DK147626B - PRIMARY BUNDLE FOR TUFFED TAPES - Google Patents

Description

in 147626

The invention relates to a primary base for tufted carpets of the kind specified in the preamble to the claim.

A tufted rug has at least two parts. The first is a primary bottom and the second is tufted loop loops that usually pass through and are supported by the primary bottom. In a tufted rug, loop loops, which are either cut or not cut, emerge from one side and are usually associated with loops on the opposite side or the floor side.

Fine mesh tufting means tufts with approx. 4 or more tufts needles per cm in the firing direction. Fine masks generally range from approx. 0.25 cm to approx.

0.25 cm, which corresponds to 3.9 tufts needles per minute. cm and 0.13 cm corresponds to 7.9 tuftene cm. Head heights, yarn titer and loops per. cm in the chain direction varies from style to style so that no exhaustive correlation can be established for fine mesh tufting. For fine mesh tufting, the pile heights are generally in the range of from 3 mm to approx. 15 mm; luvarn titer ranges from 75 tex to approx.

250 tex, but tex values as high as approx. 300, are unknown and the number of loops per cm in the chain direction ranges from approx. 3.1 to approx. 7.9. As the meshes become finer and the pile heights become shorter, any discontinuities resulting from either needle or band deflection become aesthetically very noticeable.

Woven fabric with a chain of ribbons or strips, such as that described in T.M. Rhodes (cited later), however modified so that the filament yarn is of the multi-filament type, can be used as a primary base in tufted rugs with fine meshes. However, there are still many aesthetic problems associated with insufficient uniformity of the hood. The stability of the tufted support layer is generally not sufficient to avoid deflection and distortion during staining or application of a foam support. Unmistakable is understood the state of the fabric where, due to the tension developed during the weaving, the yarn forms an angle with the warp yarn that deviates from the intended angle of 90 °. It should be noted that distortion of the colored image in tufted rugs with fine meshes generally has a more critically detrimental effect on the aesthetic appearance of the rug than in other types of tufted rugs.

By distortion of the colored image is meant the condition of the tufted carpet where the blanket does not exhibit the desired uniform staining and pattern clarity due to bending and distortion of the tufted carrier layer during staining or application of foam substrates.

It should be noted that attempts to stabilize the woven support layer by applying adhesives to overcome the above disadvantages often have a detrimental effect on the tufts process and, for this reason, generally did not produce a good result.

With the emergence of primary bundles of ribbons or fibers of synthetic polymers, such as the primary bottoms described in H.A. Schwartz et al. in USA. patent no.

3,359,934 (1967) and by T. M. Rhodes of U.S.A. Patent No. 3,110,905 (1964), problems have arisen with the colorability of primary bottoms in general, and in particular those made from polyolefins such as polypropylene and polyethylene resins and the like. The reason for these problems is that, in the event that it cannot be stained with the same dyes as the plywood fibers, the support layer will produce a light shade and impair the desired overall light reflectivity. In addition, the rug will lack the desired uniform staining and pattern clarity after deep staining of the pattern. For the sake of discussion, both of these undesirable aspects of a carrier layer that are not color compatible with the pile loops will be referred to as "color distortion" problems.

Of the many methods which have been attempted to solve color distortion problems, only the attainment of dye-compatible fibers with the pile loops in sufficient quantities to form a thin sub-surface of fibers visually covering the specified support layer has gained widespread commercial application. The method of obtaining fibers on a support layer is described by R.H.

Kimmel et al. in USA. Patent No. 3,605,666 (1971). A primary bottom made using this method comprising wetting will throughout this specification be referred to as a primary bottom with the applied cover.

It should be noted that the reason for using different types of fibers for the carrier layer relative to those used in the pile loops is dictated by commercial considerations in the sense that colorable pile loops are generally much more expensive than the material used to form the support layer for the primary base.

However, there are several drawbacks associated with both fabrication and properties of primary bottoms with a stitched cover layer. These are: (1) production rates for the needle process decrease with decreasing fiber titer values, growing weights of the web, and increasing number of needle stitches / cm, and there are also noise problems with the needle process; (2) some of the effective covering force of the needled fibers is lost due to a portion of the needled fibers extending through to the underside of the support layer; (3) the fibers in the fibrous web formed by carding may tend to work their way through and out of the primary bottom with padded cover (fiber bleed) having adverse effects on the properties and appearance of the finished carpet; (4) although finer fibers produce greater coverage / web weight of the pigmented, colored or color compatible fiber layer, it is practically limited to how far one can go into fiber fineness because the needle stitching process is slower the finer the fibers; (5) tuft locking (measured in accordance with ASTM D-1335-67) is reduced in a primary bottom which has been reached before tufting; and (6) the total fracture strength of a tufted primary base is reduced by the needle stitching process.

It is an object of the invention to provide a primary bottom for a tufted rug and of the kind specified in the preamble to the claim, which primary floor must eliminate all or substantially all of the foregoing technical disadvantages set forth in (1) to (6).

The primary bottom according to the invention is characterized by the characterizing part of the claim. It has been found that at the primary bottom according to the invention, the covering layer can be completely absent, since the support layer and the web can be sufficiently bonded together by a melt bond produced by heat and pressure influence.

It is known from DK Patent Application No. 877/71, DK Patent No. 133 038, DE Publication No. 2 237 599 and US Patent No. 3,955,022 primary bottoms to tufted carpets, which primary bottoms have a woven or nonwoven support layer, to which a fiber layer is bonded which can be dyed with the same dyes as the pile yarns to be used in tufting. However, for none of these primary bonds, the web and the carrier layer are bound together only by a melt bond.

Thus, according to the invention, there is provided a primary bottom, especially for fine-mesh tufted rugs, which overcomes many of the above-mentioned problems with fine-mesh tufting.

In a particularly preferred embodiment of the primary bottom, the thermoplastic support layer is woven, at least the weft yarn is a multifilament yarn having a total titer between 200 and 1500 dtex, and between approx. 2 and 20 dtex'per filament. The warp yarn has a titer between approx. 200 and 1500 dtex, and the nonwoven web contains both hot melt and non hot melt fibers.

2 Weight per m of the nonwoven web is preferably 5 to 50 g, in particular, however, less than ca. The woven thermoplastic support layer may be made from flat strips or at least in the firing direction may consist of multiple filaments. The support layer may be made of a polymer of one or more 1-alkenes of up to 8 carbon atoms and may itself be tuftable.

The primary base according to the invention can be made by depositing a web of fibers on a woven, non-woven or knitted support layer by conventional machinery, such as that which can be purchased from Hergeth AG, Maschinenfabrik und Apparatebau Duelmen FRG, where the specified web is heat-fusible to the support layer, and that it is heat-melting the web to the support layer. The term "heat-fusible" in this specification is defined by claiming the ability to form a bond under the influence of both heat and pressure. The web generally consists of a mixture of two fiber types, the first of which may be at least partially colored, colorable, coated or pigmented, heat-fusible to the support layer at a temperature equal to or below the heat or melt fusion temperature of the support layer. , and which also shows good results during and preferably at least approx. 2.8 ° C below the melting point (determined according to A5TM D 2117-64) of another fiber species in the mixture. Preferably, the second fiber type is at least partially color compatible with the tufted loop loops to be introduced later to form a tufted rug.

The second type of fiber may also be at least a partially colorable or pigmented fiber, and is not in itself fusible or heat-meltable to the support layer.

The first fiber type provides the bond of the second fiber species in the path to the carrier layer and provides the carrier layer with color coverage, optionally with the second fiber type. In this specification, with claims everywhere, it is sought that the term "fiber type" should involve the possibility of one or more different fibers in the same class, i.e. one or more primary fiber species heat-fusible with the support layer, and one or more secondary fiber species not heat-fusible with the support layer.

Methods for producing a dyeable fiber such as e.g. a polyalkene fiber by incorporating a color-receptive additive is disclosed in U.S.A. Patents Nos. 3,819,758 (1974), 3,834,870 (1974), 3,820,949 (1974), and 3,926,553 (1975).

Methods for preparing a pigmented fiber such as e.g. a pigmented polyalkylene fiber, is well known in the art.

It should be noted that the support layer alone is generally capable of being tufted 2 and that the weight per unit weight is equal to the weight. m of the nonwoven web which consists of primary and secondary fiber species and which is bonded to the support layer is preferably as small as possible but sufficient to provide as high a dimensional stability as may be required in subsequent steps of carpet making, as well as sufficient coverage to avoid significant color distortion problems. In general, this fiber web will not be tuftable unless it is bonded to the indicated support layer. A support layer which alone is not capable of being tufted must achieve such ability after a fiber web has been bonded thereto.

In general, the greater the peel strength, the greater the weight percent of binder fiber, based on the total weight of the web. The yarn titer and the length of the fibers in the web cannot be arbitrarily selected, but must be chosen so that no obscurity, i.e. non-uniformity of a mapped trajectory. Fiber lengths of considerably greater than 150 mm can be used, provided that sufficiently large yarn titers are used. As the titer of a fiber approaches 1.2 dtex and its length progressively becomes greater than 150 mm, the haze becomes an ever-growing problem.

A method of making a primary base for rugs with tufted pile loops comprises: (1) forming a web of fibers on a woven, non-woven or knitted carrier layer, capable of being tufted with pile loops, both in denier and mesh. ranges from coarse to fine, wherein the web comprises 5 to 100%, preferably 15 to 100% by weight, relative to the total weight of the web, of a primary fiber type which is heat or melt-bondable to the support layer and which is at least partially may be colorable, pigmented or colored and having a titer of at least 1.2 dtex and a fiber length of at least 5 mm and 95 to 0.0%, preferably 85 to 0.0% by weight, relative to the total weight of the web, of a secondary fiber type which may be at least partially color compatible with the tufted pile loops, colorable or pigmented, and having a titer of at least 1.2 dtex and a fiber length of at least 5 mm; and (2) making use of heat and pressure to produce both a bond between the first fiber species and the support layer, and - in the case where a secondary fiber species is used - a bond between the primary fiber species and the secondary fiber type whereby the web is bonded to the support layer.

Path weights are generally as low as possible, however, sufficient dimensional stability and coverage capability must be achieved to avoid significant color distortion problems. One web weight per m of at least 3 g is needed 2. Path weights per m which have been found to be satisfactory generally ranges from 3 to 70 g, preferably in the range of 5 to 50 g.

2

Gram intervals in lane weights per m for commercial primary bottoms with stitched cover layer is approx. 33 to 135 g.

The web weight to achieve a particular level of coverage depends, among other things, on the depth of the color from the dye or pigment used in the fibers present in the web. In view of the improved traceability achieved by the present invention, compared to primary bottoms with padded topcoats, there are particular advantages in using web weights below approx. 25 g / m. A particular technical advantage of the primary bottoms according to the invention is that it is possible to use web weights below 25 g / m to obtain the same coverage or better coverage in tufted carpets than with primary floors with stitched cover layers where web weights of between approx. 33 and 135 g / m. Thus, tufted carpets made with primary bottoms according to the invention can be produced using a considerably smaller weight of colorable, pigmented or stained web than tufted carpets produced with primary bottoms with sealed cover layers.

1A7626 9

The indicated secondary fiber type comprises fibers which are not heat-fusible to the support layer so that only bonds between the primary fiber type and the secondary fiber type can occur.

In general, any carrier layer, woven, nonwoven or knitted, capable of being tufted can be used to which heat-meltable, thermoplastic fibers can be heat- or pressure-bonded. Thermoplastic support layers useful in accordance with the invention may be made of polyalkenes, polyamides, polyesters, vinyl polymers and acrylate polymers.

Woven support layers containing fibers which are preferably flat fibers of rectangular cross-section and having a dtex value of 200 to 1500 dtex (decigram / kilometer) in both the warp yarn and the yarn, in particular with 3.9 to 11.8 weft yarns. cm, are particularly useful. In the case of fine-mesh tufted rugs, these woven backing layers preferably consist of multifilament yarns with single filaments between approx. 2 and approx. 20 dtex with round or multilobal cross sections. The multifilament yarn preferably has 10 to 20 turns per minute. m.

The heat and pressure bonding can be made by passing the layers between two counter-rotating rollers, the one closest to the cover layer being heated to a temperature sufficient to produce heat fusion between the primary fiber species, i.e. the heat-meltable fiber species, and the support layer, and the bond is produced in the case of a secondary fiber species, between the primary fiber type and the secondary fiber species, without seriously softening the other fiber species, i.e. the temperature is below, and preferably at least 2.8 °, below the melting point of the secondary fiber. For example, if using a polyamide-6 fiber and a fiber of 147626 and a polypropylene or other polymer substrate made from one or more 1-alkenes of up to 8 carbon atoms, the temperature indicated is in the range of about 160 and 200 ° C, i.e. the melt-fusion temperature range of polypropylene. The other of the counter-rotating rollers contacts the uncovered side of the support layer and is heated to a temperature in the range of about 10 to about 100 mm. 0 and 160 ° C, and the linear pressure in the constriction can be up to approx.

350 Kp per linear cm. The linear velocity of the support layer in the machine direction through the narrowing is in the range of up to approx. 60 m / minute.

Several arrangements involving both smooth and embossed rollers can be used. In a first arrangement, a smooth steel roller or chrome plated roller contacts the cover layer, and either an embossed roller or a smooth roller with a flexible or deformable surface contacts the uncovered side of the support layer. An example of such a deformable surface is one covered with cotton-made paper. In this first arrangement, the pressure is preferably between ca. 180 Kp / linear cm and approx. 300 Kp / linear cm. With a pressure well below 180 Kp / cm, the fiber web does not adhere well to the support layer, but with a pressure well above 350 Kp / cm, the support layer can be adversely affected. In another arrangement, an embossed roller contacts the tire layer and the opposite side contacts either a smooth steel roller or one having a deformable surface, such as e.g. a surface of paper made of cotton. In the second arrangement, the pressure is preferably between approx. 20 Kp / linear cm and approx. 180 Kp / linear cm. With a pressure well below 20 Kp / linear cm, the fiber web does not adhere well to the support layer, but with a pressure well above 180 Kp / linear cm, the support layer can be adversely affected.

In general, the number of protrusions of the pre-formed roller in both arrangements is in the range of approx.

2 and 80 projections / cm, preferably in the range of about 30 and 50 projections / cm, providing an effective embossed area of approx. 10-50 µm, preferably 20 - 40 µm of the surface of the primary substrate.

In connection with the second arrangement, the peel strength of the fiber web from the support layer will generally be greater the greater the number of projections / cm when all other factors such as the square meter weight of the cover layer, linear pressure and temperature of the calender rolls, and linear velocity in machine direction, kept constant.

Furthermore, the optimum height of projections is mainly determined by the wear rates of these projections.

When using a roller with a non-deformable surface, such as a chromium plated roller, as opposed to the embossed roller, with decreasing heights of projections, there is a tendency for calendered webs to adhere to the embossed calender roller instead of being easily separated therefrom. treatment. However, when using a deformable roll, such as one coated with cotton made of paper, there is a substantial reduction in this tendency of adhesion to the point where it does not interfere with the treatment.

The temperature of the calender rolls will depend in part on the thermal density and thermal conductivity of the nonwoven 2 web and the weight per unit weight. m thereof and the velocity of the support layer through the narrowing in the machine direction. If the track is heavier, higher temperatures and lower speeds are preferred. In general, higher temperatures tend to allow greater speeds of the carrier layer in the machine direction.

It is important to note, however, that the speed of the needle process is largely dependent on the yarn titers and / or web weights, but that the speed of the calendering process is not significantly influenced by the yarn titre and / or web weights.

Other heating methods that can be used in conjunction with pressure to achieve bonding of a web to a support layer are infrared radiation, ultrasonic, magnetic and dielectric heating of suitable coatings and / or fiber components.

Primary bottoms made using the above methods are suitable for tufting with a pile weight in the range of 150 to 2000 g / m, and a height in the range of 3 to 30 mm. generally larger, especially where fine titer fiber webs are used, significantly larger than for a primary bottom with sealed cover.

It has been found, for a given support layer and a tufted loop, that the tuft lock for the primary floor according to the invention is substantially larger than the tuft lock obtainable in a primary floor with a worn cover layer.

It has been found that, in order to obtain the same color-compliant fiber cover factor in a primary base according to the invention, in comparison with a primary base with sealed cover layer, only half the weight of the color-compatible fibers in the nonwoven web is required.

The web is formed on the support layer by conventional web forming agents, such as e.g. a conventional mapping machine orienting the fibers in one direction, or the fibers may be randomly oriented by means of a random mapping, as is the case with a Fehrer K 12, or a cross path may be used.

147626 13

After forming the web on the support layer, the material is fed to a calender having the temperature which largely depends on the melting point (ASTM D 2117-64) of the heat-meltable fiber present in the web. It will usually be lower than approx. 300 ° C and must be carefully controlled to avoid the tendency of the web to wrap around the heated rollers. More specifically, the materials having a low softening point can be calendered between rollers having a temperature of approx.

150 ° C. The pressure of the calender should preferably be dimensioned to allow linear pressures of up to approx.

350 Kp / linear cm. Static electricity buildup problems can be avoided by treating the web with moisture during treatment and / or by maintaining a relative humidity of approx. 60¾ in the furthest area in the flow direction of the material.

EXAMPLE 1

A nonwoven web weighing 20 g / m consisting of 30 wt o matt polypropylene fibers with a titer of 3.1 dtex and a length of 60 mm, and 70 wt o matte polyamide fibers having a denier value of 3 , 5 dtex and a length of 60 mm were made in a cart line from Hergeth, consisting of a bale opener of type MBL, a pre-opener, a material transport fan of type TV 300, a starting material control, a vibrating slit of type DS, a compact mapping machine of type JK and an edge remover. The limit viscosity measured with an Ubbelohde viscometer in a concentration range between 1 g and 62.5 mg per ml. The 100 ml solvent of the polyamide fiber determined according to ASTM D 789 at 20 ° C was 57 ml / g in m-cresol and 35 ml / g in 90¾ formic acid. The melt flow of the polypropylene determined according to a modified version of ASTM D 1238 was 13 g / 10 minutes at 190 ° C and 2.16 Kp force.

The fiber layer consisting of these fibers was led to the upper narrowing of a three-roll calender (type RKK 340 from Ramisch Kleinewefers), where this fiber layer 147626 14 is distributed on a support layer in the form of a polypropylene woven fabric with the style number 2400 sold from Patchogue

Plymouth. Style 2400 is a smooth weave with 9.4 shots 2 pr. cm and with a weight per m of 107.7 g. The titer of the warp yarn fiber is 525 dtex and the titer of the shot yarn fiber is 1050 dtex. The upper roller of this calender has an embossing pattern and the middle roller is a smooth steel roller. The rollers are heated with a flow of hot oil under controlled pressure, and in the present case the upper roller had a temperature of 195 ° C and the lower roller had a temperature of 130 ° C. The composite structure was embossed at a pressure of 80 daN / cm and treated at a rate of 14 m / min.

Peel strength

The adhesion between the cover layer and the support layer (determined according to a modified version of the test technique specified in DIN 53530) exhibited a value of 3 N compared to the adhesion found for the cover layer in a primary base with the applied cover layer, corresponding to a value close to 2 N.

The modified portion of the sample comprises the adhesive on the cover of an adhesive tape, such as that sold by Beiersdorf AG, Hamburg, which adhesive tape is then rolled twice with a 4.2 kg metal roller with a width greater than the sample; thereby providing a better adhesion to the cover layer. The sample is trimmed at each edge to produce a width of 50 mm. The cover layer with the adhesive paper on top is separated from the support layer over a specified portion, corresponding to the fact that the support layer can only be secured in the stationary jaw of the specimen specified later. The support layer is then secured in the stationary jaw and the laminate consisting of the cover layer and the adhesive paper is secured in the moving jaw of the breaking strength test apparatus described in DIN 51221. The breaking strength is then determined according to DIN 53530 by means of an analysis according to DIN 53357, namely by pulling the jaws apart to measure the force required to tear the layers apart.

Test of_turn lock ° 9_tufte ability ^

A piece of the primary bottom, 10 m long, 1 m wide and made according to the above method, was tufted. The loop loops are formed of a twisted yarn consisting of two single yarns of 1260 dtex fiber made from 100 ό nylon 6, with a 0.64 cm pile height and a distance between two consecutive tufts, measured in the firing direction, of 0.4 cm, and a pile weight of approx. 520 g / cm. The appearance of this product was determined by visual inspection by two technicians who made independent observations.

Tufted lock according to a slightly modified version of ASTM D 1335-67, i.e. The use of only one tufts clip and loop hook, but not a cylindrical specimen holder of the cut-off type, was measured for a primary bottom with pinned cover layer and the primary bottom was prepared according to the example. Each primary bottom was tufted under the same conditions with the same pile yarn as described above. In the case of the tufted primary bottom with pinned cover layer a value of 85 cN was found and in the case of the tufted primary bottom of the invention a value of 140 cN was found.

Breaking tension of a tufted rug made with primary bottoms according to the invention and with a sealed cover.

Two pieces of primary bottoms are prepared by the process set forth in Example 1. Two different tufts operations are then applied to each of these, one at 3.1 loops per unit. cm and the other with 2.6 loops per cm. cm. The pile loops have a spacing of 0.4 cm, measured in the firing direction, and the pile loops consist of two single polyamide-6 yarns with 1260 deniers, which were joined together to form a single yarn. The tufted rug is then stained by means of a staining process comprising raising in a dye bath prior to determining fracture strength in the warp and weft directions. The results in deca-Newton, daN, are summarized as follows:

Direction Primary bottom with the fabric Product according to the _decklaq_ invention__ I just finished After you just finished- By condition tufting you state tufting Chain 42 40 * 50 46 *

Shots 56 26 * 64 29 * «eat 42 42 ** 50 48 **

Shots 56 23 ** 64 27 **

Tufted with 2.6 loops / cm.

Tufted with 3.1 loops / cm.

EXAMPLE 2 About Pigmented Polypropylene Used in the Primary Bottom of the Invention1 70 parts of an Amoco 5013 polypropylene for 1 part of polypropylene, D 1937, sold by Hercules, were melt blended and extruded and oriented to fibers with a titer of 3.1 dtex. The main difference between the two polypropylenes is that the D 1937 quality contains 35% by weight of carbon black, which is not the case with the Amoco 5013 quality.

A fiber web of 25 parts of the above pigmented polypropylene to 75 parts of the above non-pigmented polypropylene fiber, each having a titer of 3.1 dtex and a length of 60 mm, was formed at style number 2400 and fused thereto using of the method described in Example 1 as a method of preparing a primary bottom according to the invention.

The results were satisfactory.

Example 3: About a colorable polypropylene used in the primary bottom of the invention

A fiber made of polypropylene containing 2% by weight of poly (1,3-di- (4-piperidyl) propane adipamide) based on the weight of Amoco 5013 polypropylene was used in the same manner as the pigmented polypropylene in previous examples.

The primary base was tufted and stained by immersion in an aqueous solution containing as the only dye 0.5 wt% Terasil Blue BGL (CI Disperse Blue 73), 2 wt% wetting agent and a sufficient amount of formic acid to give a pH of 5 at a liquid ratio of 50: 1.

The blanket was placed in a bath at 50 ° C. The temperature of the bath was raised to the boiling point and kept there for 1 hour. The blanket was then rinsed and kept in an aqueous 2% wetting agent for 15 minutes at 50 ° C.

The results regarding the staining were satisfactory.

Example 4: About primary bottoms using different fiber weight ratios

Primed carpets for tufted carpets have been prepared using the method of Example 1 for a process for making primary carcasses according to the invention, according to the following table: 18 U7626 Weight of carrier layer m Polyamide-6 Polypropylene 48 20 7: 3 110 20 7: 3 250 20 7: 3 600 20 7: 3 110 20 9: 1 110 20 7: 3 110 20 5: 5 110 20 3: 7 110 20 1: 9 110 20 0: 10 110 8 7: 3 110 12 7: 3 110 16 7: 3 110 20 7: 3 110 25 7: 3 110 30 7: 3 110 40 7: 3 110 50 7: 3 110 20 7: 3

The above table shows the relationship between the specific weight of the support layer, the specific weight of the web and the weight ratio of the two specifically specified components of the web, in connection with the primary bottoms of the invention.

EXAMPLE 5: About primary bottoms especially suitable for tufted rugs with fine mesh.

A heat-meltable web having a surface weight of 25 g / m is applied as described in Example 1 on both sides of a smooth woven support layer during two consecutive calendering steps.

The smooth weave exhibits 10.2 warp yarns. cm and 4.3 shotgun per cm in the shot. Both warp and weft yarns are 500 dtex multifilament yarns, with each filament being approx. 5 dtex and has a round cross section and the yarn has approx. 15 turns per day m. The web consists of 100% by weight of polypropylene heat-meltable fibers, as set forth in Example 3, with a titer of 3.1 dtex and a length of 60 mm.

A bond is formed between the web and the support layer in the constriction of the two counter-rotating rollers. One of the listed