WAD MAT AND METHOD FOR PRODUCING THE SAME

Abstract: Wad mat for e.g. padding material in the clothing industry, furniture industry or bed linen industry is formed of separate fibre clusters (10) bonded to each other. The clusters (10) are bonded to each other by means of binder fibres (11), which are different from the fibres forming the clusters (10).

Description: Wad mat and method for producing the same The invention relates to a wad mat presented in the preamble portion of claim 1 and to a method for forming a wad mat, presented in the preamble portion of claim 6. The wad mats used as padding in bed linen, furniture and clothing are constituted according to the present art of fibres which have been brought together on a support by means of an air current for example. In the structure of the mat of this kind the fibres are closely joined together and form a quite dense struc¬ ture. As the mat formed by this structure is used as an interior part of various textiles, sufficient "settleability", that is flexibility is not achieved, and neither sufficient dimensional stability and insulation capacity. Further, this method is restrict¬ ed to the use of relatively thick fibres (above 6 dtex) . Further, the method is known where the wad mat is formed in a sort of way inside the finished product by blowing therein down-like fibre bundles. The mat will not easily be retained together and for example in bed linen it will tend to become accumulated at some area. The purpose of the invention is to eliminate the above-mentioned drawbacks. For accomplishing this purpose the wad mat according to the invention is mainly characterized by what is presented in the characterizing portion of claim 1. By forming the mat of individual fibre clusters which are bonded together the settleability, dimensional stability and thermal insulation capacity of the above-mentioned products can be improved without deteriorating other properties. The processability of the wad mat in course of manufacturing it to a final product will not be hampered either. The appended subclaims show some advantageous variants for the structure of the wad mat according to the invention. The fibre clusters can be bonded to each other by means of binder fibres, which can be of different type than the fibres of the clusters. Further, the fibre clusters can be formed of synthetic fibre material softening at a higher temperature, such as of polyester fibres, and the binder fibres can at least on their surfaces comprise synthetic fibre softening at a lower temperature, such as polyethylene. The purpose of the invention is also to disclose a method by which the above-mentioned fibre mat can be manufactured. For realizing this purpose the method in accordance with the invention is mainly charact- erized by what is presented in the characterizing portion of claim 6. The wad mat is so formed that the individual fibre clusters constituted of fibres are brought together onto a support, whereafter they are bonded to each other. In accordance with the variants presented by the appended subclaims the fibre clusters can be bonded together by means of thermal bonding by utilizing fibres softening at a lower temperature than the fibres of the clusters in the thermal bonding. Further, the clusters can be pre-bonded to each other by needling. The invention will be described in the following more closely with reference to the appended drawings, wherein Fig. 1 shows a wad mat according to the invention in cross-section, Fig. 2 shows the use of the wad mat in a finished product, and Fig. 3 shows schematically the manufacturing line of the wad mat. Fig. 1 shows the structure of the wad mat according to the invention. The wad mat comprises separate fibre clusters 10 formed of fibres joined to each other. The clusters have mainly the shape of a sphere or oval. The clusters are formed of fibres whose length is more than 2 times, preferably more than 3 times the greatest dimension of the sphere or oval. In the clusters the fibres are entangled together forming a structure approximately resembling a ball of yarn. The length of the fibres is 30 to 60 mm and the greatest dimension of the clusters is most prefe¬ rably between ca. 3-8 mm. In the direction of thickness of the mat there are several clusters on top of each other. The thickness of the mat according to the invention varies within the same range as that of normal wad mats, for example 1-3 cm. As fibre material can be used for example polyester fibre of 1-3 dtex with a high melting point, which is useful as regards the manufacture and use of the mat. The fibre clusters 10 are bonded to each other with fibres whose surface is of thermoplastic material softening at a lower temperature than the softening temperature of the fibre material in the cluster. The amount of these fibres can be ca. 5-15 wt-% of the total amount of the fibres in the wad mat and they can be either on their surfaces only or entirely of said material. In the case of polyester fibres, the binder fibres can be for example polyethylene fibres or polyethylene-coated so-called bicomponent fibres, for example fibres with a polyester core. By subjecting the wad mat to thermal bonding the clusters 10 can be fixed to each other owing to the adhesive action caused by the softening/melting material of the binder fibres 11, thus consolidating the mat to a stable and non-shrinking structure. The fibre clusters 10 are preferably bonded to each other mechanically by needling prior to the thermal treatment. The same fibres 11 that are used as thermally bonding fibres are preferably utilized also in the needling. When polyester is used as the fibres of the clusters 10, binder fibres 11 can be thicker fibres than the polyester fibres, being ca. of 7 dtex, comprising polyethylene at least on their surfaces and having a length of ca. 50 mm. Instead of these fibres the binder fibres can be also fibres with the same tex-value as the fibres of the clusters, or fibres which are thinner than them. For the sake of needling, fibres of ca. 50 mm have proved to be practical, but they can, of course, have also some other lengths. In Fig. 2 is shown the use of the wad mat in a finished product. The wad mat according to the invention is placed between two surface layers 12 when forming clothes, seat cushions, quilts, sleeping bags and pillows. The layers can in addition be joined together at their opposite sides in a manner known as such by stitches, this point being indicated by reference numeral 9 in Fig. 2. As shown by the figure, by virtue of the dimensionally stable, well consolidated structure of the mat clusters 10 will be present also between the stitches. Fig. 3 shows a manufacturing line of the wad mat according to the invention seen from the side. In the following, the manufacturing method of the wad mat will be described with reference to said figure. Raw-material can be such fibre material in which the fibres are already entangled to each other owing to the fact that they are "crimped". It is possible to make this kind of fibres from various synthetic fibres and natural fibres. In point 1 the fibre bales are fed onto a conveyer and the fibre bundles formed of the fibres are opened only to the extent that the fibres remain as loose fibre clusters in which the fibres are entangled to each other due to their inherent crimp. In a carding equipment in point 2, performing a gentle carding, the fibre clusters are mixed with binder fibres used for the bonding in an amount of ca. 5-10 % calculated on the total weight of the final mat, whereafter they are blown to point 3. The fibres are blown into a cyclone 3a, in which they remain a relatively long time to densify the fibre clusters to a spherical shape. Suction exerted on the clusters through a perforated plate forming the upper wall of the cyclone is utilized in this operation. From the cyclone the fibre clusters fall on conveyors 3b feeding them onto the surface of a spike roll 4, which throws the fibres and fibre clusters in an air current which forms a relatively even mat from the fibre clusters and binder fibres on a support 5. Said air current conveying the fibres is passed through said support. The mat so formed is thereafter passed to needling to point 6, in which the fibre clusters are pre-bonded with the binder fibres mechanically by needling. Thereafter the mat, which is relatively well retained together at this stage, is passed to thermal bonding to point 7, where the final bonding is effected by means of the binder fibres in the above-described manner. After the thermal bonding the mat is passed to a reeling equip- ment 8, in which it can be wound to a reel comprising a 50 m length of mat for example. The obtained half-fabricate can be thereafter be used in all purpose where the usual, previously known wad mat is used. The advantages of the use of the wad mat according to the invention in the clothing industry are in that it can substitute for the blowing method by means of which the wad has previously been blown in between the outer layers. The wad mat according to the invention can be easily handled in the half- fabricated state, because it is well retained together, and consequently it can be easily processed, for example cut to patterns. The wad mat will also be better retained at its place than blown fibre. The "settleability", that is flexibility of an obtained garment is also better than that of the previous pro¬ ducts. Further, a better thermal insulation is obtained because owing to the properties (dimensional stability) of the mat it will also be present under the stitches, as illustrated in Fig. 2. Owing to the easy process- ability and good integrity the mat can also be lami¬ nated to the fabric when desired. In addition, more surface materials can be used than in the blowing method, because the blowing method has always required air-permeable surface materials. The use of the wad mat according to the invention affords to the furniture industry the same advantages as above. It can be stated in addition that the manufacture of seat cushions is considerably faster when using wad mat than with the blowing method. The manufacture of various quilts, sleeping bags and pillows have the same advantages as above. It can be stated in addition that the wad mat according to the invention will better retain its position and does not necessarily need transverse stitches in the quilts. When synthetic fibers are used, all products have the common advantage of a good resistance to washing. The wad mat can be manufactured of all such fibres which can be formed to separate fibre clusters, in which the fibres are entangled with each other. The "crimp" in the fibres causing the entangling can be created in the fibres by coating the fibres having a suitable length on one side thereof with a material shrinkable by heat, by causing tensions in synthetic fibres in conjunction with their manufacture or in any other suitable way. The fibre clusters can be also blends of fibres of different types, such as of fibres having different tex-values. Moreover, in the finished mat some fibre clusters can be partly or entirely opened. The raw materials of the wad mats falling within the scope of the invention can thus vary within a broad range, the common denominator for all of these being that the structure comprises both fibre clusters and binder fibres joining them to a uniform mat.

Claims: Claims : 1. Wad mat for e.g. padding material in the clothing industry, furniture industry or bed linen industry, said mat being constituted mainly of fibrous material, characterized in that the wad mat is formed of separate fibre clusters (10) bonded to each other. 2. Wad mat according to claim 1, characterized in that the clusters (10) are bonded to each other by means of binder fibres (11) . 3. Wad mat as claimed in claim 1 or 2, characterized in that the fibres forming the fibre clusters (10) are synthetic fibres. 4. Fibre mat as claimed in any of claims 1-3, characterized in that the binder fibres (11) are fibres softening at a lower temperature than the softening temperature of the fibres of the clusters (10) , and the clusters are joined together by means of the binder fibres (11) being at least partly melted or softened. 5. Wad mat as claimed in any of the preceding claims, characterized in that the fibre clusters (10) have approximately spherical shape, such as the shape of a sphere or oval, and the average of the greatest dimension of the clusters is within the range of 3 to 8 mm. 6. Method for forming a wad mat in which the fibres are brought together in such a manner that they form a uniform layer, characterized in that the wad mat is formed by bonding together separate fibre clusters (10) . 7. Method as claimed in claim 6, characterized in that the clusters are bonded to each other by means of binder fibres (11) . 8. Method as claimed in claim 7, characterized in that the clusters (10) are bonded to each other by means of thermal bonding by utilizing the binder fibres (11) which glue the clusters to each other influenced by heat. 9. Method as claimed in claim 7 or 8, characterized in that the clusters (10) are bonded to each other mechanically by means of the binder fibres (11) . 10. Method as claimed in claim 9, characterized in that the mechanical bonding is effected by needling.

Inventors: NIEMINEN JORMA, NIEMINEN, JORMA
Applicants: SCANWOVEN AB OY, OY SCANWOVEN AB
Application year: 1991
Main classification: D04H1
IPC codes: D04H1