The sheath-core spinning of multilobal conductiveA kind of include one deck be wrapped in the continuous insulation crust of synthetic polymer of the conducting polymer core that contains carbon black and synthetic fiber filament with antistatic property by Hull (Hull) at United States Patent (USP) 3,803, done introduction in No. 453.Core section shown in this patent is circular.In some product purpose occasion, such as the Work Clothes of in clean room, wearing, even require further to eliminate the static tendency, and require the hope that the fiber blackness is hidden opposite with those, require to have higher core visibility.
Core is that the core-skin type long filament of trilobal cross section is that people are known.This core-skin type long filament can adopt United States Patent (USP) 2,936, and the spinnerets of the sort of type of being introduced in No. 483 is made.Although adopt a kind of like this spinnerets can produce useful products of the present invention, then be a target that is worth effort improving aspect the maintenance trilobal core profile by spinning technique.The present invention not only provides the spining technology after a kind of the improvement that a kind of novel long filament that can disperse electric charge rapidly also is provided.
Fig. 1 and Fig. 2 are the cross sectional representation of core-skin type long filament of the present invention, in order to show trilobal and quatrefoil core and how to determine desired structural parameters;
Fig. 3 is along a distribution plate of 3-3 cross section intercepting among Fig. 4 and the partial sectional view of a spinnerets;
Fig. 4 is the bottom view of distribution plate shown in Figure 3.
The present invention has the important content of two aspects.It provide a kind of include one deck be wrapped in the conducting polymer core that constitutes by the conductive black of disperse in the thermoplastic synthetic polymer the synthetic thermoplastic fibres that forms polymer the continuous insulation crust and have the novel synthetic fiber filament of antistatic property, the cross section of this core is three to sexfoil, and have and be at least 2 sex change ratio, each leaf L/D ratio is 1 to 20, L is the length of the straight line from the central point of line between the two adjacent valleys minimum points of leaf both sides to this leaf solstics herein, and D is the leaf Breadth Maximum that records in the direction perpendicular to L.The present invention also provide a kind of in the melt-spun process of sheath core fiber the improved technology of holding core contouring boundary preferably, in this melt-spun process, a kind of polymers compositions constitutes sheath component, and a kind of different polymers compositions constitute this core constituent and also wherein core have three or more leaf.This technology comprises that the crust of synchronous extrusion molten and core respectively form component and make their processes by the aperture of spinning, thereby makes sheath component be wrapped in core constituent fully, and its improvement part comprises by following step and comes holding core cross section configuration:
1) send the core constituent materials flow of fusion by a passage aperture that is positioned at spinnerets pore top to desired multiple leaf-shaped section,
2) along lead to spray line plate pore inlet port periphery from around send the sheath component materials flow of fusion to so that make it be wrapped in core constituent fully to core,
3) the sheath component materials flow of control fusion leaves the flowing of part in space at the inlet port periphery along the spinnerets pore, so as to make flow into each leaf between materials flow in the zone more than the materials flow that flows in the leaf zone,
4) each molten component is cured after leaving the spinnerets aperture.
The electrostatic dissipation fiber is well-known in this professional domain, and uses in weaving industry many years.A kind of successful especially fiber is a United States Patent (USP) 3,803, the sort of fiber of being introduced in No. 453.This fiber is by respectively as two kinds of thermoplastic component sheath-core bicomponent fibres that co-extruded is made under molten condition of crust and core.Its crust insulate.Its core polymer has electric conductivity by the fusion conductive black.This crust is used for increasing the intensity of fiber, the core of parcel black, and the protection core is to prevent contingent cut-out and layering when core exposes at fiber surface.Some current final use requires fiber to have bigger anti-electrostatic effect and considers less to its color.Especially, have stronger hope, wish to the core color see more clear a kind of differentiating method with the clothes that is not protected as the clothes that uses core to be protected and core.The applicant has found that this respect can pass through United States Patent (USP) 3,803, and No. 453 sheath core fiber carries out sex change to be realized.This sex change mainly comprise adopt with this patent in used core have the core of same composition but the plane of structure shape of core adopts three to sexfoil, its sex change ratio is at least 2, and each leaf L/D ratio is 1 to 20.Fig. 1 illustrates a kind of like this cross section shape.
Fig. 1 is the cross sectional representation of a sheath core fiber, and trilobal core that is wrapped up by a crust shown in the figure is as what arrive seen in the amplification picture of microphoto.The characteristic of core and crust will be described in more detail below.The sex change ratio determine what this professional skill field people knew, but for simplicity, can be by determining referring to Fig. 1.This sex change ratio is meant the ratio of trilobal core minimum circumscribed circle radius and each leaf maximum inscribed circle radius of trilobal core.In Fig. 1, be to represent with A/B.
Also can draw for the definite of each leaf L/D ratio referring to Fig. 1.Article one, straight line is that minimum point with two adjacent valleys of leaf both sides links up and obtains, and another straight line L is the line of the center of article one straight line to this leaf solstics.The leaf Breadth Maximum that the D value representation records on the direction perpendicular to L.Fig. 2 is the cross-sectional view with circular fiber of quatrefoil core.
Continuous yarn spinning process of the present invention is to consider that suitably the different performance of two kinds of components finishes by two polymer sheath core fiber spinning equipments of routine.This long filament is to be easy to adopt known spining technology with for example at United States Patent (USP) 2,989, and that base polymer of being introduced in No. 798 is made.The technology of this spinning with polyamide material is at United States Patent (USP) 2,989, done further description in No. 798.Succeeded in developing the new technology after a kind of improve, made to have three, four, five or the sheath-core bicomponent fibre of sexfoil core when extruding, can keep the profile boundary preferably.To be explained below.
Be used for technology after the improvement in the core-skin type bi-component silk thread spinning of following example 1 and example 2 and be improvement to the core-skin type bi-component fusion spinning technique of routine.In common process, core feeding polymer flow and crust feeding polymer flow all are advanced in the spinneret component that comprises filter screen and screen cloth, and then deliver to a polymer flow and be assigned to plate on a plurality of apertures fusion, these holes are used to the core that is shaped, and wrap up this core with crust.To help to understand this improved technology referring to Fig. 3 and Fig. 4.The core polymer is delivered to passage 2 and above the import of leading to the pore 3 on the spinnerets 5, discharge.Sheath polymer enters in the space that is kept by unshowned pad between plate 5 and the plate 8 through the passage 7 of distribution plate 8.Sheath polymer near the inlet port of spinnerets pore 3 from around send to the core polymer flow, two kinds of polymer flows flow through pore 3 with skin, core relation, finally from the spinneret nozzle (not shown) ejection of the outlet of pore 3.This improved technology can keep the wide boundary of core lobed wheel preferably.This be by the control fusion the sheath component polymer flow along the periphery of the inlet port of spinnerets pore to the flowing of core polymer flow so that make flow into each leaf between sheath polymer stream in the zone realize more than the method that flows into the sheath polymer stream in each leaf zone.This can realize by only strengthening those each section passages that import in each zone between leaf of the passage that is used for making sheath polymer enter pore.Therefore, as shown in Figure 3 and Figure 4, on distribution plate 8, erode away some recessed portions 10 so that the sheath polymer stream of increase can be flowed in each zone of leaf.
The long filament crust can be made up of any squeezable, synthetic, thermoplasticity, fibre-forming polymer or copolymer.These polymer comprise TPO, for example polyethylene and polypropylene, polyacrylic acid, polyamide and the polyester that becomes fine molecular weight.The sheath polymer of particularly suitable is a polyhexamethylene adipic acid amine, poly-own (interior) acid amide, and polyethylene terephthalate.
The stretch capability of long filament of the present invention and other physical property depend primarily on sheath polymer.For the high long filament of intensity, skin material can be with having high molecular weight polymers and the higher polymer of those draw ratios.Though the long filament that does not stretch of the present invention can provide enough intensity for some purposes, the long filament of drawn is better.In some application scenario, for example long filament of the present invention need with other long filament stand to resemble hot fluid sprays that bulking is handled or other bulk processing the high-temperature process occasion, importantly sheath polymer will have sufficiently high fusing point to avoid occurring soft or melting phenomenon under this condition.
The long filament core of antistatic fibre is made up of the conductive black of disperse in a kind of polymer thermoplastic matrix material.United States Patent (USP) 3,803 is mainly considered in the selection of this core material, the electric conductivity and the processing characteristics of No. 453 detailed descriptions.Carbon black concentration in the core can be 15% to 50% selection.Have been found that 20% to 35% content can obtain the high conductivity of preferable level when processing characteristics keeps comparing reasonable level.
The core polymer also can be selected from same group of used material of crust or can select non-fibre-forming material, because it is being protected by crust.For non-antistatic fibre, that yes is non-conductive for the core of bicomponent fiber.
The size of the core cross-sectional area in the bicomponent filament yarn only need be enough to reach desired antistatic property, and can hang down by volume to 0.3%, preferably greater than 0.5% less than 35%.Its lower limit depends primarily on the suitable successional ability of making the crust/core long filament with enough homogeneous qualities simultaneously of core of maintenance under the lower condition of core volume.
Can adopt conventional long filament drawing process, but must careful operation the wedge angle of fracture or damage occur with the core of avoiding occurring causing antistatic fibre.In general, preferably adopt hot-stretch, just in drawing process, adopt some auxiliary long filament heat treated.Do like this and help to make core material further to soften and help the stretching of long filament.These antistatic long filaments can extend silk with the not position of common synthetic fiber and the common long filament that stretches is pooled capital.
For general application scenario, the DENIER of every rhizoid of long filament of the present invention (dpf) is preferably less than 25dpf less than 50.
Long filament of the present invention is aspect all types of textiles final uses, and comprising knitting, synthetic tuft is weaved and nonwoven textiles, and goodish electrostatic protection can both be provided.These long filaments can contain conventional additive and stabilizing agent, for example dyestuff and age resister.The weaving processing that this long filament can stand kind type is comprising curling distortion, washing and bleaching etc.This long filament can mix and can be used as staple fibre or long filament with short fibre yarn or filament yarn.
Above-mentioned long filament can or mix with other long filament or staple fibre in the fabric knitting process in any suitable operation (for example spinning, stretching, distortion, plying, rewinding, spinning) of spinning.In these operation process, should note reducing the undesirable fracture of wire phenomenon of antistatic long filament
Bi-component polymeric stream is in case spray the spinnerets aperture and promptly cool off and begin and solidify.Generally do not wish conductive fiber is applied too big spin-drawing power, because make to reduce the quality of antistatic fibre like this.Other bicomponent fiber is not subjected to the restriction of this point.
Test procedure
The intensity of silk thread and percentage elongation are to adopt the ASTM(american standard of testing material) the D-2256-80 test.The assay method of the relative viscosity of polyester polymers (LRV) is at United States Patent (USP) 4,444, done in 710(Most) introduce.The assay method of the relative viscosity of polyamide (RV) is disclosed in United States Patent (USP) 4,145, in No. 473 (Samuelson).The mensuration of the surface electrical group rate of fiber is by AATCC(AATCC) test method 76-1987 number carries out.The mensuration of the static characteristic of felt rug is carried out for 134-1986 number with the AATCC test method.Quiet decay data are to adopt Federal Test Mettod Std.No.101C(federal test method standard No.101C) method 4046(1980 March 13) measure.Sex change ratio and L/D ratio are to obtain from the cross section mensuration that microphoto printed off as this professional domain people are familiar with knowing.
Followingly respectively giving an example, except control device, all is to be used to illustrate the present invention rather than to constitute limitation of the invention.Leafy core minister silk of the present invention all is described to each example of example 3 in example 1.
Example 1
Having relative viscosity is 23.5(LRV) the crust of polyethylene terephthalate and the core-skin type long filament that contains the polyethylene core of 28.4% carbon black carry out spinning and no stretching and winding with 1200 meters speed of per minute.Subsequently this conductive core part that contains long filament weight 6% is heated to 140 ℃ with the yarn that contains six roots of sensation long filament, and stretches by the listed draw ratio of table 1.Sample with circular conductive core part is to adopt as United States Patent (USP) 2,936, shown in Figure 11 similar spinneret component in No. 482 carries out spinning, and the spinning with long filament of trilobal core is to utilize to have adopted Fig. 3 and spinneret component shown in Figure 4 and the improved technology of the present invention of spinnerets to carry out.The sex change ratio of this trilobal conductive core part is 5, and L/D ratio is 3.Trilobal core yarn is darker than the color of circular core yarn.After stretching, the yarn of this tool conductive core part is inweaved in the 28 cut jerseys of 100% terylene by the interval with 5/16 inch.The yarn that these samples are recorded and the various performances of fabric are listed in the table 1:
Table 1
The circular trilobal of core shape
2.35 times 2.10 times of draw ratios
Total Denier values 35.9 40.0
Intensity, g/d 1.81 1.61
Percentage elongation, % 28.9 21.4
Fabric property
Sheet resistance
ohms/unit sq. 1.5×10 1.9×10
The United States Federal's test method 4046
Standard 101C(90% decay)
Time (second)/2 second charging level
From :+5KV 33/,900 0.23/275
-5KV 9.5/-950 0.20/-300
The fabric that has trilobal conductive core part yarn is compared with the fabric that has circular conductive core part yarn, has the quiet decay time of much lower sheet resistance value and much shorter.
Example 2
Nylon 66 with 46RV is made crust, is similar to circle shown in the example 1 or trilobal conductive core as core, makes core-skin filament yarn (40 DENIER, 6 monofilament), and different is that the draw ratio with 3.2 times stretches to it in the time of 110 ℃.The sex change ratio of trilobal conductive core part is 4 and L/D ratio is 2.With these conductive core part fiber 1225 Denier nylon carpet yarns plying and directly to the velveteen blanket tufting of enclosing the land.Two kinds of carpets all are to measure with the AATCC134 test method.The measured value 0.8KV that contains the carpet of the yarn of being with the trilobal core will be far below using the measured value 1.2KV that has the made carpet of circular conductive core part yarn.
Example 2
Adopt introduce among 2,936, No. 483 Figure 11 of United States Patent (USP) in spinneret component, can produce core-skin type product with 24% conductive core part that is wrapped in by 76% polyethylene terephthalate crust.Made have or circle or trilobal (its sex change ratio is 2.0, and L/D is 1.0) long filament of conductive core part, core contains 32.0% carbon black (" Vulcanp ", can buy from Cabot Corp company), it is combined to and is equivalent to high-melting-point index low-density polyethylene film shape product.
Finished fiber cools off through 21 ℃ air, 1.84 times stretching, and under 1372 meters/component velocity, be wound into 6 strands of monofilament, 35 DENIER products.Behind the process thermal annealing (130 ℃) that reduces to shrink, product is made into fabric and measures so that carry out electrostatic dissipation.
The woven fabric of being prepared is as follows:
Non-conductive yarn-150 DENIER, 34 monofilament-3.3Z twist polyester fibers.
Electrostatic dissipation yarn-100 DENIER, described electrostatic dissipation yarn above 34 monofilament-4S twist polyester fibers add 1.
Weaving process:
96 warp thread, 88 weft yarns, 8 * 8 herringbones
Warp thread-1 an electrostatic dissipation yarn adds 23 non-conductive warp thread.
Weft yarn-2 an electrostatic dissipation yarn adds 22 non-conductive weft yarns.
Fabric:
A. contain the trilobal core
B. contain circular core
Antistatic property
Resistive thread rate ohms/cm(length) (according to sample)
A.3.7×1011
B.7.4×1011
Fabric resistivity (AATCC 76-1987) ohms/unit squire.(is after heat setting and washing)
A. warp-wise-2.9 * 1012, to-2.7 * 1012
B. warp-wise-greater than 1 * 1014, to-greater than 1 * 1013