Formed filter element
First Claim
1. A process of forming a filter element comprising a formed filter medium, the process comprising:
- blending an aqueous slurry comprising a bicomponent fiber and a glass fiber;
immersing a perforate support in the aqueous slurry, wherein the perforate support is suitably open to allow the passage of water while depositing fibers onto the perforate support;
applying a vacuum across the perforate support for a period of time sufficient to form a wet layer of fibers on the perforate support;
removing the perforate support having the wet layer formed thereon from the aqueous slurry;
extracting water from the wet layer to form a perforate support having a fibrous filter layer formed thereon; and
heating the perforate support having the fibrous filter layer formed thereon to a temperature sufficient to melt one component of the bicomponent fiber, to form a filter element comprising the perforate support having a formed filter medium disposed thereon, wherein the formed filter medium has a basis weight of at least about 500 grams/meter2;
wherein the process further comprises adding an additive to the aqueous slurry or to the formed filter medium, the additive comprising a surface finish compound, a compound to change the surface energy of one or more fibers, an acid, a base, a fluorocarbon, a flame retardant compound, an antistatic compound, or a combination thereof.
2 Assignments
0 Petitions
Accused Products
Abstract
A filter medium for use in filtering a mobile fluid made from at least a bicomponent fiber. Other fibers, particles, or other materials can also be entrained in the filter medium. The filter medium has a substantial thickness compared to filters of the prior art. The fiber length and diameter dimensions are selected to obtain desired filter characteristics including thickness, basis weight, pore size, filtration efficiency, pressure drop, burst strength, and manufacturing efficiency. Further, a multilayer filter medium can be provided with ease. Each layer can have a different composition, pore size, basis weight, and so forth, thus providing the ability to build multiple functionality into the filter media of the invention.
428 Citations
39 Claims
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1. A process of forming a filter element comprising a formed filter medium, the process comprising:
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blending an aqueous slurry comprising a bicomponent fiber and a glass fiber; immersing a perforate support in the aqueous slurry, wherein the perforate support is suitably open to allow the passage of water while depositing fibers onto the perforate support; applying a vacuum across the perforate support for a period of time sufficient to form a wet layer of fibers on the perforate support; removing the perforate support having the wet layer formed thereon from the aqueous slurry; extracting water from the wet layer to form a perforate support having a fibrous filter layer formed thereon; and heating the perforate support having the fibrous filter layer formed thereon to a temperature sufficient to melt one component of the bicomponent fiber, to form a filter element comprising the perforate support having a formed filter medium disposed thereon, wherein the formed filter medium has a basis weight of at least about 500 grams/meter2; wherein the process further comprises adding an additive to the aqueous slurry or to the formed filter medium, the additive comprising a surface finish compound, a compound to change the surface energy of one or more fibers, an acid, a base, a fluorocarbon, a flame retardant compound, an antistatic compound, or a combination thereof. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29)
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30. A process of forming a filter element comprising a formed filter medium, the process comprising:
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blending an aqueous slurry comprising a glass fiber and a bicomponent fiber comprising a binder component; immersing a perforate support in the aqueous slurry, wherein the perforate support is suitably open to allow the passage of water while depositing fibers onto the perforate support; applying a vacuum across the perforate support for a period of time sufficient to form a wet layer of fibers on the perforate support; removing the perforate support having the wet layer formed thereon from the aqueous slurry; extracting water from the wet layer to form a perforate support having a fibrous filter layer formed thereon; and heating the perforate support having the fibrous filter layer formed thereon to a temperature sufficient to melt the binder component of the bicomponent fiber, to form a filter element comprising the perforate support having a formed filter medium disposed thereon; wherein the formed filter medium has a basis weight of about 500 grams/meter2 to 3,000 grams/meter2; and wherein the filter element does not include a binder other than the binder component of the bicomponent binder fibers. - View Dependent Claims (31, 32, 33, 34)
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35. A process of forming a filter element comprising a formed filter medium, the process comprising:
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blending a first aqueous slurry comprising a bicomponent fiber and a glass fiber; immersing a perforate support in the first aqueous slurry, wherein the perforate support is suitably open to allow the passage of water while depositing fibers onto the perforate support; applying a vacuum across the perforate support for a period of time sufficient to form a first wet layer of fibers on the perforate support; removing the perforate support having the first wet layer formed thereon from the aqueous slurry; vacuum drying the perforate support having the first wet layer formed thereon to form a first dry media layer; optionally heating the perforate support having the first dry media layer formed thereon to a temperature sufficient to melt one component of the bicomponent fiber; blending a second aqueous slurry that is different from the first aqueous slurry; immersing into the second aqueous slurry the perforate support having the first dry media layer, which is optionally heated to melt one component of the bicomponent fiber; applying a vacuum across the perforate support for a period of time sufficient to form a second wet layer of fibers on the first dry media layer; and removing the formed filter medium and second wet layer from the aqueous slurry; vacuum drying the perforate support having the second wet layer formed thereon to form a second dry media layer; heating the perforate support having the first and second dry media layers formed thereon to a temperature sufficient to melt one component of the bicomponent fiber, to form a filter element comprising the perforate support having a formed filter medium disposed thereon, wherein the formed filter medium has a basis weight of at least about 500 grams/meter2. - View Dependent Claims (36, 37, 38, 39)
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Specification