Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B43—WRITING OR DRAWING IMPLEMENTS; BUREAU ACCESSORIES
  • B43K—IMPLEMENTS FOR WRITING OR DRAWING
  • B43K19/00—Non-propelling pencils; Styles; Crayons; Chalks
  • B43K19/14—Sheathings
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B27—WORKING OR PRESERVING WOOD OR SIMILAR MATERIAL; NAILING OR STAPLING MACHINES IN GENERAL
  • B27N—MANUFACTURE BY DRY PROCESSES OF ARTICLES, WITH OR WITHOUT ORGANIC BINDING AGENTS, MADE FROM PARTICLES OR FIBRES CONSISTING OF WOOD OR OTHER LIGNOCELLULOSIC OR LIKE ORGANIC MATERIAL
  • B27N3/00—Manufacture of substantially flat articles, e.g. boards, from particles or fibres
  • B27N3/04—Manufacture of substantially flat articles, e.g. boards, from particles or fibres from fibres

Definitions

• the present invention relates to a rigid fiberboard material. More particularly, the present invention relates to a rigid fiberboard useful in the manufacture of pencils.
• Incense cedar typically grows among large stands of fir trees and, in the past, has been obtained through the "clear-cutting" of such trees. However, severe restrictions are about to be placed on the "clear cutting" operations commonly practiced by the timber industry. Thus, incense cedar will have to be selectively harvested from the fir forests in which it grows. This will, of course, result in a substantial rise in the cost of cedar to pencil manufacturers. Cedar costs will be further increased by restrictions on the supply of this wood. Approximately one-third of the incense cedar harvest area will shortly be taken out of production to protect endangered species of wildlife such as the "Spotted" Owl.
• Jelutong has, to this point, been a low cost substitute for incense cedar; however, this is likely to change in the very near future.
• the fragile rain forest ecosystem in which this wood grows is easily damaged by harvesting operations.
• access to much of the growing area has already been restricted by the Indonesian and Malaysian governments in an effort to protect their nations' rain forests from degradation.
• illegal harvesting of jelutong from restricted areas is widespread.
• several environmental groups have called for a boycott of those pencil manufacturers who employ jelutong in the manufacture of their pencils.
• the increased demand for jelutong as a substitute for cedar in the manufacture of pencils has prompted some environmental organizations to designate jelutong as an endangered tree species.
• the present invention meets the above-stated objects and other objects which will be readily apparent by providing a rigid fiberboard and a pencil formed therefrom.
• the fiberboard comprises fibers, filler, binder, lubricant and water proofing agent.
• the fiberboard may further comprise at least one processing aid.
• a rigid fiberboard made according to the invention is useful as a substitute for the incense cedar and jelutong currently used to make pencil shafts. Moreover, the fiberboard is substituted directly into the currently employed pencil manufacturing process.
• the rigid fiberboard is formed in a wet laid process on conventional papermaking equipment. Initially, the fiberboard is formed in large sheets, each having a length of about 132 inches, a width of about 110 inches and a thickness of from about 0.15 to 0.18 inches, or in rolls. Each sheet or roll is then cut, in an automated cutting process, into slabs measuring approximately 2.75 inches by 7.25 inches; slabs of this size closely approximate the natural wood slabs currently supplied to pencil manufacturers.
• each pencil is formed from a portion of two fiberboard slabs, a top slab and a bottom slab, adhered together.
• each slab Prior to adhering the slabs together, each slab is grooved under grooving wheels, and the bottom slab has polyvinyl acetate glue or other suitable wood glues applied into its grooves through an appropriate dispenser. Once the glue has been applied, fired graphite lead is laid into the grooves of the bottom slab and lightly pressed into place under a roller. The top slab is then adhesively treated to apply adhesive into its grooves and onto the flats between the grooves. The top slab is then attached to the bottom slab and held in place under pressure until the adhesive dries.
• the dried slabs are squared with a diamond-tipped rotating blade and then passed to a shaping machine with top and bottom knives and shaped into the familiar hexagon by first cutting the bottom slab and then the top. After three or four coats of paint have been applied, the pencils are printed. The pencils are then pressed into an end constrictor to reduce the diameter at one end so that the ferrule and eraser can be applied.
• the invention provides a rigid fiberboard that eliminates the need to use natural woods from ecologically sensitive areas in the manufacture of pencils, but also the fiberboard itself can be made largely from recycled materials such as recycled newspaper and pulp by-products. Moreover, because the fiberboard is made in a wet-laid process on papermaking equipment it is far more uniform than the natural woods presently being used which evidence a good deal of variation among individual trees and among the parts of a single tree.
• the rigid fiberboard taught by the present invention comprises from about 38 to about 75% by weight of fibers.
• the fibers form the basic structural network for the fiberboard and, when properly combined with other constituents, provide the fiberboard with a wood-like quality.
• a wide variety of both natural and man-made fibers may be utilized; preferably, however, cellulose fibers are used. It has been found that cellulose fibers derived from recycled materials produce excellent results.
• the fiberboard comprises secondary cellulose fibers derived from, for example, one or more of the following sources: recycled newspapers, kraft bags, corrugated boxes, cotton linters, denim fibers, bleached papers, kraft papers and cotton rags. The use of these recycled, biodegradable fibers not only results in reduced costs but also provides an environmentally attractive product.
• Virgin cellulose fibers from, for example, wood pulp may also be used, either alone or in combination with other types of fibers.
• the fiberboard may also comprise man-made fibers. Suitable man-made fibers include, for example, polyester fibers, acrylic fibers, aramid fibers, rayon fibers, nylon fibers and glass fibers.
• the material further comprises from about 10 to about 30% by weight of filler.
• filler A large number of both organic and inorganic particulates have been found useful for this purpose such as, for example, perlite, vermiculite, glass microbubbles, corn cob flour, rice hull flour, nut shell flour, fruit pit flour, wood flour, cork dust, ground rubber, phenolic resin microbubbles, carbon microbubbles and saran microbubbles.
• Certain fibers commonly referred to by those skilled in the art as bulking fibers, may also be used together with the particulate fillers. Suitable bulking fibers are, for example, "HBA” fibers available from Weyerhaeuser Paper Co., Tacoma, Washington and "INTERFIBE” fibers available from Interfibe, Inc., Portage, Mich.
• the filler comprises one or more organic particulates formed as by-products in various industries such as the lumber, agriculture and food industries.
• wood flour from Wilner Wood Products Co., Norway, Maine, cork dust available from Maryland Cork Co., Elkton, Maryland, corn cob flour supplied by Composite Materials, Inc., Montgomery, Alabama, corn starch and mixtures thereof have been found to be particularly suitable.
• filler materials which are recycled biodegradable by-products from other industries a more economical and environmentally safe product can be achieved.
• the fiberboard further comprises from about 10 to about 35% by weight of binder.
• binder Any binder recognized by those skilled in the art as suitable for the fiber/particulate formulation described above may be used.
• the binder preferably is a thermoset resin, a water soluble gum or a combination of the two.
• Suitable thermoset resin binders used either alone or in combination, are phenolic resins, melamine resins, urea-formaldehyde resins, latex resins and epoxy resins.
• Water soluble gums which have been found to be particularly useful are guar gum, carboxymethyl cellulose and hydroxyethyl cellulose.
• the binder is a phenolic resin binder such as the resins sold under the trademark "PLYOPHEN” by BTL Speciality Resins, Malvern, Ark., Reichhold Chemicals, Inc., Warren, NJ, "CASCOPHEN” by Borden Packaging and Industrial Products, Vancouver, B.C., "VARCUM AND DUREZ” from Oxychem, Tonowanda, NY or a combination of these resins and carboxymethyl cellulose.
• the fiberboard further comprises from about 2 to about 15% by weight of a lubricating agent to help insure that it will sharpen correctly.
• a lubricating agent to help insure that it will sharpen correctly.
• a number of lubricants have been found to be suitable for this purpose including, for example, polyethylene powder, emulsified wax, powdered wax, talcs, stearates, fatty acids and mixtures of these materials.
• the lubricant is either polyethylene powder, such as that available from USI Chemicals Co., Cincinnati, OH under the trademark “MICROTHENE” or “PARACOL” wax emulsion from Hercules, Inc. Wilmington, DE, stearic acid or mixtures thereof.
• the fiberboard further includes from about 0.4 to about 1.5% by weight of a water proofing agent.
• the water proofing agent is wood rozin size, a by-product of the pulp industry, or a silicone-based water repellant.
• the water proofing agent is wood rozin size available from Hercules, Inc., Wilmington, DE under the trademark "PEXOL" 243.
• the fiberboard further comprises 0 to about 3% by weight of processing aids.
• processing aids Any number of a wide variety of processing aids commonly used by those skilled in the art may be employed including, for example, one or more of the following: retention aids, anti-foaming agents, coagulants, floculents and pH modifiers.
• retention aids such as "KYMENE” 557H from Hercules, Inc., Wilmington, DE or "AMRES" 8855 from Georgia Pacific, Crossett, Ark., have been found to be particularly advantageous.
• a retention aid of this type not only provides better retention of fines but also enhances the wet strength of the fiberboard.
• the fiberboard may further include one or more dyes to provide the familiar reddish color of pencils made from cedar.
• chrysoidine and paper red are particularly suitable.

Landscapes

• Life Sciences & Earth Sciences (AREA)
• Engineering & Computer Science (AREA)
• Manufacturing & Machinery (AREA)
• Wood Science & Technology (AREA)
• Forests & Forestry (AREA)
• Dry Formation Of Fiberboard And The Like (AREA)
• Paper (AREA)
• Treatments For Attaching Organic Compounds To Fibrous Goods (AREA)
• Reinforced Plastic Materials (AREA)
• Compositions Of Macromolecular Compounds (AREA)

Applications Claiming Priority (4)

Publications (1)

Family

ID=27109191

Family Applications (1)

Country Status (5)

Cited By (7)

Families Citing this family (5)

Citations (5)

• 1992
  • 1992-03-16 CA CA002063115A patent/CA2063115C/en not_active Expired - Fee Related
  • 1992-03-23 JP JP4065029A patent/JPH0596899A/ja active Pending
  • 1992-04-06 EP EP92105939A patent/EP0518018A1/en not_active Withdrawn
  • 1992-06-10 BR BR929202205A patent/BR9202205A/pt not_active IP Right Cessation
  • 1992-06-12 KR KR1019920010168A patent/KR100209070B1/ko not_active IP Right Cessation

Patent Citations (5)

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