating can provide, for example, a protection which enables the plastic body to resist temperatures of greater by about 10-40°C or more with respect to the body without the coating, also according to the thickness of the layer or layers of coating.
The portion 2a of the body 2 comprises at least a zone of the body 2 which is subject to ultraviolet radiation during functioning of the lamp 4 mounted on the body 2. Alternatively the body 2 can be entirely coated with the protective coating 5. As can be seen in figure 3 and figure 4, the lamp-holder 1 can further comprise a casing 6 in which the body 2 is housed. The casing 6 can also be realised in plastic material and, in a variant which is not illustrated, it can also be coated with a layer of protective coating.
The lamp-holder 1 further comprises electrical contacts arranged internally thereof and destined to enable electrical connection of the end 8 of the lamp 4 with respective electric wires 7.
In the invention, the protective coating 5 comprises at least a layer of nano- ceramic material, or alternatively several layers of the material.
The coating comprising nano-ceramic material can further comprise a plurality of additives, of known type, destined to enable application thereof on the product or to perform other functions, such as a desired colouring or the other functions besides.
The additives enable obtaining, starting from the nano-ceramic powder, a paint destined to be used for painting the portion of product made of plastic material, or a fluid or liquid destined to be used for dipping the portion of product made of plastic in the nano-ceramic material, or for spraying the nano-ceramic material on the portion of product.
The additives may volatilise, entirely or in part, during a step of sintering of the product made of plastic material in the nano-ceramic coating kiln. The protective coating can have any thickness appropriate for the purpose, but the coating preferably has a thickness as small as possible in order to attain the set aims. The protective coating can have, for example, a thickness of the order of micrometres (micron) and for a lamp-holder it can be for example less than 150 micrometres, less than 50 micrometres, or less than 35 micrometres, such as not to influence the tolerances and dimensional precision of the body 2. The thickness of the protective coating can be for example in the order of 20-40 micrometres. The thickness of the protective coating can also be less or more than the values indicated in the case of products made of plastic material in which there are particular requirements for extremely slim coating or coating of a more significant entity.
The coating materials can also comprise further additives destined to improve adhesion to the body 2. In an embodiment, the lamp-holder 1 can further comprise an intermediate layer of gripping material between the body 2 and the layer of protective coating 5, destined to increase adhesion of the layer of protective material to the body 2.
A plurality of layers of protective material can be comprised, or even of gripping material.
In a further embodiment, the lamp-holder 1 can further comprise a preparation treatment between the body 2 and the layer of protective coating 5, destined to increase adhesion of the layer of protective coating to the body 2. The preparation treatment can be performed for example by sand-blasting or a sandblasting surface treatment with corundum (both in themselves of known type). The layer of protective coating 5 can be applied by spraying, painting or by immersion of the body 2 in the protective material. The layer of coating 5 can be applied with any other method suitable for the purpose.
In an embodiment, the method relates to manufacturing of a lamp-holder 1 comprising at least a step of applying, to at least a portion 2a of the body 2 made of plastic material of the lamp-holder 1, at least a layer of protective coating 5 comprising nano-ceramic material, destined to protect the portion 2a of the body 2 at least from an ultraviolet radiation emitted by a lamp 4 mounted on the body, or to provide a heat protection of the portion 2a and thus to increase the maximum working temperature to which the portion 2a can be subjected. The step of applying at least a protective coating 5 can comprise the step of spraying a protective material onto the portion of body 2 and/or a step of dipping the body 2 in a protective material and/or a step of painting the body 2 with a protective material.
The method can further comprise a step of applying an intermediate layer of gripping material on the body 2, or a step of performing a preparation treatment of the body 2, destined to increase adhesion of the layer of protective coating to the body 2, before the step of applying at least a layer of protective coating 5. The method further comprises a step of heating at least the portion 2a of the body 2 of the lamp-holder, after the step of applying the layer of protective coating 5 in order to sinter the protective coating made of a nano-ceramic material. The step of heating, in itself of known type and therefore not described in detail but only with respect to the most significant aspects for the present invention, can be performed by firing the lamp-holder (or the portion of lamp- holder) in a kiln. In the invention, this step can be performed, for example, at a temperature of the order of 200°C/240°C, and for a duration of a few minutes for example, from about 5 minutes to about 40 minutes or beyond, typically about from 15 to about 30 minutes.
The step of heating is therefore performed at temperatures that are much lower than the temperature required for sintering lamp-holders internally realised in ceramic material (about 1300°C) and for much shorter durations than those required in that case (in the order of 12-24 hours according to the type of kiln used); for this reason the present method has a significantly lower energy consumption.
The present invention enables obtaining one or more of the following advantages.
First and foremost, the invention enables products made of a plastic material, for example a lamp-holder, to be obtained which are able to obviate the problems encountered in the prior art.
The invention further enables a very high number of new products to be realised in plastic material which at present are made of other materials because of the need for heat resistance, structural resistance, resistance to UV rays or other types, thus enabling the field of application for plastic materials to be considerably increased.
A product or lamp-holder of the invention can be realised in plastic material, with all the consequent advantages (among which is included dimensional precision), but is free of the problems connected with deterioration due to the emission of UV rays by a lamp.
Of particular significance is the fact that the realising of a product, for example a lamp-holder, in a plastic material as in the invention exhibits, with respect to a product made of ceramic material, at least the following advantages: dimensional stability, shape stability, the possibility of treating the whole workpiece or only a part thereof (which might be the critical surface thereof which is subject to higher temperatures/UV irradiation), increased mechanical resistance both for use of plastic in the place of ceramic material both because of the subsequent coating treatment and the subsequent coating treatment, reduction of weights (transport and movement), possibility of making the parts lighter (as the product can be "lightened" by creating shapes having hollow parts or removed parts where no material is required, while with ceramic material the shapes are necessarily "full" and heavier also for this reason, apart from the intrinsic weight of the material), possibility of coupling of several pieces, including by snap-fit (while with particular ceramic materials this is not possible as the material is absolutely rigid).
Furthermore, a product made of a plastic material realised using a method according to the invention exhibits a greater resistance to high temperatures with respect to products realised in the same plastic material in the prior art, for example by increasing the maximum working temperature of the products up to the order of 20-40°C or more.
Further, the invention enables treatment with nano-ceramic both whole products and only one or more portions of interest of the products made of plastic material in order to solve the drawbacks of a particular case, and is therefore flexible and adaptable to any requirements.
Furthermore, it is noteworthy that a product or lamp-holder of the invention are simple and economical to produce. The invention also makes available a method for realising products in plastic material, for example a lamp-holder having a body made of a plastic material, which are simple and economical to manufacture and which enable shorter working times as well as a lower energy consumption.