FR3109114A1 - Manufacture of a molded part from shredded thermosetting composites and shredded glass fibers - Google Patents

Abstract

The present invention relates to a method of manufacturing a molded part (PM) comprising: - a supply (S1) in a hopper of first shreds (BR1) of elements in thermosetting composite material and of second shreds (BR2) of elements fiber filler; - a mixing (S2) in a mixer of said first (BR1) and second (BR2) ground materials to obtain a mixture (MIX1); - an addition (S3) in the mixer of a binder (LI1, LI2) to obtain a viscous mixture (MIX2); and - molding (S5) of said molded part (PM) by introducing said viscous mixture (MIX2) into a mold.

Description

Manufacture of a molded part from shredded thermosetting composites and shredded glass fibers

The present invention relates to the field of the manufacture of molded parts, and more particularly the manufacture of molded parts from waste thermosetting composite materials and waste glass and/or carbon fibers.

One of the objects of the present invention is to provide a solution for efficiently and inexpensively recycling waste thermosetting composite materials and waste glass and/or carbon fibers.

One of the other objects of the present invention is to provide a liquid formulation of a matrix based on shredded thermosetting composite materials and shredded glass and/or carbon fibers.

The present invention will find many advantageous applications in the field of industry, and in particular in the nautical industry and shipbuilding.

Other advantageous applications could also be envisaged for the recycling of thermosetting composites such as, for example, the recycling of thermosetting composites from wind turbines at the end of their life.

State of the art

Composite materials have interesting mechanical properties including strength and lightness.

Thus, composite materials, and in particular thermosetting composite materials, are used in large quantities in the nautical and shipbuilding industry: such composite materials are used, for example, in the manufacture of boat hulls.

However, the treatment of waste associated with these materials remains problematic.

These composite materials mainly comprise a polymer resin matrix and a reinforcing structure consisting of inorganic fibers such as glass and/or carbon fibers.

The polymers used are generally unsaturated polyesters which, after being brought into contact with the reinforcing fibers, are polymerized (or crosslinked) to form a three-dimensional network resulting in a thermosetting polymer.

Given this structure, thermosetting polymers, unlike thermoplastic polymers, cannot be reworked with heat.

So far it has been very difficult, if not impossible, to recycle such waste.

Also, the vast majority of thermosetting resin waste, including that from the nautical industry, is forced at the end of its life to follow a treatment process that provides for burial or incineration with household waste.

This seems very unsatisfactory both for financial reasons and for ecological and environmental reasons.

Alternative recycling techniques are known which aim to process thermosetting composite materials to manufacture new mechanical parts.

Certain recycling techniques are known which consist in using shredded scrap or manufacturing scrap from at least one molded product or at least one end-of-life molded product made of composite material consisting of a matrix based on at least one thermosetting polymer (polyester) reinforced with layers of fibers (fiberglass and/or carbon).

These fibers provide at least part of the reinforcing load of a composition for molding a new product.

The glass and/or carbon fibers therefore contribute to the structural reinforcement of the new product.

The Applicant indeed submits that the tests carried out on samples show that the percentage of fibers used greatly varies the performance related to the mechanical resistance of the new products.

The Applicant also submits that the technique for molding new products remains very restrictive. It is indeed necessary to lay the sheets of glass fibers and/or carbon in the mold before molding and introduction of the thermosetting resin.

This requires the intervention of an operator, which remains restrictive and costly.

In addition, these techniques of the prior art require the use of sheets of new glass and/or carbon fibers; this does not contribute to the recycling of glass and/or carbon fibres.

For all of these reasons, the Applicant observes that the solutions of the state of the art are not fully satisfactory.

The present invention aims to improve the situation described above.

The present invention aims more particularly to remedy the various drawbacks mentioned above by proposing a simple, economical and effective solution for recycling both waste thermosetting composite material and waste glass and/or carbon fibers.

To this end, the object of the present invention relates, according to a first aspect, to a method of manufacturing a molded part comprising the following steps:
- A supply in a hopper of first shredded elements of thermosetting composite material and second shredded filler elements;

- mixing the first and second ground materials in a mixer to obtain a mixture;

- addition to the mixer of a binder capable of reacting with the mixture to formulate a viscous mixture; And

- a molding of the molded part by introducing the viscous mixture into a mould.

Thus, thanks to the succession of these different technical steps, characteristic of the present invention, it becomes possible to recycle the elements made of thermosetting composite material (for example of the polyester type) and the fillers (of the glass fiber type and/or carbon), such elements being present in large quantities in the hulls of boats for example or in wind turbines, or others.

The process provides for mixing together shredded materials from this waste (polyester and glass fibers for example) and adding a binder which causes a thermomechanical or chemical or thermochemical reaction to obtain a viscous mixture then allowing the production of a casting.

It will be noted that, contrary to the prior art, the glass and/or carbon fiber waste is presented here as filling fillers and not as reinforcing fillers having a structural effect. As a result, the technique used allows efficient recycling of these fibers from manufacturing scraps from the hulls of boats or wind turbines, for example.

It will also be noted that, unlike the prior art, the method according to the present invention accepts the presence of wood and polyurethane foams (PET). We know here that boat hulls include such materials, which makes the process particularly effective in the field of the nautical industry and shipbuilding.

Advantageously, the first ground materials represent a percentage by weight at least equal to 85%, preferably equal to 90%, and the second ground materials represent a percentage by weight less than or equal to 15%, preferably equal to 10%.

Here, these percentages by weight are given on the total weight of the mixture.

In one embodiment implementing so-called thermosetting recycling, the binder is a thermosetting resin.

Preferably, this thermosetting resin is of the polyester resin type.

Advantageously, a catalyst is added to the mixture during the addition step.

Preferably, this catalyst has a percentage by weight of 2% on the total weight of the mixture. Such a percentage of catalyst makes it possible to effectively accelerate the reaction and thermosetting recycling.

In an alternative embodiment implementing thermoplastic recycling, the binder comprises a plurality of polymer granules.

In this mode, provision is preferably made for the method to include, following the step of adding the binder, heating of the mixture.

Such heating accelerates the polymerization of the mixture.

Advantageously, the molding step includes an injection of the viscous mixture into the mould, said injection comprising an implementation of an injection screw of the Archimedes screw type housed inside a plasticizing tube comprising a heat resistence.

We understand here that the actuation of the Archimedes screw makes it possible to convey the viscous mixture through a die to inject it into the mould.

In an advantageous embodiment, the mixing is carried out under pressure conditions of less than 0.2 bar. Such pressure conditions for mixing are implemented for thermosetting recycling.

Preferably, the mixing is carried out under vacuum. This accelerates the reaction to obtain the liquid formulation based on the ground material originating from the elements made of thermosetting composite material and the elements made of fiber filler (glass and/or carbon fibers for example). This helps to reduce air bubbles before injection.

For thermoplastic recycling, mixing is not carried out under such pressure conditions (less than 0.2 bar).

Advantageously, the supply step includes an introduction into the hopper of shredded felts and/or textile pieces (technical textiles such as for example boat sails) and/or ropes.

This broadens the spectrum of recycled products from the nautical industry.

It should be noted that these shredded materials also represent a filler and do not have any structural effect.

Advantageously, the method according to the present invention comprises grinding at least of the elements made of thermosetting composite material and/or of the elements in fillers to obtain first and second ground materials.

Preferably, this grinding step is carried out so as to obtain ground materials in the form of flakes having a length of 2 to 20 millimeters.

Advantageously, the method according to the present invention comprises, following the grinding step, a sieving of the first and/or second ground materials.

Advantageously, a colorant is added to the mixture during the addition step.

Preferably, the fillers are glass fibers and/or carbon fibers.

The object of the present invention relates, according to a second aspect, to a use of the method as described above, in which the first shredded materials are derived from waste elements made of thermosetting composite material and the second shredded materials are derived from waste elements filling fillers of the glass fiber and/or carbon fiber type.

Such use is particularly appreciated for the recycling of this waste.

Preferably, the waste comes from the nautical industry.

Alternatively, this waste can come from other industries such as the wind industry to recycle wind turbines at the end of their life.

Advantageously, the molded part is a substantially parallelepipedal slender part of the slat type. It can also be a blade.

The manufacture of such molded parts can be used to design boat pontoons for example; such pieces in the form of slats and/or slats can indeed have the appearance of teak or another equivalent exotic wood (appreciated in the nautical world).

Correlatively, the object of the present invention relates, according to a third aspect, to an installation for manufacturing a molded part, said installation comprising:

- a hopper configured to receive first shredded thermosetting composite material elements and second shredded filling filler elements;

- a mixer configured to mix the first and second ground materials in order to obtain a mixture;

- addition means configured to add a binder to the mixture in said mixer, said binder being capable of reacting with the mixture to formulate a viscous mixture; And

- a mold configured to make a molded part from the viscous mixture.

Advantageously, an installation according to the present invention further comprises means configured for the implementation of the steps of the method as described above.

Thus, the present invention, by its various structural and functional technical characteristics, provides players in the recycling industry and manufacturers (in particular of boats and/or wind turbines) with a technique that is simple to implement and effective allowing to reuse waste from thermosetting composite materials and glass and/or carbon fibers.

Brief description of the appended figures

Other characteristics and advantages of the present invention will become apparent from the description below, with reference to Figures 1 to 3 which illustrate various embodiments which are devoid of any limiting character and in which:

FIG. 1 schematically represents an installation for manufacturing a molded part according to an embodiment of the present invention;

FIG. 2 schematically represents an installation for manufacturing a molded part according to another exemplary embodiment of the present invention; And

FIG. 3 represents a flowchart illustrating the method of manufacturing a molded part according to an exemplary embodiment of the present invention.

detailed description

The present invention will now be described in the following with reference in conjunction to Figures 1 to 3 appended to the description.

As a reminder, one of the objectives of the present invention is to recycle certain waste from the boating and shipbuilding industry, including in particular waste comprising thermosetting composite materials and waste comprising glass fibres.

Such waste comes for example from molded parts such as boat hulls.

This detailed description for the sake of clarity will focus on an example of application in the field of boating and shipbuilding.

This is in no way limiting: A person skilled in the art will understand here that he can transpose this example of application to other fields in which the waste also includes thermosetting composite materials and glass fibers such as example in the field of wind power.

Recycling such waste thermosetting composites and glass fibers to manufacture new molded parts is made possible by the present invention.

It will be noted that FIGS. 1 and 2 both represent installations 100 which differ from each other in that they each implement a different molding technique.

On the other hand, we find in the two installations 100 illustrated in FIGS. 1 and 2 all the other common technical means for the implementation of the invention.

In each of the two examples described here, there is a specific installation 100 comprising in particular a hopper 10.

In these two examples, the operator during a step S1 loads into the hopper 10:
- first shredded BR1 comprising waste thermosetting composite materials such as for example shredded polyester; And
- second ground materials BR2 comprising glass fiber waste.

The use of glass fibers as filler is characteristic of the present invention; this differs in particular from the state of the art in which it is found that glass fibers have a structural effect and are used as reinforcing fillers.

Preferably, provision is made in these two examples for a distribution of the ground materials BR1 and BR2 according to the following percentages: the first ground materials BR1 represent a percentage by weight of approximately 90% and the second ground materials represent a percentage by weight of approximately 10% , said percentages by weight being given on the total weight of said mixture.

The hopper 10 therefore stores the ground first BR1 and second BR2 for a determined storage period.

During this step S1, provision can also be made to fill the hopper 10 with other waste to be recycled, such as shredded materials BR3 of ropes, felts and/or textile parts. Such waste is found in abundance in the nautical industry.

It will be understood that the installation 100 can also comprise upstream of the hopper 10 one or more grinders (not represented here) configured to grind the waste beforehand in order to obtain the shredded materials BR1, BR2 and BR3.

Thus, in the production chain provided for in these examples, it is possible to provide for the transport by trucks (or others) of waste from the naval industry (for example: boat hulls at the end of their life or manufacturing scrap ).

Here, the trucks dump this waste in dumping areas provided for this purpose.

This waste is then conveyed by conveying means (not shown here) to the shredder(s).

It is for example possible to provide a first grinder which grinds during a step S0_1 the waste comprising the elements of thermosetting composite material to provide the first shredded material BR1 and a second grinder which grinds during a step S0_2 the waste comprising fiber elements of glass to provide the second BR2 shredded material.

Here, the first and second grinders are configured to grind the waste into shredded material in the form of flakes with a length of between 2 and 20 millimeters.

Such dimensions contribute in particular to obtaining shredded materials BR2 serving as fillers.

It is also possible to provide a third grinder which grinds during a step S0_3 the other waste ropes, felts and/or textile parts to obtain the shredded material BR3.

In these two examples, it is also possible to provide a sieve (not shown here) allowing S0_4 sieving of the shredded materials BR1, BR2 and BR3 before loading into the hopper 10.

This sieving step S0_4 makes it possible to filter the shredded material for the subsequent step below.

It will be noted that this screening step is limited and remains optional.

Furthermore, the method implemented in the context of the present invention accepts the presence of wood and PET foams in the ground material; this is particularly interesting in the field of the nautical industry and shipbuilding: plywood or balsa wood and PET foams are used in large quantities in the manufacture of thermosetting parts as reinforcement and sandwich principle.

In these two embodiments, the hopper 10 is located directly above a mixer 20.

Once the hopper 10 is filled, it pours the shredded materials BR1, BR2 and BR3 into the mixer 20 by gravity emptying.

After pouring the shredded material into the mixer 20, the operator can initiate the subsequent mixing step S2 by first lowering the pressure within the mixer 20 so as to create a vacuum. The creation of a vacuum reduces the air bubbles before injection of the material and thus facilitates the molding.

This stage of mixing S2 under vacuum of the ground materials BR1, BR2 and BR3 is carried out for a determined mixing period to obtain a mixture MIX1.

In each of these two examples, an addition S3 is then provided in said mixer 20 of a binder LI1 or LI2, or reagents. Such a binder LI1 or LI2 is selected to react with the mixture MIX1 in order to obtain the formulation of a viscous mixture MIX2. This addition S3 of a binder LI1 or LI2 is implemented by addition means 50.

In the embodiment of Figure 1, the binder LI1 added during this step S3 is a liquid thermosetting resin, for example here a polyester resin.

Such a polyester resin can for example be an orthophthalic unsaturated polyester resin, a vinylester resin or even an epoxy resin.

Provision is then made in this example to also add a catalyst CA which makes it possible to accelerate the reaction of the polyester resin LI1 with the mixture MIX1 of ground materials BR1, BR2 and BR3.

It may be, for example, a catalyst of the organic peroxide type.

This first example corresponds to a thermosetting recycling.

In the embodiment of Figure 2, the binder LI2 added during this step S3 comprises polymer granules.

Preferably, this example requires in this case to provide a rise in temperature S4 of the mixture MIX1 with the binder LI2 to obtain after thermal reaction and polymerization a viscous mixture MIX2.

This second example corresponds to thermoplastic recycling.

In one example as in the other, a viscous mixture MIX2 is obtained.

Provision may also be made during step S3 for the addition of a dye CO, in order to obtain from the colored viscous mixture MIX2 a molded part PM having the desired color.

The operator will then proceed, using a mold 30, to the molding S5 of one or more PM molded parts based on this viscous mixture MIX2.

This molding S5 will be described according to the two examples provided here. Those skilled in the art will however understand that other techniques may be implemented for the S5 molding of the PM part.

In the example of Figure 1, there is a mold 30 with injection means 31 of the nozzle type allowing the viscous mixture MIX2 to be injected into the mold 30.

The operator can actuate these injection means 31 to initiate the molding operation and allow the injection of said mixture.

In this example, the mold 30 is in two parts 30A and 30B which close on each other and together define the matrix of the mold 30 into which the viscous mixture MIX2 is introduced. It will preferably be noted here that the part 30B, here the upper part, is closed against the part 30A, here the lower part, according to a closing pressure of between 0.4 and 1 bar.

In order to bring the viscous mixture MIX2 into the matrix of the mold 30, the injection means 31 implement a suction through the matrix and a suction pipe 32 between -0.1 and -0.6 bar to suck in said viscous mixture and spread this throughout the matrix.

Sealing is implemented at the level of the suction duct by seals 33.

The closing vacuum is implemented by suction between the seals.

Once the viscous mixture MIX2 has been injected into the mold 30, the molding operation S5 as such can begin.

In the embodiment of Figure 2, an alternative molding is provided with the implementation of an Archimedes screw 35, the actuation of which makes it possible to convey the mixture MIX1 in the plasticizing tube 34 towards a die opening in mold 30.

In this example, the tube 34 further comprises a heating resistor 36; it is here the heating resistor 36 which allows the heating of the mixture MIX1 to obtain the viscous mixture MIX2.

On leaving the die, it is therefore understood here that the mixture MIX2 is in the viscous state and can be easily introduced into the mold 30 for the molding S5 of the part PM.

Whatever the molding technique, it will be understood that the viscous formulation obtained with the first BR1 and second BR2 ground materials makes it possible to obtain a paste whose introduction into the mold makes it possible to manufacture molded parts, which allows recycling simple and effective thermosetting composite waste and fiberglass waste.

In the application described here, the die used allows the molding of a substantially parallelepipedal slender PM part of the slat, panel or blade type. Here, such a molded PM part can be used to make lathing for boat decks with the appearance of exotic wood such as teak. Such an exotic wood is particularly appreciated in the field of boating because it gives a luxurious character to the ship. On the other hand, the use of exotic wood is very expensive; the Requester also submits that a shortage of exotic wood supply is to be anticipated in the coming years.

The application of the invention in the field of boating is for these reasons particularly appreciated.

It should be noted that this detailed description relates to a particular embodiment of the present invention, but that in no case this description is in any way limiting to the subject of the invention; on the contrary, it aims to remove any possible imprecision or any misinterpretation of the following claims.

It should also be noted that the reference signs placed between parentheses in the following claims are in no way limiting; these signs have the sole purpose of improving the intelligibility and understanding of the following claims as well as the scope of the protection sought.

Claims (21)

Method of manufacturing a molded part (PM) comprising the following steps:
- a supply (S1) in a hopper (10) of first ground materials (BR1) of elements made of thermosetting composite material and of second ground materials (BR2) of filling filler elements;
- a mixing (S2) of said first (BR1) and second (BR2) ground materials in a mixer (20) to obtain a mixture (MIX1);
- an addition (S3) in said mixer (20) of a binder (LI1, LI2) capable of reacting with the mixture (MIX1) to formulate a viscous mixture (MIX2); And
- molding (S5) of said molded part (PM) by introducing said viscous mixture (MIX2) into a mold (30). Process according to Claim 1, in which the first ground materials (BR1) represent a percentage by weight at least equal to 85%, preferably equal to 90%, and the second ground materials (BR2) represent a percentage by weight less than or equal to 15 %, preferably equal to 10%, said percentages by weight being given on the total weight of said mixture. Method according to claim 1 or 2, wherein said binder (LI1, LI2) is a thermosetting resin (LI1). Process according to Claim 3, in which the thermosetting resin (LI1) is of the polyester resin type. Process according to Claim 3 or 4, in which a catalyst (CA) is added to said mixture (MIX1) during the addition step (S3). Process according to claim 5, wherein said catalyst (CA) has a weight percentage of 2% on the total weight of said mixture (MIX1). A method according to claim 1 or 2, wherein said binder (LI1, LI2) comprises a plurality of polymer granules (LI2). Process according to Claim 7, which comprises, following the step of adding (S3) said binder (LI2), heating (S4) of said viscous mixture (MIX2). Method according to claim 8, in which the molding step (S5) comprises an injection of said viscous mixture (MIX2) into said mold (30), said injection comprising an implementation of an injection screw (33) of Archimedes screw type housed inside a plasticizing tube comprising a heating resistor. Method according to any one of the preceding claims, in which the mixing (S2) is carried out under pressure conditions of less than 0.2 bar. Process according to Claim 10, in which the kneading (S2) is carried out under vacuum. Process according to any one of the preceding claims, in which the first (BR1) and/or second (BR2) ground materials are in the form of flakes having a length of 2 to 20 millimeters. Method according to any one of the preceding claims, in which the step of supplying (S1) includes an introduction into the hopper (10) of ground materials (BR3) of felts and/or textile pieces and/or cords. Process according to any one of the preceding claims, which comprises a grinding (S0_1) of at least the elements made of thermosetting composite material and/or the filling filler elements to obtain first (BR1) and second ground materials (BR2). Method according to claim 14, which comprises, following the grinding step (S0_1), a sieving (S0_2) of the said first (BR1) and/or second (BR2) ground materials. Process according to any one of the preceding claims, in which a colorant (CO) is added to the mixture during the addition step (S3). A method according to any preceding claim, wherein the fillers are glass fibers and/or carbon fibers. Use of a process for manufacturing a molded part (PM) according to any one of the preceding claims, in which the first ground materials (BR1) are derived from waste elements made of thermosetting composite material and the second ground materials (BR2) are from waste elements in filling fillers of the glass fiber and/or carbon fiber type. Use according to claim 18, wherein the waste comes from the nautical industry. Use according to claim 18 or 19, in which the molded part (PM) is a substantially parallelepipedal slender part of the slat type. Installation (100) for the manufacture of a molded part (PM), said installation (100) (100) comprising:
- a hopper (10) configured to receive first shredded materials (BR1) of thermosetting composite material elements and second shredded materials (BR2) of filler fiber elements;
- a mixer (20) configured to mix said first (BR1) and second (BR2) ground materials in order to obtain a mixture (MIX1);
- adding means (50) configured to add a binder (LI1, LI2) in said mixer (20) in order to obtain a viscous mixture (MIX2); And
- a mold (30) configured to make a molded part (PM) from said viscous mixture (MIX2).