|
Described is a composition of expandable vinyl aromatic polymers for making expanded articles or extruded expanded sheets, which contains: a) a polymeric matrix obtained by polymerising a base comprising 50-100 wt % of one or more vinyl aromatic monomers and 0-50 wt % of at least one copolymerisable monomer; b) 1-10 wt %, with respect to the polymer (a), of an expandable agent included in the polymeric matrix; and thermally non-conducting filler containing: c) 0.05-25 wt %, with respect to the polymer (a), of coke in particle form with an average diametre (d50) (size) of the particles ranging from 0.5 to 100 mcm, having a surface area, measured according to ASTM D-3037-89 (BET), ranging from 5 to 200 m2/g, and d) 0.05-10 wt %, with respect to the polymer (a), of expanded graphite in particle form with an average diametre (d50) (size) of the particles ranging from 1 to 30 mcm, having a surface area, measured according to ASTM D-3037-89 (BET), ranging from 5 to 500 m2/g Also described is an expandable article made from said composition, having density ranging from 5 to 50 g/l and thermal conductivity ranging from 25 to 50 mW/(m-K). Described is an extruded expanded sheet made from said composition, which includes a cellular vinyl aromatic polymer matrix having density ranging from 10 to 200 g/l, an average cell size ranging from 0.01 to 1.00 mm and containing from 0.1 to 35 wt % of thermally non-conducting filler comprising said coke in particle form with average diametre (d50) of the particles ranging from 0.5 to 100 mcm and surface area, measured according to ASTM D-3037-89 (BET), ranging from 5 to 200 m2/g, and said expanded graphite in particle form with average diametre (d50) of the particles ranging from 1 to 30 mcm and surface area, measured according to ASTM D-3037-89 (BET), ranging from 5 to 500 m2/g. Described is a method of producing said composition in form of spheres or granules, which involves aqueous suspension polymerisation. Also described is a method of producing said composition in form of spheres or granules by continuous bulk polymerisation. Described is a method of producing said extruded expanded sheet from vinyl aromatic polymers, involving: a1) mixing the vinyl aromatic polymer in granule form and at least one thermally non-conducting filler, comprising 0.05-25 wt %, with respect to the polymer, of said coke in particle form with an average diametre (size) of the particles ranging from 0.5 to 100 mcm, having a surface area, measured according to ASTM D-3037-89 (BET), ranging from 5 to 200 m2/g, and 0.05-10 wt %, with respect to the polymer, of said expanded graphite in particle form with an average diametre (d50) (size) of the particles ranging from 1 to 30 mcm, having a surface area, measured according to ASTM D-3037-89 (BET), ranging from 5 to 500 m2/g; b1) heating the mixture (a1) to temperature ranging from 180°C to 250°C to obtain a molten polymer which is homogenised; c1) adding at least one expanding agent and, optionally, other additives, for example said self-extinguishing system, to the molten polymer; d1) homogenising the molten polymer containing the expanding agent; e1) uniformly cooling the molten polymer (d1) to temperature not higher than 200°C and not lower than Tg of the obtained polymer composition; f1) extruding the molten polymer through an extrusion head to obtain an expanded polymer sheet. |
|
Bromated polymers as flame extinguishers and polymer systems containing said polymers Flame-extinguishing polymer composition contains a combustible polymer mixed with a bromated flame-extinguishing additive selected from one or more compounds given below: (i) a copolymer containing styrene and 2,3-dibromopropylmaleimide repeating units; (ii) a bromated polyester containing bromine atoms bonded with aliphatic groups; (iii) an allyl ether which is bromated on a novolac resin ring; (iv) 3-bromo-2-hydroxypropyl ether of novolac resin; (v) 2,3-dibromopropyl ether cresol-novolac resin, and (vi) a bromated polymer or a copolymer obtained via ROMP. |
|
Method of producing filled chemically cross-linked foamed polyolefin involves mastication of polyolefin and mixing with target additives: a chemical cross-linking agent, a foaming agent and a decomposition activator in given amounts to obtain a foaming composition, moulding into a sheet workpiece, foaming and mechanical treatment of said workpiece; at the mixing step, chemically cross-linked polyolefin wastes are first added to the foaming composition as filler, said wastes being taken in ratio of 0.1-1:1 (pts.wt) with respect to the weight of polyolefin, followed by further mixing with target additives and mastication in one process cycle which is carried out in a rotary mixer at temperature of 90-150°C. Disclosed also is a composition of filled chemically cross-linked foamed polyolefin. |
|
Elastic foam material made of particles based on polyolefin/styrene polymer mixtures Thermoplastic foam material consists of expandable thermoplastic particles containing a polymer matrix which consists of a styrene polymer, polyolefin and a hydrogenated or non-hydrogenated styrene-butadiene block copolymer, which form a continuous phase rich in the styrene polymer and a dispersed phase rich in polyolefin. The foam material has cells with average size ranging from 50 mcm to 250 mcm. The cladding of the cells has a nano-cellular structure with pore diameter of 100-500 nm. The method of producing thermoplastic foam materials from said particles consists of the following steps: a) obtaining a polymer matrix by mixing said thermoplastic polymers, b) the obtained polymer matrix is saturated with a foaming agent and granulated to obtain expandable thermoplastic polymer particles, c) the expandable thermoplastic polymer particles are pre-foamed to obtain particles of foam material, and d) the pre-foamed particles of foam material are welded in a mould under the action of hot air or steam to obtain moulded articles from foam material consisting of particles at operating pressure which is set sufficiently low in order to preserve the nano-cellular structure in the cladding of the cells. |
|
Invention relates to foamed granular composite materials based on vinyl aromatic polymers, having improved heat-insulation properties, and a method for production thereof (versions). The composite material has density of less than 40 g/l with content of closed pores of less than 60%. The material is also characterised by presence of heterophase areas consisting of materials which are partially miscible with the polymer matrix and/or cavities which are embedded inside the polymer matrix. Said cavities are gas and/or liquid cavities which mainly consist of a foaming system, and inside said heterophase areas there a non-uniformly distributed graphite material with degree of graphitisation, calculated using a Meyer-Mering formula, of at least 0.2. The polymer matrix is a synthetic thermoplastic polymer containing at least 60 wt % of the matrix with respect to total weight of a polymer obtained from a vinyl aromatic monomer. The disclosed granular materials enable to obtain foamed articles with low density, having high insulating capacity with minimum thickness of the panel and with cost comparable to commercially available products. The foamed articles satisfy self-extinction technical requirements of the B2 test according to specification DIN 4102 part 2, with reduced use of self-extinguishing filler materials. |
|
Method and device for production of polymer granulate Proposed method comprises the following steps. Making polymer melt 2 to be cooled by first static cooler 9, adding at least one additive 25 to cooled polymer melt 2, admixing at least one additive 25 to said melt by screw extruder 13, adding at least one foaming agent 31 to said melt to mix is with melt by said extruder 13. It comprises also second cooling of melt 2 by second static cooler 37, and pelletising cooled melt 2. Proposed device comprises first and second static coolers 9, 37 for mixing additives 25 and foaming agents 31. Note here that first cooler 9 is arranged ahead of screw extruder 13 while second cooler is arranged behind said extruder. |
|
High-quality polymer foam from fluorinated alkene foaming agents Invention relates to a method of obtaining heat-insulating polymer foam, heat-insulating polymer foam and a method of using heat-insulating polymer foam. The polymer foam contains 95 wt % or more of one or more polymers selected from a group consisting of styrene and a styrene-acrylonitrile copolymer, and additionally contains one or more foaming agents from a specific group of fluorinated alkenes in concentration ranging from 0.03 mol to 0.3 mol per 100 g of polymer foam. The method of obtaining heat-insulating polymer foam involves a step for preparing a foamed composition and expanding the foamed composition to form polymer foam. The method of using the heat-insulating polymer foam involves a step for placing the polymer foam between two surfaces, where on of the two surfaces is at a different temperature from the other. |
|
Method of dry foaming of polystyrene Proposed method comprises short-term heating of PVC granules in air, applying short-term vacuum to heated granules, cooling the later in vacuum to below temperature of polystyrene plastic state, and, after cooling, vacuum breaking. Drying heating of PVC granules is performed in tight container filled with hot air. Note here that vacuum is created by pumping air from said tight container. Granules are cooled, mainly, due to heat power radiation. |
|
Microwave foaming of foam polystyrene granules Invention relates to foaming foam polystyrene granules containing pentane and isopentane and may be used in construction, production consumable patterns and moulding of articles and packages. Besides it may be used for both premary foaming and additional foaming of granules after primary foaming. Proposed method comprises proportioning initial granules, foaming them by steam treatment in foaming chamber, drying in drying chamber, cooling in cooling chamber, and storing foamed, dried and cooled granules in bins. Foaming is performed in microwave field in vertical waveguide chamber during steam treatment. Steam is generated in entire volume between loaded granules due to evaporation in microwave irradiation of water kept in microwave chamber in two sources, limited and recoverable sources. Limited source is made up of water film applied on granules in loading to envelop every granule. Recoverable source consists of steam generator working body saturated with water made up of porous deliquescent material arranged in waveguide chamber zone with maximum intensity of microwave radiation electric field. |
|
Technique and facility for generation of polymer particles Invention refers to the method and facility for generation of expanded or capable of expanding polymer particles. Expanded or capable of expanding polymer particles (10) are obtained from polymer melt (11) and recycle polymer melt (12). At least part of recycle polymer melt (12) is derived from recycle polymer particles containing expanding agent (5). Recycle polymer melt (12) is obtained at the stage of melting-down of recycle polymer particles containing expanding agent (5) in the side extruder (6) using the heating device (19). In this process the expanding agent is removed from the recycle polymer melt (12) in the degasser (13). After that the recycle polymer melt (12) and polymer melt (11) to which liquid expanding agent is added (2) are mixed into one polymer melt (24), dispersed and homogenized in the mixing device (7), and then is processed until expanded or capable of expanding polymer particles are obtained. |
|
Composition for producing expandable polystyrene Expandable granules of styrene polymer are obtained through direct saturation of molten polymer with a foaming agent in a system of static mixers. The method involves feeding an additive into the melt and granulation of the obtained melt using a submersed granulator. The additive used is oxidised or non-oxidised polyethylene fibre with drop point higher than 70°C in amount of 0.1-2.5 wt % per weight of the granules of the expandable styrene polymer. An additional additive used can be antipyrene hexabromocyclododecane. |
|
Invention describes a foamed vinylaromatic polymer containing a) a matrix obtained via polymerisation of 100 wt % vinylaromatic monomer; b) 1-10 wt % (per amount of polymer (a)) foaming agent incorporated in the polymer matrix; c) 0.01-25 wt % (per amount of polymer (a)) technical carbon, characterised by average diametre between 30 and 2000 nm, specific surface area between 5 and 40 m2/g, sulphur content between 0.1 and 1000 parts per million and ash content between 0.001 and 1%; d) 0-10 wt % (per amount of polymer (a)) graphite; e) 0-10 wt % (per amount of polymer (a)) aluminium; f) 0-10 wt % (per amount of polymer (a)) antimony trisulphide, provided that the total amount of components (a)-(f) equals 100, and that concentration of matrix (a) is not less than 80 wt % and at least one of (d)-(f) is present. The invention also describes a foamed article having density between 5 and 50 g/l, characterised by thermal conductivity between 25 and 50 mW/mK, obtained after foaming at temperature several times higher than the glass transition point of the polymer and granules of the vinylaromatic polymer given above. Described is a method of improving insulating capacity of the foamed vinylaromatic polymer given above. |
|
Invention relates to foaming granular materials having composition based on vinyl aromatic polymers containing: a) 65-99.8 wt % polymer obtained through polymerisation of 85-100 wt % of one or more vinyl aromatic monomers having general formula (I) , where n equals zero or is an integer ranging from 1 to 5, and Y is a halogen such as chlorine or bromine, or an alkyl or alkoxyl radical group having 1-4 carbon atoms, and 0-15 wt % α-alkylstyrene, in which the alkyl group contains 1-4 carbon atoms; b) 0.01-20 wt %, calculated from the ratio to polymer (a) soot, having average particle diametre ranging from 10 to 1000 nm and surface area ranging from 5 to 200 m2/g; c) at least one of the following additives (c1)-(c3): c 1) 0.01-5 wt %, calculated from the ratio to the polymer (a), graphite having average particle diametre ranging from 0.5 to 50 mcm; c2) 0.01-5 wt %, calculated from the ratio to the polymer (a), oxides and/or sulphates and/or plate-like dichalcogenides of group IIA, IIA, IIB, IVB, VIB or VIIIB metals; c3) 0.01-5 wt %, calculated from the ratio to the polymer (a), inorganic derivatives of plate-like silicon; d) 0.01-4.5 wt %, calcualted from the ratio to the polymer (a), nucleation agent; and e) 1-6 wt %, calculated from the ratio to 100 parts of total weight (a)-(d) of one or more foaming substances. The invention also discloses foamed articles and a method for continuous production in a mass of foaming granular materials. |
|
Method of obtaining granules of foaming styrene polymer Invention describes a method of obtaining granules of foaming styrene polymer involving feeding molten polymer, a foaming agent, a nucleating agent and processing additives to a mixing zone, mixing components so as to disperse the foaming agent, the nucleating agent and processing additives in the molten polymer and granulation in conditions which prevent foaming. The method is characterised by that the processing additives are in form of a mixture of aluminium oxide with stearamide taken in ratio of 1:(1-50), in amount of 0.01-0.5% of the weight of the polymer. |
|
Method of continuous production of expansible plastic granulate Method is implemented by means of impregnation of plastics melt by fluid expansive additive and also by means of granulation of impregnated melt. Method is realised by use of plant which contains at least one conveying unit for melt building up pressure, in particular volumetrically pumping over conveying unit, measuring device for expansive additive, mixing and homogenising devices for melt impregnation, at least one refrigerator for impregnated melt, submerged granulator and plant control device as components. At that granulation is performed using liquid which is used in granulator as cooler and inflator for granulate, using water or salt solution in particular. By means of liquid used during granulation, increased pressure is build up, due to which it is possible to suppress bloating effect of expansive additive in uncured yet granulate at least partially. By means of plant control device, preset parametres for granulation are adjusted, namely parametres of temperature and pressure of impregnated melt at granulator input. At that mentioned parametres are measured and results of measurement are compared to preset values, and deviations from preset values are used in plant control device in order to exercise influence on heat extraction from impregnated melt using one or more refrigerators. |
|
Foamed plastic moulded objects, made from filler-containing polymer granulates, capable of foaming Invention relates to methods of foaming thermoplastic polymer granulates. Description is given of thermoplastic polymer granulates which are capable of foaming, chosen from styrene polymers, containing: from 5 to 50 wt % filler, chosen from a group containing talc, chalk, kaolin, aluminium hydroxide or glass beads; from 2 to 40 wt % intumescent graphite with average particle size in the range 10 to 1000 mcm; from 0 to 20 wt % red phosphorous or organic or inorganic phosphate, phosphate or phosphonate; from 0 to 10 wt % soot or graphite. |
|
Present invention is related to devices and methods intended for production of foam polystyrene in the form of granules. Method is described for production of foam polystyrene granules, which includes supply of foaming polystyrene granulated material into chamber of foaming device provided with blade mechanism, production of foam polystyrene granules by means of granulated material foaming in steam-air medium, temperature reduction and drying of granules directly after foaming in process of continuous mixing, pneumatic transportation of granules to stabilisation unit, aeration of granules in it in movable air medium, and the method differs by the fact that initial raw materials used is granulated material of self-extinguishing foaming polystyrene, which is powdered with antistatic substance prior to foaming, after foaming steam supply to chamber of foaming device is isolated, and granules are dried in it with simultaneous mixing by blade mechanism, with further cooling in intermediate reservoir, and in stabilisation unit granules are aerated in turbulent medium of heated air at the temperature that is not higher than temperature of hot plastic deformation of granules. Process line is also described as well as stabilisation unit for production of foam polystyrene granules. |
|
Compositions based on foamable vinylaromatic polymers with improved foaming ability Invention provides a process for continuous in-bulk production of foamable vinylaromatic polymers, which comprises following steps: (i) charging into extruder vinylaromatic polymer jointly with (a) copolymer obtained via polymerization of one or more vinylaromatic monomers and 0.1-15 wt% α-alkylstyrene, and 0-10 wt% (b) compatible polymer having crystallinity below 10% and vitrification temperature (Tg) above 100°C, provided that at least one of (a) and (b) is present in reaction mixture; (ii) heating polymers to temperature superior to relative melting temperature; (iii) adding foaming agent to molten product before extrusion; and (iv) molding, through extrusion head, optionally foamable essentially spherical granules having average diameter within a range of 0.2 to 2 mm. There are also provided foamable vinylaromatic polymers with improved foamability and additionally including 0.05 to 29% of athermic and refracting materials as well as application of foamed products having density between 5 and 50 g/L. |
|
Process of producing foamed vinylaromatic polymers Process comprises: polymerization in aqueous suspension of at least one vinylaromatic monomer in presence of suspending agent selected from phosphoric acid salts; discharging foamed granules from reaction vessel; washing thus obtained granules with aqueous solution containing 0.005-2% by weight nonionic surfactant; separating washed granules, whose surface contains no inorganic phosphoric acid salts; and drying these granules in air flow. |
|
Method of preliminary foaming of the granules of polystyrene and the device for its realization The invention is pertaining to the methods of production of the granulated expanded polystyrene from the granules of polystyrene containing isopentane or pentane, which is used as the filler for the concretes and also for the monolithic and prefabricated heat insulation of the buildings and structures with application of cement. The method of foaming provides, that the granule of polystyrene are exposed to treatment with the seam at the temperature of 95-105°С at continuous stirring action. At that the granule of polystyrene are treated with superplasticizers for the mortar and the concrete having concentration of 20-40 % in quantity of 0.3-0.4 % of the mass of the polystyrene in the air-steam medium at the pressure of 0.35-0.4 MPa. The device for realization of the method contains: the control system; the loading tank for the source granules of the polystyrene connected with the foaming assembly, which includes the paddle mixer and the assembly of the steam feeding in. The outlet of the foaming assembly through the gear of the granules unloading and through the pneumatic pipe duct with the adjustable shutters is connected to air-separators of the hoppers for ageing of the granules. The hoppers include the means for their unloading connected through the unloading pneumatic pipe duct having the controlled shutter, which is connected to the air-separator of the loading tank. The loading tank and the hoppers for ageing of the granules are supplied with the vertical material pipe duct with inlet and outlet holes arranged accordingly on the upper and the lower controlled levels, in the lower part of which there is the sensor of control over the availability of the material. The device is supplied with the tools for treatment of the granules with the liquid superplasticizers for the concrete and the mortar, which are mounted flush with the spin axis of the worm feeder and perpendicularly to it and containing the tank with the sensor unit of availability of the material. The tank is connected to the spray assembly by means of the plug valve regulating the superplasticizer feeding by the pneumatic cylinder connected with the air collector through the pneumatic distributor. The assembly of the steam feeding in contains four perforated disks-sprayers, the total of the diameters of which is equal to the radius of the bottom of the foaming assembly and which are arranged according to the coordinates: the first disk - [0, r], the second disk - [3r, 0], the third disk - [-5r, 0], the fourth disk - [0,-7r] in the bottom of the foaming assembly, where r is the radius of the disks-sprayers of the steam. There also is the perforated grate in the form of the lattice with a mesh size of 0.14 mm mounted over the bottom along the whole area at the altitude equal to (0.05-0.1) from the height H of the working chamber of the foaming assembly, and the tubular shaft of the paddle mixer of the foaming assembly, which is made sealed above and connected with tubular vanes sealed on the ends and perforated from below. The invention ensures reduction of the granules density and the duration of the superlight expanded polystyrene production process, as well as the specific power inputs. |
|
Foamed vinylaromatic polymers and a process for producing the same Foamed vinylaromatic polymers are prepared using inorganic filler having essentially spherical granulation with average diameter within a range of 0.01 to 100 μm, refractory index exceeding 1.6, and whiteness index equal to or below 22 as measured according to "Color Index". Foamed vinylaromatic polymer include (i) matrix obtained by polymerization of 50-100% of one or more vinylaromatic monomers with 0-50% of copolymerizable monomer; (ii) 1-10% (based in polymer mass) of foaming agent incorporated in polymer matrix; and (iii) 0.05-25% of above-mentioned filler. Foamed vinylaromatic polymers are characterized by density from 5 to 50 g/L and heat conductivity 25 to 50 mv/m-K. A method of preparing foamed vinylaromatic polymers involving polymerization in water suspension of one or more vinylaromatic monomers, optionally in common with at least one polymerizable comonomer, in presence of inorganic filler is also described as well as continuous foamed polymer production process. |
|
Method of preparing open-cell foamed material Invention relates to foamed material constituted by cross-linked amino-formaldehyde polymer product suitable for filtration of tobacco smoke. Foamed material according to invention contains cavities and intermediate spaces located outside of cavities, said spaces being confined by walls consisted of cross-linked amino-formaldehyde polymer product optionally supplemented by additives. Average space dimension lies within 30 to 350 μm. Considerable portion of spaces have two or more perforations with average diameter within a range of 5 to 300 μm in their walls while considerable portion of perforations of neighbor spaces are arranged relative to each other in such a way as to form continuous nonlinear path. Foamed material is characterized by porosity at least 45 vol % and specific surface area 0.1 to 15 m2/g. Method of preparing of such foamed material comprises following stages: mixing air and foaming agent solution under pressure in mixing zone of injector filled with multiple inert mixing members; passing, under pressure, non-hardened foam from mixing zone and prepolymer solution into reaction zone of injector to form curable foam; and discharging foam and drying it in air. Use of such foamed mixture as cigarette filter allows content of toxic compounds such as resins and polycyclic aromatic compounds to be lowered. |
|
Method is comprised in saturating polymer material sample, placed in high-pressure cell, with carbon dioxide under supercritical conditions at pressure 250 atm and temperature 40-120°C, cooling the cell to room temperature and slowly lowering pressure to its atmospheric value. Foaming of polymer sample saturated with carbon dioxide under supercritical conditions proceeds during 60 min of further heat treatment at atmospheric pressure. Final porosity of polymer sample is determined by heat treatment temperature. |
Another patent 2542620.