Classifications

• • A—HUMAN NECESSITIES
  • A47—FURNITURE; DOMESTIC ARTICLES OR APPLIANCES; COFFEE MILLS; SPICE MILLS; SUCTION CLEANERS IN GENERAL
  • A47L—DOMESTIC WASHING OR CLEANING; SUCTION CLEANERS IN GENERAL
  • A47L13/00—Implements for cleaning floors, carpets, furniture, walls, or wall coverings
  • A47L13/10—Scrubbing; Scouring; Cleaning; Polishing
  • A47L13/16—Cloths; Pads; Sponges
• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
  • D21H27/00—Special paper not otherwise provided for, e.g. made by multi-step processes
• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
  • D21H5/00—Special paper or cardboard not otherwise provided for
  • D21H5/26—Special paper or cardboard manufactured by dry method; Apparatus or processes for forming webs by dry method from mainly short-fibre or particle material, e.g. paper pulp

Definitions

• This invention relates generally to fibrous absorbent webs, and more specifically to a dry-formed fibrous web having improved wipe dry properties.
• feed mats formed from highly beaten wood-pulp fibres have not been employed in any airlay, or similar dry-forming process to form absorbent fibrous web structures.
• an absorbent dry-formed fibrous web characterized in that a preponderance, by weight, of the fibres are fine wood pulp fibres of a papermaking length no greater than about 6.35 mm (1/4 inch) and having a coarseness of less than 20 milligrams/100 metres, said find wood pulp fibres having experienced a freeness decrement of at least 150 by mechanical working. This magnitude of reduction in the freeness level of the wood pulp fibres is considered necessary in order to achieve the beneficial results of the invention.
• fine wood pulp fibres means fibres of a papermaking length no greater than about 6.35 mm (1/4 inch) and having a coarseness of less than 20 milligrams/100 metres. These preferably are softwoods.
• Freeness level or “freeness” in accordance with this invention, is determined by the Canadian standard for pulp freeness, TAPPI method T227 M-58.
• the absorbent dry-formed webs of this invention have significant utility in forming household and industrial wipers, and more generally, for other end uses wherein enhanced wipe-dry properties are considered to be important.
• the basis weight of the dry-formed webs of this invention is preferably less than .1356 kg/m 2 (4oz/yd 2 ,) and most preferably is in the range of .0678 - .1356 kg/m 2 (2-4 oz/yd 2 ).
• an acrylic binder, or other suitable adhesive can be applied to stabilize the web.
• the binder should constitute less than 5% of the total weight of the final web construction. It is desirable to keep the weight of binder as low as possible, consistent with desired web strength, so that the binder will not interfere unduly with the absorbent properties of the web. The addition of too much binder to the web can actually mask, or counteract the effect achieved by the mechanical working operation.
• the fibrous web is formed by a conventional airlay web forming operation.
• the air-laid web includes a low-binder level, i.e. less than 5% of the total weight of the adhesively bonded construction.
• one or more wood pulp laps, or mats can be directed into a fiberizing roll for separating individual fibres from the mats and directing them in an airstream onto a foraminous forming surface in the form of an air-laid fibrous web.
• a fiberizing technique is disclosed in U.S.Patent No.4,118,832, issued to Tralance 0. Addy and David P. Gutman, and assigned to Scott Paper Company. This patent is incorporated herein by reference.
• the air-laid web of this invention can include a minor amount, by weight, of longer staple length fibres, such as rayon, polyester and the like.
• a representative technique for forming such a web is disclosed in U.S.Patent No. -4,134,948, issued to John H. Baker, Jr. and assigned to Scott Paper Company. This patent already has been incorporated herein by reference.
• wood pulp lap(s) processed through the fiberizing equipment is (are) formed of fine wood pulp fibres of a papermaking length no more than about 6.35 mm.
• the fine wood pulp fibres utilized in this invention have experienced a freeness decrement, by mechanical working, of at least 150; preferably by being treated in a conventional beater as part of the pulp lap forming operation.
• a pulp mat, or lap formed in accordance with the above technique is quite strong and dense, and extremely difficult to fiberize.
• a debonder has been added to the furnish prior to forming the lap. This has been found to interfere sufficiently with inter- fibre bonding to permit the desired separation of the individual fibres from the lap in the fiberizing operation.
• the debonder can be of any suitable type that does not excessively interfere with the absorbent properties of the web.
• a benzyl chromium chloride debonder is employed.
• the web can be sprayed with adhesive on its opposed surfaces to stabilize the construction. If desired the web can be embossed, prior to adhesive application, in accordance with the process disclosed in the earlier-referenced Baker patent.
• the test was performed under constant temperature and relative humidity conditions (70°F ⁇ 2° F, 65% relative humidity ⁇ 2%). The test was repeated and the average of the wiped dry area observations (step 8) in square centimetres was defined as the wipe dry index for the sample being tested.
• step 8 concentric circular score lines were provided on the surface of the disk corresponding to the 50, 100, 200, 300, 400, 500, 750 and 1,000 square centimetre circles so that the side of the dry area could be determined quickly by visually comparing the dry area to a reference score line representative of a known area.
• the wipe dry index determined by the above- described test is believed to be accurate to a value of ⁇ 50. Despite this range of error, a significant difference in the wipe dry property between webs being compared., from a technical standpoint, is reflected in a difference between their wipe dry indices that is greater than ⁇ 50.
• the mechanically worked, fine wood pulp fibres are of a papermaking length no greater than about 6.35 millimetres.
• these fibres have a gradation in length down to about 1 millimetre or less, and includes a significant fraction, by weight, that is retainable on a 48 mesh screen when the fibre supply is subjected to the Bauer-McNett wet fractionation technique described in TAPPI standard T233os-75.
• the Bauer-McNett technique described in TAPPI standard T233os-75.
• about 16 to 25% of the fine wood pulp fibres, by weight will be retained on the 48 mesh screen when the Bauer-McNett technique is carried out with a series of screens having the following sequential mesh sizes: 14, 28, 48 and 100.
• the fine wood pulp fibres of a papermaking length employed to form the webs of this invention should include a fibre fraction capable of passing through a 28 mesh screen, but being retainable on a 48 mesh screen.
• Reference in the claims to wood pulp fibres "of a papermaking length" refers to wood pulp fibres having such a fibre fraction; preferably constituting over 15% by weight of such wood pulp fibres.

Landscapes

• Nonwoven Fabrics (AREA)
• Paper (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=23497901

Family Applications (1)

Country Status (3)

Cited By (4)

Families Citing this family (1)

Citations (4)

• 1983
  • 1983-04-06 AU AU13190/83A patent/AU1319083A/en not_active Abandoned
  • 1983-05-18 EP EP83302821A patent/EP0094842A1/fr not_active Withdrawn
  • 1983-05-18 JP JP8739883A patent/JPS58214570A/ja active Pending

Patent Citations (4)

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events