Patent Description:
Coalescing filtration systems are often employed as the first stage in filter/separator vessels for hydrocarbon fluids e.g. fuels. Such systems filter out particulate contaminants and coalesce (combine) highly dispersed, emulsified water particles into larger water drops. These larger water drops are then collected and removed from the system.

A variety of methodologies may be employed to achieve such coalescence. For example, small droplets of water entrained in the fuel can contact and adhere to strands of filter media (for example, fiberglass). The operating pressure in the system and fluid flow pushes the droplets along these strands until they reach an intersection of strands where they combine with other droplets, and hence coalesce, into large drops.

Embossed patterns are often pressed into the filter media. These patterns often run parallel to the machine direction causing the fluid flow to be parallel to the embossment leading to a lower embossment contact area with the water droplets. For example, in a radial flow filter using a tube of filter media that has a vertical central axis, the elongated embossments will typically have the elongated axis parallel to the radius of the tube of filter media that is perpendicular to the central axis. This elongated axis is also then generally parallel to the flow of fluid through the block of filter media from an upstream face of the block of filter media to a downstream face of the block of filter media.

In use, coalesced water droplets run down along the filter media, e.g. parallel to the central axis of the tube of filter media, to a water collection bowl. Unfortunately, this causes the water concentration to continually increase when moving from the top of the tube of filter media to the bottom of the tube of filter media leading to a high-water concentration at the bottom of the element before the water droplets get collected in the water collection bowl.

While the above systems have been found satisfactory, there remains room for improvement. Indeed, there is a constant desire to reduce the pressure drop across a filter element, with such pressure drop typically being driven by the filtration media used in the filter element. There is thus a need in the art for a filtration element and associated filtration media that exhibits a reduced pressure differential while still providing the advantages of fuel water separation, i.e. water coalescence.

The following documents may provide technical background to the present disclosure: <CIT>; <CIT>; <CIT>; <CIT>; <CIT>; <CIT>; <CIT>.

The present application provides such a filter element and associated filter media as well as methods of forming the same, as defined in the appended claims. The present application provides improvements over the current state of the art.

As defined in appended claim 1a pleated filter element comprising pleated filter media having a plurality of pleat flanks and a plurality of structural embossments is provided. The pleated filter media has a first side forming an upstream surface and a second side forming a downstream surface. The pleated filter media includes a plurality of pleat flanks and a plurality of folds. Adjacent pleat flanks are connected by a corresponding one of the plurality of folds. The plurality of structural embossments are formed in at least one of the first and second sides of the pleat flanks. Each structural embossment has a first end and a second end that defines an embossment axis of the structural embossment. The embossment axis extends at a non-parallel and non-perpendicular orientation relative to the folds connected to the corresponding pleat flank.

In one example, the pleated filter media forms a tube of filter media defining a longitudinal central axis. The folds extend parallel to the longitudinal central axis. Each structural embossment is elongated along the structural embossment's embossment axis.

A first structural embossment of the plurality of structural embossments and a second structural embossment of the plurality of structural embossments are formed in a first pleat flank of the plurality pleat flanks. The embossment axis of the first structural embossment extends at a different angle than the embossment axis of the second structural embossment.

In one example, the pleated filter media has a gravitational top and a gravitational bottom. The gravitational top is vertically above the gravitational bottom (e.g. in use). The folds extend between the gravitational top and the gravitation bottom. The embossment axis of the first structural embossment is less aligned with gravity than the embossment axis of the second structural embossment. The first structural embossment is located closer to the gravitational top than the second structural embossment.

In one example, the pleated filter media forms a block of filter media that defines an upstream face and a downstream face. The block of filter media has a flow direction through which fluid to be filtered flows from the upstream face to the downstream face. The flow direction is generally perpendicular to the plurality of folds.

In one example, the embossment axes are angled relative to the folds such that when moving in the flow direction from the upstream face towards the downstream face, the embossment axes move upward towards the gravitational top of the pleated filter media.

A third structural embossment of the plurality of structural embossments is formed in a second pleat flank of the plurality of pleat flanks. A first fold of the plurality of folds is formed between the first and second pleat flanks. The first end of the third structural embossment is positioned axially between the first ends of the first and second structural embossments along the first fold. The first end of the second structural embossment being positioned axially between the first and second ends of the third structural embossment.

The first, second, and third structural embossments form a shingled orientation, particularly when viewed in the fluid flow direction.

In one example, the plurality of structural embossments each have a width that is generally perpendicular to the embossment axis. The width increases when moving from the first end toward the second end.

In one example, the depth/height of the structural embossments increases when moving from the first end toward the second end.

In one example, the first and second structural embossments form a projection on the first side of the pleated filter media and a depression on the second side of the pleated filter media. The third structural embossment forms a projection on the second side of the second pleat flank and a depression on the first side of the second pleat flank.

In one example, the filtration media is formed into a tube of pleated filter media defining a central longitudinal axis. Each of the structural embossments forms a projection on one of the first and second sides of the corresponding pleat flank and a depression in the other one of the first and second sides of the corresponding pleat flank. A width of the projection and depth of the depression measured generally perpendicular to the corresponding axis of the structural embossment increases when moving radially away from the central longitudinal axis of the tube of pleated filter media and along the embossment axis.

In one example, a width of the projection and depth of the depression measured generally perpendicular to the corresponding axis of the structural embossment increases when moving radially away from the central longitudinal axis of the tube of pleated filter media and along the embossment axis.

In one example, the pleated filter media is formed into a tube of pleated filter media. The tube of pleated filter media defines a central longitudinal axis. The tube of pleated filter media and is configured for fluid to be filtered to flow radially through the tube of pleated filter media as the fluid is filtered. Water that is separated moves generally parallel (or more parallel) to the central longitudinal axis. The tube of pleated filter media has a gravitational top and a gravitational bottom. The gravitational top is vertically above the gravitational bottom. The central longitudinal axis and folds extend between the gravitational top and the gravitation bottom. The embossment axis of the structural embossments is oriented relative to the longitudinal axis such that when moving along the embossment axis towards the gravitation bottom. The embossment axis moves radially outward and away from the longitudinal axis. However, other embodiments may have an opposite orientation.

In one embodiment, a method of making a filter element as outlined above is provided. The method includes providing filter media; embossing the filter media with a plurality of structural embossments; and folding the filter media about a plurality of folds to form a plurality of pleat flanks.

In one embodiment, a method of filtering water from a flow of fuel is provided. The method includes passing the flow of fuel through the filter media of the filter element as the fuel flows from an inlet of the filter element to an outlet of the filter element.

In one embodiment, a filtration system including a filter head, a housing and filter element as outlined above is provided. The filter head has an inlet and an outlet. The housing defines a sump region. A filter element as outlined above is positioned within the housing vertically above, at least in part, the sump region and fluidly interposed between the inlet and outlet.

In one embodiment, a method of making filter media is provided. The method includes providing a layer of filtration media having a surface with a predetermined roughness. The method includes contacting the surface of the media with a device having a selected roughness to impart a greater roughness to the surface of the media than the predetermined roughness.

The device may be a roller a plate, a belt or other structure for imparting enhanced surface roughness. The device may also include structure for forming structural embossments.

In one embodiment, the method includes the step of compressing the media with the device. This can form the enhanced surface roughness or the structural embossments.

In one embodiment, the method includes the step of pleating the media after the media is contacted with the device.

In one embodiment, the method includes the step of forming structural embossments in the surface of the media layer.

The step of pleating the media includes forming fold lines between adjacent pleat panels. The method includes forming a plurality of the structural embossments that are elongated such that each of the plurality of the structural embossments has a first end and a second end defining an embossment axis extending between the first end and the second end. The embossment axis extends at a non-parallel and non-perpendicular orientation relative to the fold lines.

A first structural embossment and a second structural embossment of the plurality of structural embossments are formed in a first pleat panel. The embossment axis of the first structural embossment extends at a different angle than the embossment axis of the second structural embossment relative to the fold line.

In one embodiment, the filter element has a gravitational top and a gravitational bottom. The gravitational top is vertically above the gravitational bottom. The embossment axis of the first structural embossment is less aligned with gravity than the embossment axis of the second structural embossment.

A third structural embossment of the plurality of structural embossments is formed in a second pleat panel. The fold line is formed between the first and second pleat panels. The first end of the third structural embossment is positioned axially between the first ends of the first and second structural embossments along the fold line and the first end of the second structural embossment is positioned axially between the first and second ends of the third structural embossment.

In one embodiment, the plurality of structural embossments each have a width that is generally perpendicular to the embossment axis. The width increases when moving from the first end toward the second end. In some embodiments, this will be in a radially inward direction when the filter media is formed into a tube of pleated filter media. In other embodiments, this may simply be in a generally downstream direction e.g. from an upstream face to a downstream face of the filter media pack, such as in a panel filter element.

In one embodiment, the first and second structural embossments form a projection on a first side of the layer of filter media and a depression on the second side of the filter media. The third structural embossment forms a projection on the second side of the filter media and a recess on the first side of the filter media.

In one embodiment, the step of contacting the surface of the media with a device having a selected roughness to impart a greater roughness to the surface of the media than the predetermined roughness occurs on at least <NUM>% and more preferably at least <NUM>% of the filter media that does not include structural embossments.

In one embodiment, at least <NUM>% of the surface of the filter media has been manipulated to include at least one of an increased surface roughness, a fold line and/or a structural embossment.

In one embodiment, the roller or plate has a surface roughness of at least 35µ and more preferably at least 190µ.

In one embodiment, the enhance surface roughness of the filter media is <NUM>µ and more preferably at least <NUM>.

In one embodiment, the step of contacting the surface of the media with a device having a selected roughness to impart a greater roughness to the surface of the media than the predetermined roughness is performed without removing material of the filter media.

In one embodiment, the step of contacting the surface of the media with a device having a selected roughness to impart a greater roughness to the surface of the media than the predetermined roughness is performed by compacting the filter media to form the greater roughness.

In one embodiment, the surface of the layer of filter media is an upstream surface of the layer of filter media that is an exposed surface.

In one embodiment, the layer of filter media is a pre-laminated media formed from a plurality of media layers. The step of contacting the surface of the media with a device having a selected roughness to impart a greater roughness to the surface of the media than the predetermined roughness does not simultaneously secure the plurality of media layers to form the layer of filter media.

In a particular implementation, the filter media is unwound from a roll of filter media in the laminated state prior to performing any surface roughness enhancement processes.

In one embodiment, the surface is not subsequently coated or covered after the step of contacting the surface of the media with a device having a selected roughness to impart a greater roughness to the surface of the media than the predetermined roughness.

In one embodiment, the surface roughness of the filter media layer has a contact angle measured using a Goniometer using water of between <NUM> degrees and <NUM> degrees and preferably at least <NUM> degrees.

In one embodiment, a filter element is provided. The filter element includes a pleated filter media pack formed from a layer of filtration media. The layer of filtration media forms a plurality of pleat panels formed by a plurality of fold lines. The filtration media has an upstream surface and a downstream surface. The upstream surface is compressed to have a desired surface roughness.

In one embodiment, the surface roughness of the upstream surface is greater than the surface roughness of the downstream surface.

In one embodiment, the upstream surface of the layer of filtration media is exposed such that fluid to be filtered first contacts the upstream surface of the layer of filtration media. As such, the surface that provides the desired roughness is not located between different layers of filter media. Further, the crevices or voids that form the surface roughness are not filled with other material.

In one embodiment, the layer of filtration media includes structural embossments in the upstream surface of the media layer.

In one embodiment, a plurality of the structural embossments are elongated such that each of the plurality of the structural embossments has a first end and a second end defining an embossment axis extending between the first end and the second end. The embossment axis extends at a non-parallel and non-perpendicular orientation relative to the fold lines.

In one embodiment, a first structural embossment and a second structural embossment of the plurality of structural embossments are formed in a first pleat panel. The embossment axis of the first structural embossment extending at a different angle than the embossment axis of the second structural embossment relative to the fold line.

In one embodiment, the filter element has a gravitational top and a gravitational bottom, the gravitational top being vertically above the gravitational bottom. The embossment axis of the first structural embossment is less aligned with gravity than the embossment axis of the second structural embossment. The first structural embossment being vertically above the second structural embossment.

In one embodiment, a third structural embossment of the plurality of structural embossments is formed in a second pleat panel. The fold line is formed between the first and second pleat panels. The first end of the third structural embossment is positioned axially between the first ends of the first and second structural embossments along the fold line and the first end of the second structural embossment is positioned axially between the first and second ends of the third structural embossment.

In one embodiment, the first, second and third embossments are positioned between upstream fold lines and downstream fold lines (e.g. radially outer fold lines and radially inner fold lines in a cylindrical element).

In one embodiment, the first, second and third embossments are positioned at a same location between the upstream and downstream fold lines.

In one embodiment, the first, second, and third embossments are axially offset from one another along the fold lines.

In one embodiment, the plurality of structural embossments each have a width that is generally perpendicular to the embossment axis. The width increasing when moving from the first end toward the second end. In one particular embodiment, this increase in width occurs when moving towards the downstream fold lines (e.g. radially inward in a cylindrical filter element or through the media pack when moving from an upstream face towards a downstream face of a panel filter element).

In one embodiment, at least <NUM>% and more preferably at least <NUM>% of the filter media that does not include structural embossments has a surface roughness that is greater than the surface roughness of the structural embossments.

In one embodiment, the surface roughness of the upstream surface is at least 116µ which is equivalent to that of <NUM> grit sand paper and more preferably at least 190µ, which is equivalent to that of <NUM> grit sand paper and even more preferably at least 425µ, which is equivalent to <NUM> grit sand paper.

In one embodiment, the surface roughness of the upstream surface is at least equivalent to that of <NUM> grit sand paper and more preferably at least equivalent to that of <NUM> grit sand paper and even more preferably at least equivalent to <NUM> grit sand paper.

In one embodiment, the surface roughness of the upstream surface has been manipulated to be at least <NUM>% greater than in an unmanipulated state, more preferably at least <NUM>% greater than in an unmanipulated state, and even more preferably at least <NUM>% greater than in an unmanipulated state.

In one embodiment, the surface roughness of the upstream face of the layer of filter media has been provided by compressing the upstream face of the layer of filtration media and not by removal of material from the upstream face.

In one embodiment, the upstream surface of the layer of filtration media is an exposed surface and the voids in the upstream surface forming the surface roughness are not filled with or covered by other material. This does not include potential overlap of adjacent pleat panels once the filter media is folded about the pleat folds.

In one embodiment, the layer of filtration media is a pre-laminated media formed from a plurality of media layers secured to one another independent of the structures of the filtration media providing the surface roughness of the upstream face.

In one embodiment, the surface roughness of the filtration media layer has a contact angle measured using a goniometer using water of between <NUM> degrees and <NUM> degrees and preferably at least <NUM> degrees.

In an embodiment, a method of filtering water from a flow of fuel includes passing the flow of fuel through the filtration media of a filter element according to any one of the embodiments outlined above as the fuel flows from an inlet of the filter element to an outlet of the filter element.

In an embodiment, a filtration system including a filter head having an inlet and an outlet; a housing, the housing defining a sump region; and a filter element according to any one of the prior embodiments is provided. The filter element is positioned within the housing vertically above, at least in part, the sump region and fluidly interposed between the inlet and outlet.

<FIG> illustrates a simplified filter element <NUM> incorporating the teachings of the present application. The filter element <NUM> includes pleated filter media <NUM> (also referred to as "filtration media") that is formed into a block of pleated filter media and particularly a cylindrical tube. While this embodiment illustrates the pleated filter media <NUM> in the cylindrical tube, other embodiments according to the present teachings could form the filter media in to a block of filter media that is in the form of a flat panel of filter media.

Filter element <NUM> finds particular benefit in filtering water from a flow fluid, such as a flow of fuel. The filter element <NUM> may also filter particulate matter from the flow fluid.

Dirty fluid enters the filter element <NUM> through one or more inlets, illustrated by arrows <NUM>. The dirty fluid flows through the filter media <NUM> from an upstream side/face (radially outer side in the illustrated cylindrical tube of filter media) to a downstream side/face (radially inner side in the illustrated cylindrical tube of filter media) as the fluid flow through the filter media <NUM>. After passing though the filter media <NUM>, the cleaned fluid flows through one or more outlets, illustrated by arrow <NUM>.

The filter media <NUM> is preferably configured to coalesce water entrained within the unfiltered fluid such that coalesced water droplets <NUM> will be separated from the fluid. The coalesced water droplets <NUM> will flow, illustrated by arrow <NUM> to a water sump <NUM> or other collection area. The flow of water droplets <NUM> is generally parallel to gravity (illustrated by arrow <NUM>).

<FIG> illustrates a filtration system <NUM> in which the filter element <NUM> can have particular applicability. Here, the sump <NUM> is provided by a removable bowl <NUM> that is removably connected to a filter head <NUM>. The filter head <NUM> provides the inlet <NUM> and outlet <NUM>.

The filter media <NUM> is one or more layers of filter media that is folded to form a pleated layer of filter media having a plurality of folds <NUM> that define fold lines that separate adjacent pleat panels <NUM>. The folds <NUM> interconnect adjacent pairs of pleat panels <NUM> (also referred to as pleat flanks). In a preferred embodiment, the folds <NUM> are generally parallel to gravity, illustrated by arrow <NUM> in <FIG>.

Preferably, the water sump <NUM> is at a bottom end <NUM> of the filter media <NUM> while the outlet <NUM> as top end <NUM> where "top" and "bottom" are defined with reference to gravity. In this way, gravity can be used to force the coalesced water droplets <NUM> to flow toward the water sump <NUM> rather than outlet <NUM>.

As noted, the filter media <NUM> is preferably formed from pleated media with a plurality of pleat panels <NUM> separated by pleat folds <NUM>.

<FIG> is a top view of a pair of pleat panels 122A, 122B prior to being folded about fold line <NUM> that, in this embodiment, is provided by a score line during the manufacturing process. The fold <NUM> separates pleat panel 122A from pleat panel 122B, but also interconnects the two adjacent pleat panels 122A, 122B.

In tubular filter elements, such as in <FIG>, the pleat folds <NUM> (which may be provided by score lines prior to folding) include radially outer pleat folds 120A and radially inner pleat folds 120B (e.g. the radially outer pleat folds 120A may be referred to as upstream pleat folds and the radially inner pleat folds 120B may referred to as downstream pleat folds with a radially outward to inward fluid flow as illustrated by arrow <NUM> in <FIG>). The pleat panels <NUM> would generally extend radially (typically at a slight angle from perfectly radially) between the outer and inner pleat folds 120A, 120B. The outer pleat folds 120A can be considered to form a radially outer periphery or upstream face (illustrated by dashed line 119A) of the tube of filter media while the inner pleat folds 120B form a radially inner periphery or downstream face (illustrated by dashed line 119B) of the tube of filter media.

In a panel filter element, pleat folds 120A would form an upstream face of the panel filter while pleat folds 120B would form a downstream face of the panel filter element. The pleat panels <NUM> would extend generally between the upstream and downstream faces.

With reference to <FIG>, the filter media also includes a plurality of structural embossments 140A, 140B. Structural embossments 140A are formed in pleat panel 122A while structural embossments 140B are formed in pleat panel 122B.

<FIG> illustrates an upstream surface <NUM> (see also <FIG>) of two pleat panels 122A, 122B of the filter media <NUM> prior to folding about fold line <NUM>, which is opposite a downstream surface <NUM>. In operation, dirty fluid will first contact upstream surface <NUM> and then pass through filter media <NUM> with cleaned fluid exiting the filter media <NUM> through downstream surface <NUM>.

The filter media has a plurality of manipulations according to embodiments of the application. The first manipulation is the formation of the pleat fold <NUM>, which could be a score or crease.

A second manipulation is the formation of the structural embossments 140A, 140B. With reference to <FIG> and <FIG>, in this embodiment, embossments 140A are negative embossments as they form a plurality of depressions in the upstream surface <NUM> and a plurality of protrusions in the downstream surface <NUM> of the filter media <NUM>. Embossments 140B are positive embossments as they form a plurality of protrusions in the upstream surface <NUM> and a plurality of depressions in the downstream surface <NUM>.

While this embodiment illustrates the embossments from alternating pleat panels <NUM> alternating between positive and negative embossments, in some embodiments, all the embossments could be positive or all of the embossments could be negative. Further, in some embodiments, a single pleat panel <NUM> could have both positive and negative embossiments.

Each of the embossments <NUM> includes a first end <NUM> and second end <NUM>. The embossments <NUM> extend longitudinally between the first and second ends <NUM>, <NUM> along an embossment axis <NUM>.

In the illustrated embodiment of <FIG>, the embossments taper between the first and second ends <NUM>, <NUM>. In particular, the width W (illustrated by a double headed arrow in <FIG>) of the embossments <NUM> perpendicular to embossment axis <NUM> increases when moving from the first end <NUM> toward the second end <NUM>. This results in a tear-dropped shape. In other embodiments, the width can remain constant and need not increase when moving radially inward.

At least a portion of each embossment <NUM> has width W that is at least double the thickness of the filter media and preferably at least <NUM> times the thickness of the filter media. In some embodiments, at least a portion of some or all of the embossments has a width W that is at least <NUM> times the thickness of the filter media.

In some implementations, the height H of the embossments <NUM> increases when moving along the embossment axis <NUM> from one end to the other end of the embossment. As illustrated in <FIG>, the height H increases when moving along the embossment axis <NUM> away from fold <NUM>. While described in terms of height H, the depth of negative embossments can have a similar orientation. At least a portion of each embossment <NUM> has height H that is at least double the thickness of the filter media and preferably at least <NUM> times the thickness of the filter media. In some embodiments, at least a portion of some or all of the embossments has a height H that is at least <NUM> times the thickness of the filter meida.

In some embodiments, the pleat panels <NUM> would be folded relative to one another about fold <NUM> such that the second ends <NUM> of the embossments <NUM> would be positioned radially closer to the central axis <NUM> of the tube of filter media <NUM>. In a flat panel filter, the embossments <NUM> would generally get wider when traveling from an upstream face toward a downstream face of the panel (e.g. in the direction of flow through the filter media panel. However, in other embodiments, the orientation of the first and second ends <NUM>, <NUM> could be switched such that the second ends <NUM> of the embossments <NUM> would be positioned radially farther from the central axis <NUM> of the tube of filter media <NUM> than the first ends <NUM>.

This angled orientation helps coalesce entrained water as the dirty fluid flows across the upstream face <NUM> of the filter media <NUM> and particularly the embossments <NUM>. The embossments also help maintain spacing between the adjacent pleat panels 122A, 122B once folded.

With reference to <FIG>, in addition to tapering, in some embodiments, the embossment axis <NUM> extends at a non-parallel, non-perpendicular orientation relative to the folds <NUM> and gravity <NUM>. Preferably, the non-parallel, non-perpendicular orientation creates a shingled pattern when viewed in the radial direction, which helps reject more water drop <NUM> from entering the media.

<FIG> is a simplified illustration of filter media <NUM> better illustrating the shingled orientation.

In a preferred configuration, the orientation of the embossment axis <NUM> from one embossment <NUM> to the next embossment <NUM> changes when transitioning from the top end <NUM> towards the bottom end <NUM>. In particular, the orientation of vertically lower embossments <NUM> is steeper relative to the radial direction and closer to parallel to the pleat folds <NUM> and gravity <NUM> the closer the corresponding embossment <NUM> is located relative to bottom end <NUM>.

The different angles of the embossment axes <NUM> from one embossment to the next is further illustrated in <FIG>. Here, the embossment axes <NUM>' of the two lower embossments 140A' and 140B' are steeper than the embossment axes <NUM> of the two upper embossments 140A and 140B. Notably, embossments 140B, 140B' are shown in dashed lines as they are formed in a pleat panel that is hidden behind the pleat panel that forms embossments 140A, 140A'.

It is also noted that the embossments <NUM> of <FIG> are not teardrop shaped and are instead oval, which is an alternative shape.

The increasing steepness when moving toward the bottom <NUM> increases the water blocking effect of the embossments <NUM>. This blocks the water droplets <NUM> from entering the upstream pleated section of the filter media resulting in overall utilization of the surface area for filtration and better performance of the bottom section of the filter element <NUM>. This is particularly beneficial as the separated water droplets <NUM> move vertically downward toward the bottom end <NUM> and sump <NUM>. The increased water blocking performance helps compensate for the fact that the downward flow of the water <NUM> results in the bottom portions of the filter element <NUM> having a high water concentration before the water is collected in sump <NUM>. The increasing angle of the embossment axes <NUM>' as compared to embossment axes <NUM> increases the water blocking performance of the lower portion of the filter media <NUM>.

In preferred embodiments, the embossments 140A of pleat panel 122A overlap with embossments 140B of pleat panel 122A when viewed perpendicular to the folds <NUM>. As such, the first end of an embossment 140B is positioned vertically between the first ends of two adjacent embossments 140A. However, it is preferred that the first end of an embossment 140A is positioned vertically between the first and second ends <NUM>, <NUM> of an embossment 140B.

The angle of the embossment axis <NUM> relative to the flow of fluid through the media <NUM> (e.g. the generally radial direction) helps prevent the push through of coalesced water droplets by blocking the re-introduction into the media <NUM> and also uses gravity to assist with water separation.

As illustrated in <FIG>, in one embodiment, the embossment axes <NUM> are angled relative to fold <NUM> and gravity such that when moving in the fluid flow direction, the embossment axes <NUM> move toward the top <NUM>. This orientation causes the water droplets <NUM> to move radially outward (illustrated by arrow <NUM>), as the droplets <NUM> move vertically downward due to gravity <NUM>. This further promotes removal of the water from the fluid being filtered. With reference to <FIG>, the water droplets would move outward towards the vertical wall of the bowl <NUM>. However, the reverse orientation could be implemented.

Adjacent the plurality of embossments 140A, 140B <NUM>, the filter media <NUM> has a plurality of flat surface regions <NUM>.

Preferrably, the structural embossments 140A of one pleat panel 122A are axially offset from the structural embossments 140B of the adjacent pleat panels 122B along the fold <NUM> such that when the panels 122A, 122B are folded relative to one another about fold <NUM>, the embossments 140B are positioned axially between embossments 140A along fold <NUM>. This allows embossments 140B to cooperate with and/or align with the flat surface regions <NUM> of the adjacent pleat panel 122A, 122B. This helps maintain appropriate spacing between the pleat panels 122A, 122B.

In a preferred embodiment, these surface regions <NUM> have been manipulated to have increased surface roughness. More particularly, the filter media <NUM> is generally formed with a first surface roughness and then the user manipulates the filter media <NUM>, and particularly in these flat surface regions <NUM> to increase the surface roughness.

In one embodiment, the surface roughness of the upstream surface is at least 116µ, which is equivalent to that of <NUM> grit sand paper and more preferably at least 190µ, which is equivalent to that of <NUM> grit sand paper and even more preferably at least 425µ, which is equivalent to <NUM> grit sand paper.

In one embodiment, the surface regions <NUM> have, after manipulation, a surface roughness of at least 116µ and more preferably at least 425µ. It should be noted that in some preferred embodiments, the embossments <NUM> have a height of at least three times greater than the surface roughness.

In some embodiments, the surface roughness of the filter media after being manipulated is increased by at least <NUM>% more preferably by at least <NUM>% and even more preferably by at least <NUM>%.

In some embodiments, the surface roughness of the upstream surface <NUM> is greater than the surface roughness of downstream surface <NUM>. Typically, but not always, the surface roughness of only the upstream surface <NUM> is manipulated as this is the surface that is first contacted by the dirty fluid that has the entrained water. The surface roughness helps increase the surface energy of the upstream surface <NUM> and thus the water separation capabilities thereof.

In <FIG>, the increased surface roughness is illustrated schematically by dotted stippling on the surface of the filter media <NUM>. This roughness may be referred to as micro roughness.

<FIG> illustrates a simplified filter media processing system <NUM>. The system includes a filter media supply <NUM>, which is typically a roll of filter media that will be used to form filter media <NUM>. The filter media is unwound from the roll and subsequently processed.

Downstream from the filter media supply <NUM> is a media manipulation station <NUM> that includes one or more media manipulation tools <NUM>, <NUM> that performs surface manipulation to one or more surfaces and/or regions of the filter media.

In a particular implementation, the media manipulation station <NUM> include media manipulation tools in the form of opposed compression rollers. In another implementation, the media manipulation tools are provided by a pair of opposed belts. In a further implementation, the media manipulation tools are provided by a pair of linearly actuated stamping plates that move toward and away from one another along an axis that is generally perpendicular to the flow media through the media manipulation station <NUM>.

In one implementation, the media manipulation station <NUM> only manipulates one side of the filter media, and particularly the side of the filter media that would become upstream surface <NUM> described above. In such an embodiment, the media manipulation tool <NUM>, <NUM> that cooperates with that side of the media would manipulate the surface roughness of the corresponding surface of the filter media to increase the surface roughness as compared to an original surface roughness of the filter media.

Preferably, the media manipulation station <NUM> modifies the surface roughness without removing any or substantially any of the filter media, e.g. without abrading or laser etching of the media. Instead, it is preferred to modify the surface roughness simply by compressing the filter media. Removal methods can, among other things, leave debris on the filter media.

In one implementation, the media manipulation tool <NUM>, <NUM> that defines the desired surface roughness is formed from a material that is more rigid than the other one of the media manipulation tools <NUM>, <NUM>. In some implementation, the media manipulation tools <NUM>, <NUM> may have the surface roughness profile laser etched into the surface of the tooling.

In one embodiment, the same media manipulation tool <NUM> or <NUM> has both the structural embossment and surface roughness features formed therein. In some embodiments, the media manipulation tool <NUM>, <NUM> is entirely free of surface roughness features and only provides the structural embossments.

In some implementations, the media manipulation tool <NUM>, <NUM> has a rigid member that provides the structural embossment profiles formed therein and a micro-roughness film is attached to the rigid member. The micro-roughness film would surround the structural embossment profiles.

In some implementations, the media manipulation station <NUM> has a two-step process where the roughness and structural embossments are formed using separate sets of tooling that are aligned sequentially such that one process is performed first and then the other process is performed. Typically, the roughness process would occur first. Again, other systems may have only one of the various different media manipulation features.

In some implementations, structural embossments do not have the surface thereof manipulated to increase roughness and only the remainder portion of the pleat panel (e.g. substantially planar portions of the filter media) are manipulated to provide improved surface roughness.

In a preferred implementation, the media manipulation tools <NUM>, <NUM> have both a positive and negative structural embossment feature that align to form a single structural embossment. For example, a projection of tool <NUM> would align with and press filter media into a corresponding recess of cooperating tool <NUM> to form an embossment. However, while cooperating projection/recess features (e.g. cooperating positive and negative features) may preferably be used to form the structural embossments, the surface roughness features will typically not be formed with such a positive/negative arrangement. Instead, the surface roughness features would be formed simply by one or the other tool <NUM>, <NUM> without cooperating features between tools <NUM>, <NUM> that cooperate to form the surface roughness.

In one implementation, the filter media is a laminate of a plurality of layers of filter media. This laminate is formed and the layers thereof are secured to one another prior to passing through the media manipulation station <NUM>.

Further, it is preferred that the surfaces that have had the surface roughness enhanced and increased, it is preferred that these surfaces are not subsequently coated. This is particularly true because the surface roughness added to the filter media is not used as a means for securing separate layers together. Instead, the surface roughness should remain unencumbered by other material such that the improved water separation features remain.

Downstream from tool <NUM>, <NUM> is a folder <NUM> that causes the adjacent pleat panels <NUM> to be folded about the corresponding pleat folds <NUM>.

<FIG> is a photograph of filter media <NUM> that has been manipulated to include a fold <NUM> to define pleat panes 322A, 322B, structural embossments 340A, 340B and flat surface regions <NUM> with enhanced roughness.

<FIG> is a photograph similar to <FIG>. However, the filter media did not include the enhanced surface roughness surrounding the structural embossments.

<FIG> is a photograph of an unmanipulated sample of the filter media used for the arrangements of <FIG> and <FIG>.

The Applicants have performed various tests to compare the operational parameters of filter media of all three arrangements of <FIG>. However, not all tests were performed on the sample that did not include surface roughness.

<FIG> compare the contact angle for the control filter media of <FIG> and the modified filter media of <FIG>. The contact angle of water on the surface of the corresponding medias was tested using a Goniometer. It was determined that the sample with the surface roughness increased had a greater contact angle. More particularly, the control sample had an average contact angle of <NUM>° plus or minus <NUM> (average of two values) while the sample with increased surface roughness had an average contact angle of <NUM>° plus or minus <NUM> (average of two values).

<FIG> illustrates a comparison of the flow restriction vs. flow rate based on SAE J905. The liquid used was ultralow sulfur diesel (ULSD). As illustrated, the modified samples each had reduced pressure drop than the control sample at a same flow rate.

<FIG> illustrates a comparison of water separation efficiency over time tested according to SAE J1488. The test flow rate was <NUM> gpm. The flow was outside-in with a cylindrical filter element.

<FIG> plots the pressure drop over time for the three samples tested according to SAE J1488. The test flow rate was <NUM> gpm. The flow was outside-in with a cylindrical filter element.

Claim 1:
A pleated filter element (<NUM>) comprising:
pleated filter media (<NUM>) having a first side forming an upstream surface (<NUM>) and a second side forming a downstream surface (<NUM>), the pleated filter media including a plurality of pleat flanks (<NUM>) and a plurality of folds (<NUM>), adjacent pleat flanks (122A, 122B) connected by a corresponding one of the plurality of folds (<NUM>); and
a plurality of structural embossments (<NUM>) formed in at least one of the first and second sides of the pleat flanks (<NUM>), each structural embossment (<NUM>) having a first end (<NUM>) and a second end (<NUM>), the first and second end defining an embossment axis (<NUM>) of the structural embossment, the embossment axis (<NUM>) extending at a non-parallel and non-perpendicular orientation relative to the folds (<NUM>) connected to the corresponding pleat flank (<NUM>);
wherein a first structural embossment (140A) of the plurality of structural embossments and a second structural embossment (140A') of the plurality of structural embossments are formed in a first pleat flank (122A) of the plurality pleat flanks, the embossment axis (<NUM>) of the first structural embossment (140A) extending at a different angle than the embossment axis (<NUM>') of the second structural embossment (140A'); and
wherein a third structural (140B) embossment of the plurality of structural embossments is formed in a second pleat flank (122B) of the plurality of pleat flanks, a first fold (<NUM>) of the plurality of folds being formed between the first and second pleat flanks (122A, 122B), the first end (146B) of the third structural embossment (140B) being positioned axially between the first ends (146A, 146A') of the first and second structural embossments (140A, 140A') along the first fold (<NUM>) and the first end (146A') of the second structural embossment being positioned axially between the first (146B) and second ends (148B) of the third structural embossment, the first (140A), second (140A'), and third (140B) structural embossments forming a shingled orientation.