Methods of fabricating composite articles and related articles and structures

Abstract

Composite articles of manufacture and methods of making the same are provided herein. In one embodiment, a composite article includes a fiberglass component having a color of pantone 376C. Subjecting the fiberglass component to various environmental conditions result in the fiberglass component exhibiting a color of pantone 376C. Thus, the fiberglass component does not fade and become lighter or hazy in appearance, but takes on an appearance of deeper hue and/or saturation, providing longer life of the appearance of the fiberglass component.

Description

BACKGROUND

Ladders are conventionally utilized to provide a user thereof with improved access to elevated locations that might otherwise be inaccessible. Ladders come in many shapes and sizes, including straight ladders, extension ladders, stepladders, and combination step and extension ladders. So-called combination ladders may incorporate, in a single ladder, many of the benefits of multiple ladder designs.

Ladders known as straight ladders or extension ladders are ladders that are conventionally not self-supporting but, rather, are positioned against an elevated surface, such as a wall or the edge of a roof, to support the ladder at a desired angle. A user then ascends the ladder to obtain access to an elevated area, such as access to an upper area of the wall or access to a ceiling or the roof. A pair of feet or pads, each being coupled to the bottom of an associated rail of the ladder, are conventionally used to engage the ground or some other supporting surface.

In many cases, ladders are constructed from composite materials such as fiberglass. For example, the rails of ladders are often formed of a fiberglass or other composite material in an effort to provide a ladder that is lightweight and/or nonconductive. Having a lightweight ladder is often important in being able to transport and set up a ladder. Having a ladder that is not electrically conductive is important to a variety of workmen, such as electricians and utility workers, that often work around power lines or power equipment and need a ladder that does not potentially conduct electricity from the power source to ground.

Fiberglass components used in ladders, and in other structures and devices, are often colored for aesthetic purposes, functional purposes, or both. For example, often ladder rails are colored for purposes related to trade dress (so that a buyer can quickly identify the source of the ladder), for safety purposes (e.g., to make the ladder more visible to users and others in an area where the ladder is being used), for other reasons, or for a combination of such purposes.

However, one difficulty that has plagued the ladder industry, as well as other industries utilizing fiberglass components, is the fading of the color of the fiberglass material. For example, a ladder (or other device or structure) may include components made of yellow or orange fiberglass materials. After exposure to environmental conditions, including exposure to the UV rays of the sun, the yellow or orange color may fade, significantly reducing—if not eliminating—any safety benefits (e.g., attempts to improve visibility) provided by the use of such a color. The fading of the color is sometimes described as having a something of a “translucent” look, although this is not technically correct since the materials may still be generally opaque. Rather, the materials take on a look that is reduced in color saturation and have something of a hazy or milky look to them. Oftentimes, when the ladder or other structure is used on a daily basis, such fading may occur in as little as a year or less of time.

One example of this fading can be seen in FIGS. 1A and 1B wherein color photos depict a sample shown as a newly fabricated, black resin-based component 10 (e.g., fiberglass material) prior to weathering/environmental exposure (see FIG. 1A) and as a faded black resin-based component 12 after weathering/exposure (see FIG. 1B). Another example of this fading can be seen in FIGS. 2A and 2B, wherein color photos depict a sample that is shown as a newly fabricated orange resin-based component 20 (e.g., fiberglass material) prior to weathering/environmental exposure (see FIG. 2A) and as a faded orange resin-based component 22 after weathering/exposure (see FIG. 2B). It is clear that the hue and/or saturation of color of these priot art fiberglass components lightens subsequent to exposure to environmental conditions, significantly altering its appearance.

For these reasons and others, there is a continuing desire in the industry to provide improved functionality of ladders and also to other industries utilizing composite materials such as fiberglass.

SUMMARY

The present disclosure is related to composite articles of manufacture and related methods. In accordance with one embodiment, a ladder is provided which includes at least one fiberglass component having a color of pantone 376C.

In one embodiment, the fiberglass component includes a rail.

In one embodiment, the ladder further comprises a plurality of rungs coupled with the rail.

In one embodiment, the fiberglass component exhibits a minimum absorbance of light at a wavelength of approximately 536 nm.

In accordance with another particular embodiment, a ladder is provided including at least one fiberglass component having a color of pantone 383C.

In one embodiment, the fiberglass component includes a rail.

In one embodiment, the ladder further comprises a plurality of rungs coupled with the rail.

In one embodiment, the fiberglass component exhibits a minimum absorbance of light at a wavelength of approximately 536 nm.

In another particular embodiment, a method is provided for fabricating a fiberglass component, the method including providing a resin and a plurality of fiberglass fibers, and adding a pigment to the resin to provide a color of pantone 376C to the fiberglass component.

In one embodiment, the method further comprises forming a shape from the resin and fibers.

In one embodiment, forming a shape includes pultruding the shape.

In one embodiment, pultruding the shape includes forming a rail for a ladder.

In one embodiment, the method further comprises altering the color to pantone 383C.

In one embodiment, altering the color to pantone 383C includes exposing the shape to UV rays.

In one embodiment, resin includes a polyurethane resin.

In one embodiment, the polyurethane resin comprises polyol and isocyanate.

BRIEF DESCRIPTION OF THE DRAWINGS

The patent or application file contains at least one drawing or photograph executed in color. Copies of this patent or patent application publication with color drawing(s) will be provided by the Office upon request and payment of the necessary fee.

The foregoing and other advantages of the invention will become apparent upon reading the following detailed description and upon reference to the drawings in which:

FIGS. 1A and 1B show a first set of prior art fiberglass components before and after environmental exposure, respectively;

FIGS. 2A and 2B show a second set of prior art fiberglass components before and after environmental exposure, respectively;

FIG. 3 is a perspective view of a ladder according to an embodiment of the present disclosure;

FIGS. 4A and 4B are photographs comparing fabricated fiberglass components with accelerated-weather-tested fiberglass components according to an embodiment of the present disclosure;

FIG. 5 is a graph showing absorbance as a function of wavelength for a first set of sample fiberglass components according to an embodiment of the present disclosure;

FIG. 6 is a graph showing absorbance as a function of wavelength for a second set of sample fiberglass components according to an embodiment of the present disclosure.

DETAILED DESCRIPTION

Referring to FIG. 3, a ladder 100 is shown according to an embodiment of the disclosure. The ladder 100 is configured as an extension ladder and includes a first assembly, which may be referred to as a fly section 102, and a second assembly, which may be referred to as a base section 104. The fly section 102 is slidably coupled with the base section 104 so as to adjust the ladder 100 to various lengths (or, rather, heights). The fly section 102 includes a pair of spaced apart rails 106A and 106B (generally referenced as 106 herein for purposes of convenience) with a plurality of rungs 108 extending between, and coupled to, the rails 106. Similarly, the base section 104 includes a pair of spaced apart rails 110A and 110B (generally referenced herein as 110 for purposes of convenience) with a plurality of rungs 112 extending between, and coupled to, the rails 110.

In one embodiment, the rails 106 and 110 may be formed of a composite material such as a fiberglass composite material. The rails 106 and 110 may be formed using a variety of manufacturing techniques. For example, in one embodiment, the rails may be formed using pultrusion or other appropriate processes associated with composite manufacturing. In one embodiment, the rails 106 and 110 may be formed generally as C-channel members exhibiting a substantially “C-shaped” cross-sectional geometry.

The rungs 108 and 112 may also be formed from a variety of materials using a variety of manufacturing techniques. For example, in one embodiment, the rungs 108 and 112 may be formed from an aluminum material through an extrusion process. However, such an example is not to be viewed as being limiting and numerous other materials and methods may be utilized as will be appreciated by those of ordinary skill in the art. In one embodiment the rungs 108 and 112 may include a flange member (also referred to as a rung plate) for coupling to associated rails 106 and 110. For example, the flanges may be riveted or otherwise coupled with their associated rails 106 and 110. Examples of rungs and flanges according to certain embodiments are described in U.S. Patent Application Publication No. 2016/0123079, published on May 5, 2016, the disclosure of which is incorporated by reference herein in its entirety.

One or more mechanisms, often referred to as a rung lock 114, may be associated with the first and second assemblies 102 and 104 to enable selective positioning of the fly section 102 relative to the base section 104. This enables the ladder 100 to assume a variety of lengths (or, rather, heights when the ladder is in an intended operating orientation) by sliding the fly section 102 relative to the base section 104 and locking the two assemblies in a desired position relative to one another. By selectively adjusting the two rail assemblies (i.e., fly section 102 and base section 104) relative to each other, a ladder can be extended in length to nearly double its height as compared to its collapsed or shortest state as will be appreciated by those of ordinary skill in the art. The rung lock 114 is cooperatively configured with the fly section 102 and the base section 104 such that when the fly section 102 is adjusted relative to the base section 104, the associated rungs 106 and 110 maintain a consistent spacing (e.g., 12 inches between rungs that are immediately adjacent, above or below, a given rung). Examples of rung locks according to certain embodiments are described in the previously incorporated U.S. Patent Publication No. 2016/0123079.

The ladder 100 may additionally include a number of other components such as bearing members 116A and 116B, which may be positioned, for example, at or adjacent an end of a rail of either the fly section 102 or the base section (although they may be positioned at locations intermediate of rail ends as well), to help maintain the fly section 102 and base section 104 in their slidably coupled arrangement and also to maintain the unique spacing of the rails of each section 102 and 104 as further discussed below. In certain embodiments, these bearing members 116A and 116B may be configured to provide improved strength and rigidity to the ladder 100 while accommodating the slidable coupling of the fly section 102 with the base section 104. As described above, in various prior art components, fading can be seen in FIGS. 1A and 1B wherein color photos depict a prior art sample shown as a newly fabricated, black resin-based component 10 (e.g., fiberglass material) prior to weathering/environmental exposure (see FIG. 1A) and as a faded black resin-based component 12 after weathering/exposure (see FIG. 1B). Another example of this fading can be seen in FIGS. 2A and 2B, wherein color photos depict a prior art sample that is shown as a newly fabricated orange resin-based component 20 (e.g., fiberglass material) prior to weathering/environmental exposure (see FIG. 2A) and as a faded orange resin-based component 22 after weathering/exposure (see FIG. 2B). It is clear that the hue and/or saturation of color of these prior art fiberglass components lightens subsequent to exposure to environmental conditions, significantly altering its appearance.

In accordance with one embodiment of the present disclosure, the rails (or other components) may be made of a fiberglass material having a specific color that provides a number of various advantages over prior art configurations. For example, the composite components may be configured with a color that provides high visibility for users and others that may be working or otherwise functioning in proximity to the ladder. In another example, the composite components may be configured to substantially retain saturation, rather than fading, even after exposure to environmental conditions such as UV rays from the sun.

In one particular example, the fiberglass components (e.g., the rails 106A, 106B, 110A and 110B) may be formed of a fiberglass material having a high-visibility green color. One example of a high-visibility green includes a color classified as pantone 376C. In one embodiment, the fiberglass materials may be formed to exhibit an initial color that is classified as pantone 376C. It has been found that use of such a color not only provides a high visibility to the fiberglass component (e.g., a ladder rail), but also, unexpectedly, does not fade when exposed to environmental conditions. Rather, it has been discovered that fiberglass components configured with such a color actually darken in their appearance after exposure to significant UV light to a color that may be classified as pantone 383C.

In forming a fiberglass component exhibiting a high-visibility green color such as described above, an appropriate pigment may be added to the resin to provide the initial color (e.g., pantone 376C). While other resins may be used (e.g., polyester, vinylester or epoxy resins), in one particular embodiment, a two-part polyurethane resin may be used which includes polyol as one part and isocyanate as the second part. In one example embodiment, a pigment, such as that available from Chromaflo Technologies Corp., having a headquarters at Ahtabula, Ohio, under pigment number HDR-55390 PMS 375C GREEN, may be added to the resin to obtain the desired color. The resin may be used in the fabrication of fiberglass components, such as by a pultrusion process or other appropriate means of fabrication.

Referring briefly to FIG. 4A, in one embodiment, fiberglass components 200 were formed using the above techniques to provide the fiberglass component with an initial color of pantone 376C. The components 200 were then subjected to testing in a QUV accelerated weather tester which is used to reproduce the results of exposure to sunlight, rain and dew. In one particular test, the components 200 were subjected to 1,000 hours of exposure which is intended to approximate a full year of exposure to the South Florida sun and accompanying environment (e.g., humidity, rain, etc.). As shown in FIG. 4B, the tested components 202 (i.e., after exposure to 1,000 hours of exposure in the QUV accelerated weather tester), unexpectedly, did not fade or exhibit a hazy appearance as conventional fiberglass materials do. Instead, the tested components 202 actually darkened in hue and/or saturation.

This unexpected result provides a solution to both providing high-visibility to fiberglass components (e.g., a ladder component such as a rail) as well as durability in the appearance and finish of the fiberglass components, particularly when exposed to environmental conditions such as sun light, humidity, due, rain, snow, etc.

Referring now to FIG. 5, a graph shows testing results for a first sample (including a graph 300 for a first control sample—referred to as “Control 1”—and a graph 302 for a first exposed sample—referred to as “Exposed 1”). The graph depicts absorbance of the sample on the vertical axis vs. wavelength of light depicted along the horizontal axis. Table 1 set forth below set forth relevant data for the graph.

TABLE 1
Control 1
Peak #	λmax (nm)	Height (Abs)	λmin (nm)	Height (Abs)
1	650	0.637	536	0.354
2	404	1.137	370	1.126
3	308	1.209	260	1.107
4	236	1.206	200	1.035
Exposed 1
Peak #	λmax (nm)	Height (Abs)	λmin (nm)	Height (Abs)
1	646	0.589	560	0.436
2	350	1.205	256	1.071
3	238	1.082	200	0.912

Referring to FIG. 6, a graph shows testing results for a second sample (including a graph 310 for a second control sample—referred to as “Control 2”—and a graph 312 for a second exposed sample—referred to as “Exposed 2”). The graph depicts absorbance of the sample on the vertical axis vs. wavelength of light depicted along the horizontal axis. Table 2 set forth below set forth relevant data for the graph.

TABLE 2
Control 2
Peak #	λmax (nm)	Height (Abs)	λmin (nm)	Height (Abs)
1	650	0.623	536	0.351
2	408	1.098	370	1.084
3	310	1.151	258	1.010
4	234	1.129	200	0.955
Exposed 2
Peak #	λmax (nm)	Height (Abs)	λmin (nm)	Height (Abs)
1	646	0.601	558	0.445
2	356	1.223	256	1.072
3	238	1.084	200	0.907

With reference to FIGS. 5 and 6, and TABLES 1 and 2, it is noted that specimens similar to those shown and described with respect to FIG. 4A and 4B (e.g., the “exposed samples being subjected to environmental conditions or simulations as described above) were analyzed as to their reflectance/absorbance properties. As can be seen, the minimum absorbance (i.e., “Peak #1” in TABLES 1 and 2 for each of the samples—and as identified in box “A” in FIG. 5), which corresponds with maximum reflectance, shifts from a wavelength of 536 nm to a wavelength of 560 nm (Exposed 1) or 558 nm (Exposed 2), while maintaining a relatively low level of absorbance (and, thus, a high level of reflectance). Further, it is noted that the absorbance of light in the UV spectrum decreases, as shown in box “B” in FIG. 5 for the exposed sample. This may provide further advantages in the specimen resisting UV light and the associated damage that might be incurred by exposure thereto.

While an extension ladder is shown in FIG. 3, the colors and processes described herein may be used in other forms of ladders as well, including step ladders, step stools, platform ladders, articulating ladders (or other combination type ladders), or any type of ladder wherein a portion of the ladder is formed of fiberglass or other composite materials utilizing a colored resin. Additionally, embodiments of the present disclosure may be applied to or combined with ladder accessories including trays, platforms and other devices. Some examples of other ladder types as well as ladder components and accessories include those described in U.S. Provisional Patent Application No. 62/404,672 filed on Oct. 5, 2016, U.S. Pat. No. 8,365,865, issued Feb. 5, 2013, to Moss et al., U.S. Pat. No. 9,145,733 issued Sep. 29, 2015, Worthington et al., and U.S. Patent Application Publication No 2015/0068842, published on Mar. 12, 2015, U.S. Pat. No. 8,376,087, issued on Feb. 19, 2013, U.S. Pat. No. 8,701,831, issued on Apr. 22, 2014, U.S. Pat. No. 7,086,499, issued Aug. 8, 2006, U.S. Pat. No. 8,997,930, issued Apr. 7, 2015, and U.S. Pat. No. 9,163,455, issued Oct. 20, 2015, the disclosures of each of which are incorporated herein in their entireties.

Additionally, the present invention is useful in any type of fiberglass component (or other components formed from resin based materials) exclusive of ladders.

While the invention may be susceptible to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and have been described in detail herein. However, it should be understood that the invention is not intended to be limited to the particular forms disclosed. Rather, the invention includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the following appended claims.

Claims

1. A ladder comprising: a pair of rails; anda plurality of rungs extending between, and coupled to, the pair of rails;wherein at least one rail of the pair of rails includes a fiberglass material having a color of pantone 376C;wherein the fiberglass material is configured to change to a color of pantone 383C after exposure to ultraviolet light.

2. The ladder of claim 1, wherein the fiberglass material includes a polyurethane resin.

3. The ladder of claim 2, wherein the polyurethane resin comprises polyol and isocyanate.

4. The ladder of claim 1, wherein the at least one fiberglass component exhibits a minimum absorbance of light at a wavelength of approximately 536 nm.

5. The ladder of claim 1, wherein the at least one fiberglass material is configured to change to the color of pantone 383C after exposure to about 1000 hours of ultraviolet light.

6. A ladder comprising: a rail;a plurality of rungs coupled with the rail;wherein at least one of the rail and a rung of the plurality of rungs comprises a fiberglass material having a minimum absorbance of light having a wavelength of about 536 nm;wherein upon exposure to ultraviolet light, the minimum absorbance is configured to shift to about 558 nm or to about 560 nm.

7. The ladder of claim 6, wherein the fiberglass material includes a polyurethane resin.

8. The ladder of claim 7, wherein the polyurethane resin comprises polyol and isocyanate.

9. The ladder of claim 6, wherein absorbance of light in the ultraviolet spectrum of the at least one fiberglass material decreases upon shifting of the minimum absorbance.

10. The ladder of claim 9, wherein the decrease in the absorbance occurs at or about a wavelength of light of 236 nm or 238 nm.

11. The ladder of claim 9, wherein the ultraviolet spectrum includes light having a wavelength of about 300 nanometers or less.