Method for manufacturing fabrics with a rib structure on both sides, and fabrics manufactured according to this method

Abstract: A method for weaving fabrics with a two-sided rib structure, such as e.g. false bouclé fabrics, whereby on a weaving machine, from weft threads (1), (2), (3), (4) and warp threads (7-10) of a series of warp thread systems, a fabric is formed with sets (1, 2), (3, 4) of at least two weft threads running one above the other, whereby each warp thread system comprises at least three pattern warp threads (8), (9), (10), of which two (8), (9) opposite each other, respectively along the upper side and the lower side of the fabric, form a number of ribs (11) whereby they are alternately rib-formingly passed round over one or several sets of weft threads (1), (2), (3), (4) and are interlaced in the fabric, while each additional pattern warp thread (10) is inwoven in the fabric between weft threads (1), (2); (3), (4) of the sets over which other pattern warp threads (8), (9) are rib-formingly passed round. The additional pattern warp threads hold the weft threads of the aforementioned sets at a greater distance from each other in the fabric, so that a greater rib height is provided, and the fabric more closely approximates a loop pile fabric than the known fabrics. Furthermore with each additional pattern warp thread (10) an additional colour can be added to the fabric, so that a more varied fabric can be obtained.

Description: This invention relates to a method for manufacturing fabrics with a rib structure, in particular false bouclé fabrics, whereby on a weaving machine, by inserting weft threads in successive sheds between warp threads of a series of warp thread systems, a fabric is formed with sets of at least two weft threads running one above the other, whereby in each warp thread system two pattern warp threads opposite each other, respectively along the upper side and the lower side of the fabric, form a number of ribs whereby these pattern warp threads alternately along their respective fabric side are rib-formingly passed round over one or several sets of weft threads and are interlaced in the fabric. This invention also relates to fabrics with a rib structure which are manufactured according to such a method, in particular false bouclé fabrics, comprising a number of sets of at least two weft threads running one above the other which are inwoven by warp threads of a series of warp thread systems, of which two pattern warp threads opposite each other, respectively along the upper side and the lower side of the fabric, form a number of ribs whereby these pattern warp threads alternately along their respective fabric side are rib-formingly passed round over one or several sets of weft threads and are interlaced in the fabric. A fabric with a rib structure which approximates the appearance of a loop pile fabric or bouclé fabric, is called a false bouclé fabric. In this specification and in the claims of this patent application the terms "lower side" and "upper side" of a fabric are only used to indicate the two different sides of the fabric. The aforementioned terms must be interpreted in the sense of "the one side" and "the other side". The literal meaning of the terms "upper side" and "lower side" may therefore not give rise to any restriction on this invention. According to a known weaving method for manufacturing a false bouclé fabric, which has the above mentioned characteristics, tension warp threads are inwoven stretched in the fabrics and in each weft insertion cycle on the weaving machine two weft threads are simultaneously inserted one above the other. In successive insertion cycles the two weft threads are in relation to the tension warp threads alternately inserted along the upper side and along the lower side of the fabric. In warp thread systems located next to each other a first and a second pattern warp thread of a different colour are provided in order to be able to make a design or a pattern visible with the two colours along the upper side of the fabric. The first pattern warp thread is alternately rib-formingly passed over the two weft threads along the upper side of the fabric and interlaced between the two weft threads along the lower side of the fabric, in order to achieve a rib structure on the upper side of the fabric and to form the design or the pattern. The second pattern warp thread is interlaced opposite the first pattern warp thread, alternately between the two weft threads along the upper side of the fabric and passed round over the two weft threads along the lower side of the fabric. The colour of the second pattern warp thread is then not visible on the upper side, but it is on the lower side of the fabric. The second pattern warp thread forms a rib structure on the lower side of the fabric. With these known fabrics the weft threads are inwoven by the pattern warp threads. With each insertion cycle a rib line is produced (alternately along the upper side and along the lower side of the fabric). Both the upper side and the lower side of this known fabric have a rib structure. On the lower side of the fabric a type of negative (with swapped colours) is obtained of the two-coloured design which is visible on the upper side of the fabric. A disadvantage of this method is that the fabrics thus produced cannot closely approximate the appearance of the real loop pile fabrics or bouclé fabrics. Furthermore the designs or patterns provided on these fabrics only have two different colours. The purpose of this invention is to provide a method for manufacturing a fabric with a rib structure on both sides, with which the appearance of the real loop pile fabrics is far more closely approximated, and with which at the same time the possibility also exists of forming designs or patterns with more than two colours in the fabric. This objective is achieved according to this invention, with a method having the characteristics mentioned in the first paragraph of this specification, by providing at least one additional pattern warp thread in each warp thread system and inweaving it between weft threads of the sets over which other pattern warp threads are rib-formingly passed round. Because of the fact that the additional pattern warp threads are between the weft threads of the aforementioned systems, they hold these weft threads at a greater distance from each other in the fabric. Because of this a greater rib height is provided, so that the rib structure becomes clearer and the fabric more closely approximates a loop pile fabric. Furthermore with each additional pattern warp thread an additional colour can be added to the fabric. The pattern warp threads of each warp thread system preferably have a different appearance, in particular a different colour, while each pattern warp thread is so provided that it has on at least one fabric side one or several visible parts corresponding to a design or pattern to be formed. Thus a fabric is obtained with a design or a pattern whose appearance on the one hand is more varied (e.g. has greater wealth of colours), and on the other hand more closely approximates the appearance of a loop pile fabric, in comparison to existing fabrics which have a rib structure on both sides. By utilising the method according to this invention tension warp threads are preferably also provided in the fabric, while the sets of weft threads over which pattern warp threads along the upper side of the fabric are passed round and the sets of weft threads over which pattern warp threads along the lower side of the fabric are passed round are respectively above and below the tension warp threads. Because of this ribs are obtained with a maximum height, so that an excellent approximation to the appearance of a loop pile fabric is obtained. Moreover successive sets of weft threads of the fabric are preferably also provided alternately above and below the tension warp threads. Because of this a rib is formed alternately along the upper side of the fabric and along the lower side of the fabric. According to a very preferred method according to this invention on the weaving machine in successive insertion cycles in each case one set of weft threads is inserted. This makes it possible in each case to form one rib per insertion cycle. A greatly preferred fabric according to this invention is obtained if each set of weft threads consists of two weft threads running one above the other. When weaving according to the double rapier weaving method the tension warp threads after each weft insertion cycle must be brought from a position below both rapiers to a position above both rapiers, and vice versa. This lifting is considerable and results in a great strain of the warp threads and the weaving frames drive. This can be remedied by manufacturing the fabric on a weaving machine with three weft insertion means (with respective insertion levels), and in the successive weft insertion cycles by not inserting a weft thread alternately in the bottom insertion level and in the top insertion level. With this method the tension warp threads only have to be moved upwards and downwards over one rapier height. Another aspect of this invention is a fabric manufactured according to the method of this invention. Apart from the characteristics mentioned in the second paragraph of this specification a fabric according to this invention also comprises more particularly in each warp thread system at least one additional pattern warp thread which is inwoven in the fabric between weft threads of the sets over which other pattern warp threads are rib-formingly passed round. The advantages of such a fabric in relation to the known fabrics ensue from the above mentioned advantages of the method according to this invention. In such a fabric the pattern warp threads of each warp thread system preferably have a different appearance, in particular a different colour, and each pattern warp thread is so provided that it has on at least one fabric side one or several visible parts corresponding to a fabric or pattern to be formed. This invention will now be further explained in the following specification of two preferred methods for manufacturing false bouclé fabrics according to this invention. These methods are only described by way of example and no part of the following specification may therefore be considered as a restriction on the protection claimed by this patent application. In this specification reference is made to the drawings attached hereto and provided with reference numbers in which figure 1 represents a schematic cross-section according to the warp direction of a false bouclé fabric, manufactured according to the method according to this invention, and figure 2 represents a schematic cross-section according to the warp direction of a false bouclé fabric in which the locations are indicated where according to a variant method weft threads are not inserted. The method according to this invention can be implemented on a double rapier weaving machine, provided with two weft insertion means which per weft insertion cycle can insert a respective weft thread (1), (2) one above the other at a respective insertion level. On the weaving machine several warp thread systems are provided next to each other. Each warp thread system comprises three differently coloured pattern warp threads (8), (9), (10) and a tension warp thread (7). By means of a three-position jacquard machine, preferably an open-shed jacquard machine, these warp threads (7-10) are so positioned in each weft insertion cycle in relation to the aforementioned insertion levels that the weave represented in figure 1 is obtained; in which the weft threads (1), (2); (3), (4) inserted during successive insertion cycles are alternately above and below the tension warp threads (7), and are inwoven as sets of two weft threads (1, 2), (3, 4) running one above the other two pattern warp threads (8), (9) alternately form ribs (11) along the upper side and the lower side of the fabric because of the fact that they are alternately passed round over a set of weft threads (1, 2) located above the tension warp threads (7) and are interlaced in the fabric between the two weft threads (3), (4) of the following set of weft threads (3, 4) located below the tension warp threads (7), and a third pattern warp thread (10) is inwoven alternately between the two weft threads (3), (4) of a set of weft threads (3), (4) located below the tension warp threads (7), and is inwoven between the two weft threads (1), (2) of a set of weft threads (1, 2) located above the tension warp threads (7). Opposite each other, respectively along the upper side and the lower side of the fabric, the two rib-forming pattern warp threads (8), (9) form a number of ribs (11). From a specific weft insertion cycle the pattern warp thread (8) which initially formed ribs (11) along the upper side, starts to form ribs (11) along the lower side, and the pattern warp thread (9) which initially formed ribs (11) along the lower side, starts to form ribs (11) along the upper side. This change occurs such that the different colours of these two pattern warp threads (8), (9) are visible in the correct locations on the upper side and the lower side of the fabric in order to form a respective design on each fabric side. The method according to this invention can advantageously be implemented on a triple rapier weaving machine with three weft insertion means which are provided in order in each weft insertion cycle to insert a weft thread simultaneously at respective insertion levels. According to this preferred method alternately no weft thread is inserted on the top insertion level (6) and on the bottom insertion level (5) (see figure 2) so that in each weft insertion cycle two weft threads (1), (2); (3), (4) are inserted one above the other, and the same fabric is obtained as that from figure 1. The tension warp threads (7) because of this only have to move over one rapier height, so that the warp threads (7-10) and the weaving frames drive are less strained. The method according to this invention can also be implemented on a quadruple rapier weaving machine, whereby no weft threads are inserted alternately on two top and on two bottom insertion levels.

Claims: Method for manufacturing fabrics with a rib structure, in particular false bouclé fabrics, whereby on a weaving machine, by inserting weft threads (1), (2); (3), (4) in successive sheds between warp threads (7-10) of a series of warp thread systems, a fabric is formed with sets (1, 2), (3, 4) of at least two weft threads running one above the other, whereby in each warp thread system two pattern warp threads (8), (9) opposite each other, respectively along the upper side and the lower side of the fabric, form a number of ribs (11) whereby these pattern warp threads alternately along their respective fabric side are rib-formingly passed round over one or several sets of weft threads (1, 2), (3, 4) and are interlaced in the fabric, characterised in that in each warp thread system at least one additional pattern warp thread (10) is also inwoven in the fabric between weft threads (1), (2); (3), (4) of the sets over which other pattern warp threads (8), (9) are rib-formingly passed round. Method for manufacturing fabrics with a rib structure, according to claim 1 characterised in that the pattern warp threads (8), (9), (10) of each warp thread system preferably have a different appearance, in particular a different colour, and that each pattern warp thread (8), (9), (10) is so provided that it has on at least one fabric side one or several visible parts corresponding to a design or pattern to be formed. Method for manufacturing fabrics with a rib structure, according to claim 1 or 2 characterised in that tension warp threads (7) are provided in the fabric, and that the sets of weft threads (1, 2) over which pattern warp threads (8), (9) along the upper side of the fabric are passed round and the sets of weft threads (3, 4) over which pattern warp threads (8), (9) along the lower side of the fabric are passed round are respectively above and below the tension warp threads (7). Method for manufacturing fabrics with a rib structure, according to claim 3, characterised in that successive sets of weft threads (1, 2), (3, 4) of the fabric are provided alternately above and below the tension warp threads (7). Method for manufacturing fabrics with a rib structure, according to any of the preceding claims, characterised in that on the weaving machine in successive insertion cycles in each case one set of weft threads (1, 2), (3, 4) is inserted. Method for manufacturing fabrics with a rib structure, according to any of the preceding claims, characterised in that each set of weft threads (1, 2), (3, 4) consists of two weft threads running one above the other. Method for manufacturing fabrics with a rib structure, according to any of the preceding claims, characterised in that the fabric is manufactured on a weaving machine with three weft insertion means with different insertion levels, and that in the successive weft insertion cycles no weft thread is inserted alternately in the bottom insertion level (5) and in the top insertion level (6). Fabric with a rib structure, in particular a false bouclé fabric, comprising a number of sets (1, 2), (3, 4) of at least two weft threads running one above the other which are inwoven by warp threads (7-10) of a series of warp thread systems, of which two pattern warp threads (8), (9), opposite each other, respectively along the upper side and the lower side of the fabric form a number of ribs (11) whereby these pattern warp threads alternately along their respective fabric side are rib-formingly passed round over one or several sets of weft threads (1, 2), (3, 4) and are interlaced in the fabric, characterised in that in each warp thread system at least one additional pattern warp thread (10) is also inwoven in the fabric between weft threads (1), (2); (3), (4) of the sets over which other pattern warp threads (8), (9) are rib-formingly passed round. Fabric with a rib structure according to claim 8, characterised in that the pattern warp threads (8), (9), (10) of each warp thread system preferably have a different appearance, in particular a different colour, and that each pattern warp thread (8), (9), (10) is so provided that it has on at least one fabric side one or several visible parts corresponding to a design or pattern to be formed.

Inventors: DEBAES JOHNNY, SMISSAERT LUDO, VANDOORNE NICO, DEBAES, JOHNNY, SMISSAERT, LUDO, VANDOORNE, NICO
Applicants: WIELE MICHEL VAN DE NV, N.V. MICHEL VAN DE WIELE
Application year: 1999
Main classification: D03D27
IPC codes: D03D27, D03D13