CN102465740A - Dry-process-formed sealing gasket of automobile three-way catalytic converter and preparation method of sealing gasket - Google Patents

Abstract

The invention relates to a dry-method formed sealing gasket of an automobile three-way catalytic converter, which is characterized by comprising the following raw materials in parts by weight: 50-100 parts of ceramic fiber; 5-40 parts of unexpanded vermiculite; 20-30 parts of a 30% sodium bentonite solution; 25-35 parts of flexible acrylic copolymer emulsion; 80-120 parts of water. By introducing sodium bentonite as a plasticizer and taking the dough kneading and extruding process of the food industry as a reference, the traditional wet papermaking production process of the sealing gasket of the automobile three-way catalytic converter is overturned, and the dry dough extruding process is innovatively adopted. The better structural uniformity of the product is ensured, and the density and the fastening force of the product are improved.

Description

Dry forming automobile three-way catalytic converter liner and preparation method thereof

Technical field

The invention belongs to the ceramic fibre material technical field, be specifically related to a kind of dry forming automobile three-way catalytic converter liner and preparation method thereof.

Background technique

Atmosphere polluting problem serious day by day in the city is caused by automobile to a great extent.Automobile is to TSP, SO₂, CO, NO_x, Pb average share rate be respectively 15%, 3%, 81%, 41%, 80%.According to statistics, the about 3000kg of CO of per 1000 cars discharge every day, the about 400kg of HC, NO_xAbout 150kg.Average every burning 1t gasoline produces about 70kg pollutant.About 2.2 hundred million t of global automobile annual discharging CO account for more than 1/3 of global emissions.Automobile is a mobile source, and the harmful substance of its discharging is distributed in subaerial air-flow, and its concentration is directly proportional with the automobile total release.Maximum concentration overhead about 1m, is in the breathing zone, and is very big to the human influence.Find CO, HC, NO at vehicle flowrate for 1000～2000 time monitoring gaseous emission situation per hour_xAccount for more than 80%～90% of whole harmful gases Deng harmful gas.The pollutant of motor vehicle emission mainly contains CO, HC, NO_x, TSP, particulate matter, and the SO of a little₂, harmful gas such as aldehydes, BaP, about 98%CO, NO_xWith 60% hydrocarbon and 100% SO almost₂, aldehydes, polycyclic arene compound all be that offgas duct through automobile enters atmosphere.

The purification method of vehicle exhaust mainly contains two kinds at present, and a kind of is emission controls by improving combustion, and another kind is an external purification.Emission controls by improving combustion is through changing the structure of motor, making full combustion of fuel or the part waste gas of discharge is burnt once more, to reduce the harmful matter in the waste gas; External purification mainly adopts the catalytic purification method.Used catalysis method has catalytic oxidation, catalytic reduction oxidizing process and three-way emission control method at present, and countries in the world all trend towards using the three-way emission control method at present.Ternary catalyst purifier mainly is made up of catalyst carrier, catalyzer, liner and housing four parts.

In the world, catalytic converter has formed the whole world four big catalyzer groups through long-term application market and competition, two big ceramic monolith groups, and a big automobile liner group has monopolized the world market.Main grouping has got into Chinese individual proprietorship or joint founding the factory at present.In the world vehicle catalytic converter use the maximum supplier of liner as general headquarters in the 3M of Minn. company, basically the world car catalytic converter is monopolized with liner market.The said firm conforms with user's request to producer's supply of mainly producing catalytic converter in the world and has high performance ceramic seal liner; Four of patents aspect the automobile sealed liner have been applied in China; Raw material relates to aluminum silicate fiber, crystal alumina fibre, various expanding material and the Bond of various different contents; Preparation process has wet moulding, paper technology, braiding, acupuncture etc., and product is that various ways is compound.

Liner effect in the catalytic converter is extremely important, and it is fixed, damping device between carrier and the housing.Because case material generally selects stainless steel for use, carrier material be ceramic, thereby the thermal expansion coefficient of housing is generally about 10 times of thermal expansion coefficient of carrier, and it is bigger that thermal expansion coefficient differs.Therefore the gap in the time of will causing range of temperature big between carrier and the housing increases problem, and this just needs bed course to have special hot expansibility, in enclosure interior the moving consequence such as carrier fragmentation that causes of string takes place to avoid carrier.

At present, liner commonly used has wire netting and two kinds of forms of ceramic seal liner, and both respectively have pluses and minuses.Generally select for use the ceramic seal liner to use liner as catalytic converter, this liner has comprehensive preferably usability, and mainly contain following three parts and form: ceramic fiber has good high-temperature resistance; Expanding material mainly plays thermal expansion and heat-blocking action; Tackiness agent has enough intensity and is beneficial to assembly manipulation.The ceramic seal liner of producing at present has shortcomings such as the vermiculite dispersion is inhomogeneous, cost of production height when adopting wet papermaking process to produce.For this reason, need a kind of new formulation product of exploitation and a new technology route, solve the vermiculite dispersing uniformity, solve the too high problem of cost of production simultaneously.

Summary of the invention

The objective of the invention is: a kind of dry forming automobile three-way catalytic converter liner and preparation method thereof is provided; Make that automobile three-way catalytic converter gasket construction is more even; Density and fastening force are more reasonable; In conjunction with tightr, improved the hot strength and the fastening force of liner simultaneously.

The technical solution adopted for the present invention to solve the technical problems is: a kind of dry forming automobile three-way catalytic converter liner is provided, it is characterized in that being made up of the raw material of following parts by weight:

50～100 parts of ceramic fibers

5～40 parts of unexpanded vermiculites

Concentration is 20～30 parts of 30% sodium bentonite solution

25～35 parts of flexible acrylic acid copolymer emulsions

80～120 parts in water.

Described dry forming automobile three-way catalytic converter liner is characterized in that being made up of the raw material of following parts by weight:

80 parts of ceramic fibers

20 parts of unexpanded vermiculites

Concentration is 25 parts of 30% sodium bentonite solution

30 parts of nano silicon and acrylate copolymer emulsions

100 parts in water.

Described ceramic fiber is an aluminum silicate fiber.

Wherein aluminum silicate fiber is high-purity aluminum silicate fiber winding-up cotton that Shandong Luyang share co.,ltd produces; Product code name LYGX-321; This fiber is that the synthesis material with high temperature oxidation aluminium powder and quartz flour is raw material, adopts the electric furnace of resistance type fusion through jetting into fine prepared.

Described flexible acrylic acid copolymer emulsion is nano silicon and acrylic acid copolymer emulsion.

Wherein the flexible acrylic acid copolymer emulsion is the organic bond of liner of the present invention.

Unexpanded vermiculite (Xinjiang product) is used for doing thermal expansion material, and improves the intensity of ceramic fiber liner through compound use sodium bentonite and nano silicon and acrylate copolymer emulsion bond.

Sodium bentonite is meant the one-level sodium bentonite, its specific targets such as following table:

Described dry forming automobile three-way catalytic converter liner is characterized in that adopting following making method:

(1) batching and face operation

Aluminum silicate fiber, unexpanded vermiculite powder, nano silicon and acrylate copolymer emulsion and sodium bentonite solution adding dough mixing machine are carried out and face;

(2) squeeze the face molding procedure

The pug that makes in the step (1) is dewatered through dough-sheeter and forms wet base;

(3) drying process

With the wet base after the moulding, send into the papermaking dry machine and carry out thermal dehydration.

The length of described aluminum silicate fiber is 2～5mm.

The described papermaking dry machine of step (3) is digester (-tor) formula dryer or plane expanded metals formula dryer.

Wherein the described dough-sheeter of step (2) is the industrial dough-sheeter of traditional food with a hopper, two pairs of pair rollers and a console table.When in traditional dough-sheeter, carrying out dry method compression moulding, through the pressure of adjustment dough-sheeter and volume density and the thickness that liner is adjusted in the gap.

Beneficial effect of the present invention is:

(1) through introducing sodium bentonite as plasticizing agent, that uses for reference food industry squeezes musculus cutaneus technology with face, has overturned automobile three-way catalytic converter liner traditional wet paper technology, and the adoption of innovation dry method is squeezed musculus cutaneus technology.Guarantee the better structural homogeneity of product, improved density of product and fastening force.

(2) adopt dry method and face technology, behind the adding unexpanded vermiculite, vermiculite in flake can evenly disperse, and can be combined in one with ceramic fiber securely.

(3), when guaranteeing liner normal temperature pliability and intensity, improved the hot strength and the fastening force of liner through compound use inorganic bonding agent sodium bentonite and organic bond nano silicon and acrylate copolymer emulsion.

Embodiment

Below in conjunction with embodiment the present invention is described further.

T in said following examples₀The thickness that the thumb pad layer is initial; T₁The minimum thickness of bed course during finger to finger test; T₂The maximum ga(u)ge of bed course during finger to finger test; T₃The thickness of finger to finger test back pad layer.

Embodiment 1

The raw material proportion of composing is: 80 parts of aluminum silicate fibers, Xinjiang produce 40 parts of unexpanded vermiculites, and concentration is 25 parts of 30% sodium bentonite solution, 30 parts of acrylate copolymer emulsions, 100 parts in water.Add dough mixing machine and carry out and face and about 10 minutes of face time, length of staple is 2～5mm.After 30 minutes, squeeze the face moulding with the industrial dough-sheeter of traditional food at ageing mixture under this state then, be of a size of 1200 * 600mm, product was sent in the expanded metals formula papermaking dry machine and is dried after moulding finished, and through cutting, finally realized the present invention again.Product performance index of the present invention is following:

Should refer to these product performance:

(1) liner thickness: 1mm

(2) general liner surface density: 1050g/m²

High density liner surface density: 6200g/m²(packing density=liner weight/gap)

(3) compressive strength:＞0.1N/mm²

(4) expansion character:

Once circulate: 0.345N/mm²Load-carrying is under 23 ℃～750 ℃ ± 10 ℃

T₁/T₀≥0.85 T₂/T₀≥1.40 T₃/T₀≥1.10

50 circulation: 0.345N/mm²Load-carrying is under 23 ℃-750 ℃ ± 10 ℃

T₅₀/ T₀>=1.30 (minimum expansion temperature is not less than 410 ℃)

T₅₀/ T₀>=1.25 (minimum expansion temperature is not less than 360 ℃)

Embodiment 2

The raw material proportion of composing is: 50 parts of aluminum silicate fibers, Xinjiang produce 30 parts of unexpanded vermiculites, and concentration is 20 parts of 30% sodium bentonite solution, 35 parts of acrylate copolymer emulsions, 80 parts in water.Add dough mixing machine and carry out and face and about 10 minutes of face time, length of staple is 2-5mm.After 30 minutes, squeeze the face moulding with the industrial dough-sheeter of traditional food at ageing mixture under this state then, be of a size of 1200 * 600mm, product was sent in the expanded metals formula papermaking dry machine and is dried after moulding finished, and through cutting, finally realized the present invention again.Product performance index of the present invention is following:

(1) liner thickness: 4mm

(2) general liner surface density: 2865g/m²

High density liner surface density: 8400g/m²(packing density=liner weight/gap)

(3) compressive strength:＞0.1N/mm²

(4) expansion character:

Once circulate: 0.344N/mm²Load-carrying is under 22 ℃-750 ℃ ± 10 ℃

T₁/T₀≥0.85 T₂/T₀≥1.40 T₃/T₀≥1.10

50 circulation: 0.344N/mm²Load-carrying is under 22 ℃-750 ℃ ± 10 ℃

T₅₀/ T₀>=1.30 (minimum expansion temperature is not less than 410 ℃)

T₅₀/ T₀>=1.25 (minimum expansion temperature is not less than 360 ℃)

Embodiment 3

A kind of three-way catalytic converter liner, its raw material proportion of composing is: 100 parts of aluminum silicate fibers, Xinjiang produce 5 parts of unexpanded vermiculites, and concentration is 30 parts of 30% sodium bentonite solution, 25 parts of acrylate copolymer emulsions, 120 parts in water.Add dough mixing machine and carry out and face and about 10 minutes of face time, length of staple is 2-5mm.After 30 minutes, squeeze the face moulding with the industrial dough-sheeter of traditional food at ageing mixture under this state then, be of a size of 1200 * 600mm, product was sent in the expanded metals formula papermaking dry machine and is dried after moulding finished, and through cutting, finally realized the present invention again.Product performance index of the present invention is following:

(1) liner thickness: 7mm

(2) general liner surface density: 4695g/m²

High density liner surface density: 12400g/m²(packing density=liner weight/gap)

(3) compressive strength:＞0.1N/mm²

(4) expansion character:

Once circulate: 0.345N/mm²Load-carrying is under 23 ℃-750 ℃ ± 10 ℃

T₁/T₀≥0.85?T₂/T₀≥1.40?T₃/T₀≥1.10

50 circulation: 0.345N/mm²Load-carrying is under 23 ℃-750 ℃ ± 10 ℃

T₅₀/ T₀>=1.30 (minimum expansion temperature is not less than 410 ℃)

T₅₀/ T₀>=1.25 (minimum expansion temperature is not less than 360 ℃)

Claims (7)

1. dry forming automobile three-way catalytic converter liner is characterized in that being made up of the raw material of following parts by weight:

50～100 parts of ceramic fibers

5～40 parts of unexpanded vermiculites

Concentration is 20～30 parts of 30% sodium bentonite solution

25～35 parts of flexible acrylic acid copolymer emulsions

80～120 parts in water.

2. dry forming automobile three-way catalytic converter liner according to claim 1 is characterized in that being made up of the raw material of following parts by weight:

80 parts of ceramic fibers

20 parts of unexpanded vermiculites

Concentration is 25 parts of 30% sodium bentonite solution

30 parts of nano silicon and acrylate copolymer emulsions

100 parts in water.

3. dry forming automobile three-way catalytic converter liner according to claim 1 and 2 is characterized in that described ceramic fiber is an aluminum silicate fiber.

4. dry forming automobile three-way catalytic converter liner according to claim 1 and 2 is characterized in that described flexible acrylic acid copolymer emulsion is nano silicon and acrylic acid copolymer emulsion.

5. dry forming automobile three-way catalytic converter liner according to claim 1 is characterized in that adopting following making method:

(1) batching and face operation

Aluminum silicate fiber, unexpanded vermiculite powder, nano silicon and acrylate copolymer emulsion and sodium bentonite solution adding dough mixing machine are carried out and face;

(2) squeeze the face molding procedure

The pug that makes in the step (1) is dewatered through dough-sheeter and forms wet base;

(3) drying process

With the wet base after the moulding, send into the papermaking dry machine and carry out thermal dehydration.

6. dry forming automobile three-way catalytic converter liner dry forming technology according to claim 5, the length that it is characterized in that described aluminum silicate fiber is 2～5mm.

7. dry forming automobile three-way catalytic converter liner dry forming technology according to claim 5 is characterized in that the described papermaking dry machine of step (3) is digester (-tor) formula dryer or plane expanded metals formula dryer.