FI69762C - MATTA FOER BEHANDLING AV GASER OCH AONGOR - Google Patents

Description

, B1 ... ANNOUNCEMENT AQH (.0 6 11 UTLÄCGNINGSSKRIFT ~ 7 'D ^ Q patent granted (45) Patent re.! - Zolat 26,5.80 (51) Kv.lk. * / Lnt.CI. * B 01 0 39/11 »(21) Patent application - Patentansökning 790475 (22) Filing date - Ansökningsdag 13.02.79 (FI) (23) Starting date - Giltighetsdag 13 * 02.79 (41) Has become public - Blivit offentlig 1 4.

National Board of Patents and Registration Date of publication and publication. -

Patent and registration authorities Ansökan utlagd och utl.skriften publicerad 31.12.85 (32) (33) (31) Privilege claimed - Begärd priority 13.02.78 USA (US) 877190 (71) (72) Max Klein, 257 Riveredge Road, Tinton Falls, New Jersey 07724, USA (74) Oy Kolster Ab (54) Carpet for gas and vapor treatment -Matt for handling gas and ocean

The invention relates to porous media, briefly referred to as gas-vapor mats or gas-vapor filtration or treatment mats, which have good tensile strength and porosity to maintain good flow rates, but which are nevertheless sufficiently dense to allow the formation of finely divided solids and / or entrained liquid particles. aerosols or gases and / or vapor streams as well as for the collection and separation of liquid droplets therein and which are also capable of separating gases from these streams.

The gas-steam treatment mats according to the invention consist mainly of (a) very small (e.g. on average 6.3 μιη) diameter glass fibers consisting of several filaments and having a length of only about 6.35 mm and mixed with them (b) ( i) expanded thermoplastic styrene polymer and / or lower olefin and / or (ii) flexible polyurethane foam from so-called microparticles, wherein none of the components (i) and (ii) 69762 is brittle in expanded form and a small amount of (c) (i ') is an organic binder insoluble in cold water but soluble in hot water and inert to glass fiber and polymeric microparticles; and with respect to the other components of the mat as well as the gas and / or vapor streams to which the mat is exposed, or (ii ') a combination of cotton fibers and microparticles made by hand-cardboard (described later). An embodiment used for gas separation also includes polyester fibers and activated carbon as components.

A product comprising only glass fibers, such as "Owens Corning DE 636" (shown in Example 1), has been prepared using polyvinyl alcohol (98% hydrolyzed) as a binder, but its use has been relatively limited. It has been used, for example, as a partition for batteries and as a base for roofing with tar. However, no such product of glass fibers and polyvinyl alcohol (PVA) is known to have been used to treat the gas or steam streams described above.

For several years, various industries have paid attention to the harmful presence of solid particles or fine liquid droplets, which are released into work areas and often move through fans or flues to the outside air, causing harmful environmental problems. In some cases, these have been purely dust particles formed when working with inorganic substances, such as the recovery of minerals from ores or in grinding or polishing operations.

In other cases, there are also liquid droplets generated in chemical operations such as electroplating, spray coating, or in the manufacture of certain synthetic resins. In some other cases, there may be harmful gases, such as sulfur dioxide, which is released into the air when burning high-sulfur fuel oil or bituminous coal. In the production of polyphenylene oxide-polystyrene blend polymers, emissions occur as part of resin particles or pellets, dust particles and oily plasticizer droplets, which are apparently aerosolized into the air.

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Some attempts have been made to overcome these inconveniences by using (i) a filter, such as a glass fiber mat bonded with a phenol-formaldehyde resin binder, or (ii) glass wool air filters in window openings or other outlets. However, these filters are generally bulky, but not dense enough to trap fine particles or gases, thus allowing undesired gas or liquid flows to pass through and thus further into the outside air. In addition, the tensile strength of some of these mats is disadvantageously limited, among other disadvantages, which often too often results in fractures that require interruptions in use due to unfavorable time-consuming repairs.

Other companies include the use of electrostatic precipitators, such as the long-known "Cottrell" electrostatic precipitator, but their installation, as well as operation and maintenance, are expensive and do not trap sulfur dioxide, for example.

These disadvantages can be eliminated by using the gas-steam filters or treatment mats according to the invention. The porosity and tensile strength of these mats have been improved compared to the fiberglass PVA products described above, which are used as battery partitions and roofing sheets.

In general, the gas-vapor treatment mats of the invention generally consist of glass fibers (usually comprising multiple filaments) selected to be 6.35 mm in length, but less than the length at which the fibers tend to entangle and having a diameter of about 3-12 and, in general, for ease of handling, 6.3, mixed with microparticles of a expanded thermoplastic styrenic polymer or expanded lower polyolefin which is a polymer of an ethylenically unsaturated hydrocarbon monomer having 2 to 6 carbon atoms (in which case none of these polymers are present) or with resilient polyurethane foam microparticles, wherein the glass fibers and polymeric microparticles are in the form of a sheet or web permeable to a gas and / or vapor stream and bonded together (a) (mainly at their junctions) by a suitable organic binder insoluble in cold water, butsoluble in hot water (i.e. at about 80 ° C 4 69762 such as PVA) and which is inert to microparticles, glass fibers and other components of the mat, as well as to gases (including any entrained liquid droplets or aerosols and fine particles) that come into contact with or are treated by the mats. or (b) held together by a combination of cotton fibers and polymeric microparticles made by hand-cardboard (as shown in Example 5), or by a mixture of binders (a) and (b), said binder being evenly distributed in the microparticles and glass fibers so as to hold these components adhere to each other in the above form without destroying the permeability of the mat.

The amount of microparticles is about 2-50% of the mat, preferably about 10-35% and even more preferably about 15-25%; and the amount of compatible organic chemical binder is about 2-10% and preferably 5-8% or the amount of the fiber combination of cotton fibers and microparticles is about 5.8-11% and the glass fibers form the remainder of the mat. The tensile strength of the mats ranges from about 0.2 to 5.34 kg / cm and the porosity ranges from about 159 to 914 liters per 2 cm per cm at 0.43 kg.

The microparticulate component of the gas / steam mats of the invention is an expanded, thermoplastic styrene polymer or lower polyolefin that is not brittle when expanded, or a resilient polyurethane foam that is also not brittle when expanded. These expanded thermoplastic styrene polymer or lower polyolefin microparticles are described in more detail, for example, in U.S. Patent 4,207,378 as an expanded thermoplastic polymer that is not brittle to the expanded and selected from the group consisting of polyethylene and polyethylene polymers of styrene polymer is characterized in that it is in the form of microparticles having (a) a length of about 40 to 325 μm and a width of about 20 to 325 μm, (b) which are almost completely or completely free of intact cells of the expanded polymer particles from which the polymer is derived. is made, (c) the contours of the individual microparticles are generally uneven, and (d) their density is from about 85% to almost the same density as the unexpanded polymer used to form the aforementioned expanded polymer.

5 69762 These microparticles of expanded thermoplastic styrene polymer or lower polyolefin are prepared starting from particles of an expanded, thermoplastic styrene polymer or lower polyolefin (which are not brittle when expanded). By particles is meant a separate free-flowing form of these styrenic polymers and lower polyolefins, such as (i) granules of different sizes prepared by chopping the corresponding extruded polymer into relatively short particles, commonly referred to as pellets or crystals (as in the case of a styrene polymer or pellets) or pellets). in the case of a mixture of polystyrene, (ii) styrene-polymer beads of different sizes obtained by suspension polymerization or otherwise, such as by molding in a mold particles obtained by grinding some of these polymer forms, (iii) the so-called "crumbs" including coarsely ground, molded polymer or waste of such polymer of various particle sizes, for example, thickness 3.175 mm, width 6.35 mm and length 9.535 mm, and (iv) any other fine forms of these plastics.

The preparation and properties of resilient polyurethane foams are described, for example, in Handbooks of Foamed Plastics, Bender, Rene J., Section X, pages 173-236, Lake Publishing Corporation, Libertyville, Illinois, USA (1955), "Polyurethanes:

Chemistry and Technology ", Saunders & Frisch, Chapter VII, Part II, Interscience Publishers, New York, NY USA (1964) and" The Development and Use of Polyurethane Foams ", Doyle, EnN, pages 233-256, McGraw Hill Book Company , New York, NY USA (1971).

The density of the resilient polyurethane foam suitable for forming microparticles of polyurethane foam is preferably not more than 72.14 g per liter, preferably in the range of 360-120 g / l, and their recovery is excellent after 75% bending with a height loss of less than 1% (as determined by the American test). Society of Testing Materials D-1564-64T ").

The resilient polyurethane foam is not obtained in the same particle forms mentioned above, such as styrene polymer and lower polyolefins, but rather as continuous foam bodies as a result of the polyurethane-forming reaction. Thus, the polyurethane foam bodies are first torn into particles (e.g., similar to those used to fill different articles).

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Polyurethane foam microparticles are described in more detail in, for example, U.S. Patent No. 4,200,679, and consist of ruptured and interconnected filamentous portions of adjacent cells of resilient foam that are substantially completely free of intact cells and cellular windows, and are generally tripod-shaped. and wherein the thread portions have hook-like protrusions, teeth and grooves formed by the rupture of the cells and cell windows of the resilient foam used as the starting material.

Microparticles of an expanded, thermoplastic styrenic polymer or lower polyolefin that are not brittle when expanded, or a resilient polyurethane foam are prepared by comminuting the corresponding expanded starting polymer into pieces in a comminuting machine such as that manufactured by Fitzpatr. in which, according to their publication No. 152 (copyright 1968), widened fixed vanes (marked "Code DS225") are used to replace the vanes or other chopping parts and mounted for rotation in a grinding chamber (model DAS06), both of which are shown on page 5 of this publication. is liquid-tight, as indicated, for example, by their markings Code M44D6 or Code NA44D6 (top of page 3 of their brochure 152).

The horizontal cross-section of this grinding chamber of the DAS06 model is rectangular and has two opposite, parallel, completely vertical walls fixed integrally from each of its opposite edges to a separate pair of opposite vertical curved walls with the convex sides facing outwards.

16 similar slatted tear arms are separately detachable but fixedly spaced from their closely spaced lower portions around the drive arm and secured thereto in the center of its free attachment ends. These arms extend radially from the axis (e.g., 127 mm from the axis to the end of each arm), with each of the first of the four arms extending horizontally toward one curved wall, the other of the four extending vertically, the third of the four toward the second curved wall, and the fourth vertically downward.

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The cross-section of each arm is rectangular in a plane running along the entire length of the shaft and this arm and 180 ° of the length of the arm deviating therefrom. The outermost end of each arm is perpendicular to its two wider sides (width 5.4 mm) and its narrow or impact edge (width 9.525 mm) is parallel to the direction of rotation. This narrow edge is also perpendicular to the two wider sides, which are parallel to each other for most of their width and the last thirds of their sides taper towards each other and their rear edge forms a knife-sharp edge.

Both of the free ends of the shaft pass through a respective sealing sleeve located in the vicinity of two parallel vertical walls and further through bearings mounted on respective bearing housings fixed to the machine frame and extending outwards from the respective walls. The drive wheel is mounted on both ends of the shaft and extends outwards from the respective mounting bearings.

The bottom of the grinding chamber is a replaceable plate-shaped, curved screen which is concave downwards with an inner radius (from the center axis of the drive shaft) equal to the length of the grinding arm plus a margin of 0.762 mm. The dimensions and shape of the rectangular circumferential opening of the screen are such that it can be removably attached to the bottom opening formed by the four walls of the grinding chamber for removal.

The screen is interleaved with, for example, circular openings with diameters ranging from 0.102 to 3.175 mm, and are located close to each other with the distance between the openings being such that the screen remains sized under operating conditions.

With the exception of the feed material hopper feed opening at one end, the remainder of the chamber lid is curved and upwardly convex with a radius of curvature (from the drive shaft axis) sufficient for the rotating arms to provide 0.762 mm clearance for multiple (e.g., three) pre-tear bars (approximately 20.32 mm long). , 35 mm) with respect to the inward surfaces, the bars extending 3,175 mm over their entire length inside the grinding chamber and spaced apart and parallel to the axis of the drive shaft.

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The desired drive wheel on the drive shaft is connected to the drive wheel of the motor shaft by means of drive belts and can be operated at speeds in the range of about 4,700 to 8,000 rpm and more efficiently in the range of about 5,000 to 7,500 rpm.

According to an embodiment of the invention, the so-called the basic components of gas / vapor adsorption filtration or treatment mats are (a) glass fibers, (b) microparticles, and (c) an organic binder, each of which is generally in the above range relative to each other, together with finely divided activated carbon (primary gas adsorbent), which is less than the amount at which undesirable dusting of the carbon particles can occur and a combination of fibers with a sufficient amount to prevent dusting of the carbon particles and a sufficient amount of fibrous terephthalate polyester to maintain the tensile strength of the mat in the above range without adversely reducing the porosity of the mat.

Thus, for example, in addition to the three main components (a), (b) and (c), these adsorbent filtration and treatment mats may contain up to about 25% activated carbon, a range of about 2 to 22% polyester fibers and about 2 to 30% fiber combination.

Any gas adsorbent activated carbon obtained from various sources, for example charcoal, coal, waste oil distillation waste or pecan shells, can be used.

In general, the manufacture of gas / steam treatment mats comprises appropriate amounts of (a) an expanded thermoplastic styrenic polymer and a lower polyolefin from polyethylene to polymethylpentene and a resilient polyurethane melt-in-one (as used in papermaking) and a mixture of ingredients (a) and (b) for a short time, but long enough so that both are substantially free of lumps and agglomerates and so that they are mixed substantially evenly, with a microparticle content of about 5-50 parts and the proportion of glass fibers is about 4-45 parts and the addition of an organic binder (as described above) or a fiber combination (as will be described later) in the amount of 9 69762 is sufficient to give the finished carpet tensile stress and porosity. both of which are in the above areas; then transferring the resulting mixture to the feed chamber at a concentration of about 0.1-0.5% of the mixed microparticles and glass fibers and then mixing this mixture only to maintain a uniform dispersion.

The dispersion is then fed from the feed chamber to the feed box of the flat wire machine, for example at a rate of about 3.3 to 5.5 kg per minute, and at the same time diluted evenly with water, feeding water to the feed box at a rate of about 3,800 to 9,000 liters per minute.

The resulting diluted feed slurry is then passed to a flat wire machine at a speed such that a moist mat is formed having a basis weight of about 2.25 to 22.5 kg after drying and the wet mat is continuously removed from the wire and passed to a suitable drying system.

The gas / vapor treatment mat can be prepared by adding to the mixture in the pulp, preferably before the addition of the binder, separate amounts of sodium hexametaphosphate and concentrated sulfuric acid in such a ratio that the pH of the mixture drops to 2.5.

The gas / vapor adsorbent treatment mats are prepared by steps comprising preparing a composite suspension of cotton fibers and microparticles in water made separately from a handboard (as described in more detail below) and preparing a separate suspension of microparticles in water in the following proportions.

A suspension is then prepared in the feed box of the flat wire machine by mixing the amount of water in a given range into the fiber composite suspension and adding fiber-forming polyethylene terephthalate polyester in an amount that contributes to the finished carpet in the effective range without adversely affecting its porosity. An amount of finely divided activated carbon of up to about 25% of the total solids content of the finished mat is then added with stirring, and the aqueous suspension of microparticles is added in an amount to give a microparticle content of about 10-30% to the finished mat.

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The final suspension consists of a suspension of glass fibers, microparticles and a binder in which the amount of each component is in the above range for the gas / vapor treatment mat and in proportion to the other solids in the finished mat to achieve the desired tensile strength and porosity. The final suspension of all these ingredients is passed to the feeder box at a rate corresponding to that given to mats lacking carbon and polyester, and then diluted with water and dried.

When using an organic binder in the manufacture of the mat, it is preferable to add this material to the suspension at the final stage of mixing before feeding the suspension into the machine feed box and also to apply radiant heat to the web leaving the flat wire machine at a temperature in the range of about 600-70 ° C. This rapidly dissolves the organic binder in the water in the mat and improves the drying of the organic binder at the junctions of the water-insoluble components.

The preparation of the desired styrenic polymer, lower polymer, or polyurethane microparticles from the corresponding expanded polymers (styrenic polymers, lower polyolefin, or polyurethane) is described, but not limited, by the following preparation of polystyrene microparticles.

Example A

Microparticles of expanded polystyrene pellets 425 liters of expanded impregnated, extruded polystyrene pellets (crystals) were expanded to about 6.35 mm, about 12.7 mm in size, with substantially round pellets as shown above, and a bulk weight of 12 g per liter. with a diameter of 10,16 cm and a length of 7,62 cm and a curved sieve with holes 0,1016 mm in diameter at the bottom.

The rotor speed was adjusted to 6,000 rpm and the feeder was adjusted to feed pieces of expanded polystyrene at a rate of 35.4 liters every five minutes (i.e., 425 liters per hour). The expanded polystyrene 11 69762 feeders to be fed into the feeder were moistened with a sufficient amount of water so that their outer surface was covered substantially completely. Thus, wetted pieces of expanded polystyrene were continuously fed into the feeder at a rate of 35.4 liters every 5 minutes and at the same time water was injected into the grinding chamber through a 1.6 mm diameter orifice at a rate of 7.57 liters per minute.

The mixture of expanded polystyrene microparticles leaving the bottom screen of the grinding chamber was collected in an open tank with a bottom plug, where free water settled to the bottom and the polystyrene microparticles with bound water (relative to 2 parts by weight of microparticles per 98 parts of water). The free water was allowed to drain away, leaving the plastic mass of the expanded polystyrene microparticles formed in the water physically bound to them. The plastic mass weighed 255.15 kg and contained 1.5 kg of microparticles and 250.05 kg of water bound to them.

27.24 kg of this plastic mass was placed in a densely woven double cotton bag under pressure until 22.71 liters of water had escaped upon compression. The remaining 4.08 kg containing 544 g of expanded polystyrene microparticles was then dried in an open oven at 43.33 ° C.

Any thermoplastic expanded styrenic polymer or lower polyolefin, neither of which is brittle in the expanded state or any resilient, foamed (i.e., expanded) polyurethane that is not brittle when foamed, can be prepared in accordance with Example A by substituting any other expanded polystyrene used as starting material. with polymer particles.

The preparation of the gas / steam treatment mats according to the invention is illustrated by the following non-limiting examples.

Example 1

A basic gas / steam mat in 15,139 liters of water in a pulping machine (papermaking) (with a slightly larger volume) was fed 23.27 kg (dry weight) of polystyrene microparticles (as an aqueous product containing 8% solid microparticles) by means of an endless 12 69762 belt conveyor. The contents of the pulping machine were then mixed for three minutes as the rotor rotated at 506 rpm, whereupon the microparticles dispersed in water.

With stirring, 22.73 kg of sodium hexametaphosphate and then 3.785 liters of concentrated sulfuric acid (98.6% I 2 SO 4) were added. The pH of the batch was then 2.5.

Stirring was stopped and a total of 113.64 kg of 6.35 mm long glass fibers (6.3 μm in diameter) of Owens-Corning electric grade DE 636 containing several filaments per fiber (and bound starch, oil and cationic acid) were added (from several packages). with a binder containing a surfactant).

The rotor mixing was restarted and continued for 10 minutes, and 10.25 kg (cold) of water-swellable polyvinyl alcohol (98% hydrolyzed) (hereinafter abbreviated as PVA) was added as a binder during the last 30 seconds. The initial mixture of the pulping device thus obtained was pumped into the feed tank of the cholester (which was used only to store the received pulping mixture) and mixed only to the extent that the insolubles remained in suspension.

7,570 liters of water (for rinsing) were then added to the pulverizer and mixed to suspend any glass fibers and / or microparticles that had precipitated and remained as the pulverizer stock mixture was pumped into the cholester feed tank. The resulting so-called flushing device rinsing mixture was then pumped into the cholester tank and mixed there with the original flushing mixture to obtain a starting mixture for the manufacture of a mat containing 0.64% solids.

This starting mixture for the production of the mat was then pumped into the feed box of the machine (also the feed material container) and its contents were mixed in the same way as in the feed box of the pulping device. From this feed box, 4.32 kg of solids per minute was fed into the flat wire machine feed box from the carpet preparation mixture and clear dilution water was added at a rate of 6,056 liters per minute.

69762

The resulting uniform web-forming suspension (diluted in a feed box) was passed to a moving flat wire machine wire (86 threads in the machine direction and 60 in the cross direction) moving at a speed of 15.24 m per minute (m / min) to obtain an initial with a basis weight of 19.1 kg after subsequent drying.

Damp carpet (with flat wire machine) with a thickness of 9.525 mm. after passing through the suction boxes at the outlet end of the flat wire machine, it switched to an endless belt conveyor (112 x 84 mesh screen) also at a speed of 15.24 meters per minute. Then, about 1.5 meters before the end of the flat wire machine, the damp carpet (with this conveyor) passed under a battery (length about 60.5 cm) formed by about 10 cm of infrared lamps (52.4 kilowatts, 3.8 amps, 480 volts, 60-phase single-phase current) , whereby a temperature of 649 ° C was formed on the surface of the mat by means of a control resistor. Thus, exposing the wet mat to this temperature for about 2.4 seconds caused the PVA to dissolve rapidly.

The partially dry web passed through a tunnel dryer (about 3.67 meters long and about 1.83 meters wide) at a temperature of about 121 ° C and then alternately above and below six consecutive dryers (the temperature of the first drum was 113 ° C and then increasing so that the temperature of the last drum was 127 ° C). The final dry mat was then passed through two stretch rollers and further to the storage roll. The dry mat, which was smooth on both sides, easily wrapped around this roll without tearing or wrinkling.

With a basis weight of 19.1 kg of finished gas / vapor mat (Gurley porosimeter, manufactured by W. & LEGurley of Troy, New York, USA), the porosity was approximately 602.8 in 1 minute (2 / min) square decimetres ( dm) per area of the mat with a pressure difference of 2.54 cm H 2 O (250 Pa).

Based on the starting amounts of the main ingredients, the finished, dry gas / steam treatment mat contains about 15.8% expanded polystyrene microparticles, about 77.2% glass fibers, and about 6.97% polyvinyl alcohol binder. The concentrations of these main components can be varied depending on the desired porosity of the mat, the gas or vapor flow rate, and the density of the mat by appropriately varying the concentrations of the components. For example, the porosity can be reduced by reducing the concentration of microparticles to the desired level up to a minimum level of about 2% without reducing the tensile strength accordingly.

Alternatively, the porosity and flow rate can be increased by increasing the proportion of microparticles, as in some preparations, up to 50%.

Example 1 can be repeated by partially reducing or eliminating the amount of sulfuric acid and also by reducing the amount of hexametaphosphate (commonly used to improve glass fiber dispersion) or completely removing it when preparing the initial pulping suspension based on the observation that microparticles appear to improve dispersion of solids when mixed. in the water.

Depending on the end use of the gas / steam mats, their basis weight can be reduced or increased by decreasing or increasing the solids content in the aqueous suspension in the feed box or by increasing or decreasing the wire speed of the flat wire machine. The change may be partially complete.

Example 2

Using a gas / steam mat, polyurethane microparticles, 21.5 g (furniture grade) of resilient polyurethane microparticles containing 20% solids were dispersed in a 3.5 liter stainless steel vessel containing 3 liters of water (thus 4, 3 g of dry microparticles and 17.5 cm 2 of water) using an air-operated mixer. 15 g of the same 0.635 cm long DE 636 glass fibers (as in Example 1) were then added and mixing was continued. During the last 10 minutes of stirring for one hour, 1.375 g of PVA (same as in Example 1) was added with stirring.

60% of the obtained dispersion was then poured onto a sieve of a conventional laboratory hand-held paper sheeting apparatus (the apparatus consists of a 30.48 cm high brass tank with a 20.32 cm square base) and mixed from the surface. The dewatering valve was opened, whereby the solid components of the slurry formed a sieve-shaped sheet, and water was drained through the sieve by gravity from the slurry, the density of which increased continuously. When no more water was removed from the sheet by gravity, the wet sheet was dried in a drying oven at 121 ° C in a stream of hot air which was allowed to flow for five minutes. The resulting dry hand sheet weighing 12.57 g had a tensile strength of 1.41 kg / cm and a porosity of 579 liters per square decimeter per minute.

In Example 2, neither sodium hexamethephosphate nor sulfuric acid was used because the microparticles tend to improve the dispersion of the glass fibers, which were introduced into the water largely as fibers in several bundles. Other mats of this invention can be made in the same manner without these inorganic additives from other microparticles of effective polymers.

Example 3

Example 2 using a fiber combination as a binder instead of PVA

Example 2 was repeated except that during the mixing following the addition of glass fibers, 60 g of the fiber composite suspension of Example 5 containing 1.2 g of fiber composite solids (comprising fiberized, bonded cotton fibers and polystyrene microparticles) was added instead of PVA.

The manufacture of the mat was completed as in Example 2. The obtained 2 dry mats had a porosity of 355 l / min / dm and a tensile strength of 0.61 kg / cm.

Example 4

Example 3 using polystyrene instead of polyurethane

Example 3 was repeated using polystyrene microparticles instead of polyurethane microparticles and a fiber combination as a binder instead of PVA. The obtained dry fabric had a tensile strength of 0.22 kg / cm.

An adsorbent body containing gas / vapor filtering or treating mats of the present invention is shown in the following non-limiting example.

Example 5

Activated carbon-containing adsorbent mat, (a) preparation of a fiber composite suspension

A fiber composite suspension (referred to by this name as 16 69762 cotton fibers and microparticles made by handboard are defibered in one fiberizer) was prepared by adding 363.6 kg (by dry weight) of hand-made paperboard (used in papermaking and containing 1,454.4 liters of dry weight in fibers) and 181.8 kg of calculated) polystyrene microparticles (6% solids and 2,848.5 liters of bound water) to 13,354 liters of water in a pulverizer and mixed for three minutes (as in Example 1) to disperse the cotton wool fibers and microparticles in water without lumps and agglomerates.

This dispersion of cotton fibers and microparticles was pumped into a (papermaking) holester with a pressure roller set at 65% of maximum and rotating at 110 rpm for six hours (with a freeness number of 760 initially, it had dropped to 600). The roll adjustment was then changed to obtain a stronger fiberization and less beating effect by using only the brush roll pressure when the roll merely touched the layer. The desired result was obtained after two hours, when the freeness number was found to have dropped to 450. The contents of the cholesterol (now a fiber combination suspension) were stored in the cholesterol using only enough agitation to keep the dispersion suspended for later use.

Hand-made cotton fibers are those commonly used in the manufacture of writing paper to form its cotton content. They were made mainly from pieces of cotton cloth and cotton linters, which are washed (bleached if necessary) and separated into fibers (e.g. in a cholester) with a length of about 4.23 mm to 1.27 cm, fed to a hand-held cardboard machine and passed through pressure rollers, leaving about 2.1 mm thick web (moisture content about 80%) and then folded back and forth onto a transport base, usually into a pin weighing about 363.8 kg.

(b) The microparticle suspension in 7,570 liters of water in a pulverizer was mixed with 136.4 kg (dry weight) of polystyrene microparticles (as an aqueous product containing 16% microparticles and 715.9 liters of water) and mixed to obtain a uniform dispersion and then stirring only what is needed soon. for use.

69762 (c) Cholesterol filling suspension

The cholester filler suspension was prepared in a cholester feeder box (i) by feeding 30,280 liters of water, (ii) mixing 189.3 liters of the fiber composite suspension described above to give a dilute fiber combination suspension, (iii) mixing 91 kg of easily water-dispersible, semi- , an optically bleached polyethylene terephthalate polyester (preferably 1.27 cm long fibers with a denier of 1.5, spun by a conventional melt process and finished to be particularly compatible with most anionic, cationic or non-ionic binders and which quickly forms an excellent dispersion of numerous choleric additives) solution viscosity was 770 to 20 (dissolved in 1/2 g of polymer in 50 ml of solvent, 40 parts by weight of tetrachloroethane and 60 parts by weight (phenol) at 25 ° C (solution viscosity is the viscosity of the polymer solution divided by the viscosity of the solvent, subtract 1 from the result and divide by luv Ulla 1,000); melting point 48.67 ° C, non-shrinking in boiling water and elongation at break 45% (sold under the name Trevira 101 ', manufactured by American Hoechst

Corporation, Fibers Division, Spartenburg, South Carolina 29301); when polyethylene terephthalate fibers are used in the suspension, a relatively low solids content is required, (iv) by mixing 172.7 kg of finely divided activated carbon (Nuchar, manufactured by Westvaco Corporation, Covington, Va. 24426) and (v) by mixing the above-described microparticle suspension containing 136.4 kg ( dry weight) of polystyrene microparticles as an aqueous product (containing about 16% microparticles as solids), thus adding 716 liters of water to the originally added 7570 liters and finally (vi) adding 4 163.5 liters of fiber composite suspension (containing 193.4 kg solids) 15 140 liters of the following glass fibers, microparticles and binder suspension containing 187.7 kg of suspended solids.

(d) Glass fiber, microparticle and binder suspension This suspension was prepared according to the procedure of Example 1 (first 4 capsules) by adding 11,354 liters of water to the pulverizer, mixing 22.73 kg (by dry weight) of polystyrene microparticles as an aqueous product (containing 6% solids and 356 liters of water), by dissolving 22.73 kg of sodium hexametaphosphate and 3.8 liters of sulfuric acid (98.6%) and mixing 113.64 kg of 6.35 mm long glass fibers and 10.23 kg of the same PVA fibers. This suspension was pumped into the hopper feed box.

The pulping device was then rinsed by adding 3,785 liters of water and mixing the contents as in Example 1. The resulting rinsing suspension was then mixed with the fiber suspension in the cholester feeder box to obtain a suspension containing glass fibers, microparticles and binder as a second flat wire feed composition.

With agitation in the fiberization feeder box, this homogeneously mixed planar current machine feed was passed to the flat wire machine feeder box at the same rate and with the same amount of dilution water mixed as in Example 1 and further to the flat wire machine wire. After passing through the suction boxes, the obtained wet web was further transferred to an endless belt conveyor and then dried by passing under a coil formed by infrared lamps and above and below the six dryers.

The final activated carbon-containing adsorbent mat was uniform in appearance and had a basis weight of 15 to 15.45 kg, a porosity of 353.7 liters per minute per square decimeter, and a tensile strength of 1.074 kg / cm in the machine direction and 0.895 kg / cm in the cross direction.

The polystyrene microparticles used in Examples 1, 4 and 5 may be partially or completely replaced by another useful expanded thermoplastic styrene polymer or lower polyolefin or resilient polyurethane, none of which is brittle in the expanded state. Lower polyolefins from polyethylene to polymethylpentene also include polypropylene and polubutylene.

In all of Examples 1-5 and variations thereof, the microparticles can be used with any amount of water bound to them or dry. In these examples, the microparticles were used with varying amounts of water bound to them because of their easy availability in this form and thus because of their lower cost.

Similarly, the cotton fibers used in making the fiber combination were made on a hand-held cardboard machine, which usually contains about 80% water, because it is economical to do so. However, this does not preclude the use of cotton fibers in a dry state if they are available or so desired for a particular reason.

Westvaco's NUCHAR S-N 'activated carbon in Example 5 can be replaced with another Westvaco activated carbon. For example, if the mat is used to adsorb phenol, Westvaco's NUCHAR N-A '* (provides acidic wash water when washed with water) can be advantageously used because this acidity helps to better adsorb phenol.

Each of these two grades of activated carbon can be replaced by Φ. · Some other available one, for example DARCO ', currently' R1 'is manufactured by I.C.I. (USA) Ltd., and a NORIT product manufactured by American Norit Co. are useful. Barneby-Cheney activated carbon obtained from pecan shells is particularly effective, for example, in adsorbing sulfur dioxide from a gas stream, having a much higher adsorption capacity than activated carbon obtained from other sources. Thus, in Example 5, its activated carbon can be completely replaced by Barneby-Cheney.

The polyester of Example 5 may be replaced by another fibrous terephthalate polyester, for example FORTREL polyethylene terephthalate and KODEL nuclear methyl-1,4-cyclohexanedimethanol. Example 5 and examples derived therefrom may also be considered as examples in which the polyester separately are replaced by each of these other polyesters, respectively, and can all be used in any of the available 1.5 and 3 denier diameters.

The mats of this invention are effective in removing and / or recovering various gases or vapors, either inorganic or organic, for example sulfur dioxide, chlorinated alkanes such as carbon tetrachloride and other chlorinated alkanes, and benzene and phenol.

Although the invention has been described by means of a detailed description of certain embodiments thereof, it is to be understood that various substitutions and modifications may be made within the scope of the appended claims, which are intended to cover modifications of these embodiments as well.

Claims (14)

20 69762 1. A mat for the treatment of gases and vapors, characterized in that it contains the following components: glass fibers with a length ranging from 6,35 mm to a value less than the length at which they tend to intertwine and having a diameter of 3 - 12 jum; microparticles of an expanded thermoplastic polymer which is not brittle in its original expanded form and which is a styrene polymer or a lower polyolefin selected from the group consisting of polyethylene, polypropylene, polybutylene and polymethylpentene, or a resilient polyurethane foam microparticle; and at least one binder which is (a) a compatible organic binder insoluble in cold water but soluble in hot water and inert to glass fibers, microparticles and other mat components, and / or (b) a fiber combination of cotton fibers and any of said microparticles, wherein said binder is evenly distributed throughout the carpet; and wherein the ratios of the components of the mat are as follows: (i) the microparticles comprise about 2-50% by weight of the final mat; (ii) the binder comprises about 2 to 10% by weight of the final mat when using an organic binder, and about 5.8 to 11% by weight of the final mat when using a fiber combination; and (iii) the remainder of the mat consists of glass fibers; wherein the final carpet has a tensile strength of about 0.2 to 5.3 kg / cm. Gas and steam treatment mat according to Claim 1, characterized in that the microparticles are a styrene polymer. A gas and vapor treatment mat according to claim 2, characterized in that the styrene polymer is polystyrene. A mat for the treatment of gases and vapors according to claim 1, characterized in that the microparticles are made of polyurethane. A gas and vapor treatment mat according to claim 1, characterized in that the 69762 microparticles are a lower polyolefin. A mat for the treatment of gases and vapors according to claim 5, characterized in that the polyolefin is polyethylene. Mat for treating gases and vapors according to one of Claims 1 to 6, characterized in that a fiber combination (b) is used as the binder. A mat for the treatment of gases and vapors according to claim 7, characterized in that the fiber composite binder comprises cotton fibers produced by a hand-held cardboard machine and polystyrene microparticles. Mat for treatment of gases and vapors according to one of Claims 1 to 6, characterized in that an organic binder (a) is used. A mat for the treatment of gases and vapors according to claim 9, characterized in that the organic binder is polyvinyl alcohol which is at least 98% hydrolysed. A gas and vapor treatment mat according to claim 10, characterized in that it contains 77.2% glass fibers, 15.8% polystyrene microparticles and about 6.97% polyvinyl alcohol, and wherein the glass fibers have a length of about 6.35 mm and a diameter of 6. , 3 ^ m. The gas and vapor treatment mat of claim 9, further comprising: (i) a particulate additive of finely divided activated carbon in an amount ranging from about 2% by weight to a value less than that of: dusting of the particulate additive from the final mat begins with a significant amount of (ii) fibrous terephthalate polyester in an amount of about 2 to 12.2% by weight of the final mat; and (iii) a fiber combination in an amount of about 2-30% by weight of the final mat. A mat for the treatment of gases and vapors according to claim 12, characterized in that the polyester is polyethylene terephthalate. 22 69762 Gas and vapor treatment mat according to Claim 13, characterized in that the polyethylene terephthalate polyester is in the form of easily water-dispersible, semi-opaque, optically bleached fibers which are finished to be compatible with most anionic, cationic or non-ionic binders. and rapidly form excellent dispersions with a large number of different paper raw materials and additives, and having a solution viscosity at 25 ° C of 770 to 1/2 g dissolved in 50 ml of a solvent consisting of 40 parts by weight of tetrachloroethane and 60 parts by weight phenol, with a melting point of 48,67 ° C, which do not shrink in boiling water and have an elongation at break of 4 5%. 23 69762