Classifications

• • 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
  • B27N3/08—Moulding or pressing
  • B27N3/086—Presses with means for extracting or introducing gases or liquids in the mat
• • 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
  • B27N3/08—Moulding or pressing
  • B27N3/18—Auxiliary operations, e.g. preheating, humidifying, cutting-off
• • 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
  • B27N3/08—Moulding or pressing
  • B27N3/24—Moulding or pressing characterised by using continuously acting presses having endless belts or chains moved within the compression zone

Definitions

• the present invention relates to a method of continuously producing profiled lignocellulose-containing board or strip-like products according to the preamble of claim 1 , and to an arrangement for carrying out the method in accordance with the preamble of claim 7.
• a common way of producing, e.g., profiled structural elements such as skirting boards, cornices, window linings, architraving or furniture components is to plane or mill the desired profile either from solid wood or from fibreboard, preferably MDF (Medium Density Fibreboard).
• MDF Medium Density Fibreboard
• the unsuitability of using this technique to mill such products from medium density fibreboard is obvious. Firstly, it would involve a production chain and transport chain consisting of many expensive inter- mediate steps and operations and would mean that the profiled product would have different densities in cross-section and therewith absorb different amounts of paint or varnish at discrete locations. The milling operation would also result in high material losses. For instance, more than 50% of the starting material can be lost when milling products to pronounced profile depths.
• a standard example of this production chain may be as follows: Dried and glue-coated fibres are produced in the MDF plant and shaped into mats which are pressed into boards which are then edge-trimmed and ground. Losses are experienced in the form of edge trim and dust from the grinding operations.
• the next link in the production chain consists in the transportation of board to the production unit for the profiled products.
• the medium density fibreboards are sawn into strips which form the starting blanks for the profiled products, these starting blanks being milled and ground as well as lacquered with layers of paint or varnish or are coated with some type of film for priming or decoration purposes.
• the object of the present invention is to avoid the drawbacks associated with the aforesaid production process in an economical fashion and, instead, to provide a continuous process up to the finished profiled product with as little mate- rial loss as possible.
• This object is achieved in accordance with the invention having the characteristic features set forth in the following Claims.
• the illustrated plant is based on the plant illustrated in SE 502 272, which describes a continuous steam injection process.
• Disintegrated, dried and glue- coated lignocellulosic fibre material is delivered to a forming station 1 and there formed into a fibre mat 3 which is fed into a steam injection press 2.
• the fibre mat is pressed in the press into a board product 4 which is hardened, or cured, to an extent at which the board is solid and has a given mechanical strength.
• the surfaces are further densified in a surface densifying unit 5. This process results in board that has a dense outer surface.
• the plant is designed for the production of pro- filed board or strip products in one and the same two-step process.
• a milling or cutting roll 6 is arranged between the forming station 1 and the steam injection press 2.
• the cutting roll 6 functions to impart a profiled surface structure to the lignocellulosic, glue-coated starting material in the form of the fibre mat 3 that has a density of between 20 and 200 kg/m 3 .
• the diameter of the cutting roll 6 varies across its width.
• the profile imparted to the cross-section of the mat will coincide essentially with the cross-section of the finished product.
• the profiled mat 3, which may be precompressed, is transported continuously into the steam injection press 2.
• This press includes a profiled steam roll 7 that has the same profile as the cutting roll 6.
• the mat 3 is compressed here and hardened to form a board or strip 4 that has the intended cross-section, by injecting saturated or superheated steam into the mat.
• the surface layers are further compressed in a second step, by allowing the board or the strip 4 to pass through the surface densifying unit 5 that includes one or more hot, compression roll-pairs 8 that have the same geometry as the steam roll 7 but a smaller cross-sectional area so as to obtain the desired surface compression.
• the drawing shows the cross-section 9 of the formed fibre mat 3 prior to profiling the mat.
• the cross-section 10 downstream of the cutting roll 6 illustrates the profile of the upper surface. Downstream of the steam injection press 2, the board 4 pressed therein will have the cross-section 11 , and the surface sheet in the cross-section 12 downstream of the surface densifying unit 5 will have a higher density but the same profile.
• the underside of the board can be profiled with the same technique.
• a cutting roll 6 is also arranged on the other side of the fibre mat 3 and the lower rolls 7 and 8 in the steam injection press 2 and the surface densify- ing unit 5 are provided with the same surface profile as the lower cutting roll across the respective widths thereof.
• the board or the strip produced in the first step i.e. in the steam injection press
• the board or the strip produced in the first step can be divided into several narrower strips in a continuous process, these narrower strips then being passed through one or more hot roll pairs 8 in the surface densifying unit 5. Separation of the board or strip into a plurality of strips may be effected by sawing, for instance.
• the invention enables the production of profiled lignocellulose-containing products in the form of boards and strips of uniform density throughout the whole of their cross-section and with dense surfaces that absorb equal amounts of paint over the entire product in a rapid and continuous process. Furthermore, this is achieved in the absence of losses in starting material, apart from the small losses that occur when sawing the board or strip.

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)

Priority Applications (8)

Applications Claiming Priority (2)

Publications (1)

Family

ID=20414319

Family Applications (1)

Country Status (12)

Cited By (2)

Families Citing this family (2)

Citations (2)

• 1999
  • 1999-02-01 SE SE9900331A patent/SE515273C2/sv not_active IP Right Cessation
• 2000
  • 2000-01-31 AU AU28379/00A patent/AU2837900A/en not_active Abandoned
  • 2000-01-31 CZ CZ20012762A patent/CZ20012762A3/cs unknown
  • 2000-01-31 KR KR1020017009371A patent/KR20010101696A/ko not_active Application Discontinuation
  • 2000-01-31 NZ NZ513744A patent/NZ513744A/xx unknown
  • 2000-01-31 WO PCT/SE2000/000186 patent/WO2000044540A1/en not_active Application Discontinuation
  • 2000-01-31 JP JP2000595824A patent/JP2002535174A/ja not_active Withdrawn
  • 2000-01-31 PL PL00349842A patent/PL349842A1/xx unknown
  • 2000-01-31 CN CN00803289A patent/CN1100650C/zh not_active Expired - Fee Related
  • 2000-01-31 CA CA002356893A patent/CA2356893A1/en not_active Abandoned
  • 2000-01-31 EP EP00906822A patent/EP1181139A1/en not_active Withdrawn
• 2001
  • 2001-07-30 NO NO20013729A patent/NO20013729L/no not_active Application Discontinuation

Patent Citations (2)

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