Starting composition for a foam which is suitable for capturing dust particles, method for capturing dust particles, spraying device suitable for the method
Abstract
Starting composition for a foam suitable for trapping dust particles, comprising: - a fraction of glycol ether, - a fraction of fatty alcohol, - a fraction of amine oxide, and - a fraction of fatty alcohol sulphate. A water-based foamable mixture comprising the starting composition. Method for capturing dust particles that may be released during work on a substrate using the foamable mixture. Spraying device, comprising: - a reservoir for a foamable mixture under pressure from a gas, - a spray head for spraying the foamable mixture, - a line for supplying the foamable mixture from the reservoir to the spray head, - a gas inlet in the gas and foamable mixture conduit line, the reservoir being a closed chamber without inlet comprising an amount of the foamable mixture.

Term
8.6 yearsto projected expiry
Projected expiry 14 April 2035, counted from filing; an application has no term until it is granted.
- Priority and filed
- Published
- Today
- Projected expiry
19 claims: 14 independent, 5 dependent
- 1Conclusies 1. Uitgangssamenstelling voor een schuim dat geschikt is om stofdeeltjes weg te vangen, omvattende:- een fractie glycolether, - een fractie vetalcohol, - een fractie amineoxide, en - een fractie vetalcoholsulfaat.
- 2Uitgangssamenstelling volgens conclusie 1, welke een vloeibaar concentraat is, dat bij voorkeur water omvat en bij meer voorkeur 10 tot 40 gew.% water.
- 3Uitgangssamenstelling volgens een van de voorgaande conclusies, omvattende:- 1 tot 20 gew.% fractie glycolether, bij voorkeur 5 tot 15 gew.%, - 1 tot 20 gew.% fractie vetalcohol, bij voorkeur 5 tot 15 gew.%, -0,1 tot 10 gew.% fractie amineoxide, bij voorkeur 0.2 tot 2.0 gew.%, - 1 tot 20 gew.% fractie vetalcoholsulfaat, bij voorkeur 5 tot 15 gew.%.
- 4Uitgangssamenstelling volgens een van de voorgaande conclusies, waarbij de fractie glycolether een of meer glycoldiethers omvat, waaronder bij voorkeur 2-(2butoxyethoxyjethanol.
- 5Uitgangssamenstelling volgens een van de voorgaande conclusies, waarbij de fractie vetalcohol een of meer C12-C16 vetalcoholen omvat.
- 6Uitgangssamenstelling volgens een van de voorgaande conclusies, waarbij de fractie amineoxide een of meer trialkylamine-N-oxiden omvat, waaronder bij voorkeur coco-alkyldimethylamine-N-oxide.
- 7Uitgangssamenstelling volgens een van de voorgaande conclusies, waarbij de fractie vetalcoholsulfaat een of meer vetalcoholethersulfaten omvat, waaronder bij voorkeur vetalcoholethersulfaten die C12-04 vetalcoholen omvatten.
- 8Schuimbaar mengsel op waterbasis, dat 2 tot 5 gew.% van de uitgangssamenstelling volgens een van de voorgaande conclusies omvat.
- 9Schuimbaar mengsel volgens conclusie 8, met een oppervlaktespanning van 2040 mN/m, in het bijzonder 22-32 mN/m.
- 10Schuimbaar mengsel volgens een van de conclusies 8-9, met een viscositeit van 40-80 mPa.s.
- 11Schuimbaar mengsel volgens een van de conclusies 8-10, met een verschuimingsgetal van 8 tot 20.
- 12Werkwijze voor het wegvangen van stofdeeltjes die tijdens werkzaamheden aan een substraat kunnen vrijkomen, omvattende de stappen van:- het vermengen van een gas met een schuimbaar mengsel, en - het onder overdruk uit een sproeiinrichting sproeien van het met een gas vermengd schuimbaar mengsel op het substraat voordat de werkzaamheden worden aangevangen, waarbij een schuimlaag wordt gevormd op het substraat welke een 50%uitwateringstijd heeft van ten minste 20 minuten, en bij voorkeur ten minste een half uur, volgens de norm NEN-EN 1568.
- 13Werkwijze volgens conclusie 12, omvattende de stap van het verwijderen van de schuimlaag op het substraat na het uitvoeren van de werkzaamheden aan het substraat.
- 14Werkwijze volgens een van de conclusies 12-13, waarbij een schuimbaar mengsel wordt toegepast volgens een van de conclusies 8-11.
- 15Werkwijze volgens een van de conclusies 12-14, waarbij de sproeiinrichting omvat:- een reservoir voor een schuimbaar mengsel dat onder druk staat van een gas, - een sproeikop voor het versproeien van het schuimbaar mengsel, - een leiding voor het toevoeren van het schuimbaar mengsel vanuit het reservoir naar de sproeikop, - een gasinlaat in de leiding voor het vermengen van het gas en het schuimbaar mengsel, waarbij in de leiding tussen de gasinlaat en de sproeikop een poreuze vaste structuur aanwezig is, die als doorgang voor het schuimbaar mengsel fungeert, bij welke doorgang een voorschuim wordt gevormd uit het schuimbaar mengsel.
- 16Werkwijze volgens conclusie 15, waarbij in de leiding tussen de gasinlaat en de sproeikop twee poreuze vaste structuren op afstand van elkaar aanwezig zijn die beide als doorgang voor het schuimbaar mengsel fungeren. 10
- 17Werkwijze volgens conclusie 16, waarbij de doorsnede van de leiding afneemt tussen de twee vaste poreuze structuren, in de richting naar de sproeikop.
- 18Werkwijze volgens een van de conclusies 15-17, waarbij de sproeikop van de sproeiinrichting een hoofdzakelijk spieetvormige uitgang heeft.
- 19Sproeiinrichting, omvattende:- een reservoir voor een schuimbaar mengsel dat onder druk staat van een gas, - een sproeikop voor het versproeien van het schuimbaar mengsel, - een leiding voor het toevoeren van het schuimbaar mengsel vanuit het reservoir naar 20 de sproeikop, - een gasinlaat in de leiding voor het vermengen van het gas en het schuimbaar mengsel, waarbij het reservoir een gesloten kamer zonder inlaat is, die een hoeveelheid van het schuimbaar mengsel volgens een van de conclusies 8-11 omvat. 1/5 2/5 Fig. 2a Fig. 2b 3/5
Independent claims19
115 paragraphs, as filed
Starting composition for a foam suitable for trapping dust particles, method for trapping dust particles, spraying device suitable for the method.
The invention relates to a foam suitable for trapping dust particles. Such a foam can be used in work on a substrate where there is a risk that dust particles will be released from or from the substrate that are harmful to the environment and to humans. Generally speaking, this refers to dust particles that float in the air and thereby adversely affect the airways or the skin, for example. Examples of dust particles that are undesirable for them to float freely in the air are particulate matter, asbestos fibers and mold.
The work may, for example, be drilling or otherwise completely or partially removing the substrate in the context of renovation or remediation work on a home. The activities also include simply cleaning substrate surfaces.
In particular for work where asbestos particles or asbestos fibers can be released, the safety standards are set very high due to the high risks for people performing the work. Traditionally, asbestos removal in a building creates an enclosed space with an underpressure. Persons in this room wear special protective clothing, including respiratory and face protection. Due to the underpressure, the air in the room is continuously sucked away and guided over a HEPA filter, so that dust particles that have been released into the air are led away and resp. captured. Although widespread, this method is expensive and moreover cumbersome for the implementers. In addition, the performers may only work under these circumstances for a limited time.
The US patent application US2007 / 0295369 proposes in that connection to apply a foam to places in a building from which dust particles can be released during work. The foam is formed from a precursor, or a foamable mixture, that is mixed with an expansion gas. The foamable mixture is then sprayed with a sprayer to form a foam layer. The foam layer must be thixotropic, ie of such a nature that the foam is stable under static conditions and flows under dynamic conditions (e.g. under shear forces exerted on the foam). It is thus achieved that during drilling operations, etc., in which shearing forces are exerted on the foam, the foam flows and also reaches deeper parts where dust particles are also released. The composition for the foam is traded under the brand name 'Foamshield', and is traded by the company Foamshield Europe.
After work, the foam with the dust particles trapped inside it is removed with a cloth and transferred to a suitable container.
Tests with the foam composition 'Foamshield' have shown that the foam formed only remains on a selected surface for a short time. On a vertical wall, the foam already starts to slide down a few seconds after application along the wall, so that a foam layer that covers sufficiently is present for only a few minutes. The adhesion of the foam to the bottom layer is thus insufficient for application to vertical walls. The same disadvantage applies to the foam when it is mounted on a ceiling. The foam on a floor also appears to flow relatively quickly, even without the influence of dynamic conditions. The so-called watering-out time of the foam, ie the length of time in which the foam dismounts into a liquid, is relatively short. When cutting into a substrate on which the foam is applied with, for example, a grinding wheel, the flow is, because of the thixotropic character, even faster, and the foam layer will inevitably move from the original location. These disadvantages make the foam composition less suitable for operation as a dust scavenger, because the work must be carried out in a relatively very short time to prevent the foam composition from disappearing to a considerable extent and thus being insufficiently effective as a scavenger of dust particles.
The object of the invention is to provide a composition for a foam which, when sprayed into a foam layer, yields a better result in comparison with the prior art. In addition to a foam layer with improved adhesion to a substrate, this objective also requires adequate stability of the foam formed, expressed in the so-called drainage time determined by the time period in which 50% of the foam has been demixed into a liquid after it has been applied . In addition, it is an object of the invention to achieve a good degree of foaming of the composition, which is expressed in a foaming number, which is the ratio between the volume of the foam formed and the volume of the foamable mixture.
To achieve the above object, the invention provides, according to a first aspect, a starting composition for a foam suitable for trapping dust particles, comprising:
- a fraction of glycol ether,
- a fraction of fatty alcohol,
a fraction of amine oxide, and
- a fraction of fatty alcohol sulfate.
The term fraction is used herein to mean that each fraction can contain one or more types of the said component.
It has been found that when the above composition is mixed with water to a foamable mixture in a suitable ratio, which is subsequently sprayed in a suitable manner, a foam layer that adheres better to a substrate, as a result of which shearing of vertical walls or dripping of ceilings occurs less quickly.
Moreover, the foam layer formed appears to be more than sufficiently stable over time. In addition, the composition has a suitable foaming number of, for example, 8 to 20 when using conventional spraying devices.
In this context, the term "capture" means that the foam can receive loose dust particles in the foam structure as if it were an absorbent, and in particular relates to situations in which dust particles are released during work on a substrate.
The starting composition according to the invention is preferably a liquid concentrate, which preferably comprises water and more preferably 10 to 60% by weight of water.
A liquid concentrate has the advantage that it is easy to handle and can be mixed well in larger volumes of water.
The starting composition according to the invention particularly preferably comprises:
- 1 to 20% by weight fraction of glycol ether, preferably 5 to 15% by weight,
- 1 to 20% by weight fraction of fatty alcohol, preferably 5 to 15% by weight,
-0.1 to 10% by weight fraction of amine oxide, preferably 0.2 to 2.0% by weight,
- 1 to 20% by weight fraction of fatty alcohol sulfate, preferably 5 to 15% by weight.
At the above levels of the components of the composition, the composition has been found to be effective in achieving the object of the invention.
It is preferred for the starting composition according to the invention that the fraction of glycol ether comprises one or more glycol diethers, including preferably 2- (2-butoxyethoxy-ethanol). This glycol ether is a suitable component for increasing the solubility of the composition.
It is preferred for the starting composition according to the invention that the fatty alcohol fraction comprises one or more C12-06 fatty alcohols.
It is preferred for the starting composition according to the invention that the amine oxide fraction comprises one or more trialkylamine N-oxides, including preferably cocoalkyldimethylamine N-oxide. This amine oxide is a surfactant and therefore a suitable component for reducing the surface tension of the foamable mixture.
For the sake of clarity, it is noted that coco-alkyl has the meaning of a 02-08 alkyl group.
It is preferred for the starting composition according to the invention that the fatty alcohol sulfate fraction comprises one or more fatty alcohol ether sulfates, including preferably fatty alcohol ether sulfates comprising 02-04 fatty alcohols. This fatty alcohol sulfate is a surfactant and therefore suitable component for reducing the surface tension of the foamable mixture.
For example, the fatty alcohol sulfate is used in the form of its sodium salt.
An example of a suitable starting composition according to the invention is given below where the remainder is water.
<td>dust</td><td>concentration</td>
<td>2- (2-butoxyethoxy) ethanol</td><td>5 to 15% by weight</td>
<td>C12-16 fatty alcohols</td><td>5 to 15% by weight</td>
<td>cocoalkyldimethylamine N-oxide</td><td>0.2 to 2.0% by weight</td>
<td>sodium C12-14 fatty alcohol ether sulfate</td><td>5 to 15% by weight</td>
A starting composition according to the invention is marketed under the name "Dustcover", "Fiber cover" or "Fiber cover."
According to a special aspect of the invention, it also relates to a water-based foamable mixture comprising 2 to 5% by weight of the starting composition according to the first aspect of the invention.
Such a diluted mixture is directly usable for being sprayed into a foam layer using a suitable spraying device. For the foamable mixture, it is particularly preferred to use a content of 3 to 4% by weight.
In addition, it is preferred that the foamable mixture according to the invention has a surface tension of 20-40 mN / m, in particular 22-32 mN / m
Moreover, it is preferred that the foamable mixture according to the invention has a viscosity of 40-80 mPa.s.
The foamable mixture according to the invention has a particularly preferred foaming number in the range of 8 to 20.
According to a second aspect of the invention, it relates to a method for trapping dust particles that may be released during work on a substrate, comprising the steps of:
- mixing a gas with a foamable mixture, and
- spraying the gas-mixed foamable mixture onto the substrate under excess pressure from a spraying device before the activities are started, a foam layer being formed on the substrate which has a drainage time of at least 20 minutes, and preferably at least half a minute hour according to the NEN-EN 1568 standard.
Any suitable excess pressure can be used for the method according to the invention, wherein an excess pressure of 2 to 4 bar, in particular 2.5 to 3 bar, is preferred. For example, air is used as the gas.
Preferably, the method according to the invention comprises the step of removing the foam layer on the substrate after performing the work on the substrate.
For example, the foam layer is removed with a cloth that is then processed as waste.
In the method according to the invention, it is preferred that a foamable mixture is used according to the above-mentioned special aspect of the invention.
With a special preference, in the method according to the invention, a spraying device is used which comprises:
- a reservoir for a foamable mixture that is under pressure from a gas,
- a spray head for spraying the foamable mixture,
- a line for supplying the foamable mixture from the reservoir to the spray head,
- a gas inlet in the conduit for mixing the gas and the foamable mixture, and wherein a porous solid structure is present in the conduit between the gas inlet and the spray nozzle, which porosity acts as a passage for the foamable mixture, at which passage becomes a pre-foam formed from the foamable mixture.
The porous solid structure increases the mixing of the foamable mixture that is liquid with the gas, thereby incorporating more gas dispersed into the foamable mixture. A foamable mixture is thus created with a higher gas content, which in this context is referred to as pre-foam.
When using the above-mentioned spraying device for the method according to the invention, in the line between the gas inlet and the spraying head, two porous solid structures are preferably present at a distance from each other, both of which function as a passage for the foamable mixture.
By including a porous solid structure twice in the pipe, the effectiveness of forming a pre-foam is increased.
Viewed in the flow direction of the foamable mixture from the mixing chamber to the spray head, a first porous solid structure is arranged, for example, which is made up of a mesh-like material which preferably has an elongated, conical shape. At some distance downstream, a second porous solid structure is arranged which is preferably embodied as a barrier wall of some thickness, with an open-cell structure.
The reservoir is preferably suitable for being set at a gas pressure of 2 to 4 bar, because these are pressures that preferably work according to the invention. In addition, the reservoir is provided with an inlet for foamable mixture and an inlet for gas, so that both substances can be replenished in the reservoir after they have been consumed during the use of the device.
Other preferred embodiments of the spraying device used for the method according to the invention relate to:
- a decrease in the cross-section of the pipe between the two fixed porous structures, in the direction towards the spray head; resp.
- a spray head which has a substantially spit-shaped outlet.
A decrease in the cross-section of the line in the direction of the spray head increases the speed of the foamable mixture introduced, and thereby supports the formation of pre-foam within the line, as well as the formation of foam leaving the spray head.
When the foamable mixture resp. When the prefoam leaves the spraying device through a spray head which has a substantially spit-shaped outlet, a broad, flat jet is obtained which has been found to be effective in achieving the advantages of the invention.
According to a third aspect of the invention, it relates to a spraying device, comprising:
- a reservoir for a foamable mixture that is under pressure from a gas,
- a spray head for spraying the foamable mixture,
- a line for supplying the foamable mixture from the reservoir to the spray head,
- a gas inlet in the conduit for mixing the gas and the foamable mixture, wherein the reservoir is a closed chamber without inlet, which comprises an amount of the foamable mixture according to the special aspect of the invention.
Such a spraying device can be used directly without the need for external means to build up a gas pressure. Such a spraying device functions as a spray can and is intended for direct and one-time use: the closed chamber without inlet does not allow the reservoir to be filled with additional quantities of foamable mixture and gas.
The invention will be explained below with reference to the accompanying figures, in which:
Figure 1 schematically shows a spraying device according to a preferred embodiment of the invention;
Figures 2a and 2b show partially cut-away parts of the device from Figure 1;
Figure 3 shows the use of the spraying device when applying a foam layer to a substrate from which dust particles can be released during work;
Figures 4a-c show the results of a comparison test of the adhesion of a foam layer based on a foamable mixture according to the prior art and a foamable mixture according to the invention.
FIG. 1 shows a spraying device 1 with a reservoir 3 for a foamable mixture 5 which is under pressure from a gas 7, which in this case is air. The foamable mixture is an aqueous solution of 3% by weight of the starting composition according to the example above. A spray head 11 is provided for spraying the foamable mixture, as well as a line 9 for supplying the foamable mixture from the reservoir 3 to the spray head 11. A gas inlet 14 is provided in the first part of the conduit 9 for mixing the gas 7 and the foamable mixture 5. In the circle the gas inlet 14 is shown in enlargement, the conduit 9 being provided with a narrowing through-holes 16 for gas inlet, through which gas is mixed therein during passage through the line 9 of the foamable mixture 5. At the end of the pipe 9 there is provided a control member 15 for the user, comprising a handle 16, a dosing lever 18, and a pressure gauge 20. An extension tube 22 connects the pipe system in the control member 15 to the spray head 11.
FIG. 2a shows, separately from each other, the parts of the pipe system in the operating member 15 comprising:
- a coupling piece 21 for coupling line 9 to a tube 24 with narrowed end and provided with a main valve 26,
- a narrowed tube 28 that can be connected to the end of tube 24 and is provided with a dosing valve 30,
- a filter 23 of mesh-like material, also connected to the coupling piece 21, which is in the form of a closed cone and through which the foamable mixture flows during use before it flows into the tube 24.
FIG. 2b shows, separately from each other, the parts of the pipe system from the operating member 15 to the spray head 11 comprising:
- the extension tube 22,
- an end pipe 34 with foldable part 35,
- the disassembled parts of spray head 11 comprising:
- a sleeve-shaped end 36 for guiding the foamable mixture from the end pipe 34 to the nozzle,
- two flow-through barrier bodies 38 with a porous open-cell structure arranged in the end 36,
- a nozzle 40,
- a protective cap 42.
For the sake of clarity, the parts 36 and 40 of the nozzle are shown in three dimensions and in an enlarged manner at the top of Fig. 2b.
FIG. 3 shows a user 50 in protective clothing 52 with airway protection 54, who directs the spraying device operator 15 to a substrate 57 on which he sprays a foam layer 55 in accordance with the method according to the invention. After the substrate 57 has been completely covered with the foam layer 55, work can be carried out on the substrate, while it is practically prevented that dust particles from the substrate are released into the air and pose a risk to the person carrying out the work.
The invention is explained in more detail below with reference to an example in which the invention is compared with a starting composition which is available on the market under the name 'Foamshield'.
Comparison test for the foamable mixture
A starting composition with components according to the table below and supplemented with water to a total of 100% by weight, was then diluted to a 3% by volume aqueous solution. In the context of the application, this solution is referred to as a foamable mixture.
<td>dust</td><td>concentration</td>
<td>2- (2-butoxyethoxy) ethanol</td><td>5 to 15% by weight</td>
<td>C12-16 fatty alcohols</td><td>5 to 15% by weight</td>
<td>cocoalkyldimethylamine N-oxide</td><td>0.2 to 2.0% by weight</td>
<td>sodium C12-14 fatty alcohol ether sulfate</td><td>5 to 15% by weight</td>
According to the NEN-EN 1568 standard, the following properties of the 3 volume% solution were measured:
<td>property</td><td>measured value</td>
<td>Density</td><td>1.01</td>
<td>Spread coefficient</td><td><3 mN / m</td>
<td>Foam number *</td><td>9.0</td>
<td>50% drainage time *</td><td>31 minutes</td>
<td>Surface tension</td><td>27 mN / m</td>
<td>Viscosity</td><td>60 mPa.s</td>
* measured after spraying a foam layer on a flat substrate by spraying the foamable mixture with a suitable spraying device, in accordance with the standard
NEN-EN 1568.
A comparison test was performed with a 3 vol.% Solution of the 'Foamshield' concentrate. For a sprayed-on foam layer of 'Foamshield', a foaming number of 10.0 and a 50% drainage time of 7 minutes was 10 seconds. measured.
The foamable mixture according to the invention has a suitable and comparable foaming number, while the 50% drainage time compared to 'Foamshield' has been greatly increased from 7 minutes to about half an hour.
The Foamshield solution was sprayed onto a smooth vertical concrete wall with a suitable sprayer over a pre-marked surface. In the same manner and under the same conditions, the foamable mixture according to the invention was sprayed onto a smooth vertical concrete wall over a pre-marked surface. This test was performed to compare the adhesion quality of both foam layers.
The resulting foam layer and its course over time is shown in the photos of Figures 4a (30 seconds after application), 4b (120 seconds after application) and 4c (180 seconds after application). The left photo shows the foam layer 1 of 'Foamshield', the right photo shows the foam layer 4 of a foamable mixture according to the invention.
The figures show that the 'Foamshield' foam layer has already slipped about 120% after 120 seconds from the marked sprayed surface 2, and after 180 seconds almost 75% of the surface 2 is no longer covered by the foam layer. On the other hand, the foam layer obtained according to the invention appears to cover the vertical surface 6 to a very high extent even after 180 seconds.
The foam layer obtained according to the invention thus has an increased adhesion to substrates with a smooth surface relative to a "Foamshield" foam layer. Most probably the improved 50% drainage time plays a major role in this.
6 sheets
Sheet 1 Sheet 2 Sheet 3 Sheet 4 Sheet 5 Sheet 6
Every citation, both ways
| Document | Relation | Office | Category | Cited during | Relevant claims |
|---|---|---|---|---|---|
| EP1674560A1 | Cites | European Patent Office (EPO) | X | Search report | 1-7 |
| US5872088A | Cites | United States of America | XI | Search report | 1-3,5-7 |
5 members in 3 offices
Priority claims2
| Document | Office | Kind | Date |
|---|---|---|---|
| 2014633 | Netherlands (Kingdom of the) | A | |
| NL20152014633 | – | – | – |
Members5
| Document | Office | Kind | |
|---|---|---|---|
| NL2014633AThis record | Netherlands (Kingdom of the) | A | |
| WO2016167657A2 | World Intellectual Property Organization (WIPO) | A2 | |
| NL2014633B1 | Netherlands (Kingdom of the) | B1 | |
| WO2016167657A3 | World Intellectual Property Organization (WIPO) | A3 | |
| EP3283228A2 | European Patent Office (EPO) | A2 |
Numbers
- Publication
- 2014633
- Publication, DOCDB
- 2014633
- Publication, EPODOC
- NL2014633
- Application
- 2014633
- Application, DOCDB
- 2014633
- Application, EPODOC
- NL20152014633
Titles2
- English
- Starting composition for a foam suitable for trapping dust particles, method for trapping dust particles, spraying device suitable for the method.
- Dutch
- Uitgangssamenstelling voor een schuim dat geschikt is om stofdeeltjes weg te vangen, werkwijze om stofdeeltjes weg te vangen, sproeiinrichting geschikt voor de werkwijze.
Classification
- CPC, 5
- C09K3/22
- B08B3/003
- B05B7/0037
- B05B7/267
- B09B2101/35
- IPC, 5
- C09K3 22
- B05B9 01
- B08B3 00
- B08B15 00
- B09B3 00