ROOFTOP CANVAS

Abstract

Rooftop canvas includes a twill texture layer having a plurality of flat warp strips extending in a longitudinal direction and a plurality of flat weft strips extending in a lateral direction perpendicular to the longitudinal direction. An imaginary line passing through an intersection of one of the flat weft strips and one of the flat warp strips and an intersection of another flat weft strip adjacent to the flat weft strip and another flat warp strip adjacent to the flat warp strip is inclined relative to the longitudinal direction and the lateral direction. The twill texture layer is superimposed on a first covering layer. The rooftop canvas can further include a second covering layer, with the first covering layer sandwiched between the twill texture layer and the second covering layer.

Description

BACKGROUND OF THE INVENTION

The present invention relates to a building material and, more particularly, to rooftop canvas.

There are more storms, hurricanes, and tornados due to climate warming and extreme climates. The building materials, including rooftop canvas, should be adjusted according to the climate change. Rooftop canvas is a modern building material and use advanced polymers to shield ultraviolet rays and provide protection. In addition to withstanding strong sunlight and providing resistance to decomposition, the rooftop canvas possesses excellent resistance to aging due to heat.

Safety is the top priority while installing the rooftop canvas on rooftops. However, a worker slips easily on conventional rooftop canvas made of asphalt when the rooftop canvas is heated, moistened, or stained with oil. Furthermore, the conventional rooftop canvas has low tear strength. Thus, the safety of the worker on the rooftop canvas is risky.

BRIEF SUMMARY OF THE INVENTION

Rooftop canvas according to the present invention includes a twill texture layer having a plurality of flat warp strips extending in a longitudinal direction and a plurality of flat weft strips extending in a lateral direction perpendicular to the longitudinal direction. An imaginary line passing through an intersection of one of the plurality of flat weft strips and one of the plurality of flat warp strips and an intersection of another of the plurality of flat weft strips adjacent to the one of the plurality of flat weft strips and another of the plurality of flat warp strips adjacent to the one of plurality of flat warp strips is inclined relative to the longitudinal direction and the lateral direction. The twill texture layer is superimposed on a first covering layer.

Each of the plurality of flat warp strips and the plurality of flat weft strips includes at least one corrugated face, and the twill texture layer includes at least one corrugated surface.

Preferably, the rooftop canvas further includes a second covering layer. The first covering layer is sandwiched between the twill texture layer and the second covering layer.

Each of the plurality of flat warp strips and the plurality of flat weft strips is made of polyolefin, preferably polypropylene.

The first covering layer is made of polyolefin, preferably polypropylene.

The second covering layer is made of one of a thermoplastic elastomer, a polyolefin elastomer, or a polyolefin plastomer, or a mixture of polypropylene and at least one of a thermoplastic elastomer, a polyolefin elastomer, and a polyolefin plastomer.

The rooftop canvas according to the present invention possesses anti-slipping properties, light shielding properties, and water permeation resistance.

The present invention will become clearer in light of the following detailed description of illustrative embodiments of this invention described in connection with the drawings.

DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a perspective view of rooftop canvas according to the present invention.

FIG. 1A shows an enlarged view of a circled portion of FIG. 1.

FIG. 2 is a perspective view illustrating an anti-slip test of the rooftop canvas according to the present invention.

FIG. 3 is a perspective view illustrating another anti-slip test of the rooftop canvas according to the present invention.

FIG. 4 shows a water permeation resistance test of the rooftop canvas according to the present invention.

DETAILED DESCRIPTION OF THE INVENTION

With reference to FIG. 1, rooftop canvas 1 according to the present invention includes a twill texture layer 11 including a plurality of flat warp strips 111A extending in a longitudinal direction and a plurality of flat weft strips 111B extending in a lateral direction perpendicular to the longitudinal direction. An imaginary line passing through an intersection of one of the flat weft strips 111B1 and one of the flat warp strips 111A1 and an intersection of another flat weft strip 111B2 adjacent to the flat weft strip 111B1 and another flat warp strip 111A2 adjacent to the flat warp strip 111A1 is inclined relative to the longitudinal direction and the lateral direction (see the imaginary lines in FIG. 1).

In the form shown in FIGS. 1 and 1A, after weaving the flat warp strips 111A and the flat weft strips 111B together to form the rooftop canvas 1, a first one of the flat warp strips 111A is located below a first flat weft strip 111B and located above second, third, and fourth flat well strips 111B. Likewise, a second one of the flat warp strips 111A is located above the first three flat weft strips 111B and located below the fourth flat weft strips 111B. An imaginary line passing through a first intersection 111C1 of the first flat warp strip 111A1 and the first flat weft strip 111B1 and a second intersection 111C2 of the second flat warp strip 111A2 and the second flat weft strip 111B2 is inclined. Other intersections of flat warp strips 111A and flat weft strips 111B are similar to this arrangement.

Since the flat warp strips 111A and the flat weft strips 111B intersect with each other, are mutually superimposed at different sections, and press against each other, the surfaces of the twill texture layer 11 are rugged, uneven, and fluffy. Each of the flat warp strips 111A and the flat weft strips 111B has a width in a range from 1.5 to 5.0 mm. The width of the flat warp strips 111A can be different from the width of the flat weft strips 111B to obtain a twill texture layer H of a desired pattern. Each of the flat warp strips 111A and the flat weft strips 111B has at least one corrugated face such that the twill texture layer 1 includes at least one corrugated surface that is more rugged, uneven, and fluffy.

The rooftop canvas 1 further includes a first covering layer 12. The twill texture layer 1 is superimposed on the first covering layer.

The rooftop canvas 1 has anti-slipping properties. Specifically, when a worker wearing rubber shoes stands on the surface of the twill texture layer 11, the bottom faces of the rubber shoes bite into the surface of the twill texture layer 11 without slipping. It has been proved in tests that slipping would not occur even if the rooftop canvas 1 is placed on a rooftop having an inclination angle of 34 degrees. The safety of the worker on the rooftop canvas is assured.

With reference to FIG. 2, in an anti-slipping test, the rooftop canvas 1 according to the present invention is placed on a carrier board 33 supported by a rod 32 connected to an angle adjuster 31. The angle adjuster 31 can be operated to change the inclination angle of the carrier board 33, and the inclination angle of the carrier board 33 is indicated by an angle indicator 34. A weight 35 is placed on the carrier board 33 to simulate the load. The test result shows that the rooftop canvas 1 according to the present invention possesses excellent anti-slipping properties.

FIG. 3 shows another anti-slipping (friction) test of the rooftop canvas 1 according to the present invention. The rooftop canvas 1 is placed on a plate 37, and a weight 35 is placed on the rooftop canvas 1. A pulling force displayer 36 is provided to apply and measure a force for pulling the weight 35. The test result shows that the rooftop canvas 1 according to the present invention possesses excellent anti-slipping properties.

The rooftop canvas 1 according to the present invention also possesses light shielding properties. Since at least one face of each of the flat warp strips 111A and the flat weft strips 111B is corrugated, at least one surface of the twill texture layer 11 is corrugated and, thus, rugged, uneven, and fluffy. Each of the flat warp strips 111A and the flat weft strips 111B can shield and reflect light beams from different angles.

The rooftop canvas 1 according to the present invention also possesses water permeation resistance. Since the flat warp strips 111A and the flat weft strips 111B are corrugated, are woven with each other, are overlapped with each other, and squeeze each other, they fill gaps therebetween and, thus, possess water permeation resistance.

With reference to FIG. 4, in a test of water permeation resistance, the rooftop canvas 1 according to the present invention is placed in a water tank 24 at an inclined angle. Water is supplied from a water pipe 25 through a valve 21, and a pressure gauge 22 is provided to measure the water pressure. Water passes through a sprinkler 23 to the rooftop canvas 1, falls into the water tank 24 and is drained via a drain 26 in the bottom of the water tank 24. The test result shows that the rooftop canvas 1 according to the present invention possesses excellent water permeation resistance.

The rooftop canvas 1 can further include a second covering layer 13. The first covering layer 12 is sandwiched between the twill texture layer H and the second covering layer 13. The second covering layer 13 provides enhanced water-resistant effect. In the form shown, each of the flat warp strips 111A and the flat weft strips 111B is made of polyolefin (polymers obtained from addition polymerization). These polymers are obtained from polymerization of many identical or different simple olefin molecules and possess better water permeation resistance properties. The first covering layer 12 is preferably made of polyolefin to enhance the water permeation resistance properties. The polyolefin for producing the flat warp strips 111A, the flat weft strips 111B, and the first covering layer 11 is preferably polypropylene (PP), obtaining effects of light weight and resistance to chemicals and heat.

The second covering layer 13 is made of one of a thermoplastic elastomer (TPE), a polyolefin elastomer (POE), or a polyolefin plastomer (POP), or a mixture of polypropylene (PP) and at least one of a thermoplastic elastomer (TPE), a polyolefin elastomer (POE), and a polyolefin plastomer (POP).

Thermoplastic elastomers (TPE), or referred to as thermoplastic rubbers (TPR), possess properties of both of rubber and thermoplastic plastics. They are in a molten state and can be easily processed at high temperatures. At normal temperature, they have better tensile strength and are easy to process with low energy consumption and can be recycled.

Polyolefin elastomer (POE) is an elastic composite material having excellent toughness and excellent resistance to aging. Polyolefin elastomer has better flowability and is compatible with poleolefin.

Although specific embodiments have been illustrated and described, numerous modifications and variations are still possible without departing from the essence of the invention. The scope of the invention is limited by the accompanying claims.

Claims

1. Rooftop canvas comprising:

a twill texture layer including a plurality of flat warp strips extending in a longitudinal direction and a plurality of flat weft strips extending in a lateral direction perpendicular to the longitudinal direction, with an imaginary line passing through an intersection of one of the plurality of flat weft strips and one of the plurality of flat warp strips and an intersection of another of the plurality of flat weft strips adjacent to the one of the plurality of flat weft strips and another of the plurality of flat warp strips adjacent to the one of plurality of flat warp strips being inclined relative to the longitudinal direction and the lateral direction; and

a first covering layer, with the twill texture layer superimposed on the first covering layer.

2. The rooftop canvas as claimed in claim 1, with each of the plurality of flat warp strips and the plurality of flat weft strips including at least one corrugated face, with the twill texture layer including at least one corrugated surface.

3. The rooftop canvas as claimed in claim 1, further comprising: a second covering layer, with the first covering layer sandwiched between the twill texture layer and the second covering layer.

4. The rooftop canvas as claimed in claim 1, wherein each of the plurality of flat warp strips and the plurality of flat weft strips is made of polyolefin.

5. The rooftop canvas as claimed in claim 1, wherein the first covering layer is made of polyolefin.

6. The rooftop canvas as claimed in claim 3, with the second covering layer is made of one of a thermoplastic elastomer, a polyolefin elastomer, or a polyolefin plastomer, or a mixture of polypropylene and at least one of a thermoplastic elastomer, a polyolefin elastomer, and a polyolefin plastomer.

7. The rooftop canvas as claimed in claim 4, wherein the polyolefin is polypropylene.

8. The rooftop canvas as claimed in claim 5, wherein the polyolefin is polypropylene.