Patent Application
20070131307
The present invention relates to a window coverings, particularly bamboo blinds, and methods of fabricating slats for such blinds.
Conventional bamboo shades are made from a panel of slats that have been cut from bamboo plants, treated and woven together. In some panels cylindrical rods or sticks are placed between each pair of slats. This panel is attached to a headrail and lift mechanism forming a roll-up shade or a roman shade.
The manufacture of bamboo slats from bamboo plants is a tedious process. First, one must find bamboo stalks suitable for use in a bamboo shade. The desired characteristics include a smooth surface and uniform colors on the surface. Raw bamboo rods with obvious color variations caused by exposure to sunlight, insect activity or other damage are excluded. Having found bamboo stalks or rods having the desired characteristics one must then cut the rods into sections based upon the desired length or width of the finished products. The cut sections must then be cleaned in a hot base solution. A typical cleaning process begins by boiling water in a large pot having a depth and diameter of from 0.8 to 3 meters. Once the water is boiling one kilogram of sodium hydroxide is added. The bamboo sections are boiled in the pot for 30 minutes with the solution temperature being maintained at 70° C. Then the bamboo sections are removed from the pot and wiped with a towel. Sometimes bamboo will discolor or change shape during the boiling step. Therefore, each section must be carefully inspected after being dried. In some bamboo shades a scorch pattern, also called a tortoise pattern, is applied to the bamboo. To create the scorch pattern the cleaned bamboo rod sections are placed side-by-side on the ground or other surface. Then water, sand, soil or combinations of these materials are randomly spread to cover portions of the raw bamboo rods. The rods are then exposed to a gas burner or torch scorching the uncovered portions of the rods. The covered portions will retain the original raw bamboo coloring while the uncovered portions will be black or dark brown. This arrangement of scorched and original surfaces is the tortoise pattern. The bamboo rods which may or may not have been scorched must next be cut longitudinally to form strips of bamboo having a desired width. These cut strips are called bamboo slats. Depending upon the type of product in which the slats are to be used, holes may be punched in the slats. Next, the slats are boiled in a solution of hydrogen peroxide and water for 30 minutes and removed for drying under the sun or baking in a furnace or oven. The baking process will result in a greenish color finish while sun drying produces a yellowish color finish on the slats Somewhat similar processes may include bonding the bamboo strips into a bamboo plate and coating the bamboo slats with a base coating and a face coating on the base coating such as are disclosed by Chen et al. in U.S. Pat. No. 5,896,903 and Nien in U.S. Pat. Nos. 6,192,949 and 6,746,745.
The traditional processes used to make bamboo slats are slow and complicated. A significant amount of chemical wastes, as well as bamboo plant waste, is generated as a by-product of the manufacturing process. The chemicals used to clean and remove grease from real bamboo slats during the manufacturing process are hazardous to the health of the worker. These environmental and health concerns have propelled the art to develop faux bamboo shades.
The faux bamboo shades which have been developed are comprised of a panel of plastic slats, and optionally plastic rods, woven together in the same manner as the slats in a real bamboo shade. This panel is attached to a headrail and lift mechanism in the same way as in a real bamboo shade. The slats in the faux bamboo shades currently available are extruded from a colored plastic material giving the slat a uniform color and appearance. Although this shade is called a faux bamboo shade, or even a bamboo shade, it does not look like a real bamboo shade. Real bamboo slats are not uniform in color or shape. They have grain patterns and vary in color from light yellows, greens and tans to light brown along the slat. Scorched slats have medium to dark brown and black color patterns. Real bamboo slats also have knots. These knots are raised portions extending across the slat that are about 5 millimeters in width and up to 2 mm in height. Such knots are typically lighter in color than the region on either side of the knot. The faux bamboo shades known in the art do not have knots or simulated knots and have a uniform thickness along their lengths. Yet, another advantage of faux bamboo shades over real bamboo shades is that they do not absorb moisture and can be cleaned by dipping them into a tub of soap and water. When a real bamboo slat absorbs or loses moisture, the slat tends to arch or bow. Such bowing does not occur in faux bamboo slats. Another advantage of faux bamboo slats over real bamboo is that faux bamboo slats can be cut more easily, being less likely to split or crack during cutting. Faux bamboo will not have mold or fungus growth such as occurs in real bamboo when exposed to moisture. Faux bamboo slats do not attract bugs and small critters. Faux bamboo can be fire retardant. Fire retardant additives can be added to the material from which the slats are extruded. Real bamboo burns easily.
Many home centers carry standard sizes of venetian blinds which can be trimmed to smaller widths using cut down machines located in the store. Because real bamboo slats can crack or chip during cutting, real bamboo shades are custom made by fabricators and blind manufacturers. There is no cut-down program currently available for bamboo shades. Faux bamboo slats can be more easily cut than real bamboo slats. Indeed, some cut-down machines currently being used for venetian blinds could make clean cuts on faux bamboo slats. Consequently, faux bamboo slats provide an opportunity for manufacturers to offer cut-down programs of the type currently being used to sell venetian blinds.
There is a need for a faux bamboo shade which has the advantages of the faux bamboo shades of the prior art yet looks like a real bamboo shade. Indeed, a faux bamboo shade which is easily mistaken for real bamboo by the average observer would be a significant advance in the art.
I provide faux bamboo slats, and a faux bamboo shade formed from a panel of such slats. The faux bamboo slats are plastic strips, preferably of polyvinylchloride, having a front face and a rear face wherein at least one face is printed with an array of colors selected and applied to simulate color and texture of a real bamboo slat. These strips may be printed or deformed to simulate at least one bamboo knot. Typically, that knot will have a width of 3 to 5 millimeters.
I further provide a method for making faux bamboo slats in which a plurality of plastic strips are run through an imprint machine having at least one print roller. The print roller or rollers are inscribed to apply a pattern to the plastic strips which simulates grain patterns and color variations from light yellows, greens and tans to light brown found in real bamboo slats. As the strips are fed through the imprint machine the pattern is printed on at least one face of each strip. Then the strips are dried, completing the process of making the faux bamboo slats. These slats can be assembled into a panel of faux bamboo slats for use in a bamboo shade. That shade may be a roll-up shade or a roman shade. These slats may also be used in shutters, sliding panels and anywhere real bamboo slats have been used.
I prefer to feed several strips in a side by side arrangement through the imprint machine. Then the pattern need not be the same on every strip. I also prefer to either print or deform at least some of the strips in a manner to simulate a bamboo knot. The strips are preferably made of polyvinylchloride.
I prefer to extrude the plastic strips which are used for the faux bamboo slats. The extruder may have a die configured to create a grain pattern on the plastic slats.
I may create a grain pattern or knots or both on the plastic strips through embossing. This process uses a pair of spaced apart embossing rollers on which a grain pattern or knot pattern has been created.
Other objects and advantages of my faux bamboo slat and method of making the slat will become apparent from certain present preferred embodiments thereof illustrated in the drawings.
Referring to
The slats 4 are imprinted in a manner to simulate the grain patterns and colors found in real bamboo slats. In a present preferred embodiment shown in
Referring now to
Referring to
The printing process enables one to create a wide array of colors and patterns from light yellows, greens and tans to light brown. Consequently, one is able to achieve a variety of bamboo appearances. A slat intended to depict raw bamboo will have more green shades than a slat intended to depict treated or processed bamboo. One can also replicate different species of bamboo through the choice of colors and patterns to be printed onto or formed into the plastic strips.
Because real bamboo shades having a scorch pattern are popular in the marketplace, I prefer that the faux bamboo shades also have a scorch pattern. As can be seen in
Although I prefer to print the grain pattern on the plastic strips, one could create a grain pattern during the extrusion process. In
Another way to create a grain pattern in a plastic strip is by embossing the strip.
The extruded strip 33 or embossed strip 40 may then be printed as illustrated in
The faux bamboo slats made in accordance with the present invention have thus far been described and illustrated as being used in roll-up and roman shades. But, their use is not so limited. The slats could be used in venetian blinds, shutters, movable and decorative panels, wall hangings and other applications in which real bamboo slats have been used.
Although I have shown and described certain present preferred embodiments of my faux bamboo shade and method of making the same, it should be distinctly understood that the invention is not limited thereto, but may be variously embodied within the scope of the following claims.
