Gutter fillers and packs with enhanced fluid flow
A filler or pack material composed of homocomponent or multi-component fibers comprising various polymers with varying melting behavior. Most suitably, the filler fabric's volume fraction is between 10% and 70%. The filler can be cut, shaped, molded and fitted into the gutter. Additionally, single component or multi-component fibers can also be used together with other solids such as foam to form filler.
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This application claims the benefit of U.S. Provisional Patent Application Ser. No. 60/490,725, filed Jul. 29, 2003; the disclosure of which is incorporated herein by reference in its entirety.
TECHNICAL FIELDThe present invention relates to materials composed of fibers, foam, sponges and other materials in a high loft, low density, porous, orientated structure that can be used as a filler in gutters.
BACKGROUND ART Gutters are designed to channel fluids (rain, molten snow, etc.) away from the structure to a down chute that will lead away from the structure. A problem with gutters is that they are exposed to the environment and can be blocked and clogged by leaves, falling tree debris, dirt, etc. The blockage can lead to structural problems and the organic matter left in the gutters can decompose and create potential health problems. The current solutions include baffles, covers and similar structures that cover the gutter preventing leaves and other materials from getting into the gutter as well as a foam filler material. In most cases, these are not effective and annual cleaning is typically required to alleviate the problems with blockage. Many of these protection devices/shields/guards need to be installed professionally, and may need significant maintenance. Representative prior art patents include the following:
More specifically, many systems and devices have been used to prevent leaves, twigs, pine needles, pollens or roofing materials from entering into rain gutters and thus downspouts.
U.S. Pat. No. 3,121,684 discloses a downspout strainer device placed into the upper end of a downspout by the use of a long pole having a hook at its upper end that engages the wire loop of the device. The strainer allows rain water to pass through it while preventing the debris entering the downspout. However, debris still enters the gutter and clogs it in time. This device also requires periodical removal and cleaning out of the accumulated material caught by the device. During heavier rainfalls such as in fall season, the strainer can catch enough leaves during a single rainfall to clog entry to the down spout.
Many devices have been developed to prevent foreign materials from entering the rain gutters and downspouts. For example, gutter guards made of wire mesh are unrolled prior to attachment to the gutters since these are present in rolled form. Also, the wire mesh can be deformed during manufacture, shipment and even during attachment. Most of the time, these wire meshes deform and gutters are still exposed to debris.
U.S. Pat. No. 4,351,134 discloses an improved wire mesh and presents a hinged gutter guard device in the form of an elongated perforated cover plate made of a relatively rigid material having hinge straps. Hinge straps are positioned within longitudinal slots and are adapted to be secured to a roof beneath the lower course of shingles. The straps can be shifted within their slots to ensure proper attachment. However, shingle debris can still pass through perforations and the gutters still must be cleaned. Further, especially in heavy rainfalls, the force of the rain water off the roof can cause part of the water to skid off the gutter guard and fall directly on the lawn below causing pitting or trenching. In time, the stress variation caused by normal use and raising-lowering of the gutter guard weakens or tears shingles, thus necessitating replacing or repair of the shingles.
Another patent, U.S. Pat. No. 4,841,686 discloses a filter attachment that fits over the gutter trench. The filter attachment is clamped with a pad of fibrous material, fiberglass, underneath it. The screen has 0.25 to 0.5 inch square openings. These openings can trap smaller particles but in time the surface of the screen clogs thus needs to be cleaned out. The cleaning process is time consuming and difficult for most of the time.
U.S. Pat. No. 3,855,132 discloses a fitted porous solid polyurethane foam material that serves as a barrier to leaves, dirt, etc. Here, there is a space between foam material and the bottom of the gutter that allows for free flow of water below the porous section while blocking the debris. The percentage void volume is critical since higher void volume increases the water transfer capacity. In this particular patent, the polyurethane foam has 95% void volume with an average of 10 pores per linear inch.
U.S. Pat. No. 5,848,857 provides an inexpensive, easy to manufacture, easy to install rain gutter shield which filters out not only large but also small foreign material permitting only rain water and other easily washed away materials to pass into the downspout. The gutter shield here has an elongated layerless screen of porous nonwoven polymeric fiber material. The porous nonwoven fiber material is a ⅛″ to ½″ thick mat of silicon carbide-polyamide fiber/flint fiber. These types of nonwovens are known in the market. It is possible to purchase these in roll form and cut into various lengths to utilize them in a rain gutter. Also, 3M company provides silicon carbide/nylon/aluminum oxide type of material known as BEAR-TEX™ nonwoven material. The rain gutter shield can be attached to the gutter at the time of mounting or be attached to already mounted rain gutters. The main filtering function is provided by the porous nonwoven polymeric fiber itself. The material is claimed to be weather resistant, flexible enough to be handled, sturdy enough to avoid sagging and stretching without the need for a backing layer. Also, it quickly lets rain water pass through it while filtering the fine solid materials.
U.S. Pat. No. 6,134,843 takes this one step further and provides a rain gutter shield that can be used with any type of existing rain gutters on most roof designs. It is disclosed that a gutter shield is provided that is economical to manufacture and install and also not adversely affected by heat or cold. The gutter shield has matting and a covering. The matting is an elongated three dimensional matting that includes plural shapes of rows, the basis of the shapes defining a first plane and the apexes of the shapes defining a second plane. The matting extends outwards from the bases. The covering is an elongated water porous fabric that has an upper and lower surface. The upper surface is smooth enough to prevent debris from being retained by the fabric material and enables debris to be blown off by ambient winds. The lower surface of the fabric is bonded to the matting. One longitudinal edge of the fabric extends outwards for the mounting device to the building and the other edge of the fabric extends for attachment to the outer lip of the gutter. This positions the shield over the opening of the gutter effectively. The plural shapes mentioned above are cones made of NYLON® that has carbon black to resist the detrimental effects of UV light. The cones are arranged in transverse and longitudinal rows. The fabric mentioned is a porous NYLON®-polyester nonwoven fabric such that when the rain or snow is gone, the debris will naturally dry and be blown off by winds. The nonwoven fabric is heat bonded to the matting. Fabric extends outward in the first plane, in both transverse directions to the length of the gutter. A portion of the fabric extends to the outer lip of the gutter to prevent debris entering the device.
Some prior gutter guards (U.S. Pat. No. 6,205,715) include gutter screens made of woven metal wire that prevents debris from entering the gutter. Metal wire screens are expensive to manufacture and install compared to nonmetal screens like plastic or NYLON® screens. Metal screens can also be awkward to remove to do the cleaning of the gutter. In addition to this, if the metal wire does not have a large enough gauge, the debris, the weight of water running off the roof onto the screen or the weight of the debris that lands on the screen well form valleys on the screen. These valleys then collect debris and interfere with the water collection. Thus, this requires cleaning later on.
There are also several commercial products designed to protect gutters from clogging that are well known but are not the subject matter of patent protection.
For example, FLOW FREE™ gutter protection system is one of these products that provides a 0.75 inch thick NYLON® mesh material designed to fit in five inch K type gutters. This device fits over the hanging brackets of the gutters and one side extends to the bottom of the gutter to prevent its collapse in to the gutter. But, this system is precut and fits only to 5 inch K type of gutters while may home owners have other types of gutters. In this particular type, the NYLON® mesh traps pine needles, shingle material, and the like and should be cleaned to avoid blocking of the flow of rain water.
GUTTER HELMET® is a commercial product for gutter protection. This device covers most of the gutter with a bullnose shaped protrusion proximate the outer edge of the gutter. The design is based on utilizing surface tension of water thus channeling the water down the bullnose in to the gutter while leaves and other debris falls down. Most of the commercial GUTTER HELMET® are affixed to the edge of the roof by screws that lead to leaks through the roof. Unless the bullnose is completely wetted, gutter helmets are not efficient and water drips directly onto the lawn causing soil erosion and water in the building basement. In winters, the dripping water causes icicles to form and can fall becoming a safety hazard. Also, dirt mildew builds up on the bullnose preventing water flow into the gutter and necessitates routine scrubbing and cleaning of the system, and in some installations gutter helmets are known to buckle from the heat of the sun. At the time of cleaning, the device needs to be removed from the gutter also, which makes cleaning harder.
The GUTTER PROTECH™ gutter protection system also uses surface tension and liquid adhesion of rainwater to direct it into the gutter trench through two rows of alternating angled slots over mini-bullnoses. As in similar designs, until the bullnoses sufficiently get wet, they do not work properly and dirt builds up on them and must be routinely cleaned to ensure flow into the gutters.
WATERFALL™ plastic gutter guard system is another commercial product present in the market. The system also uses the principle of water adhesion and includes two sets of parallel channels each having drain holes. Rain water flows from the roof onto the device into the upper channel and into the gutter trench. The second lower channel collects the remaining runoff and directs it into the gutter. The classical problem of debris accumulation with gutter guards occurs here once again. Parallel channels need to be cleaned out periodically. Since this is a rigid PVC gutter system, it cracks in cold weather thus degrading its performance and requiring replacement. Further, the device does not include end caps so birds gain entry into the gutter and build nests. Another issue with this particular commercial product is that it tends to separate from beneath shingles and be blown off the gutters.
None of the systems described above are highly effective in keeping all debris out of gutter systems. Eventually, debris builds up either on the surface of the devices or within the gutter drenches and/or downspouts.
The invention described herein is intended to overcome many of the well-known deficiencies of prior art gutter guard devices and to provide a new and improved gutter pack or gutter fill material.
SUMMARYA porous, low density, resilient, filler material that can be cut to shape, molded and fitted into a gutter in place of typical gutter guards or shields that partially cover the gutter has been developed. The present embodiment comprises a high loft, sponge-like material made from fibers, foam, or other similar materials to create a material that can be packed into the gutter. The structure is high in porosity such that the pores and the capillaries are elongated in the direction of the flow to achieve the highest flow rates possible. Foreign objects such as leaves, pine straws and the like are not anchored to the filler and are washed away or blown away. The flow characteristics are high and allow continuous flow through the network. The elongated capillaries create sufficient capillary forces to draw the fluids through faster.
Additional embodiments relate to a nonwoven material, a sponge or a foam-based product, or combinations thereof, that can be cut and packed into the gutter. The need for a cover is eliminated.
It is therefore an object to provide a gutter filler material composed of fibers, foam or similar materials to form a highly orientated structure such that all pores are longer in the direction of the flow.
It is still another object to provide for a gutter filler or pack material consisting of fibers and materials having enhanced environmental resistance and mechanical properties so as to provide for durability without impairing the physical properties of the products from which they are manufactured.
It is yet another object to provide for a gutter filler or pack material consisting of fibers and materials having low density (<10%-70% volume fraction) with sufficient resilience and porosity to allow high flow rates.
Some of the objects having been stated hereinabove, and which are addressed in whole or in part by the presently disclosed subject matter, other objects will become evident as the description proceeds when taken in connection with the accompanying drawings and examples as best described hereinbelow.
DESCRIPTION OF THE DRAWINGSSome of the objects of the invention having been stated other objects will become apparent with reference to the detailed description and the drawings as described hereinbelow.
One embodiment of the subject filler material described herein is a high loft and low density (<10%-70% volume fraction) structure that can be easily cut or molded into the right shape to pack a gutter.
A number of structure variables can be controlled to form the desired structure for product 10. In particular, fiber orientation distribution, fiber crimp and fiber diameter are the controlling elements. The ODF ψ is a function of the angle θ. The integral of the function ψ from an angle θ1 to θ2 is equal to the probability that a fiber will have an orientation between the angles θ1 to θ2. The function ψ must additionally satisfy the following conditions:
To describe the alignment of the fibers, one uses a ratio known as the Anisotropy Ratio, fp defined as:
The anisotropy parameter varies between −1 and 1. A value for fp of 1 indicates a perfect alignment of the fibers parallel to a reference direction (see
An oriented structure with values close to 1 would yield highly elongated structures.
A pore's shape can be determined by employing geometrical descriptors to characterize and quantify shape. Geometrical descriptors are straightforward measurements of boundary geometry. One determines the boundary roundness (R) by determining the ratio of boundary area to the area of a circle whose perimeter is equal to that of the boundary as depicted below.
R ranges from 0 to 1. Roundness is a measure of the similarity of a given shape to that of a circle.
A measure of the shape anisotropy may be obtained by the descriptor ellipticity (E). Ellipticity is determined by computing the lengths of the semi-major and semi-minor axes of Al and As of a best-fit ellipse of the boundary. The lengths of the semi-major and semi-minor axes can be determined from:
where Imax and Imin are the greatest and least moments of inertia, respectively. E may be calculated as:
The method employed for the measurement of roundness and ellipticity ensures that they are invariant to the geometrical transformations of rotation and translation.
In the following figures, structural variables that control behavior are demonstrated. These were created by applicants with computer simulations to illustrate idealized cases.
It is interesting to note that an increase in fiber crimp results in smaller average pore size. An increase in fiber crimp causes a shift in the distribution towards smaller pores in anisotropic structures. This occurs because an increase in crimp increases the number of crossovers especially in the direction perpendicular to the fiber axis. In random structures, the number of crossovers remains the same and increasing fiber crimp will have little or no effect on pore size.
The total number of pores as a function of fiber diameter and crimp and structures anisotropy is shown in
Thus, one preferred embodiment of the invention is a filler or pack material 10 with high compressive resilience, high porosity, low density (less than 10%-70% volume fraction) and preferably elongated pores to assist in the flow of the liquids. A random structure with more round and isotropic pores will also work, but would have lower fluid flow characteristics compared to a structure with elongated pores at the same density.
The density (preferably less than 10%-70% volume fraction) can be also controlled by fiber diameter. There is an interaction between fiber size, fiber orientation distribution, overall porosity and pore size distribution. Higher porosities can be achieved by using thicker fibers. Compressive resilience can also be improved by using thicker fibers. However, the overall flexibility of the structure will also reduce making it more difficult to cut and fit the filler material 10 in the gutter. These attributes must be balanced to achieve the highest resilience, highest porosity, and highest flexibility.
One advantageous method to make a filler material 10 of the type described is by the use of expandable foam to form a sponge. Alternatively, the structure may be made as in high loft nonwovens where fibers are formed into a web by a web formation device such as carding, airlay, wetlay or a combination thereof or other methods such as meltblowing and/or spunbonding. These webs may be stacked together to form a laminate structure or can be formed into a three dimensional embodiment by the use of mechanical bonding methods. These fibers and/or webs are then fused together, bonded by the addition of a resin, a powder, another low melt fiber or a combination thereof or by the use of resins and adhesives. Alternatively, the fibers may be bi-component, or multi-component, wherein one component would melt at a lower temperature bonding the structure together. The fibers used therein can be synthetic, man-made or natural.
Applicants contemplate that novel filler material 10 may comprise homocomponent, bi-component or multi-component fibers, and both solid and hollow fibers. Further, the filler material 10 may comprise multifilament or staple fibers having a diameter of 15 denier or less as well as multifilament and monofilament fibers having a diameter greater than 15 denier. Further, the filler material 10 may comprise fiber or foam or a combination thereof formed from polyolefins, polyamides, polyester and co-polymers, natural fibers and combinations thereof. Additionally, filler material 10 may comprise sheath/core fibers comprising sheaths that melt at a lower temperature than the fiber cores. Filler material 10 may comprise both fibers and non-fibrous elements such as foam and sponges, and the filler material 10 may be formed from woven, knitted, braided or non-woven material.
The web formation processes typically lead to an oriented structure wherein the majority of fibers are parallel to the direction in which the web is being formed and collected (machine direction). The layering is preferably done so as not to realign these fibers as the orientated structure is expected to lead to better fluid flow behavior.
It is contemplated by applicants that the novel filler material 10 may include other embodiments to aid in durability, environmental resistance or overall performance.
Finally, it is believed that other materials may be used instead of or together with fibers to form filler material 10. That is, the same process may be used to incorporate other foams, yarns and fibers, fabrics and other such solids. Therefore, additional functionality or multiple functionality is achieved by the use of multi-component fibers, foams and other materials.
EXPERIMENTAL TESTINGThere are not any widely accepted definitions describing a highloft nonwoven. One definition is: Nonwovens that are more than ⅛ inches in thickness and contain much more air or voids than fiber. Another definition is: A low density fiber network structure characterized by a high ratio of thickness to weight per unit area. The fibers can be continuous or discontinuous, bonded or unbonded. Highloft battings have no more than 10% solids, by volume, and are greater than 3 mm (0.13 inch) in thickness.
I. SAMPLE MATERIALS A. Fabric Samples used in Volumetric Flow Rate Tests In measuring Volumetric Flow Rate, 3 different types of highloft samples were precut and chosen. The samples were evaluated according to their thickness and areal mass density. The characteristics of each sample type are shown in Table 1.
In Table 1, A.M.D stands for Areal Mass Density of the samples.
Samples were produced from 100% polyester fibers with;
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- 85% 15 denier PET
- 15% sheath/core Co-Pet binder fibers
According to Table 1, I.D of sample indicates the specific numbering system used to characterize the sample. According to that, I.D numbers indicate the following;
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- Type 1: 4 inches thick sample and one square foot of the sample weighs 4 ounces. (1221 g/m2)
- Type 2: Sample that is 4 inches thick and one square foot of the sample weighs 7.5 ounces. (2289 g/m2)
- Type 3: Sample that is 5 inches thick and one square foot of the sample weighs 9 ounces. (2746 g/m2)
Since these samples were made by using drafted cross lappers, the majority of the fibers are oriented in x-y plane, with many being roughly at 45° or 135° to either the machine direction or cross direction.
One lap of a crosslapper is one complete cycle. Each lap forms two layers in the sample. If one multiplies the number of laps by the number of cross lappers on the production line, one can get the number of layers in the samples. For example, the normal set up on the line would produce 24 layers for 4 inches thick, 4 oz/ft2 product and thus 45 layers for 4 inches thick, 7.5 oz/ft2 product.
The fluid medium used in applicants' study was city water supplied from a laboratory faucet.
Weight of SamplesThe weights of samples were measured by OHAUS ES 50L (50×0.02 kg) type of scale and were recorded in Table 2.
Thickness of Samples Sample thickness was determined using Compression Tester Thickness Machine (KAWABATA Evaluation System-3) and were recorded in Table 2.
Fabric samples used in drainage tests were of the same type as used in volumetric flow rate tests. Sample lengths and widths were the same but the thickness (Type 1 and Type 2 had 4 inches of thickness; Type 3 had 5 inches). For each type of fabric, two samples were precut and weighed. Table 3 shows fabric sample weight used in drainage tests.
Drainage tests were done using these samples with/without foam materials having the same base area of fabric samples and thus covering the bottom surfaces of the fabrics.
There are two kinds of foam materials utilized in the tests and placed beneath the fabric samples in the simulated gutter:
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- ⅛ inch thick, 90 pores per inch (yellow colored)
- ⅛ inch thick, 20 pores per inch (black colored)
The results of the tests will be discussed by providing both the data obtained from tests and statistical analysis to draw reasonable conclusions.
As mentioned earlier, each test had 4 runs, first observations always being lower than the rest of the 3 observations. The reason is that samples get saturated in the first place while holding most of the sprayed water inside them and transferring little water within the first 2 minutes. Then, after saturation, water is transferred according to the structural characteristics of the samples without being stored inside the pores, because the samples were already saturated within the first 2 minutes. So, the three following observations have higher values, which is reasonable.
Because of this situation, it is necessary to classify the test results as saturated and unsaturated. Also, when one takes take a look at rainy weather conditions, one sees that rain starts slowly and maintains an average fall down for the majority of the time and then stops. This is why tests were done on a continuous manner.
As expected, when the charge rate increases, flow through the highloft nonwoven samples increases as a result of more volume of water is sprayed over the samples per unit time.
For the purpose of comparing results with a control group, the Rain Machine testing device (which simulates a roof and gutter system) was run without any type of samples or foam materials to find out the maximum volumetric flow rate and efficiency. Also, theoretical flow (assuming no loss of water) was considered so that in case of water loss it could be calculated. Table 4 illustrates the results obtained by running the Rain Machine without any samples or foam materials. Three different discharge rates were used 4.73-liters/min., 5.68-liters/min, and 6.63-liters/min.
Also, Table 5 shows the theoretical flow, which assumes no water loss.
From the tables above, it can be understood that there is a loss of water in the system. The reason of water loss is that since water comes out of spray nozzles intensely, some of the tiny water particles fly away from the Rain Machine after hitting the simulated roof surface, thus causing not all the sprayed water flow down into gutter.
The amount of water loss is 0.4 liters/min. This data was computed to each testing result obtained and necessary corrections were made while calculating flow rates and efficiencies.
According to results found in Table 4 and Table 5, Table 6 was prepared. Table 6 illustrates the efficiencies of the Rain Machine when the machine was run empty (without samples or foam materials).
As one can see from Table 6, the Rain Machine works with an efficiency of 96.27% (maximum) and 93.71% (minimum).
Effect of Sample DensityThere are three different types of highloft samples used in the tests, each having different densities. These samples are 400C400C, 400C750C, and 500C900C having densities of 1221 g/m2, 2289 g/m2, and 2746 g/m2, respectively. No foam material is used in these tests.
While choosing the samples, the structural characteristics were considered to be critical such as density because samples having too low a density would have had too open a structure and would not have acted as a filler for usage in a gutter whereas very dense samples would have been an obstacle to a good flow. Table 7, Table 8 and Table 9 show the test results of average flow rates (both unsaturated and saturated conditions) for the three different types of samples under three discharge rates.
In Tables 7, 8 and 9; Type 1, 2 and 3 indicates 400C400C, 400C750C, and 500C900C, respectively. Normally, it is expected that Type 1 sample should give the highest flow rate since it has the more open structure than the other types. When one looks at the above tables, this is true for Table 7 but not for the others. In Table 7, Type 2 sample has the best flow rate whereas on Table 8 and Table 9, the best flow rates are produced by Type 1 and Type 2 samples, respectively. However, when one takes a look at the overall results, it is possible to see that there is no significant difference among the flow rates of samples which is quiet interesting. One normally should expect a significant difference in the performance but this is not the case. The reason for this is because the flow is limited by the diameter of the downpipe, which is a parameter of flow rate in rain gutter applications.
As mentioned earlier, the samples have similar volumetric flow rates and thus efficiencies. The other approach to explain this situation might be related with the behavior of saturated fabrics under continuous flow. Once fabric pores are saturated with water, assuming samples have very similar or same pore size distribution and mean pore size and turtuosity, this is possible.
While testing the samples in the gutter, gravitational force affects the samples also and pulls down the samples while draining the water into water tank. Thus, it might be very possible that this is another factor affecting and limiting the performance of the fabric samples.
The efficiencies of the samples were also considered. When one takes a look at the efficiencies, one sees the same trend as volumetric flow rates, which is reasonable.
From the
On the overall, samples had volumetric flow efficiencies between 90-94% depending on the conditions. The results match with the expected performance of the samples, which are all lower than the Rain Machine efficiency when no samples or foam materials were used.
Effect of Foam Material TypeThere are two different kinds of foam material used in the tests.
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- Yellow Foam—⅛ inch thick, 90 pores per inch
- Black Foam—⅛ inch thick, 20 pores per inch
FIG. 13 shows both yellow and black foams under a highloft sample.
Foam materials used in tests are very light materials and their density is less than water, thus they float on water. When utilized under a highloft sample inside a gutter system, it is expected that the foams apply a push-up force to the fabrics and ease the flow of water inside the gutter. Foam materials ease the flow from the fabric to the gutter because they have highly porous structure. Also, foam materials allow drainage.
According to test results, in some cases, foam materials performed well and increased flow rates compared to tests where only fabric samples were used with no foam. However, this is not true for all cases and for each foam material.
Table 10 shows the results obtained from all of the tests.
When compared, it can be seen that the first observations (flow rates-unsaturated) in Table 10 are smaller than the first observations for all discharge rates in Tables 7, 8 and 9. This means for the first observations, yellow and black foams have smaller volumetric flow rates than the tests where only fabric samples were utilized. The reason for that is related with what happens in the first 2 minutes. Most of the water is captured inside the pores of the fabric, thus saturated the fabric and foam materials did not have enough water flowing under them to apply a push up force to the sample. Thus, foam materials acted like a barrier or another layer added up to the fabric thus decreasing the flow rate during that time.
Interestingly, most of the saturated flow rates for both foam materials in Table 10 are larger than no foam data. This is because the fabrics were already saturated and started to transfer the water instead of capturing it. This lead to water accumulation under the foam materials and a push-up force was generated by them thus easing the flow of water and increased water flow efficiencies.
Drainage capacities of the samples were calculated as follows;
Drainage Capacity (C)(grams)=Wi−Wf
where;
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- Wi: Initial weight of the water inside the drainage box at the beginning of the test
Wf: Final weight of the water inside the drainage box at the beginning of the test
Type 1 sample (see Table 11) had the maximum drainage capacity where no foam was used and Type 2 sample had the minimum drainage capacity where no foam was used. This is due to the sample porosity. Type 2 is less porous than sample 1, thus holding more water at the end of test compared to sample 1. For the same volume of Type 1 and 2, Type 1 has 24 layers whereas Type 2 has 44. Thus, Type 2 is more packed. In terms of permeability, Type 2 is less permeable than Type 1. Also, mean pore size of Type 2 sample should be lower than Type 1. The larger pores would allow more drainage compared to smaller pores. This could be the other reason why Type 1 had better drainage. Type 3 has 44 layers but its thickness was 5 inches thus, it was less packed than Type 2. This could be the reason why Type 3 had the medium drainage capacity. This were summarized in
In terms of foam material type effect on drainage, these did not increase the drainage for Type 1 sample, whereas both of the foam materials increased it for Type 2. For Type 3, yellow foam increased the drainage capacity whereas black foam decreased it.
When one takes a look at
Black foam material only increases the drainage at the densest type of sample, which is Type 2. For other types, it did not increase drainage, actually resulted with a decrease in results.
It is also beneficial to look at the drainage times of these scenarios and make conclusions about how they performed in terms of draining time.
It will be understood that various details of the subject matter described herein may be changed without departing from the scope of the invention. Furthermore, the foregoing description is for the purpose of illustration only, and not for the purpose of limitation, the invention being defined by the claims set forth below.
Claims
1. In combination:
- (a) a roof gutter of the type for collecting rain and channeling the rain to a down spout or the like; and
- (b) a porous filler material comprising fiber, foam or combinations thereof wherein the overall density of the porous filler material is between about 10%-70% by volume fraction and the pores are elongated and generally extend in the lengthwise direction of the porous filler material, and said porous filler material is positioned in the roof gutter so as to substantially fill the roof gutter and such that the pores generally extend in the rain flow direction;
- whereby rain water from the roof will readily pass through the porous filler and be channeled away and leaves, pine straw and other similar debris will be prevented from entering the roof gutter.
2. The combination according to claim 1 wherein the porous filler material comprises homocomponent, bi-component or multi-component fibers.
3. The combination according to claim 1 wherein the porous filler material comprises hollow fibers.
4. The combination according to claim 1 wherein the porous filler material comprises multifilament or staple fibers having a diameter of 15 denier or less.
5. The combination according to claim 1 wherein the porous filler material comprises monofilament or multifilament fibers having a diameter greater than 15 denier.
6. The combination according to claim 1 wherein the porous filler material comprises fiber or foam or combinations thereof selected from the group consisting of polyolefins, polyamides, polyester and co-polymers, natural fibers and combinations thereof.
7. The combination according to claim 1 wherein the porous filler material comprises sheath/core fibers comprising sheaths that melt at a lower temperature than the cores of the fibers.
8. The combination according to claim 1 wherein the porous filler material comprises a web of fibers that have been formed by carding, airlay, wetlay, spunbond, meltblown or any combination thereof.
9. The combination according to claim 1 wherein the porous filler material comprises both fibers and non-fibrous elements such as foam and sponges.
10. The combination according to claim 1 wherein the porous filler material comprises woven, knitted, braided or nonwoven material.
11. A method of preventing leaves, pine straw and similar debris from entering a roof gutter while allowing rainwater and the like to readily enter the roof gutter and be channeled away to a down spout or the like, the method comprising the steps of:
- (a) providing a roof gutter mounted adjacent the roof of a residential or commercial building; and
- (b) inserting a porous filler material comprising fiber, foam or combinations thereof into the gutter so as to substantially fill the gutter with the porous filler material, the porous filler material having an overall density between about 10%-70% by volume fraction and the pores thereof being elongated and generally extending lengthwise in the direction of the porous filler material and in the rain flow direction within the gutter;
- whereby rainwater from the roof will readily pass through the porous filler and be channeled away and the leaves, pine straw and similar debris will be prevented from entering the roof gutter.
12. The method according to claim 11 including providing a porous filler material comprising homocomponent, bi-component or multicomponent fibers.
13. The method according to claim 11 including providing a porous filler material comprising hollow fibers.
14. The method according to claim 11 including providing a porous filler material comprising multifilament or staple fibers having a denier of 15 or less.
15. The method according to claim 11 including providing a porous filler material comprising monofilament fibers having a denier of 15 or greater.
16. The method according to claim 11 including providing a porous filler material comprising fiber, foam or combinations thereof selected from the group consisting of polyolefins, polyamides, polyester and co-polymers, natural fibers and combinations thereof.
17. The method according to claim 11 including providing a porous filler material comprising sheath/core fibers wherein the sheaths will melt at a lower temperature than the cores of the fibers.
18. The method according to claim 11 including providing a porous filler material comprising a web of fibers that has been formed by carding, airlay, wetlay, spunbond, meltblown or combinations thereof.
19. The method according to claim 18 including forming the fibrous web from both fibers as well as nonfibrous elements such as foam or sponges.
20. The method according to claim 11 including providing a porous filler material comprising woven, knitted, braided or nonwoven material.
Type: Application
Filed: Sep 23, 2003
Publication Date: Feb 17, 2005
Applicant:
Inventors: Behnam Pourdeyhimi (Raleigh, NC), William Oxenham (Raleigh, NC)
Application Number: 10/669,541