TECHNICAL FIELD The invention relates to a multilayer system of textile materials for protective clothing for firefighting. This invention also relates to clothing, in particular firefighter suits, which are made from the multilayer system according to the invention. PRIOR ART

A multilayer system for manufacturing firefighting clothing is known.

A conventional firefighter suit is a multilayer system designed to provide protection against structural fires (EN 469). A conventional firefighter suit for protection in structural fires that consists of a multilayer system has a construction aimed at protecting against heat and fire. Furthermore, it should protect against water and chemicals. With these suits, comfort is subordinate to the high demands of protection. To optimise comfort, the following elements are considered: breathability, insulation factor, flexibility and weight. The element that provides protection against water and chemicals in the current conventional firefighter suit, the membrane, must be maximally permeable to water vapour in order to optimise the breathability of the clothing. Furthermore, for comfort, a balanced insulation factor is considered, sufficient to guarantee the high thermal protection against radiation and flames, but not too high to avoid excessive sweating and furthermore the flexibility and weight of the multilayer system. Comfort mainly has to do with the breathability and the insulation factor of the clothing. It determines the extent to which sweat is generated and the extent to which one can get rid of it.

There is also firefighting clothing for fighting wildfires (EN 15614) and clothing for road rescue (EN 16689). With these types of firefighting clothing, the requirements for protection against heat and fire are significantly lower and the comfort requirements much higher. Depending on the intervention, the right suit should be fitted. In practice, however, a firefighter today has one suit at their disposal, dimensioned for the 'worst case' in terms of protection, which means protection when fighting a structural fire. This suit will not be able to meet the comfort requirements and visibility requirements envisaged for wildfire fighting and road rescue. De facto this means that in many cases a firefighter has to work with an over dimensioned suit and therefore with limited comfort. The job content of a firefighter is such that less than 4% of their time is spent on structural fires. This also means that the protection offered by conventional clothing is only needed 4% of the time, and that the comfort is not adapted in 96% of the cases.

It is an object of this invention to propose a multilayer system which can be used for firefighting clothing which does not have the above-described disadvantages and can be used in all cases with suitable protection and suitable comfort.

It is another object of the present invention to propose a multilayer system that meets all technical firefighting requirements for firefighting clothing and this for the entire field of activity of the firefighter. Firefighting clothing must provide appropriate protection depending on the type of intervention, must be flame retardant and must remain intact, even after contact with a flame. Furthermore, the clothing must insulate appropriately against heat and flames and therefore offer appropriate protection against radiant heat and convection heat. The clothing must be strong and resistant to wear. The clothing should also be appropriately comfortable to wear. Wearing comfort is achieved, among other things, by providing clothing with good and rapid body moisture absorption and transmission, maximum flexibility and all this as light as possible, adapted to the type of intervention. The multilayer system should also not allow water to pass from the outside to the inside. This is particularly important to provide protection against chemicals, among other things, and against steam burns. The steam burns are also caused by a person's own sweat that cannot escape.

Traditional firefighting clothing made of a multilayer system is known and frequently used. This clothing is designed to protect against structural fires. One problem is that, depending on the situation, a different suit is actually required for a firefighting intervention if one wants to work optimally. In practice, in most cases today, only one suit will be available that meets the highest fire requirements. With these high fire protection requirements comes limited comfort. Because most interventions have to do with an over-dimensioned suit, in many cases the comfort limitations are exceeded in the interventions. It is possible that the interventions will be continued with an open vest, so that safety is no longer guaranteed. Furthermore, the conventional suit does not meet the requirements for technical assistance due to the lack of the appropriate high visibility elements and failure to meet the comfort properties applicable there, such as a minimum water vapour resistance. If intervention is required for forest firefighting, the suit does not meet the comfort properties that apply in that case, such as minimum heat resistance and water vapour resistance.

These objects, as well as other objects, are achieved by the present invention. SUMMARY OF THE INVENTION

The invention relates to a two-piece protective garment consisting of a base garment and an overgarment for use in firefighting and intervention according to claim 1. This is advantageous since the base garment can be worn as standard during interventions and external firefighting that can last for a long time, and where contact with very high heat, chemicals, smoke and the like is minimal. For this type of interventions, there are less strict requirements for the protective clothing, which can therefore meet an increased comfort. In particular, the clothing is lighter, more breathable, allowing sweat and heat to escape and to avoid wounds due to friction and the accumulation of sweat and heat.

This concerns, for example, road rescue (EN 16689), outdoor fires such as forest and heath fires (EN 15614). On the one hand, this increased comfort makes it possible to maintain these interventions for a longer period of time. On the other hand, the increased comfort helps to ensure that the protective clothing is used correctly and, for example, is not partially opened, so that protection is no longer guaranteed during the intervention. In a particularly advantageous embodiment, the invention relates to a two-piece protective garment according to claim 2. The two-piece protective garment is designed in such a way that the overgarment is worn over the base garment during interventions in structural fires where the requirements for fire protection, protection against chemicals and the like are higher. The closing system of the overgarment is constructed in such a way that it can only be closed by attaching the overgarment to the base garment and closing the base garment. This guarantees that the overgarment cannot be worn without the base garment. As a result, the overgarment is always used correctly, with the entire two-piece protective garment meeting the strictest standards (EN 469).

In a second aspect, the invention relates to a method according to claim 14.

Protective clothing has specific instructions for cleaning. These are necessary to guarantee that the protective clothing also meets all the conditions after several cleaning cycles. An additional advantage of the two-piece protective garment is that both parts can be cleaned separately. On the one hand, this makes it possible to clean only the base garment when only the base garment has been used. Thus, the overgarment needs fewer cleaning cycles. On the other hand, the base garment and overgarment can be cleaned in different ways. This makes it possible to optimise the cleaning process with a view to the functionality of the clothing. In a further aspect, the invention relates to an overgarment according to claim 15. This overgarment can be attached on top of the base garment. The overgarment cannot be worn without base garment. This makes it possible to put together a two- piece protective garment that meets the high requirements for structural firefighting EN 469.

DESCRIPTION OF THE DRAWINGS

Figure 1 is a schematic representation of the construction of an embodiment of the two-piece protective garment according to the present invention. Figure 2 is a schematic representation of an embodiment of a closing system of the two-piece protective garment according to the present invention.

DETAILED DESCRIPTION

This invention will ensure by means of base garment and overgarment that it is always possible to work with the appropriate comfort properties with the required safety needs.

Unless otherwise defined, all terms used in the description of the invention, including technical and scientific terms, have the meaning as commonly understood by a person skilled in the art to which the invention pertains. For a better understanding of the description of the invention, the following terms are explained explicitly.

In this document, 'a(n)' and 'the' refer to both the singular and the plural, unless the context clearly presupposes otherwise. For example, 'a segment' means one or more than one segment.

The terms 'comprise', 'comprising', 'consist of', 'consisting of', 'provided with', 'have', 'having', 'include', 'including', 'contain', 'containing' are synonyms and are inclusive or open terms that indicate the presence of what follows, and which do not exclude or prevent the presence of other components, characteristics, elements, members, steps, as known from or disclosed in the prior art.

The term 'corresponding' or 'correspondent' closing parts are closing parts which are designed in such a way that they can be fastened together, and thus forming one closing system. Closing parts that do not correspond will not fit together and therefore cannot be closed into one closing system. For example, a zip has a male and a female zip part, which correspond. Two male zip parts do not correspond. Two female zip parts do not correspond either. For example, a velcro system has hooks and a loop strip. Two loop strips do not correspond. Two parts with only hooks do not correspond either.

The two-piece protective garment

In a first aspect, the invention relates to a two-piece protective garment for use in firefighting and intervention, comprising: i. a base garment, suitable as clothing for technical assistance and for fighting forest and heath fires; and ii. an overgarment, suitable for wearing over the base garment, made of a multilayer system comprising an outer fabric, optionally an insulating layer, a waterproof membrane and a lining. In particular, the invention relates to a two-piece protective garment for use in firefighting and intervention, comprising: i. a base garment, suitable as clothing for technical assistance and for fighting forest and heath fires; and ii. an overgarment, suitable for wearing over the base garment, made of a multilayer system comprising an outer fabric, optionally an insulating layer, a waterproof membrane and a lining, where the whole overgarment with base garment is suitable for fighting structural fires. This two-piece protective garment is a 2-in- 1 firefighter suit. The separate base garment and overgarment can be detached from each other. The base garment can be worn as a full-fledged garment and used in interventions. The base garment preferably meets the requirements type road rescue (EN 16689) and outdoor fires (EN 15614 - forest and heath fires). The fire protection requirements for these interventions are clearly more limited than for structural fires (EN 469), but the requirements for comfort are clearly stricter.

The fire protection requirements for base garment are preferably limited to the guarantee of fire resistance of the materials and radiation protection at 20kW/m ² , with protection times in accordance with EN 16689 and EN 15614, considerably lower than the requirements for structural fire interventions (EN 469).

For structural fires, radiation protection is considered at 40kW/m ² with a protection time 60% higher and longer than for outdoor fires. In addition, protection against contact with flames is also required. The latter determines the dimensioning in EN 469. To meet these stricter EN 469 requirements, the overgarment is attached above the base garment, so that the whole is worn as a two-piece protective garment. An additional advantage is that the combination of two-piece protective garment can meet completely different requirements, without having to purchase two different firefighter suits. For forest and heath fires (EN 15614) there is an upper limit for comfort of the thermal resistance Ret of 0.055 m ² K/W. With this Ret it is impossible to meet the protection requirements of EN 469. The upper limit for water vapour resistance Ret is also much lower for EN 15614 and EN 16689 than for EN 469. EN 15614 requires an upper limit of Ret <10m ² Pa/W. With this Ret it is difficult to meet the protection requirements of EN 469, especially when membranes are involved. This problem is solved by dividing it into a base garment with increased comfort and a base garment in combination with an overgarment with maximum protection. According to one embodiment, the two-piece protective garment further comprises a closing system comprising corresponding fastening parts Si and S2 _, wherein the overgarment is provided with a first fastening part Si and wherein the base garment is provided with the corresponding fastening part S2. This closing system may be a zip or a hook-loop system, among other things. Preferably, this closing system is a zip. Figure 2 is a schematic representation of an embodiment of a closing system with a zip. The base garment (2) can close the front opening via a central zip (11). The overgarment (3) is attached to the base garment (2) by means of fastening parts (9). Both sides of the overgarment (3) are provided with a female zip part (10). The base garment is provided with the male zip part on both sides. The female and male zip parts correspond, so that the overgarment can be attached to the base garment. The two female zip parts (10) on the overgarment do not correspond, so that the overgarment cannot be closed on its own. This simply ensures that the overgarment cannot be worn on its own. To close the overgarment, it must be attached to the base garment. However, the base garment can be closed. The overgarment is provided with an extra protective part that also covers the closing system. For example, a cover fabric that fits over the closing system of the base garment. This cover fabric can possibly be attached with buttons, press studs or hook-loop strips. Preferably, this attachment of the cover fabric will be insufficiently strong to close the overgarment without the closing system. This ensures that the two-piece protective garment is always worn correctly, and prevents that only the overgarment can be worn.

According to a preferred embodiment, the two-piece protective garment passes the rain tower test EN 14360 for at least 60 minutes.

According to a preferred embodiment, the two-piece protective garment meets a filtration rate of at least 90% for flue gases and soot particles with particle size 0.1 and 10 pm tested according to the filtration protocol of Centre d'Essai Valabre (France). According to a preferred embodiment, the base garment meets a filtration rate of at least 90% for flue gases and soot particles with particle size 0.1 and 10 pm tested according to the filtration protocol of Centre d'Essai Valabre (France). According to a preferred embodiment, the base garment and the two-piece protective garment have an air permeability between 0 and 100 l/m ² s according to EN 9237 at 100 Pa.

According to a preferred embodiment, the base garment has a Ret lower than 10m ² Pa/W and the two-piece protective garment has a Ret lower than 30 m ² Pa/W measured according to ISO 11092. It is preferable to go below 5m ² Pa/w for the base garment and below 15m ² Pa/W for the two-piece protective garment.

The integral two-piece protective garment meets the requirements of protective clothing for structural firefighting interventions (EN 469). Furthermore, it is desirable to guarantee maximum comfort, with a minimum risk of burns, also due to steam generation (steam burns), and with optimal protection against toxic substances such as carcinogenic substances, and also offering resistance to rain in accordance with EN 14360.

These high and strict standards for full two-piece protective garment ensure maximum protection. As a result, the clothing meets the highest requirements for structural firefighting. Base garment

In addition to the fact that the base garment can be used as a full-fledged garment, the base garment has a second and third essential function. The base garment must support the comfort of the integral two-piece protective garment in one garment. In a preferred embodiment, the base garment conforms to standards EN 15614 and EN 16689. This allows the base garment to be used as a full-fledged garment in various regulated types of interventions where the fire service intervenes.

The base garment complies with the high visibility according to EN ISO 20471.

More preferably, the base garment is made up of a maximum of two fabrics, both fire-resistant EN ISO 14116 index 3. This fulfils the basic requirement of EN 15614 and EN 16689. More preferably, these layers are not water-repellent, rather maximally hydrophilic because the layers in the two-piece protective garment have to serve as a possible sweat buffer. This also has an influence on the operating and maintenance instructions, in order to be able to continue to guarantee the hydrophilic character during the service life. As a result, it is also advantageous to clean the base garment and overgarment separately. Even more preferably, the first textile fabric of this base garment provides protection against radiation 20kW/m ² .

Preferably, the fabric is constructed from an inherently fire-resistant fibre. Preferably, the fabric has a specific weight of 180-240 g/m ² . Preferably, the fabric is suitable for being made in high visibility colours. More preferably, the fabric complies with high visibility according to EN ISO 20471. An example of such a fabric is made up of polyamide-imide, modacrylic, lyocell and other fibres with a specific weight of 230 g/m ² .

The fabric is preferably limited in air permeability. The limitation in air permeability due to the closed structure of the outer fabric means that toxic carcinogens do not penetrate deeper into the clothing. Preferably, the air permeability is at 100l/m ² s or less at lOOPa according to ISO 9237.

The shielding against toxic products is preferably measured with the test method of the Centre de Recherche de Valabre of the French fire brigade, with an intended filtration level >90% against particles with a size of 0.1 to IOm.

In a further embodiment of the base garment, it comprises a second fabric. Preferably, this second fabric is a lining. More preferably, this lining is fire resistant. This fabric shields the wearer from the finish of the first layer. This increases wearing comfort and reduces wear. The layer is again not water-repellent and preferably hydrophilic, for the same reason with regard to the release of moisture such as sweat.

The colour of the lining is preferably dark to prevent visible soiling, for example navy blue.

A preferred fabric for the lining is a 90g/m ² polyamide-imide fabric. Similar fabrics with fire-resistant fibres such as aramid or polyamide-imide / FR viscose can also be used advantageously.

The sewing thread of the base garment is preferably a non-water-repellent aramid thread. The base garment is preferably provided with reflective strips on the outside. These ensure that the base garment, when used without overgarment, ensures sufficient visibility. More preferably, these reflective strips are water vapour permeable. This reduces the risk of steam burns at the level of the strips. This is particularly important when utilising the two-piece protective garment, these reflective strips being located within the entire two-piece protective garment.

Preferably, internal as well as external flaps are provided at the level of the front closure to completely close and protect the zips.

Overgarment

The overgarment is preferably made up of several fabrics: an external fabric whether or not combined with a thermal protection layer, a waterproof, water vapour permeable membrane, an internal lining or a laminated combination of materials. The most preferred overgarment does not comprise a waterproof, water vapour permeable membrane or laminated elements. Protective clothing without a membrane or laminated elements is described herein as 'membraneless' clothing.

The external fabric is preferably fire-resistant to EN ISO 14116 index 3. It is preferably limited in air permeability and optimally closed and treated for water and oil repellence. This is to stop other liquid chemicals in addition to water. It is preferably in a light colour to quickly visualise soiling.

The limitation in air permeability due to the closed structure of the outer fabric means that toxic carcinogens do not penetrate deeper into the clothing. Preferably, the air permeability is at 100l/m ² s or less at lOOPa according to ISO 9237.

The shielding against toxic products is preferably measured with the test method of the Centre de Recherche de Valabre of the French fire brigade, with an intended filtration level >90% against particles with a size of 0.1 to IOm.

The overgarment is preferably rainproof. More preferably, the rainproofing is achieved despite the absence of a water-repellent membrane, for instance by means of a maximally closed fabric. However, this type of fabric requires a specific water and oil repellent treatment and maintenance. This type of maintenance can be more easily achieved if it is only to be carried out on the overgarment. This allows advantageously for a water and chemical resistant firefighter suit that is still breathable. The watertightness is preferably tested according to the rain tower test EN 14360. More preferably, the overgarment meets the rain tower test EN 14360 for at least 60 minutes.

External fabrics suitable for the overgarment according to the present invention include a polyamide-imide-aramid fabric 220g/m ² , a meta- and para-aramid twin system with the para-aramid in grid 225g/m ² , optimally closed fabrics in polybenzimidazole (PBI), polybenzoxazoles (PBO) or similar high performance polymer fibres.

Preferably, the external fabric is of a light colour to quickly detect soiling.

The two-piece protective garment according to the present invention is particularly advantageous since a membrane is not strictly necessary.

At present, the membrane is considered essential in the art for shielding against toxic carcinogens and for shielding against external water and external application of chemicals. The flip side of the coin is that the membrane is a barrier that keeps the sweat in the clothes. For that reason, membranes with the highest possible water vapour permeability are desired. In any case, the rate at which sweat is produced during a strenuous effort, such as in a firefighting intervention, is considerably higher than the rate at which it can be evacuated through the membrane. As a result, there is inevitable sweat build-up in the clothing. Under the influence of external heat radiation, it can evaporate. This evaporated moisture will migrate inwards towards the skin and can end in 'steam burns'.

By avoiding the membrane, the rate at which sweat can evacuate from the clothing is substantially increased. The most recent insights indicate that toxic carcinogens can also be effectively blocked without a membrane and that watertightness can also be adequately guaranteed without a membrane. The advantage of the present invention is that the necessary difficult and expensive water-repellent treatment is only placed on the fabrics that are to receive this treatment. In contrast to traditional suits, where this treatment also ends up on the parts that should not have it. The fabrics that face the body side are preferably even water absorbent to take the moisture away from the body.

The thermal protective layer serves to guarantee thermal protection, together with the other fabrics from the complete construction of the two-piece protective garment (base garment and overgarment). Preferably, this combination complies with EN 469.

The thermal protective layer is not necessary. Tests have shown that achieving the minimum level of protection is already possible with an overgarment and base garment, where the overgarment consists of only a suitable outer fabric and a suitable lining. However, for higher standards, extra protection or a safety margin, a thermal protective layer can be added to the overgarment. The dimensioning of this is therefore determined by the margin that one wants to implement.

Suitable materials are preferably thermostable. Examples: a spunlace 45g/m ² polyamide-imide-aramid or if one takes even more of a margin, a needle felt 100g/m ² polyamide-imide-aramid. The internal lining of the overgarment can be made of the same material as the base garment. The objective is the same as for base garment: to shield the finish of the upper fabrics and to obtain a neat finish visually. In this case, however, the finish is preferably water-repellent. In this way, the lining supports the shielding of water and chemicals from the outer layer. The colour is preferably dark, such as for example navy blue.

The sewing thread of the overgarment is preferably water-repellent aramid thread. Preferably, reflective strips are also applied to the overgarment. More preferably, these reflective strips are optimally water vapour permeable, in order to avoid the risk of 'steam burns' at the level of the strips.

In a preferred embodiment, the overgarment includes reinforcements. In a more preferred embodiment, these reinforcements are optimally water vapour permeable to avoid the risk of steam burns. As a rule, quite a few reinforcement strips are provided on firefighter clothing, for example at the knees, elbows and at the height of the boots.

In a preferred embodiment, the overgarment contains filler materials. In a more preferred embodiment, these filler materials are optimally water vapour permeable, in order to avoid the risk of steam burns. They also do not absorb water. In a firefighter garment there are usually quite a few filler materials to avoid peak loads, for example at the height of the knees, elbows and shoulders. These are preferably designed to avoid depression of the protective layers during peak loads and thereby avoid local 'weak spots' in the protection. The provision of these reinforcements and filler materials in the overgarment in contrast to the base garment is advantageous as they considerably optimise the wearing comfort. In the base garment the reinforcements and fillings are not really necessary.

Preferably, the possibility of tightening the clothing is provided for in crucial places, such as the waist, the bottom of the arms, the legs and along the neck. In this way, the infiltration of toxic products into the lower layers, for example through the 'pumping effect', is prevented.

In a preferred embodiment, the two-piece protective garment is provided with a central closing mechanism, preferably a zip, for opening and closing, which is located on the base garment. More preferably, the overgarment cannot be closed alone. The overgarment is closed by linking it to the base garment and then closing the base garment. This can be done, for example, by providing corresponding zips on the overgarment and base garment, so that the overgarment can only be attached to the base garment but cannot be closed on its own. Preferably, the sliders of the central zip and the zips for attaching the two garments together are opposite each other. As a result, when unzipping, the mistake cannot be made that firefighters take off the entire garment instead of removing the overgarment. This is important when removing the protective clothing step by step in case the overgarment has to be decontaminated. The overgarment preferably consists of fire-resistant material with a specific weight lower than 300g/m ² . Preferably, the overgarment has an air permeability of less than 100 litres/s/m ² at an overpressure of lOOpa. Preferably, this fabric has been treated to repel chemicals. Preferably the fabric and the treatment is rain resistant. Preferably, the construction of the overgarment offers resistance to rain.

In a second aspect, the invention relates to a method for cleaning two-piece protective garment comprising the steps of: cleaning the base garment: cleaning the overgarment:

In a preferred embodiment, the method for cleaning the two-piece protective garment comprises the steps of: cleaning the base garment comprising a simple cleaning maintenance, preferably to be carried out by the user themselves; and cleaning the overgarment, comprising professional maintenance to ensure water and oil repellence, including, if necessary, the necessary elimination of toxic contaminants.

The advantages are as follows: cleaning the base garment:

The clothing will receive normal maintenance, preferably non-water repellent. This normal maintenance ensures that the clothing subsequently removes the sweat as well as possible from the body side by absorption and evacuation of the sweat to the outside. This type of maintenance is a simple wash and can preferably be done by the owner of the clothing themselves cleaning the overgarment: In the event of contamination of the overgarment with dangerous products when carrying out an intervention, the outer part with these toxic products can easily be detached from the base part in such a way that the base garment does not become contaminated with toxic products from the contaminated overgarment. As far as cleaning is concerned, the overgarment will require aggressive cleaning to remove the contaminated fabrics, whereas this is not necessary for the base garment. If necessary, specific decontamination techniques can be used, such as C02 cleaning, whether or not linked to a 'standard' maintenance, in the event of the presence of highly toxic contaminants. This will benefit the lifespan of the base garment, which consists of more comfortable but physically less strong materials. It is also the case that the outer fabric of the overgarment is much more subject to abrasion with the environment and the fabrics themselves. This is because kneeling, crawling and dragging firefighting equipment are normal activities in a structural intervention. Also because of the thick character, necessary to protect against heat and fire, of the total garment you get more abrasion between the legs and also at the level of the body with the arms. This wear causes the products that provide water and oil repellence to disappear or lose their efficiency. Because these are only needed on the overgarment, the after-treatment of these products can be handled much more efficiently, but there will also be a much better optimisation of the reactivation of these products. This after-treatment is a specialisation and must therefore be applied with expert knowledge with specialised products that are not freely available in the trade. This overgarment must therefore be offered for maintenance to laundries that specialise in this, but also to fire stations that are equipped to be able to apply an optimal specialised treatment.

In a further preferred embodiment, the second aspect comprises, in addition to cleaning, also the maintenance of the base garment and/or the overgarment. Cleaning and maintaining the base garment and the overgarment separately makes it possible to use different maintenance techniques for both functionalities. This also allows optimising these processes. This saves costs and time. In addition, this is particularly advantageous for treated fabrics commonly used in the overgarment. By using the base garment separately, these will require aggressive cleaning less often. By cleaning separately, higher and more qualitative cleaning and maintenance processes can be used. As a result, the lifespan of both the base garment and the overgarment can be increased. In a further aspect the invention relates to overgarments suitable for attachment to a base garment, wherein the overgarment is made of a multilayer system comprising an outer fabric combined with 1 or more layers, these multiple layers can be an insulating layer, a waterproof membrane, a lining or a combination thereof, whether or not laminated, wherein the overgarment is provided with two fastening parts Si and Sr, which do not correspond. Such an overgarment can be attached to a base garment, but is not suitable for use on their own. This guarantees the correct use of the two-piece protective garment.

The filtration protocol of the Centre d'Essais et de recherche Valabre

The diffusion of fine and very fine flue gas particles through the textile layers that make up the firefighting garment is studied in passive diffusion. The outside of the test sample is placed in direct contact with flue gases while the unexposed side is in a sealed compartment. The ratio of the concentrations of fine and very fine particles on both sides makes it possible to measure the passive diffusion characteristics of the sample.

Description of the test bench

The test bench consists of 3 cube-shaped enclosures E0, El, E2 with an inner dimension of 250 mm, connected together at the time of the test and subjected to an exhaust system in the direction from E0 to E2. A fourth E3 chamber, cylindrical in shape (internal diameter 45 mm and length: 120 mm), serves as a support for the sample and is located in the end of E2, away from El. Enclosures E0 and El contain high density vegetation smoke which is pre-filled with a generator (see below). The E2 enclosure is directly connected to an exhaust system through which air and vegetation smoke can be supplied from compartments E0 and El.

The sample is placed at one end of E3 with an airtight attachment. The other end of the cylinder is hermetically sealed with a cap and contains a sample tube. The E3 enclosure is placed in the end of the E2 enclosure to subject the outside of the sample to the smoke transferred from E0, El to E2 by the aspiration system.

Baseline measurement

The E3 enclosure without sample is placed in the E2 enclosure.

Enclosures E0 and El are first filled with dense smoke and then connected to each other and to E2. The exhaust is started for 20 seconds, the time it takes to transfer the smoke from E0 to E2. The concentrations of fine and very fine particles are then measured in E2 and in E3 after a stabilisation time of 5 minutes. This delay allows the moving particles to stabilise and diffuse passively. Given the small volume of E3, one measurement (PM1 or PM 10) is performed per test. The ratio of the average concentrations of E2 to E3 is then calculated for the particles PM1 and PM 10, respectively. The different chambers are then completely purified for the next test.

Measurement with a non-filtering reference material

The non-filtering reference fabric is installed in a leak-tight manner at the end of the enclosure E3 and then deposited in the enclosure E2. Exposure to the flue gases is carried out as in the baseline measurement and the average concentrations of fine and very fine particles are measured in E2 and then in E3.

Measurement of the test sample

The test sample is tested under the same conditions as the reference material.

The passive filtration TF of the sample (expressed in %) is calculated according to the following formula:

Fyef FQ F sample 100 100

^L sample ^L 0 wherein: R is calculated as the concentration of particles in E2 divided by the concentration of particles in E3. Here R _ref is the R value of the non-filtering reference material, Ro is the R value of the baseline measurement and R _sampie is the R value of the sample.

This filtration value is calculated for PM1: particles with 0.1-lpm diameter and PM10: particles with O.l-lOpm diameter, respectively.

Smoke protocol

The smoke is produced by a generator designed to burn plants. A metal shell connected to the E0 enclosure provides convection transfer.

The smoke is produced under controlled conditions from a constant combustible mixture in composition and mass. It consists of 4 Mediterranean plants that represent the Mediterranean herbs, shrubs and trees, respectively. The harvested plants are cut, leaving only the terminal branches and leaves. These are the most combustible elements. Then they are dehydrated in an oven at 60°C for 24 hours and then stored separately in a dry place. The mass fractions constituting the combustible mixture used in the smoke chamber are 2g Mediterranean herbs, lg Aleppo pine, lg rosemary, lg Kermes oak.

The smoke generator consists of a combustion chamber with a stainless steel chimney above it that is connected to the E0 enclosure by a flexible aluminium jacket that is one metre long. The fuel installed in a metal cup is placed in the combustion chamber of the smoke generator and then manually ignited by means of a fire starter. The smoke released during this combustion rises by convection and is concentrated in E0.

In what follows, the invention is described by way of non-limiting examples illustrating the invention, and which are not intended to and should not be interpreted as limiting the scope of the invention.

EXAMPLE 1: Multilayer system of the two-piece protective garment

Figure 1 is a schematic representation of the construction of a two-piece protective garment (1), consisting of a base garment (2) and an overgarment (3). The base garment (2) is suitable for use without the overgarment during interventions, such as outdoor fire and the like. The base garment is comfortable and can be worn for more than 6 hours. The base garment offers protection against fires in natural areas according to EN 15614 and meets the requirements for technical assistance according to EN 16689. The base garment (2) protects against heat of 20 kW/m ² (20), flue gases and soot, and has very good high visibility properties. The base garment is comfortable for the wearer (30) with a resistance to water vapour Ret lower than 10 m ² Pa/W and a resistance to heat Ret lower than 0.55 m ² K/W.

The base garment consists of a first textile fabric (7), consisting of a fire-resistant material with an air permeability of less than 100 l/m ² s at 100 Pa. The first textile fabric has a specific weight of less than 230 g/m ² . The first textile fabric absorbs moisture to evacuate this moisture from the skin to the outside. The fabric consists of a colour that meets the standard EN ISO 20471 for good visibility.

The base garment may further comprise an optional lining (8). This lining complies with EN 14116 index 3 for fire-resistant materials. The fabric preferably absorbs moisture to evacuate it from the skin and transport it to the outer layers. In this way steam burns can be prevented.

The overgarment (3) is suitable for attaching on top of the base garment. The overgarment (3) is never worn separately. The whole of the two-piece protective garment (1) is used for structural interventions according to standard 469. These interventions usually last a maximum of ¾ of an hour. The two-piece protective garment (1) protects against rain, toxic chemicals, smoke, soot, heat of 40 kW/m ² and flames of 80 kW/m ² (21). The resistance to water vapour of the two-piece protective garment Ret is lower than 30 m ² Pa/W. (31) The overgarment is made up of: an external fabric or outer fabric (4),

- an optional filling (5) optionally provided with structure, optionally provided with a waterproof, water vapour permeable membrane, and a lining (6).

The external fabric (4) consists of fire-resistant material with a weight below 300 g/m ² . The air permeability is less than 100 litres/m ² s at a negative pressure of 100 Pa. The external fabric together with the rest of the overgarment structure repels chemicals, and together with the rest of the overgarment structure is impermeable to rain according to EN 14360. The outer fabric, together with the rest of the overgarment construction, offers protection against heat and flames according to EN 11612 and EN 469 and stops smoke and soot particles.

The optional filling (5) consists of fire-resistant material with a weight below 135 g/m ² , and includes a structure provided to obtain an air barrier that provides insulation against flames and heat. The filling is optionally coupled with a waterproof, water vapour permeable membrane. Preferably, this membrane is missing.

The lining (6) has a weight lower than 150g/m ² . The lining offers repellence against chemicals and water droplets. The fabric also meets the requirements of an index 3 material according to EN 14116.

EXAMPLE 2: Closing system of the two-piece protective garment

Figure 2 is a schematic representation of the closing system of the two-piece protective garment. The base garment (2) can close the front opening via a central zip (11). The overgarment (3) is attached to the base garment (2) by means of fastening parts (9). Both sides of the overgarment are provided with a female zip part (10). These two female zip parts (10) do not correspond, so that the overgarment cannot be closed by itself. In this way it can be ensured that the overgarment is always worn in combination with the base garment.

When removing the overgarment in the event of contamination, it is advantageous that the overgarment can be removed first, without opening the base garment. In order to ensure that firefighters do not open the wrong zip, the central zip (11) is arranged opposite to the fastening parts (9).