Roller card, particularly for preparing non-woven textile webs and slivers for semi-worsted yarns

Abstract

 A card, particularly for preparing non-woven textile webs and slivers for semi-worsted yams, has multiple carding urits, (I. III) each including a cylinder (D, G) and roll combing means which cooperate with the cylinder and with which roller conveyor means are associated for conveyance to the next carding unit, in which the combing means of the final carding unit (III) include two combing rolls (H1, H2) cooperating with doffer members (P1, P2).
The combing means of the or each carding unit (I) before the final carding unit (III) include at least two combing rolls (El, E2) each with a respective associated conveyor roller (F1, F2).

Description

[0001] The present invention relates generally to cards with multiple carding units, particularly for preparing non-woven textile webs and slivers for semi-worsted yarns.

[0002] In particular, the invention concerns a roller card of the type including at least one first stage, at least one second stage, and a third stage, in which:

- the or each first stage includes a licker-in unit for the supply of staple fibres to a first carding unit formed by a cylinder and intermediate roll combing means cooperating with the cylinder,

- the or each second stage includes roller conveyor means supplied by the intermediate combing means, and

- the third stage includes a second carding unit formed by a cylinder supplied by the roller conveyor means and at least two output combing rolls cooperating with the cylinder, and doffer means fed by the output combing rolls.

[0003] Roller cards of this type are generally provided with a single first stage and a single second stage which form, with the third stage, a card with two carding units of which the first serves to supply and rough the material, and the second to improve the opening, distribute the fibre, and to form and discharge the web.

[0004] The presence of two output combing rolls instead of a single output comber allows the production to be improved from both the quantitative and qualitative aspects, since the web or sliver leaving the machine is composed of two layers with greater homogeneity and strength for the same weight as a web composed of a single layer. Furthermore, the possibility of superposing two layers allows a web or sliver of greater unit weight to be obtained.

[0005] The object of the present invention is to provide a card of the type specified above, which is able further to improve the productivity of the machine and the quality of the web or sliver produced by the machine.

[0006] According to the invention, this object is achieved by virtue of the fact that the intermediate combing means include at least two intermediate combing rolls for forming respective webs, and the conveyor means include at least two conveyor rollers each cooperating with a respective intermediate combing roll.

[0007] This characteristic considerably increases the advantages due to the presence of two output combing rolls in that the presence of two or more intermediate combing rolls, with their respective conveyor rollers, allows the cylinder of the third stage to be supplied with a greater quantity of fibre, thus achieving greater production and improved quality in terms of homogeneity and strength of the final web or sliver.

[0008] Preferably, the cylinder of the or each first stage is covered by a cloth with a low angular value and with pointed ends facing in the direction of rotation, which corresponds to that of the advance of the material.

[0009] Conveniently, however, the intermediate combers are covered by cloths with a high angular value and with pointed ends facing in the opposite direction from that of rotation.

[0010] The intermediate combers may be covered by cloths with different angles and densities, and may have different peripheral velocities.

[0011] The conveyor rollers have cloths with pointed, ends facing in the opposite direction from that of the advance of the material and strip the two combers by drawing (peripheral velocity greater than that of the combers) or by "condensation" (peripheral velocity lower than that of the combers), transferring the web just formed to the cylinder of the final stage without altering its characteristics.

[0012] The invention will now be described in detail with reference to the appended drawings, provided purely by way of non-limiting example, in which:

Figure 1 is a schematic illustration of a roller card according to the invention, and

Figure 2 illustrates part of Figure 1 on an enlarged scale.

[0013] The embodiment illustrated in the drawings relates to a roller card with two carding units, particularly for producing non-woven textile webs and slivers for semi-worsted yarns. It should be noted, however, that what is described below can also be applied to cards having a greater number of carding units.

[0014] The card illustrated is composed of a first stage generally indicated I, a second stage generally indicated II, and a third section generally indicated III.

[0015] Stage I includes an endless-belt feed conveyor A for supplying staple fibres to opening members with rolls B, C, and a first carding unit consisting of a cylinder D and two intermediate combing rolls E₁, E₂. The senses of rotation of the rollers B, C, D,E₁ and E₂ are those indicated by arrows in the drawings.

[0016] Preferably, the cylinder D is covered by a cloth with a low angular value and pointed ends facing in the direction of rotation, that is, in the direction of advance of the material.

[0017] The two intermediate combers E₁, E_2' which replace the single intermediate comber present in conventional cards, are covered, however, by cloths with a high angular value and with pointed ends facing in the opposite direction from that of the rotation.

[0018] It should be noted that the two intermediate combers E₁, E₂ may be covered by cloths with angles and densities that are the same or different, and may have the same or different peripheral velocities.

[0019] Stage II is constituted by two conveyor or doffer rollers F₁, F₂ each of which cooperates with a respective intermediate comber E₁, E₂. The two conveyor rollers F₁, F₂₁ which in practice act as transfer members between stage I and stage III, are covered by cloths with pointed ends facing in the direction of rotation indicated by the arrows, and may have a peripheral velocity greater than or less than that of the respective intermediate combers E₁, E₂. In the first case, the stripping action exerted by the conveyor rollers F₁, F₂ on the respective intermediate combers E₁, E₂ occurs by a drawing action, while in the second case it is achieved by "condensation".

[0020] Stage III includes a second carding unit formed by a cylinder G and by two output combers H₁, H₂ rotatable in the senses indicated by the respective arrows. The two combers Hit H₂ supply respective doffer members Pit P₂.

[0021] As stated above, stages I, II and III form a card with two carding units, in which stage I serves to supply and rough the material and stage III serves to improve the opening, distribute the fibre, and to form and discharge the web or sliver.

[0022] The function of the two intermediate combers E₁, E₂ is that of collecting the fibres from the cylinder D on their surfaces to form two webs. The two webs formed in the first stage are conveyed by means of the two conveyor rollers F₁, F₂ to stage III. The latter is thus supplied with a greater quantity of fibres, achieving greater production and better quality of the web or sliver. In fact, the clearing of the cylinder D by the two intermediate combers E₁, E₂ halves the faults in the feed onto the cylinder G, in that the supplied collections of fibres are separated into two different paths. Thus, in practice, it is possible to obtain a web with considerable homogeneity and uniformity even from the first stage of the card and even when starting with staple fibres of very different densities (different fibre qualities, deniers and lengths).

[0023] On the other hand, the greater production obtainable with two (or more) intermediate combing rolls . permits the use of finer cloths of greater carding power from stage I, thus allowing a further improvement in the quality of the final product.

[0024] Furthermore, the presence of two (or more) intermediate combers allows them to have different peripheral velocities and hence different dispositions of the fibres on their surfaces, thereby increasing the uniformity of the webs.

[0025] These advantages are added to those achieved by the presence of two (or more) output combers whereby, in conclusion, the card according to the invention allows substantial improvements to be obtained in the final product from both the quantitative and qualitative aspects, in terms of greater homogeneity and strength as well as greater unit weights of the webs.

[0026] Naturally, the constructional details and forms of embodiment may be varied widely with respect to that described and illustrated, without thereby departing from the scope of the present invention.

Claims

1. Roller card, particularly for preparing non-woven textile webs and slivers for semi-worsted yarns, including at least one first stage, at least one second stage and a third stage, in which:

- the or each first stage includes a licker-in unit for the supply of staple fibres to a first carding unit formed by a cylinder and intermediate roll combing means cooperating with the cylinder,

- the or each second stage includes roller conveyor means supplied by the intermediate combing means, and

- the third stage includes a second carding unit formed by a cylinder supplied by the roller conveyor means and at least two output combing rolls cooperating with the cylinder, and doffer members fed by the output combing rolls, characterised in that the intermediate combing means include at least two intermediate combing rolls (E₁, E₂) for forming respective webs, and the conveyor means include at least two conveyor rollers (F₁, F₂) each cooperating with a respective intermediate combing roll (E₁, E₂).

2. Card according to Claim 1, characterised in that the two intermediate combers (E_1' E₂) are covered by cloths with a high angular value and with pointed ends facing in the opposite direction from that of rotation.

3. Card according to Claim 2, characterised in that the two .intermediate combers (E₁, E₂) are covered by cloths with different angles and densities.

4. Card according to Claim 2, characterised in that the two intermediate combers (E₁, E₂) are covered by cloths with the same angle and density.

5. Card according to Claim 2, characterised in that the two intermediate combers (E₁, E₂) are driven at different peripheral velocities.

6. Card according to Claim 2, characterised in that the two intermediate combers (E₁, E₂) are driven at the same peripheral velocity.

7. Card according to any one of the preceding claims, characterised in that the conveyor rollers (F₁, F₂) are driven at greater peripheral velocities than the respective intermediate combers (E₁, ^E₂).

8. Card according to any one of Claims 1 to 6, characterised in that the conveyor rollers (F₁, F₂) are driven at lower peripheral velocities than the respective intermediate combers (E₁, E₂).

9. Card according to any one of Claims 1 to 6, characterised in that the conveyor rollers (F₁, F₂) are driven one at a greater peripheral velocity and the other at a lower peripheral velocity than the respective intermediate combers (E₁, E₂).

Drawing