“Optimized method for the production of a composite thermal insulation” Description Field of the invention The invention relates to the field of heat-insulating materials, in particular in the automotive sector. More specifically, the present invention proposes a new and innovative method for making a material suitable for isolating the heat generated by the engine block during combustion or during any operating step. Prior art In the automotive sector, research on new materials and, in particular, on new polymers, is always at the forefront due to the growing needs of the market. For years both customers and international regulations have been pushing car manufacturers to constantly innovate materials to provide maximum technical performance while maintaining low costs and respect for the environment. Among the most important performances that determine consumer preference, there are undoubtedly the comfort conditions of the passenger compartment, which therefore must not be affected by the heat coming from the engine or by the heat coming from the exhaust manifolds and from the muffler itself. In order to ensure the correct climatic conditions inside the vehicle, numerous materials have been developed which act as thermal insulators. Heat-insulating materials are generally placed in vehicles, in proximity to the engine and the engine compartment in order to ensure comfort inside the passenger compartment despite the high temperatures produced. The problem inherent in this type of vehicle constituent elements lies in the fact that the optimal features are obtained by combining the mechanical and thermal properties of several materials. When several materials are arranged in layers, the risk of detachment of the different layers is observed. Similarly, when a more rigid material is coupled to a less rigid one, a crushing of this second material may be observed, with consequent loss of the required performances.

Some international patents relate to this type of vehicle components, such as, for example, the Korean patent extended worldwide WO/2016/190596. This patent relates to a poly ketone fiber material obtained by centrifuging the copolymer, washing, drying and stretching. Polyketone fiber has excellent properties of resistance to mechanical stress, elongation, water resistance, heat resistance and thermal conductivity and allows the production of highly resistant objects not only at high temperatures but even bulletproof.

Although the quality of the object thus produced is high, given the high production cost, this is used for tanks and other military equipment, while it is inconvenient for more massive productions.

The object of the patent is therefore to provide an innovative production method for the production of heat-insulating material that is easily available on the market and therefore accessible to all customers, without neglecting the insulating capabilities of the material.

Description of the invention

According to the present invention, an optimized method for the production of a composite thermal insulation is implemented which effectively solves the aforementioned problems.

The method object of the present invention provides for making a non-woven fabric which, in collaboration with the aluminum foil applied on the upper part of the non-woven fabric, is capable of increasing the thermal insulation generated by the engine apparatus of the most common vehicles.

The aluminum applied to the non-woven fabric has the feature of extending and making the amount of heat emitted by the engine more uniform, so as not to always stress the same point of the carbon panel.

The heat-insulating material obtained assumes a composition called “sandwich” which further amplifies the insulating properties of the material by virtue of the plurality of layers that make up said heat-insulating material. The optimized method for the production of a composite thermal insulation involves multiple steps and related variants, everything starts with the production of non-woven fabric rolls which are subsequently unrolled by means of an unwinding roller. The fibers used are based on polyacrylonitrile and polyethylene.

Subsequently, it is necessary to cany out the tensioning and alignment maneuver of the nonwoven fabric by means of a plurality of first tensioning rollers.

In the meantime, a compound of thermosetting resin and its catalyst is prepared by a special automatic mixer. Said automatic mixer is adapted to dose the right quantity of catalyst by means of a sensor which detects the exact weight of the resin extracted from its container to proceed with the rolling.

The spreading of the resin, which by way of non-limiting example may be of the vinyl ester or epoxy type, occurs initially on one face of said non-woven fabric by means of a dispenser. Rolling, on the other hand, takes place via a plurality of lamination rollers which spread the resin uniformly over the entire non-woven fabric.

In one of its embodiments, the rolling is carried out using the vacuum technology, which requires the use of a suitable vacuum bag, a vacuum pump and suitable conduits provided with valves to manage the flow of resin. Vacuum rolling ensures a uniform distribution of resin and prevents the formation of air bubbles, which would weaken the structure.

Hardening said resin takes place by means of an oven adapted to dry and generate said composite material by means of an irreversible adhesion between said non-woven fabric and said resin. Hardening in one of its embodiments may take place inside a female mold where the non-woven fabric has been previously rolled in order to give it the shape that best suits the customer's request.

Once the resin-coating of the non-woven fabric has been completed, a quick-setting glue is applied thereto on the upper surface to ensure correct application of the aluminum foil on the upper surface of the composite material.

Once the sandwich of the heat-insulating material is completed, the thermal insulation panels are cut by means of an automatic robot provided with special blades. The dimensions of the panels are then checked by means of a laser scanner.

The material compliant with the customer's requests and the standards set by the company may proceed to storage and stowage by means of special conveyor belts.

The advantages offered by the present invention are clear in the light of the above description and will be even more apparent from the accompanying figures and the detailed description.

Description of the figures

The invention will hereinafter be described in at least a preferred embodiment thereof by way of non-limiting example with the aid of the accompanying figures, in which:

- FIGURE 1 shows the thermal insulation panel object of this innovative embodiment. It may be noted that the non-woven fabric 10, together with the aluminum foil 11, constitutes a “sandwich” adapted to insulate the heat emanating from the engine apparatus more effectively.

As may be seen from the figure, the aluminum foil 11 is glued to the non-woven fabric 10 by means of a quick-setting glue.

- FIGURE 2 shows the production line of the optimized method for making a composite thermal insulation. The non-woven fabric of pre-oxidized polyacrylonitrile fiber and fire- retardant polyethylene glycol terephthalate fiber starts from the unwinding roller 12 and, after being subjected to tensioning by special rollers 13, is wetted with resin 17 already joined to the catalyst 16.

Rolling continues by means of two lamination rollers 18 which spread the resin 17 uniformly on the carbon fibers.

An oven 19 is adapted to dry the non-woven fabric 10 obtained.

In order to apply the aluminum foil 1 1 on said non-woven fabric 10, it is necessary to deposit glue 20 on the upper surface of said non-woven fabric 10.

When the heat-insulating material is completed following the application of the aluminum foil I I, a cutting robot 21 takes care of cutting the heat-insulating material into panels, according to the dimensions requested by the customer. A laser scanner 22 analyzes dimensions and validates parts that meet company standards and requirements.

Detailed description of the invention

The present invention will now be described purely by way of non-limiting or binding example with the aid of the figures, which illustrate some embodiments relative to the present inventive concept.

With reference to FIG. 1, the heat-insulating material manufactured by the optimized manufacturing method, object of the present invention, is shown.

The non-woven fabric 10, combined with the aluminum foil 11 creates a sandwich membrane which tends to drastically reduce thermal transmittance. This allows this heat-insulating material to be often used as a lining of the engine compartment in the most common vehicles. The aluminum foil 11 is capable of reflecting heat and transmitting it over the entire surface, thus avoiding to always stress the same areas of the non-woven fabric 10.

The aluminum foil 1 1 has a thickness of a few tenths of a millimeter while the non-woven fabric 10 may even reach 5 millimeters.

With reference to FIG. 2, a production line of the method in question is shown.

Said optimized method for the production of a composite thermal insulation comprises the steps of:

- unwinding a non-woven fabric by means of an unwinding roller 12,

- tensioning and aligning said non-woven fabric by means of a plurality of first tensioning rollers 13;

- mixing a predetermined quantity of thermosetting resin 17 together with the relative cataly st 16 by means of a suitable mixer 15 with automatic control;

- spreading said resin on one face of said carbon fiber by means of a dispenser 14;

- rolling said resin 17 on the non-woven fabric by means of a plurality of lamination rollers 18;

- hardening said resin by means of an oven 19 adapted to dry and generate said composite material by means of an irreversible adhesion between said non-woven fabric and said resin 17;

- applying a quick-setting glue 20 on the surface opposite to the resin-coated one,

- applying an aluminum foil 11 on the surface of the non-woven fabric opposite to that which has been resin-coated;

- cutting the thermal insulati on obtained by means of an automati c robot 21 provided with special blades;

- checking the dimensions of the panels by a laser scanner 22;

- storing the heat-insulating material obtained, based on the dimensions of the thermal insulation panels cut out by said automatic robot 21.

The whole system is driven by an electric motor that moves the rollers.

The operators are dedicated to the maintenance of the system but especially to the replacement of the unwinding roller 12 when the roll of non-woven fabric runs out.

It should be noted that the resin 17 used in the production line may be of the vinyl ester type or of the epoxy type, depending on the quality required by the customer.

Rolling may take place inside a female mold to better model the final shape that the heatinsulating material should acquire. In that case, rolling preferably takes place with vacuum technology, that is through the use of special bags and vacuum pumps adapted to allow a more homogeneous distribution of resin 17 inside the non-woven fabric 10.

Finally, it is clear that modifications, additions or variants that are obvious to a person skilled in the art can be made to the invention described so far, without thereby departing from the scope of protection provided by the appended claims.