GB2070077A - Method of Making Stitch- bonded Textile Fabric - Google Patents

Abstract

In a stitch-bonding machine rows of simple chain stitches are inserted into a non-woven fleece 2 to consolidate and reinforce the latter using known needles 14 and slide wires 20 reciprocating and interacting in known manner. Known yarn guides 22 moving in known manner each lap at least two stitching yarns Y into notch 16 of the same needle. The yarns are synthetic multifilament flat yarns having little or no twist. Each row of stitches formed from each yarn pair exhibits significant resistance to laddering. <IMAGE>

Description

SPECIFICATION Method of Making Stitch-bonded Textile Fabric This invention concerns a method ofmaking stitch-bonded textile fabric of the type comprising a non-woven fibrous web or fleece consolidated and reinforced by a plurality of rows of yarn stitches inserted into the web.

Using known stitch-bonding apparatus, a conventional method of making stitch-bonded fabric of the aforesaid type comprises progressing a non-woven fibrous web or fleece through a stitch insertion zone wherein a plurality of hooked needles to insert the rows of stitches are reciprocated forwards and backwards through the web, each needle cooperating with a respective moving slide wire controlling opening and closing of the needle hook, providing a number of stitching yarns each corresponding to a respective said needle, providing a plurality of moving yarn guides each controlling a respective single said yarn and lapping a loop of a said single yarn into the open hook of the respective needle at the front of the web, moving the needle backwards to draw the loop in the notch through the web, translating the loop from the hook so that the loop extends about a shank of the needle and the respective slide wire during the next forward movement of the needle, and during the next rearward movement of the needle the next yarn loop lapped into the hook by the corresponding said yarn guide being pulled back by the hook and drawn through the first mentioned loop as that latter is knocked off the needle by interaction between the first mentioned loop and knock-over means at the rear of the web.

In the resultant fabric formed by this conventional method, the web is consolidated and reinforced by rows of simple chain stitches, each row being produced from a single stitch yarn. Unfortunately the rows of stitches can ladder rather easily.

One proposal to avoid this requires the closing of the needle hooks by the slides wires to be delayed, after a said single yarn is lapped into the open notch of the corresponding needle, until the hooks have moved back into the web. In this way each open hook seizes and pulls back a loop of fibres from the web with the intention of interengaging each stitch, formed in a row of stitches, with a fibre loop to prevent laddering of the stitch row. This proposal has the disadvantage of requiring the motion of the slide wires on a conventional machine to be changed in order to produce the delay usually by the fitting of nonconventional parts to change the timing of the slide wires which adds to the expense and can be time consuming to get the machine running properly.Further disadvantages of the proposal to pull loops of fibres from the web are that the web, which is the main constituent of the fabric, is being continually disturbed resulting in fabric faults such as irregular needle hole size, web irregularities, and failure to produce a regular locked stitch structure especially when the web weight or density is low. The proposal can also cause mechanical faults such as overloading of the needle by the fibre loops.

During experiments with a conventional stitch bonding machine, we have made the surprising discovery that by using wholly conventional parts and without altering the timing of the machine, stitch-bonded fabric of the aforesaid type can be produced in which the rows of stitches exhibit significant resistance to laddering.

According to the invention a method of making stitch-bonded fabric in which a non-woven fibrous web or fleece is consolidated and reinforced by a plurality of rows of yarn stitches inserted into the web comprises progressing a non-woven fibrous web or fleece through a stitch insertion zone wherein a plurality of hooked needles to insert the rows of stitches are reciprocated forwards and backwards through the web, each needle cooperating with a respective moving slide wire controlling opening and closing of the needle hook, providing a number of multifilament stitching yarns each having no twist or only a small amount of twist, providing a plurality of moving yarn guides each corresponding to a respective said needle, each said yarn guide controlling a plurality of said yarns and substantially simultaneously lapping a loop of each yarn in said plurality of yarns into the open hook of the respective needle at the front of web, moving the needle backwards to draw the combination of the loops in the hook through the web, translating the combination of the loops from the hook so that the combination of loops extend about a shank of the needle and the respective slide wire during the next forward movement of the needle, and during the next rearward movement of the needle the next combination of loops from said plurality of yarns lapped in to the hook by the corresponding said yarn guide being pulled back by the hook and drawn through the first mentioned combination of loops as that latter is knocked off the needle by interaction between the first mentioned combination of the loops and knock-over means at the rear of the web.

The same yarn guide is used to lap two or more stitching yarns substantially simultaneously into the hook of the needle corresponding to that guide.

The non-woven fleece used may be any kind known per se in the stitch bonding art.

The stitching yarn used may be any synthetic multifilament flat yarn known per se in the stitch bonding art having no twist or only a small amount of twist. For example the yarn may have a twist of about one third of a turn per metre.

The invention will now be further described, by way of example, with reference to the accompanying drawings in which: Figures 1 to 4 show a diagrammatic fragment, partly in section, of a conventional stitch bonding machine to illustrate successive stages in its operation when operating conventionally to produce stitch-bonded fabric and Figure 5 is an enlarged fragment in perspective, and partly in section, of the machine modified to carry out the method according to the invention.

In the drawings like references refer to like parts.

In the drawings, a non-woven fleece 2 is progressed downwardly in known manner through a throat 4 between a stationary front guide bar 6 and stationary knocking over sinker means 8 provided with spaced, stationary rear guide arms 10 opposite which are spaced, stationary front guide pins 12.

A plurality of horizontal hooked needles 14 are mounted in known manner side by side and reciprocated simultaneously in known manner across the throat and therefore through the fleece. Each needle moves through the space between two adjacent arms 10 at the rear and between two adjacent pins 12 at the front. Each needle has a hook notch 16, and the needle shank has an upper surface grooved longitudinally at 1 8 in which a slide wire 20 is located. The slide wires can close the needle notches and are movable simultaneously back and fourth across the throat.

Corresponding to each needle is a respective yarn guide 22. These yarn guides are moved simultaneously in known manner.

Since the machine is conventional the front guide bar 6, the sinker means 8, the rear guide arms 10, the front guide pins 12, the needles 14, the slide wires 20 and the yarn guides 22 are known per se.

With reference to Figures 1 to 4 each yarn guide controls a single stitching yarn Y in the plurality of yarns supplied, there being as many yarns as there are needles inserting rows R of stitches (only one row R shown) in the fleece.

Starting with Figure 1, the moving yarn guide 22 has already lapped a loop L2 of the yarn Y into the open notch 1 6 of the needle 14 which is at the front end of its forward stroke. The needle then retracts in the direction of arrow A whilst the slide wire 20 remains stationary so that the relative movement between the slide wire and needle results in the slide wire closing the notch 1 6 before the notch fully enters the fleece. Then the slide wire and needle retract together as shown in Figure 2 with loop L2 trapped in the notch.

At the end of the rearward stroke shown approximately in Figure 3 a loop L1 of the yarn formed during the previous cycle of operation is knocked off the needle tip, by the presence of the knocking-over sinker means 8, and slips over the loop L2.

Then the needle 14 is moved forwardly again, but forward movement of the slide wire 20 is delayed to allow the notch 16 to open so that loop L2 rides up from the notch to fit around the needle shank and forwardly moving slide wire travelling in direction B as shown in Figure 4.

At the front of the fleece the front tip of the slide wire is halted behind the notch to allow the yarn guide to lap another loop of yarn Y into the open notch.

Each needle 22 in Figure 1 to 4 inserts a corresponding row R of simpie chain stitches into the fleece.

Figure 5 shows the machine set up to carry out an embodiment of the new method in which each yarn guide 22 controls two yarns Y passing through the eye of the guide so that both yarns are lapped simultaneously into the open notch 1 6 of the needle 14 corresponding to that guide so that the loop L which is a combination of the two yarns is retracted by the needle through fleece.

Each yarn Y in Figure 5 passes singly through a space between an adjacent pair of reeds 24 in a guiding reed 26. The guiding reed is disposed between the yarn guides 22 and yarn supply means, for example a beam (not shown), on which the yarns are wound individually. The yarns may contact the reeds.

The non-woven fleece 2 can be of any kind known per se in the stitch bonding art. For example it may be of 42 denier bright bleached viscose fibre having a staple length of about 100 mm. and having a weight of about 11 5.28 gm/m2 (about 3.4 oz./sq.yd.). Each yarn Y can be any synthetic multifilament flat yarn known per se in the stitch bonding art having no twist or only a small amount of twist. For example, the yarn may have a twist of about one third of a turn per metre. The yarn can be of 167 decitex polyester.

More than two yarns Y can pass through the eye of each yarn guide 22 for lapping into the same notch 1 6 of the needle corresponding to that guide. But care must be exercised to ensure that the total weight and tension of the yarns does not overload the yarn guide or needle.

If desired, a conventional machine used for carrying out the method of the invention may be modified by omitting certain ones from the normal number of yarn guides whereby the machine operates with a lesser number of yarn guides than normal so that only those needles corresponding to retained yarn guides have yarns looped into their notches, whereas the remaining needles corresponding to the omitted yarn guides do not receive yarn. This may give the resultant fabric a markedly ribbed or striped appearance.

For example alternate yarn guides may be omitted from a conventional array of yarn guides so that only alternate needles receive yarn. In a known machine normally intended to have fourteen equispaced yarn guides per 2.54 cms. (per inch) of machine width, the number of equal spaced yarn guides in the modified machine may be seven per 2.54 cms., but the number of needles retained at fourteen per 2.54 cms.

Claims (8)

Claims

1. A method of making stitch-bonded textile fabric in which a non-woven fibrous web or fleece is consolidated and reinforced by a plurality of rows of yarn stitches inserted into the web comprising progressing a non-woven fibrous web or fleece through a stitch insertion zone wherein a plurality of hooked needles to insert the rows of stitches are reciprocated forwards and backwards through the web, each needle cooperating with a respective moving slide wire controlling opening and closing of the needle hook, providing a number of multifilament stitching yarns each having no twist or only a small amount of twist, providing a plurality of moving yarn guides each corresponding to a respective said needle, each said yarn guide controlling a plurality of said yarns and substantially simultaneously lapping a loop of each yarn in said plurality of yarns into the the open hook of the respective needle at the front of web, moving the needle backwards to draw the combination of the loops in the hook through the web, translating the combination of the loops from the hook so that the combination of loops extends about a shank of the needle and the respective slide wire during the next forward movement of the needle, and during the next rearward movement of the needle the next combination of loops from said plurality of yarns lapped in to the hook by the corresponding said yarn guide being pulled back by the hook and drawn through the first mentioned combination of loops as that latter is knocked off the needle by interaction between the first mentioned combination of the loops and knock-over means at the rear of the web.

2. A method as claimed in claim 1 in which the yarns are of synthetic material.

3. A method as claimed in claim 1 or claim 2, in which the yarns are polyester.

4. A method as claimed in any one preceding claim, in which a said yarn has twist of about one third of a turn per metre.

5. A method as claimed in any one preceding claim, in which the web comprises viscose fibres.

6. A method as claimed in any one preceding claim, in which there are other hooked needles reciprocating forwards and backwards through the web, but a plurality of yarns are not lapped into the hook of each of these other needles.

7. A method of making stitch-bonded textile fabric in which a non-woven web of fleece is consolidated and reinforced by a plurality of rows of yarn stitches inserted into the web, substantially as hereinbefore described with reference to Figure 5 of the accompanying drawings.

8. Stitch-bonded textile fabric made by the method claimed in any one preceding claim.