Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B5/00—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts
  • B32B5/22—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by the presence of two or more layers which are next to each other and are fibrous, filamentary, formed of particles or foamed
  • B32B5/24—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by the presence of two or more layers which are next to each other and are fibrous, filamentary, formed of particles or foamed one layer being a fibrous or filamentary layer
  • B32B5/26—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by the presence of two or more layers which are next to each other and are fibrous, filamentary, formed of particles or foamed one layer being a fibrous or filamentary layer another layer next to it also being fibrous or filamentary
• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21F—PAPER-MAKING MACHINES; METHODS OF PRODUCING PAPER THEREON
  • D21F1/00—Wet end of machines for making continuous webs of paper
  • D21F1/0027—Screen-cloths
  • D21F1/0063—Perforated sheets
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B3/00—Layered products comprising a layer with external or internal discontinuities or unevennesses, or a layer of non-planar shape; Layered products comprising a layer having particular features of form
  • B32B3/26—Layered products comprising a layer with external or internal discontinuities or unevennesses, or a layer of non-planar shape; Layered products comprising a layer having particular features of form characterised by a particular shape of the outline of the cross-section of a continuous layer; characterised by a layer with cavities or internal voids ; characterised by an apertured layer
  • B32B3/266—Layered products comprising a layer with external or internal discontinuities or unevennesses, or a layer of non-planar shape; Layered products comprising a layer having particular features of form characterised by a particular shape of the outline of the cross-section of a continuous layer; characterised by a layer with cavities or internal voids ; characterised by an apertured layer characterised by an apertured layer, the apertures going through the whole thickness of the layer, e.g. expanded metal, perforated layer, slit layer regular cells B32B3/12
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B5/00—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts
  • B32B5/02—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by structural features of a fibrous or filamentary layer
  • B32B5/06—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by structural features of a fibrous or filamentary layer characterised by a fibrous or filamentary layer mechanically connected, e.g. by needling to another layer, e.g. of fibres, of paper
• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21F—PAPER-MAKING MACHINES; METHODS OF PRODUCING PAPER THEREON
  • D21F7/00—Other details of machines for making continuous webs of paper
  • D21F7/08—Felts
  • D21F7/083—Multi-layer felts

Definitions

• the invention concerns papermachine clothing, and has particular, though by no means exclusive, reference to clothing for use in the press section of the papermaking machine.
• press felts comprise a woven base cloth providing adequate strength in the running direction of the felt and one or more compressible fibre layers applied thereto as, for example, by needling.
• Base cloths of the conventional kind are expensive in manufacture and, furthermore, can give rise to the incidence of marking of the paper as it passes through the press section of the papermaking machine due to the presence of knuckles formed at the cross-over points of the warp and weft yarns which form the base cloth.
• the primary object of the invention is to provide an alternative to the woven base cloth conventionally used in producing papermachine clothing which avoids, at least in part, the disadvantages inherent in known structures.
• a non-woven base cloth for use in producing papermachine clothing, the base cloth comprising plural superimposed layers of a synthetic thermoplastics material provided in mesh form, one at least of the mesh layers including load bearing yarns extending in the intended running directior. thereof.
• the base cloth includes two layers each of respective and different mesh size.
• the invention also includes a papermakers fabric comprising a base fabric as aforesaid in combination with a fibrous batt and/or a finely woven fabric at one face at least thereof and secured thereto.
• Fig. 1 is a diagrammatic perspective view of one form of base fabric constructed in accordance with the invention
• Figs. 2 and 3 are enlarged sections taken on lines II-II and III-III, respectively of Fig. 1;
• Fig. 4 is a view corresponding to Fig. 1 and shows an alternative relative alignment of the mesh layers of the base fabric
• Fig. 5 shows, in diagrammatic manner, a typical cross-section through a press felt incorporating the base fabric of the invention.
• a base fabric for use in the production of a press felt for a papermaking machine comprises a first mesh layer 11 and a second mesh layer 12 secured together in superimposed disposition.
• Mesh layer 11 presents longitudinally extending land areas 13 and transversely extending land areas 14, to give rectangular mesh openings 15 of a first size, land areas 13 including yarns 16 to provide load bearing yarns in the intended running direction of the press felt.
• Mesh layer 12 has longitudinally extending land areas 17 and transversely extending land areas 18, the mesh opening 19 also being of rectangular form but being of a second size ess than that of the openings 15 of mesh layer 11.
• longitudinal land areas 17 also include reinforcing yarns 21, the presence of such yarns is not essential .
• the mesh openings 15 of mesh layer 11 will measure 5mm x 1mm, whilst those of mesh layer 12 will measure 2mm x 0.5 mm, the two layers being 1.5 mm and 1.0 mm thick, respectively, and the upper layer serving to diffuse water present in the fabric and thereby reduce the incidence of shadow marking of the paper sheet.
• the apertures need not, of course, be of rectangular configuration, and the mesh layer having the larger apertures may lie above or below the other mesh layer as preferred.
• the preferred material for the matrix of the mesh layers is thermoplastic polyurethane (typically that sold by B.F. Goodrich under reference 58810) , whilst the reinforcing yarns of layers 11 and 12 may comprise any monofilament or multifilament yarn having good bonding characteristics ir. relation to the matrix material and physical characteristics appropriate to the context, and will typically be of 0.5 irur and 0.2 mm diameter, respectively.
• the mesh layers are conveniently manufactured in accordance with the method described and claimed in GB-A-2202873, although other methods may be preferred, such as, for example, a powder dispersal technique.
• the two mesh layers will ordinarily be secured together by thermal fusion of the abutting surfaces in conventional manner. However, it may be preferred, in some instances to join the fabrics by means of an adhesive or by ultrasonic welding or by applying a batt of fibres to the superimposed layers and needling such fibres into and through the layers.
• the longitudinal axis 22 of the mesh openings 19 is inclined with respect to the corresponding axis 23 of openings 15 of mesh 11, the individual mesh layers being of like kind to those shown in Figs. 1 to 3.
• the preferred angle of inclination shown is 45°as shown, but other bias angles may be used if desired.
• the base fabrics as shown in the drawings will be provided with a fibrous batt of conventional form an materials.
• the batt may be subjected to pre-consolidation if desired, and is secured to the base fabric by thermal bonding, by an adhesive, ultrasonic welding or by needling.
• the fibres in the batt will be randomly orientated, but, in some circumstances length orientation may be preferred.
• the batt may be built up in situ on the base fabric by means of a melt-blown technique wherein fibres are extruded onto the moving base fabric and, by virtue of their semi-molten state, adhere at their boundary surfaces to the base fabric and/or to any previously applied fibre layer.
• the degree of fineness of the fibres may be varied during batt build-up according to the specific requirements of the press felt. It is to be appreciated that spun laced, spun bonded or other non-woven web creating techniques may also be used to create the batt.
• the press felt as above proposed is of open-ended form and the ends thereof may be joined, for example, by forming loops at the ends of the coarser mesh layer in accordance with the procedures proposed in GB-A-2231838, the loops being intended to receive a pintle wire on interdigitation of loops at the respective ends, the ends of the finer mesh layer being simply brought into abutment.
• the fibrous batt whether previously formed or built-up in situ will extend across the line of join and, if necessary, can be cut transversely of the press felt in register or offset disposition with respect to the line of join, as is proposed, for example, in GB-A-223152 .
• the felt may be of endless form.
• the weight of batt applied may be reduced as compared with that necessary to avoid the incidence of marking in the context of a fabric embodying a woven base.
• the surface of the overlying mesh could be of ribbed configuration, as would be the case if the base fabric were to be embodied in a marking felt.
• the overlying mesh would be formed with knuckles, (and if required ribs,) to provide localised pressure points to encourage bonding between the successive fibre cement layers.

Landscapes

• Paper (AREA)
• Nonwoven Fabrics (AREA)
• Woven Fabrics (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=10692687

Family Applications (1)

Country Status (12)

Families Citing this family (52)

Family Cites Families (5)

• 1991
  • 1991-04-05 GB GB919107166A patent/GB9107166D0/en active Pending
• 1992
  • 1992-03-24 WO PCT/GB1992/000541 patent/WO1992017643A1/en not_active Application Discontinuation
  • 1992-03-24 CA CA002108043A patent/CA2108043A1/en not_active Abandoned
  • 1992-03-24 BR BR9205837A patent/BR9205837A/pt not_active Application Discontinuation
  • 1992-03-24 JP JP4506922A patent/JPH06509395A/ja active Pending
  • 1992-03-24 AU AU14317/92A patent/AU651879B2/en not_active Ceased
  • 1992-03-24 GB GB9206527A patent/GB2254288B/en not_active Expired - Fee Related
  • 1992-03-24 EP EP92907332A patent/EP0578678A1/en not_active Withdrawn
  • 1992-03-30 NZ NZ242165A patent/NZ242165A/xx unknown
  • 1992-03-31 ZA ZA922340A patent/ZA922340B/xx unknown
  • 1992-04-02 TW TW081102572A patent/TW211597B/zh active
  • 1992-04-03 MX MX9201549A patent/MX9201549A/es unknown
• 1993
  • 1993-10-04 FI FI934358A patent/FI934358A/fi not_active Application Discontinuation

Non-Patent Citations (1)

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