MXPA00005523A - Tampon for feminine hygiene or medical purposes and process for producing the same - Google Patents

Abstract

A tampon for feminine hygiene or medical purposes comprising a nonwoven cover having at least one, outwardly directed, smooth surface and substantially enclosing a liquid absorbing core wherein the nonwoven cover comprises atleast partly thermoplastic, heat-sealable fibers and pressed to the final shape of the tampon. Before the tampon blank is covered with the nonwoven covering web, said web was subject to the use of heat and pressure during the manufacturing of the tampon as to smooth out at least the outer surface of the nonwoven covering web, whilst maintaining the structure of the nonwoven covering web and the absorbency of the tampon. Thereby, it is achieved that the tampon can also be more easily and more comfortably introduced into and withdrawn from a body cavity before and after the days of stronger menstruation or at the occurrence of only less vaginal exudation as garment protection.

Description

TAMPON FOR FEMALE HYGIENE OR MEDICAL PURPOSES AND PROCEDURE TO PRODUCE THE SAME DESCRIPTIVE MEMORY The invention relates to a tampon for feminine hygiene or medical purposes and to a process for producing the same. The tampon, which is suitable for mass production, comprises a compressible tampon preform of liquid absorption material and at least one partial cover for the latter made of a liquid permeable nonwoven material made of at least partially thermoplastic fibers, Sealable with heat, and pressed into the final shape of the tampon. The buffers of said generic type are described in the patents of E.U.A. 4,816,100, 4,859,273, 4,863,450 and 5,004,467. Buffers usually contain hydrophilic materials in the form of fibers or foams and are compressed in a generally cylindrical form. It is known that the insertion of said structure into the vagina is often difficult and uncomfortable due to the hardness and dryness of the surface texture of the absorbent core. If the absorbent core is also composed of fibrous materials, the fibers have a tendency to separate during insertion and removal of the tampon in and from the body. The problems associated with the insertion can be resolved to some degree by the use of an applicator for plugs that provide for this one; however, the use of the applicators does not solve the problems associated with fiber loss or when the tampon is removed. EP-B 0 149 155 and GB-B 1 218 641 relate to the use of a liquid-permeable coating layer, which comprises the absorbent core and reduces fiber loss. In addition, the coating layer can reduce the friction of the surface by the absorption core coating located below it, and can contribute to a more pleasant insertion and removal of the tampon. Normally, the outer coating layer is made of a non-woven material, which has an essentially open structure, permeable to liquid and which is easier to produce (EP 0 149 155). Recently the coating layer materials have been developed in several cases, in particular with regard to the improvement of the insertion properties, for example, the cover consists of polypropylene (PP), which is described in US-B 3,683,912, or the powder bound material in Australian patent 74346/91. In addition, it has been established that similar advantages can be achieved using materials other than nonwovens, such as network structures, which are described in the U.S. patent. 5,374,258. In a similar manner, examples are provided of coating layer or wrapping materials that have been developed in order to facilitate the removal of the tampon. The absorbent core of the tampon is responsible for the creation of a high capillary suction in the vagina, as a result of which the removal of the tampon is often difficult and is unpleasant. Coating layers serving for easier removal solve said problem by methods of reducing suction action, such as a more effective coating of the absorbent core, such as for the double-wrapped buffer described in the US patent. 4,305,391, or by retaining the liquid in the fibers of the coating layer in order to maintain a smooth and flexible surface, as in the U.S. patent. 4,056,103. The present invention relates to a buffer and methods for its production and is based on characteristics in the pre-characterization clause of patent claim 1, which are contained in the specifications of the US patent. 4,816,100, 4,859,273, 4,863,450 and 5,004,467. The tampon according to the invention is therefore composed of a non-woven fiber absorbent body of a liquid-permeable coating material, thermoplastic that at least partially covers the latter and that is pressed radially until the final form of buffer. The coating material is adjusted with the absorption body, and the overall structure is rewound to form the so-called buffer preform. The preform is pressed radially and a sharp taper is formed at the insertion end, in order to impart the final shape to the tampon. Thermoplastic, non-woven materials are often the desired material for tampon coatings, since they can easily be secured to the tampon during production by the application of heat and / or pressure (U.S. Patent 4,863,450). Nonwoven materials that are produced from bicomponent fibers are particularly suitable for said process, since the polymer having the lower melting point, which forms a component of the fiber (often about 50% of the total fiber) in the form of a coating layer), it is fused, in order to form an assurance for the substrate that is below it, although the component having a higher melting point (often the fiber core) maintains its physical characteristic, in order to maintain the integrity of the coating. The invention is based on the objective of improving a tampon, which is at least partially surrounded by a nonwoven covering tape, so that, even before and after a few days of relatively heavy menstruation, or in the If only light vaginal discharges occur, it can be inserted more easily and more pleasantly, as a lingerie protection, into a body cavity and can also be removed again from said cavity. The invention achieves said objective by means of the features contained in claim 1. The invention also relates to a process for producing said buffer according to claim 6. It is established that the smoothing of the total or partially thermoplastic coating network, non-woven by calendering under the influence of heat and pressure, said softening being integrated in the continuous mass production of tampons, provides a unique opportunity, without punishments in terms of production speed, to adapt the smoothing of the network of non-woven cover, through extremely fine control, for the respective buffer that is going to produce and to optimize said smoothing from the point of view of availability, quality and quality control, waste reduction and availability requirements, for example from the point of view of necessary corrections for the dimensions. Non-woven materials consisting of bicomponent fibers, or uniform non-woven materials that are composed of a combination of fiber types having considerably different melting points and cross-sectional shapes, and which have been previously bonded by calendering through a process such as laying in air or in thermal bonding, or supplied as a network not attached directly from a carder, which can pass through the space in a calendering unit during continuous mass production of buffers, said calendering unit being composed of two soft rollers that apply pressure and temperature below melting point to the fiber component having the lower melting point. The resulting material is a very smooth and smooth product, which not only provides the facility described during insertion, by abrading and removing the tampon, but also has a pleasing appearance. Advantageous developments of the invention are contained in the subclaims. The exemplary embodiments of the buffer and methods for its production are described in more detail below with reference to the apparatus schematically illustrated in the drawings, in which: Figure 1 shows electron microscope images of the structure of a non-coating network. woven for a tampon according to the invention, in several enlargements; Figures 2 to 4 show diagrams illustrating properties of buffers with calendered nonwoven coating network; Figure 5 shows a graphic illustration of comparative values of capillary pressures for buffers with calendered or uncalendered nonwoven cover networks; Figures 6 to 11 show steps in a process for the production of a first buffer according to the invention; Figure 12 shows a first embodiment of an apparatus for the production of a first tampon according to the invention in a diagrammatic view, with which the tampons of the apparatus can be produced with a coating; Figure 13 shows a perspective view of a second embodiment of a tampon shape having a nonwoven covering network section surrounding said preform; Fig. 14 shows an enlarged view of the nonwoven covering network section before a (turned) edge is folded; Fig. 15 shows an enlarged view of the tampon preform and the nonwoven covering network section in Fig. 14 before the recovery cord is placed; Figure 16 shows a scanned drawing of an apparatus for the production of a second embodiment of a tampon according to the invention, having a network section of non-woven coating made of liquid-permeable material, on which one side is disposed a buffer preform and on the other side a bending die plate. The invention relates generally to a tampon for feminine hygiene or medical purposes comprising a nonwoven cover having at least one smooth surface facing outwards and substantially covering a liquid absorption core wherein the nonwoven cover comprises fibers at least partially thermoplastic, heat sealable, the outwardly directed surface of the nonwoven cover has a coefficient of static friction of less than 0.4. The present invention also relates generally to a process for producing a tampon for feminine hygiene or medical purposes comprising the following steps: a) continuously supplying a continuous tornado of liquid absorption made of a mixture of natural and / or artificial fibers, the The width of the twist corresponds approximately to the length of the finished tampon; b) subdivide the twine into strips of equal lengths, which are suitable for the production of tampons; c) continuously supplying a continuous, nonwoven web, which is at least partially composed of thermoplastic fibers and having an essentially open structure, permeable to liquid; d) cutting the non-woven cover network into non-woven cover network sections; e) forming each of the twines in an approximately cylindrical tampon preform with / without the nonwoven covering net section forming at least partially an outer side; f) compressing the tampon preform, together with the nonwoven covering network section which at least partially surrounds its surface, radially relative to its main axis, in the final shape of the tampon. Said method according to the invention is characterized in that the network of non-woven covering supplied in a continuous manner, prior to its cutting into individual network sections, is subjected to a treatment involving heat and pressure, in such a way that at least The outer surface of the non-woven cover network, which surrounds at least a significant portion of the surface of the tampon, is smoothed while maintaining the characteristics of the non-woven cover network and the absorption capacity of the tampon. The following information articles, which support the invention, were secured using calendered coatings which are composed of bicomponent fibers of the PE / PET coating / core type, for which the precursor materials were materials of Non-woven covering laid in air. Additionally, the fibers of the nonwoven coating to be used can be randomly oriented. The electron microscope images in Figure 1 of a material based on bicomponent fibers show that the outer layers of the lower fusion polymer of the bicomponent fibers are plasticized by the process, so that the adjacent fibers are screened at each of their points of crossing, and in this way the open regions of the material are maintained in the largest extent after the fibers are solidified by cooling. The softening of the loose fibers, the compression to a common thickness and the filling of the open regions contribute to the fact that the characteristics of the surface differ considerably from the original material. Securing the nonwoven coating network for the tampon is still possible because the low melting point component is present and, after the final product has been produced, an extremely soft and flexible surface results. It is preferred that the physical properties of the calendered material be optimized, in order to produce the best possible balance for the effectiveness of the buffer. If the base weight is very low, there are large open regions between the calendered regions, which reduces the continuity of the surface, therefore reducing the soft feel of the tampon. On the other hand, if the base weight is very high, the open region is closed by calendering, the The permeability of the coating is reduced and, as a result, the absorption capacity of the tampon is restricted. For the PE / PET system, a calendering temperature between 70-120 ° C and a pressure of 0.2 to 2.5 bar is necessary at a speed of 8-12 m / min in order to achieve smoothness. The preferred operating conditions are given by 80-85 ° C, a pressure of 0.5 bar and a speed of 10 m / min. The melting point of PE in this system is 130 ° C. Figure 2 shows that the basis weight scale for the primary materials is 14-17 g / m2, and the thickness of the primary materials is about 0.4 mm or greater for four stacked layers of the material. The passage of the primary materials through the space of a softening calender produces a material of consistent thickness of less than about 0.3 mm for four stacked layers of the material, regardless of their initial basis weight. Preferably, the thickness of four stacked layers of the material is less than about 0.2 mm. As a result, the density increases and the open region is reduced at the same time in proportion to an increase in the basis weight of the primary material. The softness of said materials was measured by reference to the coefficients of friction (Figure 3). The smooth and rough sides of the original web laid in air were calendered in the same way, in order to provide considerably lower frictional properties. A coefficient of friction of 0.2 corresponds to the known value for pure PE, and said value it probably constitutes the maximum theoretical smoothness of said material based on PE / PET, without changing the final quality and / or quantity of the fibers. It can be seen from Figure 3 that the basis weight of 8.5 g / m2 results in a supe being restricted to a rougher surface, due to the very open property of the network. It is obvious that the use of a basis weight of more than 13.5 g / m2 almost does not provide any advantage, since said value provides the theoretical maximum softness for said system. Figure 4 shows a comparison between penetration periods for primary networks and calendered networks, using an artificial and high viscosity substitute menstrual fluid. The calendering seems to substantially increase the liquid collection period, but according to Figure 5, the capillary suction force appears to increase significantly. The capillary suction force can be measured according to the procedure described in EP 0 685 215. Said data, in conjunction, suggest that while the calendering forces reduce the size of the open area of the cover material, the effective pore size The material is also reduced. The above seems to divert the possible losses in the periods of liquid penetration and in use it seems to have no importance in the runoff of the buffer and other related performance criteria. The data on the capillary forces shown in Figure 5 lead to suppose that the calendering reinforces the capillary suction force. Obviously, the calendered coating layers show higher suction forces than the original non-woven materials (black symbols) compared to white symbols). Therefore, the calendering process not only reduces the size of the open region, but also reduces the effective pore size in the nonwoven material. In tests that were carried out with artificial menstrual fluid, an increase in the capillary pressure that was exerted by the calendered material was observed in comparison with the materials without calendering, analogous. Said effect shifts the loss in open regions in the material, and it can not be observed that the absorption behavior of the buffer is negatively influenced.

Absorptive capacity The values for the absorption capacity of the buffer according to the invention listed below were ascertained in a test unit, which is described in European Patent No. 0 422 550 B1.

Coefficient of friction The coefficient of static friction between two identical nonwoven coating materials was determined with a static friction test instrument generally in accordance with the procedure described in ASTM D4918-95. A polished metal block, which is coated with the nonwoven coating material, is placed on an inclined surface, in which the nonwoven coating material is stretched. The coefficient of friction is ensured from the tangent of the angle of inclination at which the metal block begins to move. Preferably, the material has a coefficient of static friction of less than about 0.4, more preferably, less than about 0.3, and more preferably, less than about 0.26.

As indicated above, the bicomponent polyethylene / poly ester LD material that is preferably used has a weight of 11-17 g / m2, preferably 14 g / m2. The peel strength of the nonwoven coating material in the longitudinal direction is < 19 N / 39 mm or < 20 N / 45 mm. The elongation at the break in the longitudinal direction is < 55%. The sealing temperature of the non-woven material is 120-140 ° C. A preferred embodiment of the buffer according to the invention and specified above will now be described with reference to figures 6 to 14: in figure 11 there is shown a tampon 10 for feminine hygiene, which consists of a section 11 of specific length, which can be seen in figure 8 , of a calendered twine, which is composed of a mixture of natural and thermoplastic bicomponent fibers (Figures 6-9). The fiber blend preferably comprises 75% rayon fibers with an irregular cross section, preferably multi-arm or star-shaped, for example three arms, which have an adequately greater flexural strength and 25% rayon fibers standards The twine 30 has a width corresponding approximately to the length of the tampon 10. The twist section 11 is wound essentially in itself about an axis that is located transversely in its longitudinal direction and outside the longitudinal center of the twist section 11. , to form a tampon preform 12, and at the same time is provided with a recovery cord 13. The tampon preform 12 is pressed, essentially radially in relation to the winding axis, in the final form of tampon 10. the pressure, the buffer 10 is provided with 8 pressure notches, which are distributed over identical circumferential angles. An insertion end 10a of the tampon 10 is designed as a tapered shape 10b tapering sharply to a point, the shape of which is compared to the tip of a bullet. Other forms of buffer, including those described in EP 0 149 155 may also be used in this invention. According to Figure 7, a section of coating network Non-woven 15 made of a material permeable to thermoplastic liquid is sealed in said part of the twist section 11 which forms the circumferential surface of the tampon 10, using heat and pressure, however said section of non-woven coating net 15 is larger that the tampon preform 12. According to the invention, said non-woven web network section 15 is provided on both sides with an extremely smooth surface as a result of the additional calendering operation mentioned above. The softness of the outer surface of the fiction nonwoven web 15 serves the purpose of carrying out the insertion of the tampon into the body cavity more easily, even after the heaviest menstruation. Figures 7 to 9 show that the thermoplastic nonwoven web network section 15 is firmly connected to the twist 30, preferably by parallel welding lines 79 spaced apart from each other., said welding lines form an acute angle with the longitudinal direction of the twist 30. The distances between the individual welding lines 79 are such that, between the welding line 79, a liquid-permeable material of the coating network section does not woven 15 is found closely in the twine material. Other joining patterns, such as discontinuous points, etc., can also be used. The above ensures that the liquid that reaches the network section of non-woven coating 15 on the circumferential surface of the tampon is stretched immediately inside the tampon as a result of the capillary action of the fiber material in the woven taper section 11 located at the bottom. If appropriate, it is possible for the network section of non-woven cover 15 to be applied in the same way to the twine 30 with needle or securing thereto, for example by mechanical means or adhesives. The outer end 15a of the non-woven cover net section 15 extends beyond the outer end 11a of the twist section 11 and is welded using heat and pressure to the outer portion of a portion of the non-woven cover section. woven 15 which is sealed in the twist section 11. It can be seen that the liquid-permeable non-woven non-woven web section 15 is preferably narrower than the width of the twist section 11, but it flows with the edge longitudinal 11 b of the twist section 11 which forms the recovery end 10c of the tampon 10. The longitudinal edge 11c of the twist section 11 forming the insertion endOa of the tampon 10 projects over the associated edge 15c of the section protected coating 15 permeable to the thermoplastic liquid at a width corresponding approximately to the altitude of the tapered shape 10b, reaching a point, in the buffer 10 in the former insertion 10a. The liquid permeable nonwoven cover network 32 (Figure 2) is composed at least predominantly of nonwoven thermoplastic fiber material which is preferably produced from a bicomponent fiber, whose components consist, for example, of a polyester core and a HD polyethylene cover. Other materials can also be used such as other forms of polyethylene, polypropylene, ethylene-vinyl acetate and other copolymers, as well as relatively low melting point materials. It is particularly advantageous if the high pressure polyethylene has a lower melting point than polyester. Since the outer free end 15a of the thermoplastic nonwoven web network section 15 is welded to the outside of said longitudinal section of the nonwoven web section 15 which is sealed in the twist section 11, in the circumferential direction of the tampon preform 12, the nonwoven covering network section 15 forms a firmly connecting liner connecting to the latter and whose outer diameter corresponds to that of the tampon preform. A preferred process for the production of the tampon described above comprises the following steps, which are described below with reference to figures 6 to 14: According to figure 6, a calendered twister 30, which consists of a mixture of Natural or cellulose fibers which preferably have an irregular cross-section, for example having a plurality of arms, and having a width corresponding to the length of the tampon 10, are supplied continuously. The twine 30 is weakened transversely to its longitudinal direction, in each case by the so-called weakening points 31, for example when drilled, between sections 11 and a length that is necessary for the production of the tampon.

. Said weakening is additionally achieved by stretching the twine 30, so that there is a thinning of the twine 30 or a reduction in its cross section, but which does not affect the twine 30, in the stretched zone or in the weak point 31. torzal 30 moves continuously in the direction of the arrow x. At about the same time, a network of non-woven coating 32 supplied in a continuous manner (Figure 12) made of thermoplastic, liquid-permeable, non-woven coating network, which according to the invention has been subjected to calendering involving the application of pressure and heat, is cut in each case in a network section of non-woven coating 15, whose length exceeds the circumference of the tampon preform 12 shown in Figure 10. The liquid-permeable coating network section, non-woven thermoplastic 15 is then secured, for example, by sealing or needle, on the outside of a region of the twine 30 which is located at the rear in the direction of movement x of the twine 30 and opposite a weak point 31, exerting heat and pressure along the parallel welding lines 79 which run obliquely relative to the longitudinal direction of the twist 30. The arrangement of the non-woven covering network section 15 on the upper side of the twist 30 it is provided in this case so that the end 15a of the non-woven cover network section 15 which is on the outside and on the rear part in the direction of movement x of the twine 30 (figure 8) extends freely, that is to say without sealing, beyond the weak point 31 in the torzal 30. The Twister 30 is then cut at the weak point 31, so that the twist section 11 is produced. The twist section 11 is then wound essentially on itself, according to Figure 9, to form a tampon preform 12, which is shown in figure 10, about an axis running transversely with respect to its longitudinal direction and is represented in figure 8 by a winding mandrel 33. The winding of the twist section 11 is carried out in such a so that, in the circumferential direction of the tampon blank 12, one end 11a of the outer layer of the wound twist section 11 overlaps the other end 11d (see FIGS. 8 and 10) of the twisted yarn section layer 11 which is located below. By the above, a more uniform material distribution is achieved in the outer circumference of the tampon preform 12 and, consequently, an essentially cylindrical shape thereof. As can be seen in Figure 10, the length of the thermoplastic coating network section permeable to the nonwoven liquid 15 is such that the latter completely covers the circumference of the tampon preform 12 to the intended width, the free end or unsealed 15a is still initially projected on the outside. The winding operation is now completed by said unsealed free end 15a of the non-woven cover network section 15 being welded, with the application of heat and pressure, in said portion, adjacent to the circumferential direction of the preform. buffer 12 to the outer end of the twist section 11, of the network section of non-woven thermoplastic coating 15 which is sealed in the twist section 11. Since, in the process, the HD polyethylene surfaces of the fused fibers lie one on the other, the sealing pressure does not need to be very high , in order to achieve a good seal, as in the case of pre-sealing the network section of nonwoven coating 15 on the twine 30. According to FIG. 8, before the winding operation, a recovery cord 13 is located around the twist section 11, transversely to the longitudinal direction of the latter, and, if necessary, is subsequently joined at its free end. The buffer preform 12, terminated by winding in a cylindrical shape, is then supplied to a press, which preferably comprises 8 pressure jaws arranged in a star shape, by means of which the buffer preform 12 is pressed essentially radially in the final shape of tampon 10 illustrated in Figure 11. After the above, the insertion end 10a of the tampon is formed into a tapered shape 10b, running to the tip that resembles a bullet or dome, in order to carry out inserting the tampon into the body cavity even more pleasantly. For the current method, it is not significant where and how the retrieval rope 13 is applied in detail and whether the insertion end is dome-shaped or not. It should be mentioned that the length of the network section of non-woven coating 15 depends on the final diameter of the preform of buffer 10. The length of the unsealed free projection end 15a of the nonwoven cover network section 15, which is generally between 20 and 50 mm, also depends on the foregoing. If after observing in Figures 7 to 11 that the outer part of the twine 30 is covered by the liquid-permeable, non-woven, liquid-permeable coating network section 15 to a width extending from the longitudinal end 30b of the twine 30 which form the recovery end 10c of the tampon 10, only near the longitudinal edge 11c of the twist section 11 forming the insertion end 10a of the tampon 10. The longitudinal edge 11c of the twine 30 that is not covered by the network section of thermoplastic non-woven coating 15 is wide enough, so that it can be formed in order to create the tapered or domed shape 10b, running up to a tip, of an insertion end 10a of the tampon 10 following the pressure of the tampon preform 12 in the final shape of the tampon 10 At the same time, it is ensured that the insertion end 10a of the tampon 10, which is free of the non-woven covering network section 15, is directly activated by the body fluid that is taken, and consequently the tampon is able to expand without delay and, as a result, is able to develop its total absorbency and can take on the full protective function for the user. Figure 12 shows an apparatus for producing the tampon by the use of a specific method according to the invention. On the left side of the drawing there is illustrated a calendered twister 30 made from the fiber mixture described above, which is supplied continuously from a supply reel 50, in the direction of movement x, to a weakening station 51. The weakening station 51, which is presided over by a supporting roller 52, comprises, in the direction of movement x of the twine 30, a pair of drilling and clamping rollers 53 and a pair of stretching rollers 54. Although the drilling and clamping rollers 53 hold the twist 30 firmly upwards the rollers of Stretch 54 at the time of stretching, and the stretching rollers 54, with their stretching jaws 54a, perform an acceleration of the twine 30 fastened thereto in the conveying direction x, the twist 30 is thinned or reduced in section transverse in the path between the drilling and clamping rollers 53 and the stretching rollers 54, so that the weak point 31 occurs. Stretch rolls 54, 54a in the lower part of the twist 30 there is a smooth, cylindrical pressure roller 57, which cooperates with an essentially cylindrical sealing or calendering roller 62 on the upper side of the twist movement path 30, and form with said roller 62 a sealing or calendering station 60. The roller 62 can be heated in a suitable manner, for example by electrical resistance heating, and can be controlled in a counter-clockwise direction. It can be seen that, upstream of the sealing station 60 and above the twist 30 and the weakening station 51, a supply reel 66 for a continuous strip 32 of non-component fiber is provided. woven, liquid permeable and thermoplastic, whose basis weight is, for example, 14 g / m2. The non-woven strip is supplied, by means of spring-mounted rotation rollers 67, 67a, to a calendering stack 70 provided according to the invention. The calendering stack comprises two soft, heatable cylindrical pressure rollers 70a, 70b, which act on the nonwoven coating network 32 at a temperature of 70-100 ° C, preferably 80-85 ° C, and a pressure of 0.5 -2.5 bar, in order to provide said network, on the upper side and on the lower side, with a smooth surface structure, corresponding to a significantly reduced coefficient of friction, preferably of 0.2, as equivalent for the known value of pure polytetrafluoroethylene in steel, and shows the maximum theoretical smoothness and smoothness. A cutting station S comprises a pair of transport rollers 68a, 68b, which are disposed above and below the nonwoven cover network 32 and are controlled in opposite directions, and a pair of cutting rollers 69a, 69b , which are arranged after the former, which are controlled in the same way in opposite directions and of which the knife roller 69 is provided on a significant portion of a generatrix with cutters to cut the predominant part of the strip 32. The speed circumferentially of the transport rollers 68a, 68b and the cutting rollers 69a, 69b corresponds approximately to half the transport speed of the twine 30, so that the nonwoven cover network 32 can be continuously stretched from the supply spool 66, at the address of the arrow and at a speed corresponding to the length of the network section of nonwoven coating 15 of the nonwoven material to be applied. The cutting rollers 69a, 69b cut essentially, but not completely, the nonwoven cover network 32 in the transverse direction, so that the nonwoven cover network section 15, which was formed by cutting and running. forward, it is still connected to the next network of non-woven cover by some of the so-called networks. Connected downstream of the cutting station S is a vacuum roller 71. Inside the vacuum roller 71, a slide 219 is arranged., which remains stationary and is provided about 180 ° of its circumference with lateral suction openings (not shown), which make possible a suction action through smaller suction openings 220, adjacent to the previous openings, in the wall circumferential of the vacuum roller 71. The vacuum roller 71 is assigned an acceleration roller 72 of smaller diameter on the upper side, which serves to press the nonwoven covering network against the vacuum roller. The circumferential speed of the vacuum roller 71 and the acceleration roller 72 corresponds to the conveying speed of the twist 30. Therefore, the nonwoven covering network section 15 coming from the cutting station S can be stretched by suction against the circumference of the vacuum roller 71 and, in a stretched position, it can be carried lengthwise in the clockwise direction in the space formed by the vacuum roller 71 with the roller of acceleration 72. As soon as the driving end of the network section of non-woven coating 15 reaches the space between the acceleration roller 72 and the vacuum roller 71, the network section of non-woven coating 15 is accelerated to twice of the speed, that is to say the twist speed, and consequently the next network of non-woven coating 32 is completely turned off in the region of the cutting point that occurred in the cutting station S. The vacuum roller 71 now has the network section of non-woven coating 15 which is joined to its circumference by suction to the space formed by the vacuum roller 71 with the sealing roller 62. Although the vacuum roller 71 touches the sealing roller 62 on its upper side, and at this point the vacuum is blocked in the direction of rotation of the vacuum roller 71, as described below, the thermoplastic nonwoven web network section 15 is carried by adhesion, and heated , at the earliest possible time point by the heated sealing roller 62. Accordingly, the non-woven coating network section 15, as continuous placed in the space between the sealing roller 62 and the vacuum roller 71, when find the surface of the twist 30, has been preheated to such an extent that the lowest melting layer coating of the melting fibers of the non-woven coating network section 15 is fused in the grip region between the roller pressure 57 and the sealing roller 62 and, as a result of the correct setting of pressure and temperature, an intimate connection for the fibers on the surface of the twine 30 occurs.

A pressure roller 57 is immediately connected downwardly of the weakening section 51. Accordingly, only the sealing roller 62 is provided for sealing. The sealing roller 62 has a particular structure which makes it possible to carry out sealing only on a part of the circumference of the sealing roller 62, by means of heatable sealing elements 223, 224, which are disposed diametrically opposite each other in a basic body 222 and are profiled to correspond to the welding or sealing pattern. The circumferential length of the sealing elements 223 and 224 in each case corresponds precisely to the length of a non-woven covering network section 15 to be sealed in the twist section 11. Two unheated insulating elements 225, 226 they are secured to the basic body 222, deviating 90 ° with respect to the diametrically opposed sealing elements 223, 224. The circumferential curves of the insulating elements 225, 226 have the same radius as the outer surfaces of the sealing elements 223, 224 , so that the result is a circumferential surface made of circular sectors of identical radii. The arrangement of the insulating elements 225, 226 ensures that, in each case, the free or unsealed end 15a of the thermoplastic nonwoven web network sections 15 projecting over the sealing elements 223 and 224 in the opposite direction of the direction of rotation of the sealing roller 62 is placed in one of the insulating elements 225, 226 and, consequently, is not sealed to the twist 30. At the level of the sealing roller 62, below the path of twist movement 30, there is a conveyor belt 202, which comprises a large number of front drive pulleys 203 and rear turn pulleys 204, which carry continuous guide webs 205. The guide webs 205 are supported on the upper web by a support roller 206, which is located in opposition to a pressure roller 207 of significantly greater diameter at the upper side of the torsion movement path 30. The support roller 206 and the pressure roller 207 are clamped between yes, so that the twine 30 is held firmly when the twist section 11 located behind it in the direction of movement is removed from the transport system by a transport and a separation pincer mechanism 110 which is provided downwards from the conveyor belt 202. Assigned to the upper path of the guide strips 205 is a pair of tensioning rollers 208, from which the upper path of the guide strips 205 deviates obliquely downwards in the direction towards the rotating pulleys 204. Above the twist movement path 30 is a guide device 209, which likewise comprises a number of rotating pulleys 210, 211, which are axially deflected at a distance from one another in which, in turn, axially deflected, the continuous bands 212 are disposed, each disposed above the guide strips 205 of the lower conveyor belt 202. The front turn pulleys 210 of the rear guide device 209 are located close to behind the pressure roller 207, while the rear rotating pulleys 211 are disposed above the rear rotating pulleys 204 of the conveyor belt 202. In the direction of movement of the twist 30, the guide belts 205 run the belts above. continuous 212 run below the clearance 228, in which the holding pliers 110 can be moved through the opening 83 in a recovery cord attachment and attachment device 90, as will be explained below. The rear turn pulleys 211 and 204 of the upper guide device 209 and the lower conveyor belt 202 are provided, in each case, at 180 °, with radially outwardly projecting guide segments 213 and 214. The guide segments 213 and 214 run synchronously with each other and carry or guide the twine 30. When the transport and separation pliers mechanism 110 is moved, the counter for the transport direction x of the twist 30, in the direction of the space 228 between the pulleys of turn 211 and 204, said mechanism attached to the driving end of the twine 30 and pulls it, at a speed that increases with respect to the speed of transport of the twine, in the active scale of the attachment and attachment device 90 of recovery rope of a winding station 100. Although the pressure roller 207 with the support roller 206 is located at a distance from the space 228 for clamping to the driving end of the torzal 30 by the mechanism or of transport and separation tongs 110, whose distance is greater than the length of the twist section 11, the weak point 31 in the twist 30 is located in each case behind the pressure roller 207 and the support roller 206, with the result of the transport and separation pincer mechanism 110 pulling said twist section 30 extending behind the pressure roller 207, to the weak point 31, and detaching it at the weak point 31. After the section The twine 11 has been separated in this way, guided by the mechanism of transport tongs 110 in the region of the attachment and attachment device 90 of the recovery cord and of the winding station 100. Although the attachment of the cord of Recovery 13 and the joining thereof can be carried out as described below, the winding station 100 is equipped with a winding mandrel 33 (figures 3 and 12), which can be moved axially from back to front and it can be controlled in rotation. In the winding station 100, rub pads 215, 216 are provided to seal the free projection end 15a of the nonwoven cover network section 15 to said portion of the nonwoven cover network section 15 which is secured to the nonwoven cover network section 15. the tampon preform 12. The lower and upper rubbing pads 215, 216 are disposed at a radial distance from the winding mandrel 33, it being preferably possible to heat only the rub pad 215, extending it at an angle of about 190. at 280 ° in the third quadrant of a circle. A heatable sealing element 218 is arranged to move back and forth with respect to the winding mandrel 13 through an opening 217 in the lower rub pad 215, said sealing element being provided in order to seal the the unsealed posterior end 15a of the non-woven cover network section 15 for a portion of the nonwoven cover network section 15 which is secured to the circumference of the tampon preform 12. Since the end face 218a the element 218 is narrow, it is possible to weld the outer edge of the free end 15a of the non-woven cover network section 15 only along a generatrix to the material of the same non-woven cover network section 15 which is secured to the circumference of the tampon blank 12. Cutting rolls 69 cut the nonwoven cover network 32 significantly but not entirely, so that, on each side of said cut the nonwoven covering network 32 remains connected by the material networks (not shown), in a similar manner to the case of a perforation. The acceleration roller 72 arranged downwards is controlled with a rotational speed corresponding to the circumferential speed of the vacuum roller 71 and therefore to the transport speed of the twist 30. If the driving end of the nonwoven covering network 15 is placed on the active scale of the acceleration roller 72, said section of the non-woven covering network 32 which is located upwards from the cutting point is switched off and accelerates to the twist speed in such a way that the network sections of the Individual non-woven shells 15 are guided, at the correct distance respectively from each other, to the conducting end in the direction of rotation of one of the two sealing elements 223, 224.

The nonwoven covering network 32 located downstream of the release point is always softer and is stretched in the transport direction as a result of the suction action of the vacuum roller 71. Because of the extremely low mass of the network section of the separate non-woven coating 15, the latter is accelerated abruptly up to the twist speed, so that an always sharp positioning of the non-woven covering network section 15 on the vacuum roller 71 can be achieved. Figure 13 shows a alternative mode of an assembled tampon 300 before its diameter is reduced to the standard size. This comprises a tampon preform 311 formed cylindrically in an essential way made of gauze, muslin, filling or a similar absorbent material. The tampon preform 311 is covered by a cup-like liner 312, which has an annular rim 312a (Figs. 14 and 15) and extends beyond the corresponding end surface 311c of the tampon preform 311. It can be see in Figures 13 and 15 that the opposite end surface 311 b of the tampon preform 311 is attached to the lower end wall 312b, which resembles a circular area, of the nonwoven cover network 312. outer surface 311a of the cylindrical tampon preform 311 is completely surrounded by a tubular wall 312c, consisting of a number of sections, of the nonwoven covering network 312. In addition, the tampon 310 has a recovery cord 313, the which has an end 313a having the shape of a ring, which is secured to the tampon preform 311 in the region of the end surface 11c, and extends through the tubular wall 312c of the nonwoven covering network 312 and far from the latter. The recovery cord 313 is provided with a knot 313b, the formation of which is described, for example, in the US patent. 4,312,587. The tubular wall 312c of the nonwoven covering net section 312 comprises two essentially semi-cylindrical sheaths or main passages 312d having edge regions 312f which overlap and extend axially parallel to the axis of the cylindrical tampon preform 311 and the nonwoven covering network section 312, from the lower end wall 312b, in the direction of the end surface 311c of the tampon preform 311, and beyond the end surface 311c, in order to form the ring flange 312a. The tubular wall 312c in the nonwoven cover network 312 also comprises two additional sections, essentially concave / convex (hollow raised) 312e, one of which is illustrated in Figure 14, and which alternates with section 312b and extends from the lower end wall 312b in the direction of the end surface 311c. When the formation of a polygonal, preferably rectangular, non-woven cover network section 412 (FIG. 16) of liquid-permeable nonwoven cover network material is finished, an annular flange 412a is bent over the end surface 311c of the tampon preform 311, in the direction indicated by the date 312g in Figure 16, so that the cup covers the end surface 311 b, the total circumferential surface 311a and to a lesser extent, preferably at least a larger part , of the end surface 311c of the tampon preform 311, so that the fibers of the latter do not come into contact with the skin or with the tissue of the body cavity into which the finished tampon is inserted, either manually or through a standard applicator. Preferably, a rectangular nonwoven covering network section 412 is used, wherein the length of the two long sides 412c is at least 1.5 times the size of the length of one of the narrow sides 412d. The sides 412c and 412d surround the part 312b of the nonwoven cover network section 412, which for its part surrounds a central part 312a that has a circular area shape. Figure 16 also shows a tubular bending die plate 314, which is used to form the casing 312 in the nonwoven covering network section 312. The die plate 314 is composed of four parts 314a, 314b, 314c, 314d, which form a tubular guide for the tampon preform 311. The inlet for the tubular guide of the die plate 314 is designed as a truncated cone, in order to facilitate the insertion of the tampon preform 311 into a plate of die 314. The tampon preform 311 does not come into contact with the parts 314a, 314b, 314c, 314d, of the die plate 314, since a central portion 312h of the casing 312 is inserted through its face. end 311 b on the die plate, so that the central portion 312h is pushed through the die plate 314, the second portion or remaining portion 312i of the nonwoven covering network section 312 being automatically around the outer surface 311a of the tampon preform 311, with In order to form the tubular wall 312c having the flange 312a. The manner in which the flange 312a is bent into the cup shape, on the end surface 311c of the tampon preform 311, by bending arms suitable in any other form, is not shown in detail. The fold of this type is carried out in the directions of the arrows 312g, and is usually associated with a simultaneous reduction in the diameter of the cup shape. After the recovery cord 313 has been secured, the tampon preform 311 surrounded by the cup-shaped nonwoven covering network section 312 is then compressed, radially relative to the main tampon preform axis 311, at the final form of the finished tampon, while reducing the diameter of the tampon preform 311. The nonwoven web section 312 is preferably cut off from the conducting end of a liquid permeable nonwoven cover network that is continuously supplied from a supply spool. As shown in Figure 16, the nonwoven covering material is advantageously held in a vertical plane when its central portion 312h is adjacent to the inlet of the tubular die plate 314 and the other side of the central portion 312h is adjacent to the center portion 312h. the end surface 311 b of the tampon preform 311. The advancing movement of the tampon preform 311 is provided by a plunger (not shown), in order to push the non-woven covering net section 312 on the die plate 314, and in doing so molds to the cup shape. The method for converting the non-woven cover network section 312 into the cup shape surrounding the tampon preform 311 is carried out by an automatic machine, which preferably produces a greater number of buffers per unit time, and is provided with automatic devices for pressing the tampon for the purpose of reducing the diameter of the tampon preform 311, together with the nonwoven covering network section 311 that surrounds it, and at the same time for the purpose of bending the edges 312a and for the subsequent adjustment of the recovery rope 313. The pressure or compression step can be carried out simultaneously with or before or after the formation of an insertion point tapered sharply in the region of the end surface 311c in the tampon preform 311, in order to facilitate the insertion of the finished product into a body cavity. For example, each non-woven cover network section 311 can be about 130 mm long and 120 mm wide, i.e. the length can be a multiple of the width. Said nonwoven web network sections 312 can be converted into a cup shape, which is shown in Figures 15 and 16. A nonwoven web section 312 having the aforementioned dimensions is capable of covering a preform of tampon 311 considerably more advantageously than a square envelope, whose dimensions can have the lengths of 95 mm, although the area (7800 mm2) of the rectangular envelope is much smaller than the area (9025 mm2) of the square envelope. The saving of the wrapping material is thus 14%. An even more significant advantage of the improved buffer according to the invention and of the production process resides in the fact that the buffer can be produced in the coating arrangement modules available from the buffer production machines. All of the above is necessary to connect a calendering unit, for smoothing the fabric covering material according to the invention, between a supply reel for the continuous supply of the liquid permeable nonwoven coating network and a cutting extension. to produce the network sections of non-woven cover. Likewise, the existing devices to produce the applicators for the tampons do not need any other change.

Claims (9)

NOVELTY OF THE INVENTION CLAIMS

1. - A tampon for feminine hygiene or medical purposes comprising a non-woven cover having at least one smooth surface facing outwards, and substantially comprising a liquid absorption core, characterized in that the non-woven cover comprises at least partially thermoplastic fibers, heat-sealable, the outwardly directed surface of the nonwoven cover has a coefficient of static friction of less than about 0.4.

2. The tampon according to claim 1, further characterized in that the gauge of the non-woven cover is less than about 0.5 mm for four cover layers.

3. The tampon according to claim 1 or 2, further characterized in that the gauge of the non-woven cover is less than about 0.2 mm.

4. The tampon according to any of the preceding claims, further characterized in that the coefficient of static friction is less than about 0.3.

5. The tampon according to any of the preceding claims, further characterized in that the coefficient of static friction is less than 0.26.

6. - A process for producing a tampon for feminine hygiene or medical purposes, comprising the steps of: a) continuously supplying a continuous twine of liquid absorption made of a mixture of natural and / or artificial fibers, the width of the twine corresponding approximately to the length of the finished buffer, b) subdividing the twine into sections of equal lengths that are suitable for the production of tampons; c) continuously supplying a continuous, non-woven web, which is at least partially composed of thermoplastic fibers, and has an essentially open, liquid-permeable structure; d) cutting the nonwoven covering network into coating network sections; e) forming each of the twist sections in an approximately cylindrical tampon preform with / without the nonwoven covering net section forming at least partially an outer side; f) compressing the tampon preform, together with the nonwoven covering network section that at least partially surrounds its surface, radially relative to its main axis, in the final shape of the tampon, wherein, g) the continuous supply of the network of non-woven coating, before being cut into individual netting sections, is subjected to a treatment involving heat and pressure, such that at least the outer surface of the non-woven cover network, which surrounds at least a significant part of the surface of the tampon is smoothed while maintaining the properties of the non-woven coating net and the absorption capacity of the tampon 7 - The method according to claim 6, further characterized in that the nonwoven covering network is pretreated at a temperature of 80-85 ° C. 8. The process according to claim 6 or 7, further characterized during the pretreatment of the network of nonwoven coating is exerted a pressure of about 0.5-2.5 bar. 9. The process according to one of the preceding claims, further characterized in that the use of an air-laid, twisted nonwoven web covering network consists of bicomponent fibers having a polymer core with a higher melting point. and a core that coats a polymer with a comparatively lower melting point. 10. The method according to one of the preceding claims, further characterized in that the non-woven cover network is secured to the relevant twine, over a part of its area, at a temperature of 120 to 140 ° C. 11. The process according to claim 10, further characterized in that the use of a PE fiber material for the nonwoven coating network has a melting point of about 130 ° C. 12. The process according to one of the preceding claims, further characterized in that it uses a non-woven cover network having a basis weight of 11-17 g / m2. 13. The method according to claim 12, further characterized by a basis weight of 14 g / m2 for the nonwoven cover network. 14. The method according to a preceding claim, further characterized in that a coefficient of friction, measured in a static friction measuring instrument, is 0.2 for the pretreated nonwoven cover network. 15. The process according to one of the preceding claims, further characterized in that the continuous non-woven coating network is calendered at a passing speed of 8-12 m / min. 16. The method according to one of the preceding claims, further characterized in that a longitudinal section of the previously smoothed, non-woven cover network (32) is welded on the outside of the rear end of a twist section (11) of a specific length, the width of said longitudinal coating network section corresponds approximately to the length of the tampon (10), the twist section (11) is then provided with a recovery cord (13) and wound to form the tampon preform (12), so that the nonwoven covering network section (15) extends over the circumference of the tampon preform (12), which is then pressed into the final form of tampon (10), the network section of nonwoven coating (15), which is composed of bicomponent fibers, is sealed in the twist section (11) to a length corresponding approximately to the circumferential length of the tampon preform (12) and, after the twist section (11) has been wound, the unsealed end (15a), which projects beyond the twist section (11), is welded to the network section of nonwoven coating (15) by the application of heat and pressure. 1

7. The method according to claim 16, further characterized in that when the nonwoven covering net section (15) is sealed in the twine (30), heat and pressure is applied more intensely than when the unsealed end ( 15a), which extends freely beyond the outer end (11a) of the twist section (11), of the nonwoven covering network section (15) is being welded to the non-woven coating network section (15). ) sealed in the twist section (11). 1

8. The method according to claim 6, further characterized in that the central portion of the nonwoven covering network section (312) and an end surface (311 b) of the buffer preform (311) are placed adjacent to each other. each other, and the remaining portion of the non-woven covering network section (312) is placed around the total outer surface (311a) of the tampon preform (311), such that the coating network section does not Woven (312) is formed in a cup envelope of the tampon preform (311). 1

9. The method according to claim 18, further characterized in that the part of the cup is bent over the other end surface (311c) of the covered buffer preform (311). 20.- The procedure in accordance with one of the claims 18 or 19, further characterized in that the tampon preform (311) moves axially towards the nonwoven covering network section (411), such that the remaining portion of the nonwoven covering network section (412) it is formed in a tubular wall (312c) of the cup. 21. The method according to claim 18, further characterized in that the central portion of the nonwoven covering network section (412), which faces from the tampon preform (311), is placed in an alignment position with a tubular die plate (314), the tampon preform (311) then moves through the die plate (314), the remaining portion of the nonwoven covering network section (412) being tubularly positioned around the external surface (311c) of the tampon preform (311) in motion, a cup with a rim (312a) extending beyond the other end surface (311c) of the tampon preform (311) is formed. ), and the flange (312a) is then bent over the other end surface (311 c).