| Durable hand towel -> Monitor Keywords |
|
|
 
Durable hand towelRelated Patent Categories: Paper Making And Fiber Liberation, Processes And Products, Non-uniform, Irregular Or Configured Web Or SheetDurable hand towel description/claimsThe Patent Description & Claims data below is from USPTO Patent Application 20070137807, Durable hand towel. Brief Patent Description - Full Patent Description - Patent Application Claims
BACKGROUND [0001] Tabbing is a critical dispensing failure in which a small piece is pulled from a paper towel when it is desired to dispense the entire towel. This typically occurs because the user's hands are wet and the tensile force required to pull a towel from the dispenser is high. The wet tensile strength of a paper towel is typically about 30 percent to 35 percent of the towel's dry tensile strength. Thus the paper towel is put at a disadvantage when encountering the user's wet hands and the towel will often fail to dispense and leave the user holding only a small piece of the paper towel. [0002] One method that has attempted to resolve this tabbing issue has been modifications to the towel dispensers that reduce the force required to dispense such towels. Another method of addressing the issue of tabbing has been through the modification of the towel physical properties such as tensile strength and stretch, to help increase the towel durability. The increase of towel strength has generally been directed to increasing the machine direction (MD) tensile strength and MD stretch. As used herein, the term "machine direction" or "MD" means the length of a web or towel in the direction in which it is produced. The term "cross machine direction" or "CD" means the width of fabric or towel, i.e. a direction generally orthogonal to the MD. [0003] Finally, tabbing has also been addressed by improving the folding of the towel such that multiple plies of the towel material are presented to the user desiring to dispense the towel, thus multiplying the strength of the towel being dispensed. [0004] All of these methods have helped reduce the level of tabbing experienced, however, it has been found that the levels of tabbing are still unacceptable. One factor that magnifies the problem is the many towel put-ups and dispenser types from which such paper towels are dispensed. Paper towels dispense in either the MD or the CD directions depending on the format of the dispenser. Additionally, stresses that occur on all towels during dispensing impact both the MD and CD of the towel. For instance, when pulling on a hard roll towel which dispenses in the MD (i.e., the towel is dispensed in the same general direction as it was produced), stress is put primarily in the MD of the towel with secondary stresses acting in the CD of the towel. A towel dispensed in the CD, such as the SCOTTFOLD.RTM. Towel available from the Kimberly-Clark Corporation (Roswell, Ga.), experiences its primary stress in the CD of the towel with secondary stresses being applied in the MD of the towel. [0005] One limitation that is faced in addressing these issues is that paper towel basesheet manufacturing and the subsequent physical properties of such paper towels are kept the same for many towel formats and dispensers in which such towels may be used. The goal of such uniformity is often an attempt to provide one type of towel that meets the needs of as many dispensing needs and formats as possible. [0006] Another issue is that a paper towel will generally be stronger in MD compared to the CD of the same towel. As discussed, this will compromise towels dispensed in the CD and will contribute to failures when such towel is dispensed in the MD. Additionally, it has traditionally been easier to increase the MD stretch of a towel rather than increasing the CD stretch. [0007] Due to these directional forces that are applied to paper towels amongst differing dispensing formats, it has been difficult to produce a single towel basesheet that is durable enough to be reliably dispensed in these different dispenser formats with minimal tabbing. SUMMARY OF THE INVENTION [0008] In view of the issues stated above it is desired to produce a towel that has increased durability in the CD to improved the ability of the towel to dispense in the CD, and in the MD, with reduced instances of dispensing failures. The inventors have discovered an unexpected result that makes up the present invention that produces such a towel. [0009] This invention is directed to a durable paper towel made of a single throughdried uncreped tissue ply having a GMT of about 2700 grams or greater per 7.62 centimeters and a ratio of GMTEA*1000 to GMT of about 7 or greater. In some embodiments the ratio of CDTEA*1000 to CD tensile is between about 6 and about 9. In some embodiments, the stretch of the paper towel may be between about 6 percent and about 20 percent. [0010] The invention is also directed to a durable paper towel comprising a single throughdried uncreped tissue ply having a GMT of about 2700 grams or greater per 7.62 centimeters, a ratio of GMTEA*1000 to GMT of about 7 or greater, and a CD stretch between about 6 percent and about 20 percent. In some embodiments, the paper towel may have a ratio of CDTEA*1000 to CD tensile between about 6 and about 9. In some embodiments, the paper towel may have a CD stretch between about 7 percent and about 15 percent. In further embodiments, the paper towel may have a CD stretch between about 8 percent and about 12 percent. [0011] The invention is also directed to a durable paper towel comprising at least one throughdried uncreped tissue ply having a GMT of about 2700 grams or greater per 7.62 centimeters, and a CD stretch between about 6 percent and about 20 percent. In some embodiments, the towel may have a ratio of CDTEA*1000 to CD tensile between about 6 and about 9. [0012] Another aspect of the invention is a durable paper towel having a GMT of about 2700 grams or greater per 7.62 centimeters, a ratio of GMTEA*1000 to GMT of about 7 or greater, and a CD stretch between about 6 percent and about 20 percent. The towel prepared by forming a furnish of cellulosic fibers and water and depositing that furnish on a forming fabric to form a fibrous web. The fibrous web is transferred from the forming web to a transfer fabric and from the transfer fabric to a throughdrying fabric. The fibrous web is then subjected to non-compressive through-air drying to remove the water from the fibrous web. Finally, the fibrous web is removed from the throughdrying fabric without creping the fibrous web. [0013] At least one of these fabrics (transfer and throughdrying) has a topography in the CD such that CD strain is imparted to the fibrous web. In some embodiments, the transfer fabric has an increased CD strain. In other embodiments, the throughdrying fabric has an increased CD strain. In one embodiment, the throughdrying fabric has an increased CD strain and the transfer fabric does not have any appreciable CD strain. [0014] Finally, the invention is also directed to a method for making a durable uncreped throughdried paper towel having a GMT of about 2700 grams or greater per 7.62 centimeters, a ratio of GMTEA*1000 to GMT of about 7 or greater, and a CD stretch between about 6 percent and about 20 percent. The method includes the steps of depositing an aqueous suspension of papermaking fibers onto a forming fabric to form a wet web, transferring the wet web to a transfer fabric, transferring the wet web from the transfer fabric to a throughdrying fabric, throughdrying the web to form a tissue sheet, and removing the tissue sheet from the throughdrying fabric. [0015] At least one of these fabrics (transfer and throughdrying) has a topography in the CD such that CD strain is imparted to the fibrous web. In some embodiments, the throughdrying fabric has an increased CD strain. In one embodiment, the throughdrying fabric has an increased CD strain and the transfer fabric does not have any appreciable CD strain. [0016] In the interests of brevity and conciseness, any ranges of values set forth in this specification contemplate all values within the range and are to be construed as support for claims reciting any sub-ranges having endpoints which are whole number values within the specified range in question. By way of a hypothetical illustrative example, a disclosure in this specification of a range of from 1 to 5 shall be considered to support claims to any of the following ranges: 1-5; 1-4; 1-3; 1-2; 2-5; 2-4; 2-3; 3-5; 3-4; and 4-5. Test Procedures [0017] Tensile testing is conducted in the manner which is well known. More particularly, samples for tensile strength testing are prepared by cutting a 3 inches (76.2 mm) wide by 5 inches (127 mm) long strip in either the machine direction or cross-machine direction orientation using a JDC Precision Sample Cutter (Thwing-Albert Instrument Company, Philadelphia, Pa., Model No. JDC3-10). The instrument used for measuring tensile strengths is an constant-rate-of-extension (CRE) testing machine with a computer-based data acquisition and frame control system, such as an MTS Systems Sintech 11S (MTS Systems Corporation, Eden Prairie, Minn.). The data acquisition software is MTS TestWorks.RTM. for Windows (MTS Systems Corp., Research Triangle Park, N.C.). The load cell is selected from either a 50 Newton or 100 Newton maximum, depending on the strength of the sample being tested, such that the majority of peak load values fall between 10 and 90 percent of the load cell's full scale value. Primarily a 100 Newton load cell was used for this testing. The gauge length between jaws is 4+/-0.04 inches (101.6+/-1 mm). The jaws are operated using pneumatic-action and are rubber coated. The minimum grip face width is 3 inches (76.2 mm), and the approximate height of a jaw is 0.5 inches (12.7 mm). The crosshead speed is 10+/-0.4 inches/min (254+/-1 mm/min), and the break sensitivity is set at 65 percent. The sample is placed in the jaws of the instrument, centered both vertically and horizontally. The test is then started and ends when the specimen breaks. The peak load is recorded as either the "MD tensile strength" or the "CD tensile strength" of the specimen depending on the sample being tested. At least six (6) representative specimens are tested for each product, taken "as is", and the arithmetic average of all individual specimen tests is either the MD or CD tensile strength for the product. [0018] In addition to tensile strength, the stretch and tensile energy absorbed (TEA) are also reported by the MTS TestWorks.RTM. for Windows program for each sample measured. Stretch (either MD stretch or CD stretch) is reported as a percentage and is defined as the ratio of the slack-corrected elongation of a specimen at the point it generates its peak load divided by the slack-corrected gauge length. [0019] Total energy absorbed (TEA) is calculated as the area under the stress-strain curve during the same tensile test as has previously described above. The area is based on the strain value reached when the sheet is strained to rupture and the load placed on the sheet has dropped to 65 percent of the peak tensile load. Since the thickness of a paper sheet is generally unknown and varies during the test, it is common practice to ignore the cross-sectional area of the sheet and report the "stress" on the sheet as a load per unit length or typically in the units of grams per 3 inches of width. For the TEA calculation, the stress is converted to grams per centimeter and the area calculated by integration. The units of strain are centimeters per centimeter so that the final TEA units become g-cm/cm.sup.2. The TEA is measured in the MD and the CD of the samples. [0020] Additionally, the geometric mean tensile strength (GMT) is calculated from the tensile strength measurements. The GMT is calculated as the square root of the product of the MD tensile strength and the CD tensile strength. [0021] The caliper of the sheet is measured as the thickness of a single sheet using a controlled loading micrometer. The caliper is measured using a micrometer having an anvil diameter of 56.42 millimeters and a loading pressure is 2.0 kPa. The results are reported in mil (0.001 inches). To convert the results to microns multiply by 25.4. Continue reading about Durable hand towel... Full patent description for Durable hand towel Brief Patent Description - Full Patent Description - Patent Application Claims Click on the above for other options relating to this Durable hand towel patent application. ###  How KEYWORD MONITOR works... a FREE service from FreshPatents1. Sign up (takes 30 seconds). 2. Fill in the keywords to be monitored. 3. Each week you receive an email with patent applications related to your keywords. Start now! - Receive info on patent apps like Durable hand towel or other areas of interest. ### Previous Patent Application: Creping process and products made therefrom Next Patent Application: Embossed tissue products Industry Class: Paper making and fiber liberation ### FreshPatents.com Support Thank you for viewing the Durable hand towel patent info. IP-related news and info Results in 1.10703 seconds Other interesting Feshpatents.com categories: Computers: Graphics , I/O , Processors , Dyn. Storage , Static Storage , Printers 174 |
 * Protect your Inventions * US Patent Office filing 
PATENT INFO |
|
