FR2508771A1 - FILTERS FOR CIGARETTE SMOKE - Google Patents

Abstract

THE INVENTION RELATES TO A FILTER FOR CIGARETTE SMOKE. THE FILTER INCLUDES AN AXIALLY ELONGATED FILTER CORE 2 AND AROUND WHICH IS FIXED AN ENVELOPE 3 IN THE FORM OF A LAMINATED PRODUCT FORM OF PAPER 22 THERMOPLASTIC SYNTHETIC MATERIAL 20 PAPER 22. THE ENVELOPE CAN BE PROVIDED BY EMBOSSING WITH LONGITUS-LEVEL CORRUGATIONS 5 THE SURFACE OF THE CORE, THE THERMOPLASTIC SYNTHETIC MATERIAL IS PREFERABLY A POLYOLEFIN, SUCH AS POLYETHYLENE. APPLICATION TO THE FIELD OF MANUFACTURING CIGARETTES.

Description

-1 22508771

  The present invention relates to filters for tobacco smoke and relates to use as a stem casing

  of a laminated product made of paper / thermo

  The invention therefore relates to a tobacco smoke filter comprising an axially elongate filter core and an envelope formed of said laminate product which is attached thereto.

said core.

  The synthetic thermoplastic material involved in the laminated product is advantageously a polyolefin, preferably

polyethylene.

  The wrapping material used according to X la

  The present invention has a particularly advantageous combination

  desirable properties because it can be conveniently

  demented in position by means of a bonded lap joint, that it is intrinsically highly impermeable to air and smoke and that it has a good permanent embossing characteristic, with preservation of this impermeability. known envelopes have a maximum of two properties

  The wrapping material conforming to the present invention

  tion is therefore particularly advantageous to use in

  the production of filter rods with longitudinal passages

  peripheral dinals; the wrapping material can be pre-

  embossed to the necessary configuration for example it may be provided with grooves or corrugations extending longitudinally and which may be continuous or well spaced from each other by regions (for example not embossed or embossed with corrugations

  Lateral grooves or corrugations terminate

  Then, it is wrapped around an axially elongated filter core member and is secured with a glued lap joint. The embossed envelope therefore creates the necessary external impervious grooves. In some cases, for example when the embossed envelope is placed around a filter core consisting of filaments or plasticized cellulose acetate fibers when the latter are not completely cooked or hardened, the profile of the embossed envelope can be printed by itself in the filtering kernel so that both parties have profiles that basically marry completely in

  in other cases, when the core is harder at the moment of wrapping

  There is little or no adaptation of the periphery of the core to the profile of the envelope so that internal channels are also left between the core and the envelope.

  for the laminate wrapping product of other gauze profiles

  frage; for example, embossing grooves can be made by

  circumferentially pitted, longitudinally overlapping and of finite lengths, or the grooves or corrugations may be replaced by striated regions so as to form in fact outside the wrapped core a network of passages or channels

interconnected.

  The different embossing profiles of the laminate product

  envelopes are conveniently obtained by passing the enven-

  Smooth loppe between heated and cooperating embossing rollers that have the necessary surface configuration, preheating the smooth casing being sometimes advantageous for softening the thermoplastic layer.

  Filter rods using the laminated envelope

  in accordance with the present invention may be provided with an outer envelope which is in contact with the periphery of the embossed envelope; this outer envelope can be put

  in a continuous phase in the production process.

  filter immediately after placement of the embossed laminate envelope, or it may be constituted by a cape cap used to attach the individual filter element with a wrapped tobacco rod during the production of a filter layer. filter cigarette; in either case, the outer casing may be formed of a material intrinsically permeable to air and / or perforated so as to create an external air flow passage through the outer casing. outer shell into the grooves or

  external passages formed by the embossed envelope.

  The laminated envelope may, however, also be used in its smooth, non-embossed condition; be smooth

  embossed, it can be provided, for applications and structural

  Because the laminate envelope is perforated or unperforated, smooth or embossed, the filter core around which it is wound may be formed of any of a plurality of filter elements, perforations, either uniformly or in limited locations. wide range of materials and structures It may itself consist of a wrapped or non-wrapped body, the core filter material may comprise fibers or filaments

  unbound, for example, cellulose acetate fibers,

  agglomerated creped stone, etc .; the kernel can understand a structure

  composite formed of pads placed end-to-end or spaced longitudinally

  dinalement and formed of identical or different materials; the

  The core may have additive particles uniformly

  persed in it or located in spaced pockets or spaces between buffers; the core may comprise a profiled periphery (for example longitudinally grooved), and it may be provided with internal passages or cavities which may or may not be filled, the laminated envelope may surround a cavity or recess

  opening at one end of the filter and, in a filter cigarette,

  be, such a recess or cavity can be placed against the stem of

  tobacco or exposed to the buccal end.

  A type of laminate product suitable for use in accordance with the present invention is formed by extruding a sheet of the synthetic thermoplastic material and applying paper sheets on either side of the extrudate and then

  by bonding said sheets with this extrudate while the material is

  A suitable laminate product which has been obtained in this manner comprises a polyethylene core layer weighing 10 g / m 2 and having coating layers formed of a vitrified paper machine and

  each having a weight of 25 g / m Another type of

  adapted for use in the present invention.

  carries a layer of synthetic thermoplastic material which is adhesively secured to the coating paper; this layered product is again provided with a layer of polyethylene of a weight of g / m 2 on each side of which is fixed by gluing a layer of creped paper, one of the layers of paper having a weight of 25 g / m 2

  and the other a weight of 35 g / m 2 Although the laminate product used

  according to the present invention usually consists of a single layer of synthetic thermoplastic material on one or the other side a single layer of paper, it is obvious

  that the laminated product could have additional layers

  between the layers of liner paper.

  A filter in accordance with the invention has been shown in perspective view in FIG. 1, this filter comprising a core 2 formed of a bundle of cellulose acetate filaments laminated and bonded together, this bundle being surrounded by an impermeable envelope

  The latter consists of a layer of polyethylene

  a low density, 10 g / m 2 weight which is fixed on respective coating layers formed of 25 g / m 2 weight-per-gram paper and is provided by corrugation of corrugations. Extending longitudinally and extending from one end of the filter to terminate in a smooth, non-embossed zone

  6 provided at the other end of the filter The undulations 5 of the

  Veloppe 3 print themselves in the surface of the core 2 so that the latter and the envelope have mutually matching profiles. The filter has been shown attached to a wrapped tobacco rod 10. using a cap cloak 4 which has ventilation perforations 12 in coincidence with the

  channels 14 which are formed between the corrugations 5 and the cape of em-

  end 4, said channels 14 being open at the mouth end 8 of the filter and ending at a short distance from the end 7 of the stem

  of tobacco where they join the smooth envelope part 6.

  Figure 2, which is a fragmentary view of the end

  mouth of the filter in Figure 1, shows more clearly the structure of

  envelope 3 comprising the polyethylene layer 20 and

  two layers of liner paper 22.

Claims (5)

  A filter for tobacco smoke, characterized in that it comprises an axially elongated filter core around which is fixed an envelope formed of a laminate product made of paper / synthetic thermoplastic material / paper. 2 Filter according to claim 1, characterized in that the thermoplastic material 3 Filter according to the thermoplastic material 4 Filter according to said envelope comprises on at least a portion of filter according to said envelope comprises on at least a part of the la la of his   synthesis comprises a polyolefin.   claim 2, characterized in that synthesis comprises polyethylene.   claim 1, characterized in that longitudinal longitudinal passages length. claim 4, characterized in that longitudinal grooves or corrugations 1 length.   Filter according to one of Claims 1 to 5,   characterized in that the periphery of the core matches the profile of the inner surface of the envelope.   Filter according to claim 4, characterized in that   has an outer shell formed of a tip material as   on the passage of outside air laterally through the-   said material in said passages.   Filter according to claim 7, characterized in that   said tip material comprises a tip cap ensuring the incor-   poration of said filter to a filter cigarette.