GB2582353A

GB2582353A - Thermal insulation for vulcanising machine

Info

Publication number: GB2582353A
Application number: GB1903856.1A
Authority: GB
Inventors: Pereira De Jesus Reynaldo; Fernando Clemente Carosa Luis
Original assignee: MORGANITE BRASIL Ltda
Current assignee: MORGANITE BRASIL Ltda
Priority date: 2019-03-21
Filing date: 2019-03-21
Publication date: 2020-09-23
Also published as: GB201903856D0

Abstract

The present invention relates to thermal insulation and to a vulcanising machine (6, fig 9) that uses said thermal insulation. The present invention provides thermal insulation that can form an integral part of the vulcanising mould 5 or of the vulcanising machine itself, and that comprises an inner insulating layer 2 with higher thermal conductivity and lower rigidity than an outer insulating layer 3. The inner insulating layer 2 is surrounded by the outer insulating layer 3, the inner insulating layer has greater thermal conductivity than the outer insulating layer, and the insulating material thermal comprises at least two holes 4 that pass through the inner insulating layer and the outer insulating layer. Vulcanising machine comprises an upper part (7, fig 9), a lower part (8, fig 9) and vulcanising mould 5. The thermal insulation may be capable of being arranged around the tyre vulcanising mould. The outer insulating layer may be more rigid than the inner insulating layer, the inner insulating layer may consists of one from: ceramic fibre blanket, materials based on microporous silica, materials based on aerogel, materials based on diatomaceous silica, mineral blanket (rock wool) or glass-fibre blanket. The outer insulating layer may consist of one from: glass-fibre-reinforced isophthalic polyester resin, glass-fibre-reinforced epoxy resin, stainless steel sheet, aluminium sheet or plastics or non-metallic materials. Consequently, the present invention provides insulation that has higher energy efficiency, with a temperature of the cold face that is safe for the operator and that does not have to be replaced with such frequency.

Description

THERMAL INSULATION AND VULCANISING MACHINE

[1] The present invention relates to thermal insulation for tyre vulcanisation and the vulcanising machine comprising thermal insulation.

[2] Vulcanisation is one of the final steps in tyre manufacture and is characterised by the application of heat and pressure to a raw tyre. In this step, the raw tyre is put in a mould that is placed inside a vulcanising machine (or press). Said vulcanising press may be a hydraulic or eccentric press, column press, C-press or other types of presses known in the art. Furthermore, owing to the thermal characteristics of vulcanisation, the use of thermal insulation in the combination of mould and vulcanising press is recommended, as it gives the process greater thermal efficiency and energy efficiency.

PRIOR ART

[3] At present, some technical solutions are available for increasing the thermal efficiency of tyre vulcanisation. One of these techniques is known as "thermal jacket" and consists of the use of removable thermal insulation around the vulcanising mould. This removable thermal insulation consists of glass-fibre fabric, ceramic-fibre fabric or siliconised glass-fibre fabric, encapsulating other commercial insulating materials.

[4] Another existing solution consists in installing a metal cylinder around the vulcanising mould, thus encapsulating the mould and reducing heat dissipation. The metal cylinder consists of: (i) a steel sheet calendered to the size of the vulcanising mould; (ii) thermal insulation applied on this calendered sheet; and (iii) another calendered sheet on the thermal insulation employed, thus constituting a heat deflector. To summarise, the thermal insulation employed is encapsulated between the two sheets, forming a kind of sandwich.

[5] Patent documents JPH04147808A, KR20110049421, KR101787421, JP2012011730A and JPS6237107A describe forms of thermal insulation for vulcanisation processes such as the solutions described above. In general, these documents disclose an insulating ring, such as the removable jacket, consisting of insulating materials or a combination of insulating materials and metallic materials.

[6] In these references, it can be seen that the existing solutions in the prior art offer removable forms of insulation (such as the thermal jacket), i.e. which must be removed from a mould and discarded and/or mounted in another mould when moulds are changed. This form of insulation gives rise to excessive costs in the tyre manufacturing process, since it is necessary to perform several mould changes, meaning that the time lost through repetition of the procedure for removing the insulation from a mould and then installing this insulation on other mould results in an increase of production costs. Moreover, the frequent manipulation of the removable material damages the insulating fabric and generates particulate material (or powder), which is released from the insulating material. Thus, application of this insulation, which is damaged by manipulation in vulcanising moulds, means that the particulate material released contaminates tyre manufacture. Furthermore, the damaged insulation does not provide proper insulation of the vulcanising equipment (mould, press and other components), impairing the thermal efficiency and energy efficiency of the process.

[7] Tn the case of metal sheet protection there are various problems. First, it may be mentioned that the mechanical protection is still some distance from the outside surface of the vulcanising mould, meaning that the mould is not completely insulated from the surrounding air and continues to lose heat. By using metal sheet, this form of protection conducts a large amount of heat to the outside, thus losing insulation efficiency. In many cases the focus is not to guarantee efficiency of vulcanisation, and the metal sheet is only applied on the front of the machine, to protect the operators from receiving the thermal radiation emitted by the heated mould. Moreover, in general, the thicknesses of the insulating material are very small, not having been developedidesigned taking into account knowledge about heat and energy transfer. This type of protection leads to problems of labour safety, as the protection operates with temperatures of the cold face above the safe limit of operation (above 60°C).

[8] Faced with the problems that exist in the prior art, one of the aims of the present invention is therefore to supply thermal insulation that is able to form an integral part of the vulcanising mould or vulcanising machine, so as to solve the problems connected with the frequent removal and replacement of the insulation.

[9] Furthermore, one of the aims of the present invention is that said thermal insulation should not only be an integral part of the vulcanising mould or vulcanising machine, but also that it should be able to offer protection to the operator, by having a suitable, safe temperature of the cold face.

[0010] Moreover, one of the aims of the present invention is to supply thermal insulation that also possesses energy efficiency.

BRIEF DESCRIPTION OF THE INVENTION

The aims of the present invention are achieved by means of thermal insulation comprising: an inner insulating layer, an outer insulating layer, the inner insulating layer being surrounded by the outer insulating layer. The inner insulating layer has lower thermal conductivity than the outer insulating layer and the outer insulating layer is more rigid than the inner insulating layer. The thermal insulator comprises at least two holes that pass through the inner insulating layer and the outer insulating layer.

The aims of the present invention are also achieved by means of a vulcanising machine, which comprises: an upper part, a lower part and a vulcanising mould. The machine further comprises thermal insulation as described above.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Fig. 1 illustrates the thermal insulation according to the invention, without holes present.

[0012] Fig. 2 illustrates the thermal insulation according to the invention, without holes present, in front view.

[0013] Fig. 3 illustrates the thermal insulation according to the invention, with holes present.

[0014] Fig. 4 illustrates the thermal insulation according to the invention, with holes present, in front view.

[0015] Fig. 5 illustrates the vulcanising mould according to the invention.

[0016] Fig. 6 illustrates the vulcanising mould according to the invention, in front view. [0017] Fig. 7 illustrates the thermal insulation according to the invention applied on a vulcanising mould.

[0018] Fig. 8 illustrates the thermal insulation according to the invention applied on a vulcanising mould, in front view.

[0019] Fig. 9 illustrates the vulcanising machine according to the invention comprising a mould and without the thermal insulation present, in front view.

[0020] Fig. 10 illustrates the vulcanising machine according to the invention comprising a mould and with the thermal insulation present, in front view.

DETAILED DESCRIPTION OF THE INVENTION

[0021] As shown in Fig. 1, the thermal insulation 1 of the present invention comprises an inner insulating layer 2 and an outer insulating layer 3, the inner insulating layer 2 being surrounded by the outer insulating layer 3. Referring to Fig. 2, the insulation further comprises a cold face 9 and a hot face 10, the cold face 9 being the outside surface of the outer insulating layer 3 and the hot face 10 being the inside surface of the inner insulating layer 2. In one embodiment of the present invention, the thermal insulation I of the present invention is capable of being arranged around a vulcanising mould 5, for example such as a tyre vulcanising mould 5 that is used in a vulcanising machine or vulcanising press. In this preferred embodiment, the thermal insulation 1 possesses the same shape as the mould 5, so that, as is noted starting from Figs. 7 and 8, the mould 5 and the insulation 1 are of cylindrical shape. It should be emphasised that the thermal insulation 1 of the present invention may, moreover, be applied on the vulcanising machine, as will be described hereunder.

[0022] In a preferred embodiment of the present invention, said thermal insulation 1 is of a substantially cylindrical shape, since the vulcanising moulds 5 (as is noted starting from Fig. 5) possess this same shape. However, other shapes may be employed for the thermal insulation 1 within the scope of the present invention, provided that this shape is suitable for the shape of the mould 5. The diameter of the substantially cylindrical shape is characteristic of the diameter of the tyres being vulcanised and preferably varies between 0.5 m and 5.0 m.

[0023] Furthermore, the inner insulating layer 2 has lower thermal conductivity than the outer insulating layer 3. Accordingly, the heat coming from the mould encounters more difficulty in being transmitted to the outer insulating layer 3, and consequently to the exterior of the vulcanising machine. In a preferred embodiment of the present invention, during vulcanisation, the temperature (°C) ratio between the cold face 9 and the hot face 10 is less than 0.5, more preferably less than 0.4 and even more preferably less than 0.3. By way of illustration, in a given embodiment of the present invention, the inner insulating layer 2 has thermal conductivity between 0.03 and 0.12 W.M.K in a temperature range from 90°C to 540°C, and, more precisely, less than 0.05 Wilm.K at 200°C.

[0024] Furthermore, the outer insulating layer 3 is more rigid (has a higher elastic modulus) than the inner insulating layer 2. The outer insulating layer 3 is preferably at least 10% or at least 40% or at least 70% more rigid than the inner insulating layer 2. The greater rigidity may be due to the properties of the material of the outer insulating layer 3 relative to the inner insulating layer 2. The greater rigidity of the outer insulating layer 3 makes the insulation easier to manipulate by the operators. The inner insulating layer 2 preferably has a minimum density of 128 kg/m' and more preferably at least 192 kg/m3. In terms of size, it is emphasised that the inner insulating layer 2 has a thickness of up to 50 mm. The outer insulating layer is preferably formed with a thickness between I mm and 5 mm.

[0025] Regarding the materials, the inner insulating layer 2 may consist of one from: ceramic fibre blanket (e.g. Superwool0 blanket), materials based on microporous silica, materials based on aerogel, materials based on diatomaceous silica, mineral blanket (rock wool) or glass-fibre blanket. The outer insulating layer 3, in its turn, may consist of one from: glass-fibrereinforced isophthalic polyester resin, glass-fibre-reinforced epoxy resin, stainless steel sheet, aluminium sheet or plastics or non-metallic materials.

[0026] Moreover, the thermal insulation 1 comprises at least two holes 4 that pass through the inner insulating layer 2 and the outer insulating layer 3, so as to make a connection between the inside and outside of the insulating material 1. Pipes, connections, fasteners or other component elements of the vulcanisation process pass through the holes 4. For example, in vulcanisation processes that use steam, pipes for inlet of steam and outlet of condensate are introduced into the mould. In general, the number of holes 4 in the insulation is variable, depending on the configuration required for the vulcanisation process to be implemented. The at least two holes 4 preferably have an effective diameter between 5 mm and 200 mm and more preferably between 20 mm and 100 mm.

[0027] The present invention further relates to a vulcanising machine 6. This vulcanising machine 6 is preferably a tyre vulcanising press provided with an upper part 7 and a lower part 8. Both the upper part 7 and the lower part 8 have a substantially cylindrical shape, the upper part 7 having the shape of a chamber and the lower part 8 functioning as a base on which a vulcanising mould 5 is arranged. Moreover, the upper part 7 comprises at least two holes 4, such as the hole 4 already described above.

[0028] Furthermore, the upper part 7 and the lower part 8 are able to adopt at least two configurations, being apart in a first configuration and joined together in a second configuration. In this sense, in a preferred embodiment of the present invention the upper part 7 is able to move and to be retracted in relation to the lower part 8. However, in other embodiments, both parts 7 and 8 may be able to move, or else only the lower part 8 could have this property.

[0029] Said vulcanising machine 6 comprises the thermal insulation 1 described above, which may be used in the machine 6 in at least two ways. In a first preferred embodiment, said thermal insulation 1, as described above, is applied around the upper part 7 of the vulcanising machine 6. In this way, the vulcanising machine itself now possesses advantageous properties of thermal insulation (as will be explained in more detail hereunder). In a second preferred embodiment, said thermal insulation 1 is applied around the vulcanising mould 5 that is arranged inside the vulcanising machine 6 (and on the lower part 8, as already mentioned).

[0030] Based on the characteristics of the thermal insulation 1 of the present invention described above and of the vulcanising machine 6 that contains said insulation 1, it is possible to achieve a number of advantageous technical effects.

[0031] First and foremost, the present invention provides protection for the operator and for the personnel in the vicinity of the vulcanising machine 5 and this is provided on account of some properties already described here. First, the inner insulating layer 2 consists of materials with high technical performance, whereas the outer insulating layer 3 does not have to be made of materials with such high technical performance. Thus, as has been pointed out, the thermal conductivity of the inner insulating layer 2 is less than that of the outer insulating layer 3 and accordingly the ratio of the temperature of the cold face 9 to that of the hot face 10 is less than 0.5, as already described. As is well known by a person skilled in the art, in vulcanisation processes, the temperature of the mould may certainly exceed 150°C, so that exposure to the radiation generated is harmful to health. Based on the thermal insulation of the present invention, it is guaranteed that the operator will be subjected to a more suitable temperature of the cold face (for example, 75°C or less).

[0032] Another advantage of the present invention relates to the presence of the holes 4 in the thermal insulation 1. In the present invention, the holes 4, supplied in accordance with the particular features of the vulcanisation process, allow the insulation 1 to be supplied-to-measure for a specified vulcanising mould 5. Thus, according to the present invention, the thermal insulation 1 may be formed for a specific mould 5, so that, after being applied to the mould 5, the insulation 1 becomes an integral part of the mould 5, and does not have to be removed when changing moulds 5. Similarly, the thermal insulation 1 may be formed for a machine 6, including, for example, the holes 4 being present in the upper part 7 of the machine 6. Thus, on being applied on the vulcanising machine 6, the insulation I becomes an integral part thereof, and it is not necessary to remove the insulation 1 from the machine 6 when changing moulds.

[0033] Thus, with the insulation 1 being an integral part of the mould 5 or of the machine 6, there is a saving of time and other resources in the vulcanisation process, because, in contrast to what happens in the prior art, the insulation 1 and the actual mould 5 do not have to be manipulated frequently. Consequently, there is less deterioration of the insulation and it does not generate particulate material or powder, as occurs in the prior art.

[0034] Yet another advantage and effect supplied by the present invention relates to energy consumption. By means of the thermal insulation 1 of the present invention, it is possible to achieve a reduction of the order of 15% to 30% in energy consumption in the tyre vulcanisation process.

[0035] As pointed out, the present invention achieves its aims by providing thermal insulation and a vulcanising machine that overcome the problems of the prior art and offer further advantages and positive technical effects.

Claims

CLAIMS1. Thermal insulation (1) comprising: an inner insulating layer (2); an outer insulating layer (3); in which the inner insulating layer (2) is surrounded by the outer insulating layer (3), characterised in that the inner insulating layer (2) has greater thermal conductivity than the outer insulating layer (3), and in that the insulating material thermal (1) comprises at least two holes (4) that pass through the inner insulating layer (2) and the outer insulating layer (3).
2. Thermal insulation (1) according to claim 1, characterised in that the outer insulating layer (3) is more rigid than the inner insulating layer (2).
3. Thermal insulation (1) according to claim 1, characterised in that the ratio of the rigidity of the inner insulating layer (2) to the rigidity of the outer insulating layer (3) is at least 0.1 or at least 0.4 or at least 0.7.
4. Thermal insulation (1) according to claim 1, characterised in that the outer insulating layer (2) comprises a thickness in the range between I mm and 5 mm.
5. Thermal insulation (I) according to claim I, characterised in that the inner insulating layer (2) comprises a thickness of up to 50 mm.
6. Thermal insulation (I) according to claim I, characterised in that the inner insulating layer (2) consists of one from: ceramic fibre blanket, materials based on microporous silica, materials based on aerogel, materials based on diatomaceous silica, mineral blanket (rock wool) or glass-fibre blanket.
7. Thermal insulation (1) according to claim 1, characterised in that the outer insulating layer (2) consists of one from: glass-fibre-reinforced isophthalic polyester resin, glassfibre-reinforced epoxy resin, stainless steel sheet, aluminium sheet or plastics or non-metallic materials.
8. Thermal insulation (1) according to claim 1 or 4, characterised in that the inner insulating layer (2) has thermal conductivity between 0.03 and 0.12 Wim.°K in a temperature range from 90°C to 540°C.
9. Thermal insulation (I) according to claim I, characterised in that the inner insulating layer (2) comprises a minimum density of 128 kg/rn3.
10. Thermal insulation (I) according to claim 1, characterised in that it comprises a cold face (9) and a hot face (10), the cold face (9) being the outside surface of the outer insulating layer (3) and the hot face (10) being the inside surface of the inner insulating layer (2), and in that the thermal insulation is configured to achieve a temperature (°C) ratio between the cold face (9) and the hot face (10) of less than 0.5.
11. Thermal insulation (1) according to claim 1, characterised in that it is capable of being arranged around a tyre vulcanising mould (5).
12. Thermal insulation (1) according to claim 11, characterised in that it comprises the same shape as the tyre vulcanising mould (5).
13. Vulcanising machine (6) comprising: an upper part (7); a lower part (8); a vulcanising mould (5); characterised in that it additionally comprises thermal insulation (1) as defined in claims 1 to 8
14. Vulcanising machine (6) according to claim 13, characterised in that the thermal insulation (1) is applied around the upper part (7) of the vulcanising machine (6).
15. Vulcanising machine (6) according to claim 13, characterised in that the thermal insulation (1) is capable of being arranged around a tyre vulcanising mould (5).