EP1723277B1

EP1723277B1 - Method of laid fabrics production and device for laid fabrics production

Info

Publication number: EP1723277B1
Application number: EP05700504A
Authority: EP
Inventors: Milan Stejskal; Jaroslav Havlik
Original assignee: Vyzkumny Ustav Textilnich Stroju Liberec AS
Current assignee: Vyzkumny Ustav Textilnich Stroju Liberec AS
Priority date: 2004-01-29
Filing date: 2005-01-28
Publication date: 2009-07-01
Anticipated expiration: 2025-01-28
Also published as: CZ2004159A3; CZ300858B6; WO2005073444A1; CA2554247A1; DE602005015193D1; WO2005073444A8; EP1723277A1

Description

Technical field

The invention relates to a method of laid fabrics production during which are between the warp threads strands inserted wefts of required mutual distance, after which is applied an adhesive on the fabric and the fabric is dried.
The invention also relates to a device for laid fabrics production comprising means for warp threads placing and means for warp threads guiding through the working path to draw-off mechanism and next to adhesive applying mechanism and to a drying mechanism.

Background art

Laid fabrics, for instance "laid scrim" type are fabrics of basically crosshatched arrangement, where particular warp threads have mutual distances and also particular weft threads have mutual distances. These fabrics are used for miscellaneous reasons according to the character of threads or fibres used for their production, for instance while using finer threads or fibres it is possible to use these fabrics as an envelope reinforcement, while using thicker (more rugged) threads or fibers it is possible for these fabrics to use for instance as in industrial purposes etc. The fabrics are impregnated by an adhesive, which after setting provides cohesive strength in determined geometrical arrangement, similarly to for instance in leno weaves in leno fabrics. A method of and a device for laid fabric production according to the preamble of claims 1 and 5 is known from GB-A-985 476 .
There is well known a method of laid fabrics production of "laid scrim" type, during which are the warp threads separated using appropriate means, for instance warp brushes, into appropriate mutual distance and they are led to appropriate device producing space between warp threads for weft insertion. Between separated warp threads is by mechanical means inserted a weft or a group of wefts. Basically immediately after contacting the warp threads from both sides onto the weft or wefts is applied the adhesive and occurs weft fixation in determined position. Adhesive drying follows.
The disadvantage of the background art is mechanical complexity of the device for laid fabrics production, in particular of the part providing weft insertion between the warp threads. Another disadvantage of the background art is a limited manufacturing productivity of laid fabrics.
The goal of the invention intends to eliminate or at least to minimize the drawbacks of the art.

Principle of the invention

The goal of the invention has been reached by a method of laid fabric production, whose principle consists in that warp threads strands are supplied between a pair of tension rollers, between which they are merged again, while in the point before merging the warp threads strands between the tension rollers are between the warp threads inserted wefts by means of which is produced a laid fabric semi product with wefts between warp threads which is by wrapping around a part of tension roller circumference delivered to a draw-off device for next manufacturing operations of an adhesive application and drying.
This way it is possible to simplify the manufacturing process while retaining or improving the performance.
For improving inserting the wefts to a designated place between the warp threads strands is advantageous if on the weft is during and/or after weft insertion between the warp threads strands acted by a stream of an auxiliary medium in the cross direction to the weft length improving positioning the wefts between the warp threads.
To reach advantageous parameters of weft insertion, in particular high speed, reliability and stability of insertion parameters is advantageous weft insertion by means of air which does not need additional fabric alterations before adhesive application as for instance drying and it is an inexpensive and available medium.
For next performance increase of the entire method, because insertion by means of medium can today attain the highest speed around 80 m/min, it is advantageous if the warp threads are before the wefts insertion separated into m strands, where m > 2, while these strands then merge in sequence between n pairs of tension rollers, where n = m - 1 and in each point before warp threads strands merging between the tension rollers are between warp threads inserted wefts, while in each point before strands merging is between warp threads inserted each i·(n+first) weft, where i is a sequence number of a weft series inserted on all insertion devices directly one after another, while the fabric is by means of alternating wrapping around a part of tension rollers tensioned and lead towards the draw-off device for next processing.
The principle of device for laid fabrics production consists in that the means for guiding the warp threads through the working path comprise at least one pair of tension rollers, between which are separately supplied always two warp threads strands, while in the warp threads movement direction is a weft insertion device assigned to an area in front of the entry of warp threads between each pair of tension rollers and behind each pair of tension rollers is situated a laid fabric semi product tension device on a part of circumference of one of a pair of tension rollers, while behind the last pair of tension rollers is situated a draw-off device of laid fabric semi product for next processing.
Such device is simple and enables basically modular arrangement of a higher amount of insertion points and this way also increasing the productivity of laid fabrics production.
According to one preferred embodiment is the laid fabrics tension device on a part of the circumference of one of a pair of tension rollers formed by the first tension roller from the following pair of tension rollers or it is formed by a draw-off roller of the laid fabrics tension device, while the working path of the laid fabrics semi product is established continuously crossing in an alternating direction from one tension roller to another and next to the draw-off roller of the draw-off device, which simplifies the device construction because such way the tension rollers fulfil more tasks at the same time without any problems.
In terms of controlling and simplicity it is preferred if the weft insertion device is formed by an air insertion device with an air insertion jet.
For improving the weft insertion onto an appropriate point it is preferred if the weft insertion device comprises an auxiliary insertion device in a cross direction to the weft length.
In terms of ergonomic design is the device advantageous if the tension rollers pairs and weft insertion devices assigned to them are situated above each other.

Description of the drawing

The invention is schematically shown in the drawings in which Fig. 1 represents a side view of an example of embodiment of a weft insertion device between warp threads during laid fabrics production, Fig. 1a represents an axonometric view of an example of embodiment of a weft insertion device (displayed without the weft), Fig. 1b represents a detailed axonometric view of example of embodiment of warp threads separation to strands (6 strands - displayed without wefts and without insertion jets) from Fig. 1a, Fig. 1c represents an orthogonal view of embodiment from Fig. 1b (displayed without wefts and without insertion jets), Fig. 2 represents a detailed axonometric view of embodiment of weft insertion device with separated warp threads (displayed without wefts and without insertion jets), Fig. 3 represents an axonometric schematic arrangement of one fabric embodiment.

Specific description

Method of laid fabrics production consists in that the warp threads are separated into strands which are separately supplied between a pair of tension rollers, between which they are combined again and they are further delivered combined by means of wrapping around a part of the circumference of one of the tension rollers for further processing, while in the point before combining both strands between the tension rollers are between the warp threads inserted wefts by acting of insertion medium (water, air) so between the tension rollers enters a fabric with wefts inserted between warp threads and by means of wrapping around a part of circumference of one of the rollers are the wefts kept in a desired position between weft threads till setting by an adhesive. Wefts insertion between warp threads strands before entering between the tension rollers can be supported by use of an auxiliary medium acting basically crosswise to the wefts movement direction or diagonally in the wefts movement direction and improving positioning the wefts between the warp threads, e.g. similarly as well known auxiliary blow jets in weaving machines. In the Fig. 1 is shown a schematic embodiment of device for carrying out the method of wefts insertion between warp threads during laid fabrics production, which consists of a pair of distant separating rollers 1, across which is led always one warp threads strand a, b. Both warp threads strands a, b are led between tension rollers 2, which rotate in direction of arrows x, y. In the area before entering the warp threads between the tension rollers 2 is situated a weft insertion device by acting of insertion medium, for instance water or air. Weft insertion device consists of an insertion jet 6 directed to a corresponding direction between warp threads strands in the direction of tension rollers 2 lengths. The insertion device can, as the case may be, comprise also an auxiliary insertion device 60 for weft insertion improvement between warp threads entering between tension rollers 2. The insertion device inserts the wefts between the warp threads in designated intervals at defined tension rollers rotation that is at defined warp threads motion, by means of which is manufactured a laid fabrics semiproduct, which from the area between tension rollers 2 is under tension from wrapping around a part of surface of a draw-off roller 4 delivered over a surface of one of tension rollers 2 to the draw-off roller 4, after which follows adhesive applying and drying. By means of keeping the tensioned fabric semiproduct on the surface of one of tension rollers 2 and on the surface of the draw-off roller 4 is reached a stable position of wefts between the warp threads till setting by an adhesive.
In terms of reaching an appropriate manufacturing productivity of laid fabric with wefts insertion by means of a driving medium with maximum attainable weft insertion speed around 80 m/min, it is advantageous to use the above mentioned method in the following modification and in the following technical arrangement.
During mentioned modification of laid fabric production method are the warp threads in an appropriate manner positioned on a not represented bearing device, for instance on an appropriate warp beam. Warp threads are by means of appropriate not represented means, for instance warp combs, separated from each other at desired distance. Consequently the warp threads, for instance by means of represented system of separating rollers 1 in regular sequences to at least three strands, i.e. m strands, where m > 2, from which each comprises a corresponding part of warp threads. Separating the warp threads into regular sequences means that e.g. in separating into three strands is the first warp thread led in the first strand over the first separating roller, second warp thread is being led in the second strand over the second separating roller, the third warp thread is being led in the third strand, the fourth warp thread is being led again in the first strand, the fifth warp thread is being led again in the second strand, the sixth warp thread is being led again in the third strand etc. In the Fig. 1a to 1c is described separation of warp threads into six strands a, b, c, d, e, f, while the first warp thread is being led in the first strand a, the second warp thread is being led in the second strand b, the third warp thread is being led in the third strand c, the fourth warp thread is being led in the fourth strand d, the fifth warp thread is being led in the fifth strand e, the sixth warp thread is being led in the sixth strand f, the seventh warp thread is being led again in the first strand a, the eighth warp thread is being led again in the second strand b, the ninth warp thread is being led again in the third strand c, the tenth warp thread is being led again in the fourth strand d, the eleventh warp thread is being led again in the strand e, the twelfth warp thread is being led again in the sixth strand f, etc., by means of which are all warp threads separated into the desired number of strands.
From the warp threads strands is by means of described tension rollers 2, either by cascade merging of strands as shown in the drawings or by another appropriate method, next examples will follow, form weft insertion points 3 before the warp threads enter between the tension rollers 2, while to every weft insertion point 3 is assigned one insertion device working on a principle of insertion by means of an appropriate medium, for instance water or air. While the number of insertion devices is one less than the number of warp threads strands. Behind the insertion device system is a draw-off mechanism, which for instance by means of draw-off rollers 4 provides draw-off of produced fabric to next processing, e.g. to immediate applying an adhesive and following drying etc. The warp threads are during production of laid fabrics semiproduct maintained under tension, while they are kept in contact with rotating tension rollers 2, by means of which are the wefts up to fixation by adhesive reliably kept in the appropriate position on the fabric semi product. The warp threads subsequently wrap around particular tension rollers 2 as the particular warp threads strands merge into the final laid fabrics configuration.
In the shown example of embodiment the warp threads strands for the purpose of formation of weft insertion points 3 merge in a cascade manner, which means that the strand a together with the strand f before entering the first pair of tension rollers 21 form the first weft insertion point 31, the merged strands a + f together with the strand e before entering between the second pair of tension rollers 22 form the second weft insertion point 32, the merged strands a + f + e together with the strand d before entering between the third pair of tension rollers 23 form the third weft insertion point 33, the merged strands a + f + e + d together with the strand c before entering between the fourth pair of tension rollers 24 form the fourth weft insertion point 34 and the merged strands a + f + e + d + c together with the strand b before entering between the fifth pair of tension rollers 25 form the fifth weft insertion point 35, behind which comes out the formed laid fabric semi product into the draw-off mechanism. During this merging of warp thread strands are the warp threads practically constantly under tension and they are on the surface of the tension rollers so the wefts are firmly held up to fixing by the adhesive.
In the not represented example of embodiment the warp threads strands for the purpose of formation of weft insertion points 3 merge in sequence, i.e. for instance the strand a together with the strand f before entering the first pair of tension rollers form the first weft insertion point, the strand e together with the strand d before entering between the second pair of tension rollers form the second weft insertion point, the strand c together with the strand b before entering between the third pair of tension rollers form the third weft insertion point, the merged strands a + f together with the merged strands e + d before entering between the fourth pair of tension rollers 24 form the fourth weft insertion point and the merged strands a + f + e + d together with the merged strands c + b before entering between the fifth pair of tension rollers form the fifth weft insertion point, behind which comes out the formed laid fabric semiproduct into the draw-off mechanism.
In another not represented example of embodiment the warp threads strands for the purpose of formation of weft insertion points 3 merge in another appropriate manner. The specific process of merging particular strands and a formation of particular weft insertion points in principle depends only on specific arrangement of the device for laid fabric production.
In the shown example of embodiment are the tension rollers 2 arranged in pairs 21 to 25 above each other to cascade and also the insertion devices are arranged above each other to cascade. In the not represented example of embodiment are the tension rollers 2 and insertion devices arranged in another appropriate manner corresponding to the manner of dividing and merging particular strands of warp threads.
The insertion device of each weft insertion point 3 is advantageously formed by an air insertion device, which in Fig. 1 consists of shown air insertion jet directed to the appropriate weft insertion point 3 in the direction of length of tension rollers 2. The insertion device can further consist of auxiliary insertion device 60 for improving weft insertion into the weft insertion point 3 between the warp threads wrapped around the particular pair of tension rollers 2 in the cross direction to the weft insertion direction. The auxiliary insertion device can be formed for instance by an appropriate longitudinal air jet directed by its longitudinal outlet to the weft insertion point 3 between the appropriate pair of tension rollers 2. The auxiliary insertion device 60 can also be formed by an appropriate series of auxiliary air blow jets in analogy to weaving machines. The auxiliary insertion device 60 can also be formed by another appropriate device.
The insertion devices are coupled with a not represented weft insertion control device, which synchronize the action of particular insertion devices according to the demands on produced fabric, for instance also on the basis of operation speed of the entire mechanism, for instance according to the tension rollers 2 revolutions. The weft insertion control device is preferably coupled with a control device of the entire machine for laid fabrics production.
At least some of the tension rollers 2 and at least one from the draw-off rollers 4 are coupled with appropriate drive, for instance electromotor, which can be also central with an appropriate timing gear.
The device works so that the warp threads are led in their paths and they are separated into particular strands, which are subsequently being led over corresponding pairs of tension rollers 2 on which the warp threads strands merge in sequence and further lead over draw-off mechanism to the next processing of the laid fabrics semiproduct, in particular to adhesive application, drying, winding on a beam etc.
After turning the driving mechanism on the corresponding device parts start to move (rotate), by means of which the warp starts to move. Subsequently to the warp movement the insertion devices start weft insertion on weft insertion points 3, while the wefts are in particular weft insertion points 3 consequently by corresponding pair of tension rollers 2 clenched between warp threads of appropriate warp threads strand or between warp threads of merged strands of warp threads (in dependence on manner of dividing and merging of the warp threads). During formation of fabric does not occur a shed formation known at weaving machines but warp threads and wefts are in each weft insertion point 3 overlaid or if you like the wefts are inserted between the warp threads and their mutual position is being held due to tension rollers and maintaining the warp threads under tension on tension rollers because the warp threads bear on both sides onto crosswise passing wefts and the wefts are then being held on their position till application of adhesive onto the fabric. The activity of particular insertion devices is synchronized so that in the area of draw-off mechanism the wefts are regularly positioned along the fabric. Each insertion device has the same interval between insertion of particular wefts, while these intervals are in particular insertion devices phase shifted so each insertion device places into the fabric "only" each (is n + first) weft, where i is a sequence number of insertion on particular weft insertion point, n is a number of pairs of tension rollers = number of weft insertion points = number of insertion devices.
The sequence of sequential positioning of particular wefts between warp threads for embodiment according to Fig. 1a is such that the first insertion device 51 inserts the first weft 511 between the strands a and f, which form the first weft insertion point 31. The first weft 511 runs clenched between warp threads a and f along circumference of one of the first pair 21 of tension rollers 2 to the second weft insertion point 32 formed by already merged strands a + f and newly added strand e. In determined distance of the first weft 511 behind the second weft insertion point 32 (according to desired distance between particular wefts in produced fabric) the second insertion device 52 performs insertion of the second weft 522 between already merged strands a + f and newly added strand e. The first weft 511 and the second weft 522 already clenched between strands a, f and e travel along circumference of one of the second pair 22 of tension rollers 2 to the third weft insertion point 33 formed by already merged strands a + f + e and newly added strand d, while in particular point of the second weft 522 behind the third weft insertion point 33 (according to desired distance between particular wefts in manufactured fabric) performs the third insertion device 53 insertion of the third weft 533 between already merged strands a + f + e and newly added strand d. First, second and third weft 511, 522, 533 clenched between already merged strands a + f + e + d travel along circumference of one of the third pair 23 of tension rollers 2 to the fourth weft insertion point 34 formed by already merged strands a + f + e + d and newly added strand c, while in the designated point of the third weft 533 behind the fourth weft insertion point 34 (according to desired distance between particular wefts in produced fabric) performs the fourth insertion device 54 insertion of the fourth weft 544 between already merged strands a + f + e + d and newly added strand c . First, second, third and fourth weft 511, 522, 533, 544 clenched between already merged strands a + f + e + d + c travel along circumference of one of the fourth pair 24 of tension rollers 2 to the fifth weft insertion point 35 formed by already merged strands a + f + e + d + c and newly added strand b, while in the designated point of the fourth weft behind the fifth weft insertion point 35 (according to desired distance between particular wefts in produced fabric) performs the fifth insertion device 55 insertion of the fifth weft 555 between already merged strands a + f + e + d + c and newly added strand b. However, still before insertion of the second weft 522 the first insertion device 51 inserts into the first weft insertion point 31 the sixth weft, which is the new first weft 511 from the new series of wefts 511 to 555 inserted in sequence by particular insertion devices 51 to 55. This way the first insertion device 51 performs insertion with ordinal number 2, i.e. i = 2. The distance in fabric between the first weft 511 and the sixth weft (following first weft 511 ) is such that between these two first wefts 511 inserted by means of identical insertion device are in the final fabric positioned second, third, fourth and fifth weft of appropriate series of wefts 511 to 555 of appropriate ordinal number i insertion namely in each cycle repetition of insertion of wefts 511 to 555 on particular weft insertion points 51 to 55.

Claims

Method of laid fabrics production during which are between the warp threads strands (a-f) inserted wefts of required mutual distance, after which is applied an adhesive on the fabric and the fabric is dried, characterized by that warp threads strands (a-f) are supplied between a pair of tension rollers (2), between which they are combined again, while in the point before merging the warp threads strands (a-f) between the tension rollers (2) are between the warp threads inserted wefts by means of which is produced a laid fabric semiproduct with wefts between warp threads which is by wrapping around a part of tension roller circumference drawn-off to a draw-off device (4) for next manufacturing operations of adhesive application and drying.
Method as claimed in Claim 1, characterized by that during and/or after weft insertion between warp threads strands (a-f) is on the weft acted by a stream of an auxiliary medium enhancing positioning of the wefts among warp threads.
Method as claimed in Claim 1 or 2, characterized by that the wefts are inserted by means of air.
Method of laid fabrics production as claimed in any of Claims 1 to 3, characterized by that the warp threads are before the wefts insertion separated into m strands, where m > 2, while these strands then merge in sequence between n pairs of tension rollers, where n = m - 1 and in each point before warp threads strands merging between the tension rollers are between warp threads inserted wefts, while in each point before strands merging is between warp threads inserted each i-(n+first) weft, where i is a sequence number of a weft series inserted on all insertion devices directly one after another, while the fabric is by means of alternating wrapping around a part of tension rollers tensioned and lead towards the draw-off device for next processing.
Device for laid fabrics production comprising means for positioning of warp threads and means for guiding the warp threads through the working path towards draw-off mechanism (4) and next to an adhesive application mechanism and a drying mechanism, characterized by that the means for guiding the warp threads through the working path comprise at least one pair of tension rollers (2), between which are separately supplied always two warp threads strands (a-f) vhile in the warp threads movement direction is a weft insertion device assigned to an area in front of the entry of warp threads between each pair of tension rollers (2) and behind each pair of tension rollers (2) is situated a laid fabric semiproduct tension device on a part of circumference of one of a pair of tension rollers (2), while behind the last pair of tension rollers (2) is situated a draw-off device (4) of laid fabric semi product for next processing.
Device as claimed in Claim 5, characterized by that the laid fabric semi product tension device on a part of circumference of one of a pair of tension rollers (2) is formed by the first tension roller (2) from the following pair of tension rollers (2) and/or it is formed by a draw-off roller (4) of the laid fabric draw-off device, while there is established working path of the laid fabric semiproduct continuously crossing in an alternating direction from one tension roller (2) to another and next to the draw-off roller (4) of the draw-off device.
Device as claimed in any of Claims 5 or 6, characterized by that the weft insertion device is formed by the air insertion device with an air insertion jet (6).
Device as claimed in any of Claims 5 to 7, characterized by that the weft insertion device comprise an auxiliary weft insertion device (60).
Device as claimed in any of Claims 5 to 8, characterized by that the pair of tension rollers (2) and weft insertion devices assigned to them are situated one over the other.