74 results about "Gas foaming" patented technology

The invention is directed to scaffolds containing porous polymer material prepared by a process of gas foaming/particulate leaching and a wet granulation step prior to gas foaming and particulate leaching, particularly having a characteristic interconnected pore structure, as well as sustained release of protein, DNA or cells, and to methods for using such porous polymer material for preparation of scaffolds, particularly for tissue engineering.

The invention discloses a nontoxic, odorless and recoverable environmentally-friendly polyurethane foaming material and a preparation method thereof. The foaming material is characterized in that a raw material of polyurethane is adopted and is directly subjected to a physical gas foaming in the presence of a physical gas foaming agent to prepare the foaming material. The foaming material has a foaming density of 0.08-0.80 g/cm<3>, a foaming ratio of 1.5-15 times, a average pore diameter of 10-100 [mu]m, uniform distribution of cells, wherein diameter deviations of 95% of the cells do not exceed 10% of the average pore diameter. In addition, the foaming material has no surface structure and can be the foaming material with any shape. The foaming material has an adjustable softness and hardness and excellent performance, and can be widely applicable for the fields of packaging, human protector, shoe product, automobile inner garnish, amortization cushion, building energy conservation, acoustic insulating material and the like. According to the present invention, the following problems that: harmful gas is discharged during the production process of the polyurethane foaming material, and monomer residues are harmful to human health and cause environmental pollution, are thoroughly solved from the source, such that a practicable development approach is provided for green environmental protection, energy saving and emission reduction of the foaming material.

The present invention involves tissue engineering constructs made from a new composite bone graft material made from biocompatible poly(D,L-lactic-co-glycolic acid) (PLGA) and bioceramic particles exposed on its surface using a gas foaming particle leaching (GF/PL) method and infused with collagen. Methods and apparatus for of forming scaffolds are also disclosed.

The invention discloses a highly flame-resistant external wall heat preservation material and a process for producing the same, which are mainly used for the construction of isolation belts and the heat preservation of high-rise buildings and building bodies with relatively higher requirement on fire-protection rating. According to the process, the highly flame-resistant external wall heat preservation material is produced by taking modified phenol aldehyde resin with low hydroxyl content as a raw material and performing low-acid curing on the modified phenol aldehyde resin. The modified phenol aldehyde resin with the low hydroxyl content is prepared by heating phenol, formaldehyde, a modifier and chopped glass fiber firstly under an acidic condition and then under an alkali condition and then performing copolymerization and condensation on the phenol, the formaldehyde, the modifier and the chopped glass fiber. The modified phenol aldehyde resin with the low hydroxyl content, a surfactant, a gas foaming agent, a modified moisture repel and an organic acid catalytic system are cured and molded on a continuous line. The highly flame-resistant external wall heat preservation material has the following advantages that: a terminal hydroxyl group of the adopted phenol aldehyde resin is closed, so the water absorbing capacity of the material is reduced; the cured molding material has high strength and low acidity; the service life of the material is prolonged and simultaneously convenience is provided for construction; the highly flame-resistant external wall heat preservation material has excellent flame resistance, lower smoke density and a higher oxygen index; and fire protecting safety property in a construction and use process is greatly improved due to the non-smoldering property of the highly flame-resistant external wall heat preservation material.

The invention provides a bionic bone tissue engineering scaffold material and preparation method thereof, and the scaffold material has multi-level micropore structure similar to the natural bone tissue. The scaffold has multi-level bionic bone three-dimensional pore structure which can be adjusted in the range from 500 nm to 1000 mum. The preparation method of the bone tissue engineering scaffold with multi-scale controllable micropore structure includes performing three-dimensional printing with medical polymer material by using a rapid proto-typing technology, customizing the primary-level micrometer scale three-dimensional pore structure and the shape of the scaffold, and preparing the second-level micrometer and nanometer scale micropore inside of the scaffold by using supercritical gas foaming. The prepared bone tissue engineering scaffold with multi-scale micropore structure can provide the three-dimensional supporting needed by the bone tissue regeneration, can meet the requirements of protein adsorption, nutriment/metabolite transportation, cell migration, and tissue growing in different scales, and has wide application prospect in orthopedic clinic.

The invention provides highly-oriented silk fibroin based nanofiber which adopts silk fibroin as a base material, adopts a nerve growth factor as a functional material for inducing neuronal cell growth and is obtained by an in-phase spinning controller with special design through an electrospinning fiber technique. Compared with traditional nano preparation technologies such as freeze drying, gas foaming, self-assembling and the like, the nerve growth factor loaded highly-oriented silk fibroin nanofiber scaffold as an artificial nerve graft has the advantages of high efficiency, simple process, low cost and the like, has structural and functional controllability which is not likely to be realized with the traditional nanotechnology, and is better in forming effect. Meanwhile, a composite of a biological material and cells is directly spun into a composite of a bracket material and the cells once with a blended spinning technology, and compared with a tradition process of firstly bracket material preparation and later cell culture on the bracket material, the process is simple.

The invention discloses a full bio-based polylactic acid foaming material and a preparation method thereof. The method comprises the following steps: mixing dried L-polylactic acid and D-polylactic acid, and then adding a mixture to a twin-screw extruder and subjected to melt blending to obtain a polylactic acid containing a stereocomplex crystal; placing the material into an extrusion foaming machine to melt the material, then inputting a gas foaming agent into a screw through a gas injection port metering pump on the extrusion foaming machine, and uniformly mixing the material with a polylactic acid melt; reducing the temperature from a gas injection port to the screw at a head so that the temperature of the melt at the head is 110-140 DEG C and the pressure at the head is 6-8MPa, and finally performing extrusion foaming through a die, and performing cooling and fixing to obtain the polylactic acid foaming material. The method adopts L-polylactic acid and D-polylactic acid as raw materials, and forms the polylactic acid containing a stereocomplex crystal in the process of melt blending, which can significantly improve the melt strength and crystallization property of the polylactic acid. Therefore, the obtained polylactic acid foaming material has stable quality, uniform foam size, high foam density, and high foaming expansion ratio.

There is provided a method of preparing biodegradable dual pore polymer scaffolds, comprising the steps of: maintaining a polymer solution containing a biodegradable polymer, an effervescent mixture of carbonate and organic acid, and solvent at a temperature range of −196° C. to ambient temperature so as to evaporate the solvent and produce a polymer sample; and foaming the polymer sample in a mixed solution of water and alcohol. According to the present invention, the pore size of the polymer scaffolds can be easily controlled, and biodegradable polymer scaffolds can be more simply prepared compared to conventional methods such as salt leaching technique, phase separation technique or gas foaming technique. Further, since the biodegradable polymer scaffolds prepared according to the present invention have a high surface area and porosity without formation of skin layer, secretion of toxic substances and remnant phenomenon, they can be advantageously used for regenerating almost all living tissues and organs in tissue engineering.

The invention discloses a polypropylene and blends particles thereof physical gas foaming preparation method and is characterized in that the preparation method comprises the following steps: placing polypropylene and blends particles thereof in a high pressure container of which the volume is 25 times or more than 25 times of the total volume of the particles, injecting 10-20MPa of pressure gas in the container at 135-175 DEG C, keeping the temperature and the pressure for 1-30min and then relieving the pressure in a speed of 5-20MPa/s to the normal pressure to obtain the foaming particles with uniform and controllable cell and controllable foaming density. The preparation method of the invention overcomes the specific requirement that polypropylene with high melt strength is needed to use in the foaming process, and the increase of the machining temperature increases the gas permeability and shortens holding time so as to improve the production efficiency and reduce the production cost.

The invention relates to the technical field of high polymer materials, in particular to micro-foamed water-based damping coating and a preparation method thereof and aims to solve the problem that the size and the density of cells of the damping coating in the prior art are difficult to control. To solve the problem, the micro-foamed water-based damping coating is prepared from a water-based emulsion serving as a main agent, damping filler serving as main filler, organic filler serving as auxiliary filler as well as a proper amount of a crosslinking agent, a catalyst, a gas foaming agent and water; specifically, the micro-foamed water-based damping coating is prepared from raw materials by weight as follows: 10-60 parts of the water-based emulsion, 20-80 parts of the damping filler, 0.5-10 parts of the organic filler, 10-50 parts of the crosslinking agent, 0.01-2 parts of the catalyst and 5-30 parts of water, wherein the temperature of the gas foaming agent ranges from 220 DEG C to 250 DEG C, and the pressure of the gas foaming agent ranges from 8 Mpa to 10 Mpa. Besides, the invention further provides a method for preparing the micro-foamed water-based damping coating. The size and density of cells of the damping coating can be controlled effectively after the coating is foamed through the gas foaming agent.

The invention relates to a water bath type atomizing air purifying device. The device comprises a tank body, a gas collector, a gas foaming and refining device, an atomizing medium cavity, an atomizer, atomizing gas condensers and a gas collecting device, wherein the tank body is in a bucket structure or a closed rectangular hollow body structure, an air exhausting hole is formed in the upper part of the tank body and is communicated with external air, the gas collector is arranged at the outer part of the tank body, the atomizing medium cavity is arranged at the bottom of an inner cavity of the tank body and is filled with an atomizing medium, the gas foaming and refining device and the atomizer are arranged in the atomizing medium cavity, the gas foaming and refining device is communicated with the gas collector, multiple layers of atomizing gas condensers are arranged at the whole section of the middle of the inner cavity of the tank body and are located above the atomizing medium cavity, and the gas collecting device is arranged above the inner cavity of the tank body and is connected with the air exhausting hole. The water bath type atomizing air purifying device is simple in structure, reasonable in design, low in cost, and easy to generalize and can play an air purification role.

The invention discloses a production line of EPP polypropylene foaming beads, which is characterized in that devices or systems are connected in turn according to the following sequence: a low-temperature mixing system, a sealed leakage-proof feeding machine, a double-screw extruder, an underwater grain cutting system, a first depth drying system, a plasma fluidized bed reactor, a water-soluble reaction system, a second depth drying system, a surface treatment mixing system, a finished product storage hopper and a packing system; the double-screw extruder is provided with a gas foaming agent filling opening; a plasma reaction device and an inert gas filling device are arranged on a plasma fluidized bed of the plasma fluidized bed reactor; and the water-soluble reaction system comprises a water-soluble reaction kettle which is provided with an auxiliary low-temperature liquid medium filling opening and a liquid foaming agent filling opening. The foaming agent content in the EPP polypropylene foaming beads produced by the production line is even, and the product quality is stable.

The invention discloses a rich mineral paper preparation method, which comprises the following steps of: A) evenly mixing rich mineral paper master batch; B) feeding the evenly mixed rich mineral paper master batch into a charging barrel of a screw extruder, adding an ultramicro gas foaming agent with weight being 0.5-1 percent of the weight of the rich mineral paper master batch into the charging barrel, evenly mixing the rich mineral paper master batch and the ultramicro gas foaming agent and foaming, wherein the ultramicro gas foaming agent is inert gas; and C) feeding the foamed materials into a calender to produce rich mineral paper products. By evenly distributing the ultramicro inert gas with tiny size into the rich mineral paper under conditions of proper temperature and screw mixing reinforcement, the gas becomes a filling material of the rich mineral paper, the specific weight of the rich mineral paper is greatly reduced, the uniformity and the fluidity of the melt of the rich mineral paper are improved at the same time and the overall quality of the rich mineral paper is further improved.

The invention discloses a polyolefin composition, a polyolefin masterbatch, a polyolefin film and a surface decorative composite material and a preparation method of the surface decorative composite material. The composition comprises, in parts by weight, 100 parts of a polyolefin system, 0.01-3 parts of a crosslinking agent, 0.01-3 parts of a crosslinking assistant and 0.1-10 parts of a microsphere expansion agent when the weight of the polyolefin system is counted as a standard, wherein the crosslinking agent is an organic peroxide crosslinking agent, and the cross-linking assistant is an acrylate crosslinking assistant and/or a polybutadiene-based crosslinking assistant. The microsphere expansion agent is added, and a mode of microsphere expansion is adopted to replace the mode of gas foaming, so that not only can the density of the formed polyolefin film be reduced, but also no formation of pinholes in the surface of the formed polyolefin film can be achieved, and the surface structure of the polyolefin film is dense, soft and comfortable.

The invention discloses a biodegradable poly(butylene adipate/terephthalate) hollow foamed particle and a preparation method thereof. The preparation method is characterized by comprising the following steps of: carrying out a mould pressing physical gas foaming method on poly(butylene adipate/terephthalate) granules with a melting point of Tm DEG C in the presence of a physical gas foaming agent at the temperature of (Tm-25 DEG C)-(Tm+15 DEG C) and the pressure of 8-20MPa; performing constant temperature pressure preservation for 5-20 minutes; releasing pressure at the speed of 5-30MPa/s, and sampling and cooling within 30 seconds so as to obtain hollow foamed particles with a foamed shell layer and a hollow inside. Because the foamed layer is more beneficial to drug release and filling as compared with a solid and the hollow foamed particle has the biodegradable characteristic, thus the hollow foamed particle has excellent property, and is hopeful to be widely used in the fields of drug controlled release, agricultural fertilizer controlled release, filling material storage and use and the like. The preparation method is convenient, has simple process flow, wide applicable range, short production period and low cost, is environmentally-friendly and is suitable for industrial product; and the hollow foamed particle disclosed by the invention has no solvent and no impurities, and the size of the particle is controllable and adjustable.

The invention discloses an anti-compression type autoclaved aerated concrete block, and belongs to the technical field of building materials. The concrete block is prepared in the steps that, 5-20 parts of Portland cement, 6-12 parts of silica fume, 8-12 parts of quicklime, 12-18 parts of coal ash, 35-45 parts of river sand, 2-4 parts of gypsum, 5-8 parts of gas forming agent, 1-2 parts of foam stabilizer, 12-18 parts of modified additive and 20-25 parts of water are sequentially weighed by weight; the river sand and the coal ash are mixed, ground, sieved and dried to obtain mortar, the mortaris mixed with the Portland cement, and the water, the silica fume, the quicklime, the gypsum, the gas foaming agent and the modified additive are added, stirred and mixed to obtain a mixture; the mixture is mixed with the foam stabilizer, after casting molding, standing, gas forming and autoclaved curing are conducted, and the anti-compression type autoclaved aerated concrete block is obtained. The obtained anti-compression type autoclaved aerated concrete block has excellent compressive strength.

The invention relates to a rotary gas foaming device comprising a foaming chamber and a driving assembly fixedly arranged above the foaming chamber and also comprising a molten aluminum output pipe and a gas output pipe; the molten aluminum output pipe is rotatably arranged at the top of the foaming chamber along a vertical direction, the inside of the molten aluminum output pipe is hollow and communicates with the foaming chamber by a plurality of liquid outlet holes formed in the molten aluminum output pipe; the gas output pipe passes through the molten aluminum output pipe and is fixedly connected with two end surfaces in the axial direction of the molten aluminum output pipe in a sealing way; one end of the gas output pipe is fixedly connected with the driving assembly, and the other end of the gas output pipe is set to be closed and is provided with a gas nozzle; and molten aluminum is output by a high-pressure foaming gas at high pressure and is then scattered by a gas curtain, and the molten aluminum is in sufficient contact with the foaming gas for many times, so that gas foaming of the molten aluminum is realized, and the problem of foaming nonuniformity existing in the prior art is solved.

The invention discloses a formula for enhancing concrete strength and relates to the technical field of building materials. The formula comprises 70-72% of phosphorus slag, 18-23% of fly ash and 6-19% of cement; and the water-material weight ratio is 0.33-0.43, an alkaline activator accounts for 3.6-4.3% of the total weight of a cementing material, a gas foaming agent accounts for 0.2-0.3% of the total weight of the cementing material, water glass slurry accounts for 1-3% of the total weight of the cementing material, and the total amount of straw is 0.1-0.5%. The concrete strength is greatly enhanced, the application range of the concrete is expanded, the utilization rate of the concrete is increased, the preparation cost is low, and the concrete is nontoxic and harmless and has high safety coefficient and good groutability.

The invention provides a polymer supercritical gas foaming production line which comprises a production module, a hot oil heating furnace, a cooling module and a gas recovery module. High-temperature gases generated in a polymer foaming process are recovered by the gas recovery module, then cooled twice by the cooling system, and instantly enters into the production module for polymer foaming production while achieving an approximate temperature. The amount of gases consumed in the whole production process is greatly reduced, the production efficiency and the production continuity are improved, the production cost brought by gas wastes is eliminated, the production effect is effectively improved, energy is saved and the benefits are improved.