HOUSE WRAP & METHOD OF MANUFACTURE

Abstract

A continuous, wavy and intersecting pattern of filaments is deposited on a surface of a house wrap membrane using a plurality of hot melt nozzles and a controller that controls, positionally and temporally, the relative positions and flow of hot melt of the nozzles and the top surface of the membrane. Water drainage channels may be provided by depressions or viaducts.

Claims

1. A method of making a house wrap, comprising: disposing a membrane in a longitudinal direction, the membrane having a beginning, an end, a first side extending between the beginning and the end, and a second side, opposite of the first side, the second side extending between the beginning and the end, and the beginning, the first side, the end and the second side defining a perimeter, the longitudinal direction being defined along the first side extending from the end to the beginning, the perimeter defining a surface area of the membrane, and the surface area of the membrane comprises a top surface and a bottom surface, opposite of the top surface, having the top surface facing upward; depositing, during the step of disposing the membrane in a longitudinal direction, a first polymer strand of a hot melt polymer onto the top surface of the membrane, wherein the first polymer strand is disposed above the top surface, the first polymer strand is a continuous strand, and at least a portion of the first polymer strand adheres to the top surface of the membrane; depositing, during the step of disposing the membrane in a longitudinal direction, a second polymer strand of a hot melt polymer onto the top surface of the membrane, wherein the second polymer strand is disposed above the top surface, the second polymer strand is a continuous strand, and at least a portion of the second polymer strand adheres to the top surface of the membrane; controlling, positionally and temporally, the disposing of the membrane and, at the same time, hot melt nozzles utilized for depositing the hot melt polymer of the first polymer strand and the hot melt polymer of the second polymer strand such that the first polymer strand and the second polymer strand are deposited and adhered on the top surface of the membrane between the beginning, the end, first side and the second side of the membrane in a pattern of wavy, intersecting polymer strands, each of the first polymer strand and the second polymer strand being raised above the top surface of the membrane, and the pattern comprising intersecting points where the first polymer strand and the second polymer strand intersect, one over the other.

2. The method of claim 1, wherein the step of controlling forms a sinusoidal pattern for each of the first polymer strand and the second polymer strand, and positions of the hot melt nozzles for the first polymer strand and the second polymer strand such that the sinusoidal pattern for the first polymer strand is offset from the sinusoidal pattern of the second polymer strand.

3. The method of claim 2, wherein the step of controlling fixes the hot melt nozzles onto a common nozzle support member, and a position controller moves the common nozzle support member wherein the plurality of nozzles are moved at the same time such that the sinusoidal pattern of the first polymer strand is offset at a fixed offset distance from the sinusoidal pattern of the second polymer strand.

4. The method of claim 3, further comprising: positioning a flattening device such that the flattening device flattens at least one portion of the first polymer strand, the second polymer strand, or both the first polymer strand and the second polymer strand, such that water drainage channels are provided through which water drains.

5. The method of claim 4, wherein the step of positioning supports a plurality of flattening devices using a common flattening device support member such that all of the plurality of flattening devices are disposed in a spatial relation across a width of the membrane, the width being defined as the distance between the first side and the second side, and portions of the first polymer strand and the second polymer strand are flattened by the plurality of flattening devices during the step of disposing.

6. The method of claim 1, further comprising: depositing, during the step of disposing the membrane in a longitudinal direction, a third polymer strand of a hot melt polymer onto the top surface of the membrane, wherein the third polymer strand is disposed above the top surface, the third polymer strand is a continuous strand, and at least a portion of the third polymer strand adheres to the top surface of the membrane.

7. The method of claim 6, further comprising: depositing, during the step of disposing the membrane in a longitudinal direction, a fourth polymer strand of a hot melt polymer onto the top surface of the membrane, wherein the fourth polymer strand is disposed above the top surface, the fourth polymer strand is a continuous strand, and at least a portion of the fourth polymer strand adheres to the top surface of the membrane.

8. The method of claim 1, wherein the one of the hot melt nozzles utilized for depositing the hot melt polymer of the first polymer strand is raised and lowered in relation to the top surface of the membrane during the step of controlling forming a bridge, wherein the bridge is defined by a gap between the top surface of the membrane and the first polymer strand when the one of the hot melt nozzles utilized for depositing the hot melt polymer of the first polymer strand is raised temporally above the top surface of the membrane to form the gap before being returned to a lower position wherein the first polymer strand re-adheres to the top surface of the membrane.

9. The method of claim 8, wherein another one of the hot melt nozzles is raised and lowered in relation to the top surface of the membrane during the step of controlling forming another bridge defined by another gap between the top surface of the membrane and the second polymer strand, whereby water is capable of draining through the another gap.

10. The method of claim 9, wherein the step of controlling controls the raising and lowering of the one of the hot melt nozzles and the another of the hot melt nozzles such that drainage channels are provided in the pattern of wavy, intersecting polymer strands, whereby water drains through the drainage channels when the house wrap is installed.

11. The method of claim 1, further comprising a step of depositing a soluble viaduct material onto the top surface of the membrane and the first polymer strand or the second polymer strand or both the first polymer strand and the second polymer strand are deposited over the soluble viaduct materials during the respective step of depositing of the first polymer strand, the second polymer strand or both the first polymer strand and the second polymer strand.

12. The method of claim 11, further comprising a step of dissolving the soluble viaduct material after the steps of depositing.

13. The method of claim 12, wherein the step of dissolving comprises dipping the membrane in a solvent.

14. The method of claim 13, wherein the soluble viaduct material is of a sugar and the solvent is water.

15. The method of claim 1, further comprising a step of disposing a non-stick rod on the top surface of the membrane prior to the steps of depositing, wherein the steps of depositing deposit the first polymer strand and the second polymer strand over the non-stick rod; and removing the rod from the top surface of the membrane without disturbing the first polymer strand and the second polymer strand.

16. The method of claim 1, wherein the step of controlling selects a location or locations of a channel formed by a gap or a viaduct between the top surface of the membrane and the first polymer strand or the second polymer strand such that any liquid on the membrane is directed along the first polymer strand or the second polymer strand in a direction away from an edge of the membrane and toward the channel.

17. The method of claim 16, wherein the step of controlling includes imaging at least a portion of the top surface of the membrane for detecting a location for the channel, and raising at least one of the hot melt nozzles at the location for the channel, wherein the at least one of the hot melt nozzles of the first polymer strand or the second polymer strand forms a bridge over the channel.

18. The method of claim 1, further comprising positioning a flattening device such that the flattening device flattens at least one portion of the first polymer strand, the second polymer strand, or both the first polymer strand and the second polymer strand, whereby drainage channels are formed at the at least one portion of the first polymer strand, the second polymer strand, or both the first polymer strand and the second polymer strand.

19. The method of claim 18, wherein the step of positioning comprises positioning a flattening device support member supporting a plurality of flattening devices such that each of the plurality of flattening devices are disposed in a spatial relation across a width of the membrane, the width being defined as the distance between the first side and the second side, and the at least one portion comprises a plurality of portions being flattened of both the first polymer strand and the second polymer strand by the plurality of flattening devices during the step of disposing.

20. The method of claim 18, wherein the flattening device is a roller, and the step of controlling controls a height of the roller such that the height of the roller positions the roller in a lowered position and a raised position such that the roller rolls across the top surface of the membrane longitudinally during the step of disposing when the height of the roller is in the lowered position, flattening the at least one portion of the first polymer strand, the second polymer strand or both the first polymer strand and the second polymer strand, but when the height of the roller is in the raised position, no portion of the first polymer strand and the second polymer strand is flattened by the roller.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The following drawings are illustrative examples and do not further limit any claims that may eventually issue.

[0024] FIG. 1 illustrates an example of a serpentine pattern of continuous filaments that intersect on a housewrap and wheels for flattening portions of raised strands deposited on a membrane in the serpentine pattern.

[0025] FIG. 2 illustrates another example of a serpentine pattern of continuous filaments that intersect on a housewrap.

[0026] FIG. 3 illustrates yet another example of a serpentine pattern of continuous filaments that intersect on a housewrap.

[0027] FIG. 4 illustrates a side view of a machine for creating a serpentine pattern of continuous filaments that intersect.

[0028] FIG. 5 illustrates a perspective, detailed view of a portion of a serpentine pattern, showing a flattened portion of the filament a deflection region.

[0029] FIG. 6 illustrates a flow chart for a method of creating a serpentine pattern of continuous filaments that intersect.

[0030] FIG. 7 illustrates a perspective, detailed view of a portion of a serpentine pattern, showing a raised portion of the filaments that forms a bridge and viaduct.

[0031] FIG. 8 illustrates an example of one step in a method of producing a bridge and viaduct.

[0032] When the same reference characters are used, these labels refer to similar parts in the examples illustrated in the drawings.

DETAILED DESCRIPTION

[0033] In one example, such as the illustration in FIG. 1, a plurality of continuous filaments or strands intersect each other. Each raised strand forms a serpentine pattern bonded to a surface of a membrane of a house wrap. The membrane may be any of the well known membranes, such as a Tyvek house wrap (Tyvek is a trademark of Dupont). For example, FIG. 1 illustrates an example of two filaments 11, 12 that alternatingly serpentine along a longitudinal direction of house wrap membrane. The two filaments intersect along a center line region 13 of the house wrap membrane and are bonded to the surface of the membrane. The region for intersection may be controlled along a line (CL) plus or minus a distance (+Z or -Z). In one example, control allows a comparatively narrow wheel 14 to be used to flatten an intersecting portion of the two filaments at each intersecting point 31. Alternatively, a wider roller may be used to flatten each intersecting point. Additional wheels 15 or rollers may be positioned to flatten other regions of the raised strands, such as illustrated in FIG. 5, for example, where a deflection region 31, 32 of each raised strand may be flattened, leaving a drainage channel D to prevent any significant accumulation of water at the deflection region.

[0034] For example, in FIG. 1, the two filaments may be deposited onto a surface of the membrane 10 from two hot melt nozzles 41, 42 incorporated into a hot melt machine and independently controlled.

[0035] Hot melt machinery and parts are used to accomplish a variety of hot melt applications, such as machines made by the Nordson Corporation, for example.

[0036] In other examples, such as in FIGS. 2 and 3, a plurality of continuous filaments 11, 12, 17, 18, greater than two, are bonded to a surface of a membrane 10 in a serpentine, continuous and interconnected pattern from a plurality of hot melt nozzles 43-46 mounted to a rigid structure 50. In each of these examples, each filament extends from one side 16 of a membrane film 10 to an opposite side 19 of the membrane film 10, while also extending longitudinally along the length of the membrane film. By “from” and “to” it should be understood that the raised strand approaches but need not reach the one side of the opposite side. Instead, “from” and “to” may be understood as meaning the raised strands extend continuously across substantially all of the width of the membrane, leaving a narrow border free of hot melt filaments.

[0037] Melters, hot melt adhesive hoses and other hot melt parts may be coupled in a machine to connect to the plurality of nozzles for depositing continuous filaments of hot melt polymer as a raised filament bonded to the surface of a membrane. For example, hot melt filaments may be made of ethylene vinyl acetate copolymers or EVA, among them are styrene-isoprene-styrene (SIS copolymers), styrene-butadiene-styrene (SBS copolymers), and ethylene ethyl acrylate copolymers (EEA), which may be mixed with a variety of plasticizers, waxes, and resins that optimize performance. In one example, the hot melt adhesive is a polyurethane reactive (PUR), which sets up rapidly, rapidly meaning in mere seconds, and then is rigid in a matter of minutes, which makes it particularly useful for creating continuous filaments and for forming flattened portions in the continuous filaments. More than a few seconds may be provided between deposition of the hot melted PUR and the flattening of the hot melted PUR by a wheel. By flattening the hot melted PUR before it becomes entirely rigid, a non-stick or non-stick coated wheel may be used to flatten the strands, rather than resorting to higher pressure and/or temperature rollers. For example, a plurality of flattening wheels 14, 15 may be rotatably mounted to a support arm 91 supported by a pair of fixed supports 90. One or more may be positionable in a transverse direction E to the longitudinal direction of travel B of the membrane 10, for example.

[0038] In FIG. 2, three nozzles 43-45 are disposed longitudinally along a rigid member 50. The rigid member 50 is elongated in the longitudinal direction and is coupled to a position controller 60 comprising a motor and a positioning mechanism. For example, the positioning mechanism may comprise a threaded screw 61 and a matingly threaded block 62, which moves along the screw 61 as the screw is rotated clockwise or counterclockwise. A rigid support frame 63, 64 may be fixedly mounted and may be coupled to the screw by roller bearings 65, for example. Alternatively, a rod 61 may be unthreaded and may merely guide the rigid member 50 under control of a mechanical arm or cable positioner, for example. Preferably, the controller 60 includes a positive feedback for determining the position of the hot melt nozzles, at least intermittently, such as a limit switch 66 or the like. For example, it is known to include a sensor for determining when a motor makes a complete revolution about an axis for determining the location of a block 62 on a screw 61. Combination of a positive feedback switch 66 and a sensor provides positive feedback for ensuring that the sensor is operating properly. Also, one or more limit switches 66 may prevent the controller 60 from continuing beyond a point where damage to equipment or injury to an operating may occur. In one example, one or more rods 68 and roller bearings 69 are added for structural stability and to prevent binding during translation of the nozzles 43-45 back and forth across the membrane 10.

[0039] In the example of FIG. 3, a chain 71 and chain drive gears 72 positively couple threaded rods 61, 68 to the rigid member 50. The rigid member 50 is positionable in a back and forth transverse direction A relative to a longitudinal direction of movement B of an underlying membrane 10.

[0040] In FIG. 4, an example of a machine is shown. A plurality of nozzles are disposed in a line along rigid member, wherein the rigid member is translatable transversely across the surface of membrane, as the membrane is translated longitudinally. Each nozzle may begin ejecting hot melt material independently; therefore, a continuous filament of hot melt may be provided by each nozzle in turn, such that a pattern of intersecting, serpentine, continuous filaments is disposed onto the surface of the membrane. For example, two filaments are disposed on a surface as shown in FIG. 1 by activating a first nozzle 1 and a third nozzle 3 in turn, while translating the membrane in a longitudinal direction and translating the rigid member transversely first in one transverse direction and then in a second transverse direction.

[0041] FIG. 4 shows a side view of a plurality of rollers 15, each roller 15 may be able to be raised or lowered in an up and down direction F and moved transversely, as needed, even while continuing to rotate in a rotational direction W+ or W−. The rollers 15 flatten only a portion of the filaments. For example, one roller 15 may be disposed along a center line region CL of a membrane 10. For example, FIG. 5 represents a partial detail view of a flattened region, which may be either a center line CL region or a deflection region 31, 32. This partial, detail view would look the same in both regions, with a flattened portion 32 and raised portions 12, 12′ leaving a gap D between the raised portions 12, 12′. A roller or wheel 15 is shown downstream of the flattened portion 32, after flattening the flattened portion 32. When the roller 15 is disposed in direction X to flatten each point of intersection between a first filament 11 and the second filament 12, one of the raised portions 12′ is a portion of the first filament 11 and the other raised portion 12 is the second filament 12. Alternatively, when the raised portions 12, 12′ are flattened at a deflection point, then each raised portion 12, 12′ is of the same filament 12. Continuity of the filaments strengthen the membrane in every direction while providing for drainage of water. The flattened portions 32 may improve bonding between the filaments and the surface of the membrane, also.

[0042] In FIG. 6, an example of a method of making a membrane with a pattern of continuous, raised polymer strands that extend from one side of the membrane of the house wrap to an opposite side of the membrane, as a wavy, intersecting pattern on a surface of the membrane, is described in relation to a flow diagram. At step 1, a first nozzle 11 is disposed above a surface of a membrane 10. A hot melt is directed to and extruded from the nozzle 11 in step 2, as both the nozzle and the membrane are translated. The membrane may be translated in a first direction B and the nozzle may be translated in a direction A transverse to the direction of the membrane B, as illustrated in FIG. 1, for example. In FIG. 6, a decision loop P monitors the process and determines when control of the nozzles is required. For example, decision loop P determines if an additional nozzle, such as second nozzle 12 in FIG. 1, is disposed over a proximal surface of the membrane 10, or if one or more of the nozzles reaches a side of the membrane 10, or if one or more of the nozzles reaches a distal surface of the membrane 10. This can be determined from sensors, delay circuits, limit switches or a combination of these, for example.

[0043] When a second nozzle 12 is disposed over the membrane 10, then hot melt may be directed and extruded from the second nozzle in step 3. For example, an additional nozzle 12 may be disposed at a distance C in the longitudinal direction B from the first nozzle, as illustrated in FIG. 1, for example. Thus, the decision P to commence extruding hot melt from the second nozzle 12 in step 3 may be based on a time delay calculated by the distance C divided by a rate of movement of the membrane 10 in the B direction integrated over time. The integral of (db/dt) from some initial time, t1, which corresponds to the onset of hot melt extrusion from the first nozzle, to some intermediate time tc, which corresponds to the time it takes for the membrane to move a distance C, can be calculate if the rate of movement of the membrane 10 is known or measured. If the rate of movement of the membrane 10 is a constant X (in distance (m)/time (seconds)), then tc equals the distance C divided by the rate X (i.e. C/X), for example. If more than two nozzles are to be activated, then the same process may be repeated in a similar fashion for each nozzle, based on the distance between each additional nozzle and the first nozzle.

[0044] When one or more of the nozzles reaches either side of the membrane 10, then decision loop P activates a stopping and reversal of the direction step 4 for the movement of the one or more nozzles. This may be determined by a signal from a controller 60, a limit switch 66, a delay timer based on the rate of movement (as before) or a combination of these. For example, if all of the nozzles are disposed on a rigid member, then a signal can be used to stop and reverse direction of movement for all of the nozzles at the same time. Alternatively, each nozzle may be controlled independently.

[0045] When one or more of the nozzles reaches a distal surface of the membrane 10, then hot melt extrusion from that nozzle is terminated in a nozzle off step 5. The location of the distal surface in relation to the first nozzle 11 may be determined manually or automatically, using known lengths, sensors, switches or the like. Then, determining the time for stopping extrusion of hot melt from the subsequent nozzles may be determined similarly to the decision to commence the onset of hot melt extrusion, using a time delay based on distance between the first nozzle and subsequent nozzles and the rate of movement of the membrane 10, for example. When all of the nozzles are turned off, then the method of making a membrane with a pattern of continuous, raised polymer strands that extend from one side of the membrane of the house wrap to an opposite side of the membrane, as a wavy, intersecting pattern on a surface of the membrane is ended, step E.

[0046] In one example, a set of rollers or a wheel is used for flattening a portion of a filament. In this method, the wheels may be set up manually or using position controllers prior to the onset of laying filaments onto a surface of the membrane, for example. Alternatively, the height above the membrane and transverse positioning may be controlled during the process of extruding hot melt from the nozzles.

[0047] In an alternative example, instead of causing depressions in the filaments, using wheels or rollers, a process may raise portions 101 of the filaments 11 (referred to as “bridges”) to extend above the surface of the membrane, as illustrated in FIGS. 7 and 8, leaving an opening 103 (referred to a “via” or “viaduct”) under each of the bridges 101, for example. For example, the raised portions 101 may be provided by raising the nozzles or slowing the extrusion of hot melt through the nozzles at certain positions along the path of the nozzle, leaving a gap between the filament 11 and the membrane 10. This may introduce “bridges” of hot melt, if the hot melt is extruded at a temperature where the hot melt does not readily slump to the the underlying surface, without leaving a gap. This may be controlled by temperature and pressure of the hot melt nozzle, for example, in addition to raising or reducing the extrusion rate of the hot melt from the nozzle. The channel or slit (referred to as a “via” or “viaduct”) below the bridge provides for water drainage under the filament, for example. In some cases, a hot melt nozzle may need to be raised, such as to create a bridge or when one nozzle crosses a filament of another nozzle, at an intersection point. Determining the need to raise a nozzle, if raising of a nozzle is provided in the control mechanism, may be implemented using an optical or infrared imager, for example. For example, an infrared imager could detect residual heat of the extruded hot melt. Alternatively, if the nozzle is raised during the step of stopping and reversing direction 4, then the raising and re-lowering of a nozzle or nozzles could be controlled as part of the sequence for stopping and reversing direction 4. As another alternative, raising and lowering of a nozzle when a nozzle crosses a filament laid by a preceding nozzle or a soluble viaduct material may be controlled by a proximity sensor, wherein the proximity sensor is disposed in advance of the nozzle and is used for controlling the raising and lowering of the nozzle based on the distance between the proximity sensor and the nozzle and the rate of movement of the membrane (as before), for example.

[0048] In one example, a soluble viaduct material 109 may be provided on the surface of the membrane 10, such as a bead of sugar, and a hot melt filament 11, which is not soluble in a solvent, such as PUR, could be deposited over the viaduct material 109, as illustrated schematically in the detailed view of FIG. 8, for example. Subsequently, the viaduct material 109 may be dissolved by a solvent spray or dipping in a solvent, such as water or alcohol, to remove the viaduct material 109, leaving a viaduct 103 under a bridge 101 of solidified hot melt, for example. Other material and solvent combinations may be used to create the bridge and viaduct, without limiting the invention. In any case, the surface could be sprayed with a solvent or dipped in a solvent that dissolves the soluble substance, while leaving the bridge in place, after an insoluble filament or ribbon is solidified and bonded to the membrane, except where the viaduct material has formed a viaduct under the filament. In one alternative example, non-stick rods are disposed along the borders and deployed with linear actuators such that each rod 105 is disposed where a nozzle is located and each rod 105 is extended and withdrawn, mechanically, when a nozzle 43 is disposed over the rod 105. In one example, the rods 105 are made of a non-stick material, such as Teflon, or have a non-stick coating. In one example, the rod 105 is cooled by a thermoelectric cooler or a cooling liquid or gas, further increasing the rate of solidification of the filament.

[0049] In one example, condensation or water penetrating through a facing material and to a membrane 10 is diverted from a seam 120 (or edge of membrane) between membranes by a gap 124 or a viaduct 121 of a raised portion of a filament. The liquid 123, 124 is directed along a raised filament to a viaduct 125 away from the seam 120 by following along the filament 11.

[0050] This detailed description provides examples including features and elements of the claims for the purpose of enabling a person having ordinary skill in the art to make and use the inventions recited in the claims. However, these examples are not intended to limit the scope of the claims, directly. Instead, the examples provide features and elements of the claims that, having been disclosed in these descriptions, claims and drawings, may be altered and combined in ways that are known in the art.