CN1026507C

CN1026507C - Nonwoven fabric with improved abrasion resistance and method of producing same

Info

Publication number: CN1026507C
Application number: CN 91101226
Authority: CN
Inventors: 拉里·休伊·麦卡米什
Original assignee: Johnson and Johnson Medical Inc
Current assignee: Ethicon Inc
Priority date: 1985-10-02
Filing date: 1986-09-30
Publication date: 1994-11-09
Anticipated expiration: 2001-09-30
Also published as: CN1054454A

Abstract

A melt-blown microfiber fabric having improved surface abrasion resistance is disclosed, having a surface veneer of melt-blown fibers with an average fiber diameter of greater than 8 microns and in which 75% of the fibers have a fiber diameter of at least 7 microns and a wet and dry abrasion resistance of greater than 15 cycles to pill.

Description

Nonwoven fabric with improved abrasion resistance and method of producing same

The present invention relates to a kind of improved nonwoven fabric and manufacture method thereof that constitutes with microfiber webs, this cloth has very high surface abrasion resistance fastness and is particularly suitable for as medical cloth.

The present invention relates to a kind of nonwoven fabric, particularly as medical cloth." medical cloth " used herein this title refers to the cloth of purposes such as can be used for surgery cover list, operating coat, apparatus infantees.The medical cloth of this class need have certain characteristic to satisfy the requirement of these purposes to them.Described characteristic comprises intensity, resists ability (being commonly referred to as " anti-print through ability "), gas permeability, softness, drapability, the sterilizability of water or the infiltration of other liquid and hinders bacillary.

Past has been used for microfiber webs need have the occasion of barrier properties.Microfiber refers to diameter and is commonly referred to " melting and spraying " net from fiber, microfiber webs less than about 1 micron to 10 microns, because they are generally made with melt-blown process.It is generally accepted and in fibre structure, use fiber can obtain high scolding fluidity or filter characteristic and the unlikely gas permeability that exceedingly influences it than minor diameter.The cloth made from microfiber webs so far, with medical be purpose is a kind of with the microfiber webs cloth that lamination forms that combines, or strengthens the cloth that net is bonded with the spunbond thermoplastic fiber webs that its desirable strength is provided or thermoplastic film or other.

Non-woven cloth and medical cloth all there are a same performance requirement, i.e. its wear resistance.The performance of resisting surface abrasion not only influences the performance of cloth, also influences its outward appearance.For example, to rub depilation be unwelcome especially for medical cloth to surface fiber.In addition, surface abrasion also can damage the anti-print through ability and the resistance bacterium ability of medical cloth.The surface fiber depilation and the group of rising or Cheng Zhu for many be that the cloth of purposes also is unacceptable with the wiping.Topped outside one deck spun-bonded fibre net, thermoplastic film or other methods with net of humidification have been used to improve the surface abrasion resistance fastness of meltblown fibers product.

United States Patent (USP) the 4th, 041 discloses a kind of non-woven cloth No. 203, it be by microfiber webs and spun-bonded fibre net combine produce have good drapability, a kind of medical cloth of gas permeability, repellency and surface abrasion resistance fastness.

United States Patent (USP) the 4th, 196, disclose for No. 245 meltblown fibers or the same hole film of microfiber, or, be too in this method as the composition that intensity and surface-stable degree are provided in the non-woven cloth made from hole film and spun-bonded fibre product with the production method that hole film and spun-bonded fibre product combine.

UK Patent Application the 2nd, 132, disclose a kind of medical meltblown fibers laminated cloth material that can be used as for No. 939, it is to be fused with non-woven enhancing net on the point of assigned position by the melt-blown micro-fiber net to form, and this enhancing net is made with air lay method or wet net-forming process by discontinuous staple fibre.

United States Patent (USP) 4,165,352 disclose and a kind ofly are used to make by the method that melts and sprays the battery separator that thermoplastic web material makes, and this method comprises:

(a) formation melts and sprays the continuous motion multilayer net that stacked at random thermoplastic resin fibre makes by at least three layers, ectonexine is stacked respectively for wherein said each layer, by machinery or thermally coupled adjacent layer is coupled together, described inner fiber average diameter is the 2-10 micron, and described outer layer fiber average diameter is the 30-40 micron;

(b) soak the net of described motion with easy volatile solvent;

(c) the net pressurization to the immersion between warm-up mill staggered relatively reshapes it, with liquid and the described solvent of heating, drying in the mechanical means removal net;

(d) make described Netcom cross a drier to remove remaining solvent;

(e) piece that described net is cut into appropriate size has the battery separator of scolding fluidity to be applicable to.

Though other prior arts without microfiber that above-mentioned cloth compares have can be preferably in the potentiality of scolding fluidity and gas permeability to average out between the two, on cloth cover, added and had after the more coarse-fibred enhancement layer, make their advantage be restricted.Authorize and introduced a kind of few depilation in people's such as Hotchkiss No. the 4th, 436,780, the United States Patent (USP), play streak, the wiping cloth (rags) that melts and sprays that absorbability is good less, it is clipped between the two-layer spunbond layer by the intermediate layer of one deck meltblown fibers forms.

For the surface abrasion resistance fastness of usually improving meltblown web and reduce its depilation, known method is to press fiber web very real, or adds binding, or increases the content of binding.A co-pending patent application (JSU 58) provides a kind of medical cloth made from one or more layers microfiber that does not increase.So-called " strengthening " be because it does not need lamination or with the net of other patterns or film be glued together and still have sufficient intensity can be for medical.In order to make this cloth can be used for the purposes of the high wear resistance of needs, can add a spot of chemical adhesive on the surface of cloth.

UK Patent Application 2,104,562 disclose and will melt and spray cloth surface heating so that it has the method for the fineness of not losing hair or feathers, and in general known method the use heating to a certain degree and the way of compacting are arranged, for example with the microfiber webs embossing so that its wear resistance to be provided.

Cloth with enhancing stratum reticulare above-mentioned need experience twice or the above net-forming process of twice combines, and the result has increased process complexity.In addition, comparatively conventional fiber web is bonding with microfiber webs, all may cause cloth to harden with the microfiber webs compacting or to its adding adhesive, especially all the more so when needs high strength.

The purpose of this invention is to provide and have not enhancing melt-blown micro-fiber cloth and the manufacture method thereof of having improved the surface abrasion resistance fastness.

The invention provides a kind of melt-blown micro-fiber embossing net, it has improved hygrometric state and dry state surface abrasion resistance fastness, reaches 15 all just indexs of the group of rising.Wear resistance is not use additional adhesives, and under the condition of drapability of not sacrificing it or feel, obtain.

According to the present invention, the acquisition of the surface abrasion resistance fastness of cloth is that the average diameter of cementing layer fiber is greater than 8 microns owing to added the mask cementing layer that one deck is made of meltblown fibers, and wherein the diameter of 75% fiber has 7 microns at least.It is online that this cementing layer available heat embossing or additive method are adhered to the core that melts and sprays, as person described in the common pending application (JSU 58).This cementing layer is bonding with the core net, and the heat embossing of core net can be by finishing with one procedure.In addition, when making as the same one procedure of core net and a plurality of mould spray of gummed net silk, the gummed net can directly form on the face of core net, and this gummed netting gear has very high initial self bonding force, thereby can save cementing layer is adhered to the necessity that core goes on the net.

Owing to save the adhesive that adds, the invention provides and a kind ofly need not add adhesive and be dried and/or the method for the manufacturing melt-blown micro-fiber net of multiple working procedure such as curing.In addition, solidify or the dry adhesive process in impact the thermal damage of the drapability of cloth and feel potential possibility also got rid of.Owing to using slurry that the situation of cloth hardening is not also existed, making has ready conditions adjusts to the processing conditions of core net the operating mode of other advantage that helps bringing into play it most.

In addition, can make this cloth have drapability and surface abrasion resistance fastness simultaneously with the gummed armour layer of meltblown fibers, this point is to add adhesive to be beyond one's reach.Form cementing layer with meltblown fibers benefit economically also is provided, and will produce the required technology of this cloth and reduce to minimum.

Therefore, the invention provides a kind ofly without adhesive but have the cloth of improved that melt and spray or the microfiber of improved surface abrasion resistance fastness, it can be as medical cloth or wiping cloth (rags) or other purposes that need have high surface abrasion resistance fastness.In the embodiment of recommending, cloth of the present invention microfiber that do not strengthened by one deck, that melt and spray constitutes, and it has improved surface abrasion resistance fastness, for example greater than 15 Zhou Qituan, be suitable for as medical cloth, the ratio of grabbing sample tensile strength and weight of this cloth minimum is greater than 0.8 newton/grammeter ², the ratio of its minimum Erichsen (Elmendorf) tear resistance and weight is greater than 0.04 newton/grammeter ²In optimum implementation of the present invention, the hygrometric state wear resistance that cloth its embossing, that do not strengthen has can reach 30 Zhou Qituan at least, and the dry state wear resistance can reach 40 Zhou Qituan at least.When reaching these performance indications, it also have as medical cloth required scold characteristics such as fluidity, gas permeability, particularly drapability.

According to the improved melt-blown micro-fiber cloth that do not strengthen of the present invention, it has improved surface abrasion resistance fastness described cloth, its feature comprises: one deck does not strengthen thermoplasticity melt-blown micro-fiber core net at least, and the minimum of described core net is grabbed the ratio of sample tensile strength and weight greater than 0.8 newton/grammeter ², the ratio of its Elmendorf tear resistance and weight is greater than 0.04 newton/grammeter ², the basis weight of described core net is at 14 gram/rice ²To 85 gram/rice ²In the scope; With do not strengthen surface gummed stratum reticulare at the online one deck at least of described core, described gummed stratum reticulare forms by melting and spraying thermoplastic fibres, this average fibre diameter is greater than 8 microns, wherein 75% fibre diameter is at least 7 microns, have greater than 15 weeks playing the hygrometric state and the dry state surface abrasion resistance fastness of group, its basis weight is at 3 gram/rice ²To 10 gram/rice ²In the scope, the described gummed of one deck at least stratum reticulare directly is connected with the described core of one deck at least net.

According to cloth of the present invention, it is characterized in that described cloth is used the pressure sintering embossing in the discrete bond district that is interrupted, bonding zone accounts for cloth surface 5% to 30%.

According to cloth of the present invention, it is characterized in that described cloth has the hygrometric state wear resistance of at least 30 a weeks group and the dry state wear resistance of at least 40 all groups of rising.

According to the improved melt-blown micro-fiber cloth that do not strengthen of the present invention, it is characterized in that the average fibre diameter of described surface gummed stratum reticulare is about 9 microns.

Improved enhancing the according to the present invention melts and sprays cloth, described cloth has improved wear resistance, its feature comprises: one deck does not strengthen the thermoplastic core net at least, wherein at least 80% fiber directly is 7 microns or littler, the share that self adhesive effect of its fiber offers the galley proof tensile strength of this cloth is no more than 30%, with do not strengthen surface gummed stratum reticulare at the online one deck at least of described core, described surface gummed stratum reticulare is formed by the thermoplasticity meltblown fibers, this average fibre diameter is greater than 8 microns, wherein 75% fibre diameter is at least 7 microns, and its basis weight is at 3 gram/rice ²To 10 gram/rice ²In the scope, described cloth is in the discrete bond district pressure sintering embossing that is interrupted, and bonding zone accounts for 5% to 30% of cloth surface, and the minimum of this core net is grabbed the ratio of sample tensile strength and weight greater than 0.8 newton/grammeter ², the ratio of its Elmendorf tear resistance and weight is greater than 0.04 newton/grammeter ², having and the hygrometric state wear resistance and at least 40 weeks of playing group at least 30 weeks play the dry state wear resistance of group, the described gummed of one deck at least stratum reticulare directly is connected with the described core of one deck at least net.

Do not melt and spray cloth according to improved enhancing the of the present invention, it is characterized in that, the average diameter of described surface gummed stratum reticulare fiber is about 9 microns.

Manufacturing according to the present invention has the method for the melt-blown micro-fiber cloth that improves wear resistance, and its feature comprises:

(1) form one deck thermoplasticity melt-blown micro-fiber core net at least, its minimum is grabbed the ratio of sample tensile strength and weight greater than 0.8 newton/grammeter ², the ratio of its minimum Elmendorf tear resistance and weight is greater than 0.04 newton/grammeter ², its basis weight is at 14 gram/rice ²To 85 gram/rice ²In the scope;

(2) form at least one deck and do not strengthen the surface and glue together stratum reticulare with melting and spraying thermoplastic fibre in that described core is online, described gummed stratum reticulare has higher initial self adhesive effect, the average diameter of its fiber is greater than 8 microns, wherein 75% fibre diameter is at least 7 microns, and described gummed stratum reticulare basis weight is at 3 gram/rice ²To 10 gram/rice ²In the scope, its wet surfaces wear resistance and dry state surface abrasion resistance fastness are greater than 15 Zhou Qituan;

(3) the described gummed of one deck at least stratum reticulare directly is connected with the described core of one deck at least net.

Have the method for the melt-blown micro-fiber cloth that improves wear resistance according to manufacturing of the present invention, it is characterized in that 9 microns of the fibre diameter average out to of described gummed stratum reticulare.

Have the method for the melt-blown micro-fiber cloth that improves wear resistance according to manufacturing of the present invention, its feature also comprises described lamination material bonding with the pressure sintering embossing in the discrete bond district that is interrupted.

The method that manufacturing according to the present invention does not strengthen with the microfiber cloth that improves the surface abrasion resistance fastness, wherein, a kind of thermoplastic polymerization resin that can form fiber is forced through the row's aperture that is arranged in the heating shower nozzle and enters stream of inert gas under molten condition, make this resin be scattering into fiber, this fiber is collected and forms one deck net on a receiver, to form cloth, the feature of this method comprises this net by heat bonding:

(1) at first heating shower nozzle place, the polymer that keeps fusion is certain, the temperature levels of molecular degradation degree minimum, the flow velocity of control primary air, volume and temperature, the flow of polymer resin and outlet temperature are to make the ground floor thermoplastic fibre, the average diameter of this fiber is greater than 8 microns, and wherein there is 75% fibre diameter to be at least 7 microns, collect described fiber on the receiver outside certain distance and do not strengthen surface gummed stratum reticulare to form the high ground floor of self bondability, to 10 gram/rice scopes, and its wet surfaces wear resistance and dry state surface abrasion resistance fastness are greater than 15 Zhou Qituan at 3 gram/rice for described fiber basis weight;

(2) at second heating shower nozzle place, the polymer that keeps fusion is certain, the temperature levels of molecular degradation degree minimum, the flow velocity of control primary air, volume and temperature are to make thermoplastic fibre, at least 80% diameter is 7 microns or littler in this fiber, its average length is more than 10 centimetres, import one its flow in addition and be enough to the uniform high speed auxiliary air of height that cools off and keep described fiber to separate, collecting described fiber outside certain moulding distance makes it form one deck core net, interfibrous bondability is very low in this net before further this net embossing being made the formation cloth, the fiber of this described core net is to be collected in described ground floor surface to glue together on the face of stratum reticulare, and described gummed stratum reticulare directly is connected with described core net.

(3) make second layer surface gummed stratum reticulare at the shower nozzle place of the 3rd heating, its fiber is similar with the fiber of the described first gummed stratum reticulare, and will described second layer surface glues together stratum reticulare and be collected on the face that the core net exposes.

The method of the microfiber embossing cloth that does not strengthen according to manufacturing of the present invention is characterized in that the average diameter of the fiber of described gummed stratum reticulare is about 9 microns.

According to method of the present invention, its feature also comprises described which floor net bonding with the heat embossing method.

Be the content of the accompanying drawing of this specification below:

Fig. 1 is the perspective view of melt-blown process;

Fig. 2 is the profile that shows mould and auxiliary air source position;

Fig. 3 is the fragmentary detail view of extrusion die, there is shown the arrangement of " negative dislocation ";

Fig. 4 is the fragmentary detail view of extrusion die, there is shown the arrangement of " just misplacing ".

From the angle of broad sense, content of the present invention is included in the surface bonding layer of supplying with one deck meltblown fibers on one deck microfibre wire side, and the average diameter of the fiber of this surface bonding layer is greater than 8 microns, wherein has at least the diameter of 75% fiber to have 7 microns at least. When being used for most of cloth, this surface bonding layer is that the remainder that is laminated to net goes, and for example uses the embossing Method for bonding, Or combine them with other methods commonly used. Like this, this surface bonding layer can get on the fibroreticulate remainder face that is thermally bonded to again it after the moulding that comes, and the bonding zone that preferably is interrupted in dispersion is bonding. Perhaps also can make this cementing layer have the state compacted under of very high initial self bonding force on the face of fibroreticulate remainder at it, can exempt like this that specially cementing layer is adhered to the operation that fibroreticulate remainder gets on, although perhaps also need cloth is carried out heat embossing. The cloth of producing by the present invention shows the surface abrasion resistance fastness with improved hygrometric state and dry state, is particularly suitable for as wiping cloth (rags) or medical cloth.

The most in a broad sense, technology of the present invention can be implemented at the melt-blowing equipment of routine, and this conventional equipment needs to make it to have auxiliary air at a high speed through transformation, as among the common pending application JSU58 or shown in Fig. 1. According to shown in device, a kind of ball shape or granular thermoplastic resin add from hopper 10, these particles enter extruder 11 then, the temperature in the extruder is controlled in a plurality of bringing-up sections of subregion, makes resin be heated to it more than fusing point. Extruder is promoted by motor 12, and this motor enters mould 13 with the common thermal treatment zone of crossing extruder of resin transfer. Mould 13 also can have a plurality of heated zones.

As shown in Figure 2, resin enters heating clamber 29 from extruder, and the latter is between upper and

lower template

30 and 31. These upper and lower templates make the temperature of mould and the temperature of chamber 29 interior resins meet the requirements of level by heater 20 heating. Resin is extruded the aperture 17 of opening in die face from a group then. Generally along every centimetre of die width 12 apertures are arranged approximately.

The inert gas (generally being air) of general heat enters air chamber 19 from pipeline 14. This strand hot gas that is called as " primary air " flows into

groove crack

32 and 33 then, and this groove crack is arranged in the both sides of resin ejection nozzle 17. When resin flow delivery nozzle 17, hot gas is scattering into fiber with it.

Groove crack

32 or 33 width are called the air gap. The fiber that forms is become fibroreticulate perforated conveyor belt (or receiver) 22 by the hot-air bar shaped of leading, and forms one deck pad or net 26 thereon. Vacuum chamber 23 of normal operation assists to collect fiber, and vacuum chamber 23 links to each other with the pipeline 24 that vacuumizes. Conveyer belt 22 moves round cylinder 25, is continuous thereby make the net of formation.

The outlet of nozzle 17 and

airslide crack

32 and 33 can be positioned at same plane, also can stagger. The outlet contracting that Fig. 3 illustrates nozzle in the surface of mould and

groove crack

32,33 plane The inside. This arrangement is called " negative dislocation ". The size of negative dislocation indicates with two relative arrows in Fig. 3. Shown in Fig. 4 is " just misplacing ", and the outlet of nozzle 17 stretches out in outside the surface of mould and

groove crack

32,33 the plane when this position. The size that is just misplacing indicates with two relative arrows in Fig. 4. In this process program, use negative dislocation better, can adverse influence not arranged to the quality of the net produced because its allows the layout of the air gap can have bigger flexibility.

Cloth of the present invention contains layer of surface cementing layer and one deck core net. Preferably cloth comprises one deck core net, and there is the layer of surface cementing layer on its two sides. In the present invention, " cementing layer " is one deck fleece, and its basis weight is no more than 50% of cloth gross weight. More better is that the basis weight of gluing together stratum reticulare is about 25% of cloth gross weight, and preferably accounts for 15% to 25% of cloth gross weight. The net of cementing layer can separately be made with the core net, combines Face to face then. During with this method, the basis weight of the net of every layer of cementing layer must be at 6 grams/rice²About with enable easily with the core anastomose altogether. Other method is, core net and cementing layer divide upper and lower layer to form simultaneously, for example form earlier cementing layer as bottom on conveyer belt 22, make then the fiber of core net be deposited in this bottom above. In this suggested design of the present invention, one deck weight is about 3 grams/rice²Cementing layer form at conveyer belt earlier, its accepts the core net that blows then, and another layer weight of core net receive sediments on it is about 3 grams/rice²Cementing layer. Other scheme is to adopt difference step into the net will glue together the fiber laydown of stratum reticulare to two faces of core face. After this, the net of core net and cementing layer can carry out lamination, for example carries out lamination with the heat embossing method. In the time will gluing together stratum reticulare and deposit on the core wire side, if the formation condition of gummed stratum reticulare is that very high initial inter-fibre-bond or self bondability can be provided, comprise high mold temperature, do not use auxiliary air, become net apart from (back also will be described in detail) such as weak points, with regard to not necessarily needing cementing layer and core net are carried out lamination (for example using the heat embossing method), also do not need the cementing layer embossing. The core net can be through embossing before the fiber laydown of cementing layer gets on, also can not embossed. The wear resistance that the embossed layers compress material of producing by the present invention has is at least 30 Zhou Qituan when hygrometric state, be at least 40 Zhou Qituan when dry state.

Will illustrate as following, according to the method described above, might and reduce under the condition of primary air amount in the throughput that increases polymer, only just can make the present invention with a meltblown die Cloth. Then be to use a plurality of moulds in the scheme of best production cloth of the present invention.

Its most preferred aspect, the medical cloth of confession of the melt-blown micro-fiber that the present invention is a kind of improvement, do not strengthen. The ratio that the minimum of this cloth is grabbed sample tensile strength and weight is at least 0.8 newton/grammeter², the ratio of its minimum Erichsen (Elmendorf) tear resistance and weight is at least 0.04 newton/grammeter² To be described in more detail with regard to this optimum implementation below.

The requirement of medical cloth is quite strict. When cloth under regular service conditions, when for example in operating room environment, using, must have enough intensity and tear or pull open with resistance. This is all the more so for cloth of making the operating room clothes, such as operating coat, scrub clothes or surgery cover list etc. The index of weighing nonwoven fabric intensity be it grab sample tensile strength, its definition is to pull out 10 centimetres of load that wide openning is required on the sample face on the testing machine.

Grab the method for sample strength test at non-woven cloth and in ASTM D1117 standard, made regulation. Non-woven medical cloth also must be resisted and tear. Anti-tear broken intensity is generally measured with the Elmendorf tearing test, has also made regulation in ASTM D1117 standard. Grabbing sample tensile strength is with the most weak direction at cloth, and normally the horizontal minimum of cloth machine is stipulated, generally is in 45 Newton range, and its most weak direction Tear resistance is then about 2 newton. Breakage can occur at these load level clothes, but people wish that its intensity can be higher. As cloth grab that sample tensile strength can meet and exceed about 65 newton, tear resistance can meet and exceed about 6 newton, then it can be more widely used as a kind of special medical cloth. Best cloth of the present invention has the ratio of very high intensity and weight, and therefore under desirable weight, it grabs sample tensile strength and tear resistance all can reach the level higher than above-mentioned numeral. Its basis weight is generally at 14 to 85 grams/rice²In the scope.

Medical cloth also must have the performance of repelling liquid, comprises the performance of repelling the indoor blood that often runs into of hospital surgical. Since these liquid be with microorganism from an easily carrier that propagates into another place, scolding fluidity is the functional characteristic of a key of medical cloth. Scold fluidity mainly to be subjected to the impact of micropore on the cloth, its numerical value is measured according to AATCC 127-1977 standard code " hydrostatic head " test. The result of this test represents with the pressure that sees through the required water-column representative of given cloth sample. Because the limit capacity that a kind of given cloth is resisted Liquid Penetrant is decided by the microcellular structure of this cloth, the hydrostatic head test is the method for the permeation resistant nature of the medical cloth of a kind of effectively evaluating inherence. The general hydrostatic head numerical value of non-woven medical cloth that does not comprise waterproof film or microfiber web is 20 to 30 centimeter water columns. It has been generally acknowledged that such numerical value is the most not desirable to operating coat and surgery cover list, especially in the very high occasion of the infected risk of some round. 40 centimetres or higher pressure head value want more better. It's a pity that at present the operational gas permeability with cloth of high hydrostatic pressure head numerical value very by prior art production is very poor, or intensity is lower. Cloth of the present invention can reach the performance of very high anti-Liquid Penetrant.

The gas permeability of medical cloth also is a characteristic that hope has. This point especially needs for the cloth of making clothing. The gas permeability of cloth is all relevant with air penetration with wet steam spreading rate (MVTR). Because being used for the fleece of medical cloth, great majority all have suitable high wetting The vapour spreading rate, so the measurement of air penetration performance is the suitable quantitative test that its gas permeability is differentiated.

In general, cloth is loose rare, and its air penetration is also more good. Therefore, its air penetration of fleece that press very densely, only has a very thin pore structure is not good, and it is very poor usually to be considered to gas permeability. The weight that increases cloth also can reduce its air penetration performance. The method of measuring air penetration is that the not thunder of ASTM D737 standard code is translated the test of (Frazier) air void porosity. Fu Shi air void porosity is lower than 8 meters³/ decimetre²Cloth medical clothes time of putting on of making will feel slightly for a long time uncomfortable. Cloth of the present invention have good gas permeability and do not sacrifice it scold fluidity or intensity.

Medical cloth also must have good drapability, and the latter has many measuring methods, comprises the test of Ku Xike (Cusick) drapability. In the test of Ku Shi drapability, the cloth of a slice circle is clipped between the disk of two levels with one heart, and the diameter of disk is littler than the diameter of cloth specimen. The soft rivel that hangs down to form round disc circumference of cloth specimen. With the profile of these rivels project a level, with on the original measure-alike annular paper of not pushed down part of cloth specimen. Rivel projection on the paper is described, and the weight of these annular scraps of paper of weighing is cut off the scraps of paper then along the projection line of rivel, again the weight of the interior ring cut of weighing. Ring weight multiply by 100 divided by the original weight of paper ring again and just obtains so-called " suspended coefficient " in this. This coefficient is more little, and the drapability of this cloth is just more good. Cloth of the present invention is fine with the drapability that the method records. Drapability has good corresponding relation with pliability and the elasticity of cloth.

Except some above-mentioned characteristics, medical cloth also must have antistatic behaviour and flame resistance. Cloth also should have good wear resistance, and can not fall down little fiber head and come, and generally claims this phenomenon of falling fiber head to be " depilation ".

Except having characteristic above-mentioned, best cloth of the present invention is also that with the difference of the meltblown fiber web of prior art the average length of the single fiber in its net compares prior art Net in the average length of fiber to grow. The average length of fiber is greater than 10 centimetres in the core net, and better is greater than 20 centimetres, preferably between 25 to 50 centimetres. In addition, the average diameter of core network fiber should be not more than 7 microns. It should be to have the diameter of 80% fiber at least less than 7 microns that the diameter of fiber distributes, be more preferably have 90% fiber at least diameter less than 7 microns.

In explanation of the present invention, " net " this noun refers to the not bonding net of being made by melt-blown process. " cloth " this noun then refers to through heat embossing or the bonding net of other technology.

Best cloth of the present invention is the cloth that a kind of meltblown fibers heat embossing without strengthening forms, and it has one deck core net, is by fibrous greater than 10 centimetres of average length; The diameter that has 80% fiber in these fibers at least is 7 microns or less than 7 microns, at the one or both sides of this core net one surface bonding layer is arranged, and the average diameter of the fiber of this cementing layer is greater than 8 microns, and wherein 75% fibre diameter has 7 microns at least.

In the technology of making best cloth of the present invention, the fiber of core net contacts with one auxiliary air at a high speed behind the ejection mould immediately. The fiber of cementing layer then can contact with the high speed auxiliary air, also can different its contact. Auxiliary air is the surrounding air under the indoor or outdoors temperature, and when needing, this auxiliary air also can be through overcooled. Auxiliary air enters the distributor 16 that is loaded on the mould both sides from a suitable source of the gas through pipe 15 under pressure. Distributor is general the same with mould long, and it has inclined-plane 35, is having hole 27 near the die surface place. The flow velocity of auxiliary air can be regulated by the pressure in the raising pipe 15 or by a plate washer 28. Plate washer 28 is used for reducing the size in hole 27, thereby is keeping improving the air velocity that flows out from distributor in the constant situation of flow.

Nonwoven fabric of the present invention utilizes melt-blown process to make cementing layer from different being in it of the cloth that contains microfibre of prior art, the fento of the characteristic of this cementing layer fiber and core net The characteristic difference of dimension. As make the cloth with core net and cementing layer and process heat bonding by the method described in this manual, just can obtain a kind of cloth with surface abrasion resistance fastness high strength and weight ratio, good and drapability.

When being used for the melt-blown process of prior art with the fiber parties concerned, the typical products that obtains is a kind of diameter at 1 to 10 micron microfibre. In given net, the diameter of fiber is irregular, but in order to give full play to micro-fiber structure as the advantage of good filtrate, often must remain on the diameter of fiber very little. Therefore normally use average diameter less than 5 microns, sometimes even less than 2 microns fiber produce fleece. In the technology of this prior art, the typical length of produced fiber is 5 to 10 centimetres. Once mentioned in the appraising through discussion of the cloth that adopts prior art production in front, with so twice-laid netting gear very low intensity and wear resistance were arranged. The intensity of such net and wear resistance be mainly derived from fiber fall to when transmitting on the zone face interfibrous bonding. Surperficial bonding may being present between fiber to a certain degree, because in the conventional mode of production of melt blown technology, fiber also solidifies when transmitting on the zone face fully being deposited to, and the surface of their semi-molten state can be glued together on the point of cross-contact. This adhesion process is called as " self is bonding " sometimes. Self bonding degree is more high, and the integrated degree of net is also more high. If but self bondability of the fiber of this analog thermoplastic is too high, then this fleece will harden, and become coarse and quite fragile. The intensity of the net of this not embossed is what to be not enough to for the such practical use of for example medical cloth. These fleeces are carried out heat bonding generally can improve their intensity and wear resistance, but discussed as the front, if do not add surperficial enhancing ingredients or adhesive, can't produce the cloth with high surface abrasion resistance fastness with the microfibre that melts and sprays so far and come, especially can not produce the cloth that can be used for operating coat, cleans clothes and surgery cover list etc. and come.

In best cloth scheme of the present invention, when forming the core net, its fiber is length than the fiber of prior art. Using each the length of steel wire frame of rectangle when measuring fibre length is 5 lis Rice is one grade to 50 centimetres every 5 centimetres. The two-sided adhesive tape that mucous membrane is arranged that tacks down on the frame is used for clinging and collect the fiber in the air-flow. During measurement a steel wire frame is passed air-flow with the direction perpendicular to air-flow fast being close to into net conveyor place (rather than near melt and spray nozzle place). Each framework is taken a sample successively, the fiber number that clings on the framework of the every kind of length of counting then and the average length that estimates fiber. If most of fiber all is longer than 10 centimetres, then its average length is greater than 10 centimetres at least, and is perhaps better, greater than 20 centimetres, will have good intensity and still keeping the ideal characterisitics that is used as medical cloth after embossing with this net that forms. When average fiber length reaches 25 to 50 centimetres, can obtain having the cloth of height ideal characterisitics. In order to keep microfibre to resist the potentiality of Liquid Penetrant, must keep the diameter of fiber very little. That obtains scolds fluidity, needs to keep the average diameter of fiber in the core net of this programme below 7 microns, and wherein the diameter of at least 80% fiber should be below 7 microns, and preferably the diameter of at least 90% fiber should be below 7 microns. Fibre diameter then can improve the potentiality of the balance of the uniqueness between every characteristic that the present invention has as having narrower decentralization. Have very high-intensity cloth although can produce greater than 7 microns fiber with average diameter, the fluidity of scolding of such cloth will be sacrificed, thereby also can not produce and have the lightweight cloth of highly scolding fluidity.

If meltblown fiber web himself bonding degree in forming process is very low, have seldom or do not have integraty, the cloth of then cloth that forms after its embossing will the net higher than initial strength being made has much higher intensity, and outward appearance is also better. In other words, the net that has the minimum not embossed of the intensity of above-mentioned fiber size can be made the highest embossing cloth of intensity. Interfibrous initial adhesion degree is more high, and the cloth of making is just more hard, more fragile, thereby it grabs sample tensile strength and tear resistance is all lower. Reduce self bondability, the cloth of making after the embossing not only has high strength, and more soft, and drapability is more arranged. Because the integraty of the net of not embossed is lower, can measure its intensity with the galley proof test for tensile strength. Its method is with one 2.54 centimetres Wide bar-shaped sample is clipped at least also to have tests (ASTM D1117 standard) in 2.54 centimetres of wide specimen holders. Now melt and spray cloth with what technology was produced, its by warp-wise galley proof intensity of self bonding sample generally greater than press sticking after intensity 30%, often up to 70% or higher. In other words, accounted for very high share in the intensity of himself bonding intensity cloth after pressure is sticking. With self of its core net of cloth of explained hereafter of the present invention bonding only provide press sticking after below 30% of cloth intensity, be more preferably below 10%.

The weight of the net that for example, is meltblown into take nylon-6 as raw material with prior art is about 50 grams/rice², its warp-wise galley proof tensile strength is 10 to 20 newton. The cloth that preferred plan of the present invention is made, the galley proof tensile strength of the core net of its not embossed must remain on below 10 newton, preferably remains on 5 newton and just can obtain largest benefit of the present invention when following. In other words, the long fibre of producing and collecting has lower inter-fibre-bond degree, single fiber intensity is higher, just can excavate the inherent intensity of fiber itself.

Though must make the very low and diameter that makes 80% fiber of the initial adhesion degree of fiber in the core net all less than 7 microns, but such fiber web does not have very high surface abrasion resistance fastness through after the embossing, therefore often need add a kind of chemical adhesive on such cloth surface and improve its wear resistance.But add the effect of paying that such adhesive can bring infringement cloth drapability, so its addition must remain on bottom line.Only add in actual applications when can keep its adhesive dosage with enough drapability, it only can provide still can be satisfied with but not be very high wear resistance.

On cloth of the present invention, can add surperficial cementing layer that last layer is made up of microfiber by one or both sides and avoid the effect of paying adding adhesive and bring at the core net.The average diameter of fiber is greater than 8 microns in the cementing layer, and wherein the diameter of 75% fiber has 7 microns at least.In addition, in optimum implementation, its cementing layer has initial adhesion degree between higher fiber.

Put it briefly, best cloth manufactured according to the present invention is compared with the meltblown fiber web that shows the routine of producing with technology, the fiber that it is characterized in that the former core net has long average length, lower inter-fibre-bond degree, the thinner fibre diameter that higher single line intensity and dispersion train are narrower, thereby have higher resistance liquid penetrating power, it also have one deck at least by thick diameter fibrous, preferably have a cementing layer of higher inter-fibre-bond degree.

The method that obtains the desirable core net of best cloth of the present invention and cementing layer characteristic is built some the critical variablees in the control process flow process, to obtain the characteristic of desirable fiber, stratum reticulare and cloth.These variablees comprise extrusion temperature, primary air flow and temperature, secondary air flow and become net distance (from the mould to the receiver).These variablees are described as follows for having the critical desirable stratum reticulare and the influence of cementing layer characteristic:

For core net and cementing layer, keep lowlyer if will enter the temperature of the liquation of mould than the technological requirement of prior art, for example low 10 to 35 ℃, the intensity of single fiber just can be greatly improved.The general melt temperature that enters mould in technology of the present invention only exceeds than the fusing point of used polymer and is no more than about 75 ℃.

When forming the core net, the flow velocity of the flow velocity of primary air and temperature and auxiliary air and temperature must be adjusted to the fiber that can obtain this given polymer maximum intensity under stretching condition not.The high flow rate that auxiliary air uses among the present invention makes the fiber of core net prolong time and distance in the process of scattering, thereby helps to improve the intensity of fiber.Auxiliary air does not play significant feature when producing the cementing layer fiber, preferably without auxiliary air so that when forming best cementing layer, between the fiber higher initial adhesion degree is arranged.

Fibre length in core net and surperficial cementing layer is subjected to the influence of the fall progressively degree of decomposition and the air flow field uniformity of first and second air velocity, polymer, and wherein the uniformity of air flow has the importance of most critical.The very important point is the high homogeneity that will keep air-flow and fibre stream, avoid the scrambling on significantly disturbance, eddy current, itemize and other fluidised forms.Use the auxiliary air of high flow rate to help to control air/fiber a fluid stream, its cooling fiber also keeps the uniformity of the orientation of fiber molecule, produces the higher fiber of intensity, makes it to have the bigger ability that resistance is broken by inhomogeneous air-flow.

For the fiber laydown of core net is being become on the net conveyor to form netted and to have lower galley proof tensile strength, moulding air-flow and moulding distance obviously have importance.In technology of the present invention, the moulding distance is generally between 20 to 50 centimetres.At first, in order to make the core netting gear minimum inter-fibre-bond degree is arranged, fiber should considerably solidify when reaching net conveyor, is not clamminess in the surface.The time that fiber is had solidify, can become net conveyor and receiver to remove from mould.But as distance is excessive, during promptly greater than 50 centimetres, just is difficult to keep the uniformity of air/fiber flow, thereby " making a rope by twisting the strands together " phenomenon may occur." make a rope by twisting the strands together " is that a kind of indivedual some fibre twists together in air-flow and forms a branch of coarse-fibred phenomenon.The performance of the undue resistance liquid infiltration that will reduce the cloth of producing of making a rope by twisting the strands together also can influence its outward appearance.Primary air flows can be improved chance that fiber scatters and the distance that relatively prolongs its phenomenon of not making a rope by twisting the strands together highly uniformly.

The primary air volume also is an important factor.Must use enough primary air volumes under given polymer flow rate and moulding length condition, so that fiber can separate in air/fibre stream well, and the phenomenon of will making a rope by twisting the strands together is reduced to bottom line.

The use of auxiliary air is for to obtain lower inter-fibre-bond degree under the phenomenon condition of making a rope by twisting the strands together in the core net also be important not producing.As having noticed the front, secondary air streams at a high speed is effective to improving air/fiber flow uniformity.Therefore, it has improved in the downward possibility that grows up to the type distance of the condition that does not produce the nonconforming phenomenon of making a rope by twisting the strands together.In addition, owing to auxiliary air is under the room temperature, also can be lower when needing, it can be used for cooling off in the short period of time and coagulated fibre, thereby avoids using the necessity of long and harmful moulding distance.In order to make secondary ventilation system have influence to the mobile uniformity and the speed reduction rate of cooling effect and fiber, it should have enough flow velocitys, is flooded by primary air fully and its flow is also unlikely.In this technology, the flow velocity of auxiliary air is got 30 meter per second to 200 meter per seconds or the higher stream condition expected of can obtaining effectively.Obviously, can in all sorts of ways and compound mode is coordinated the flow, temperature of first and second air and moulding distance to obtain the low bondability between the fiber in the core net of not embossed.Concrete technological parameter is decided by the properties of product of polymer, Mould design and air system thereof, ratio defective product and the requirement used.

The core net of not embossed or the core net of multilayer not embossed must be glued together to form best cloth of the present invention.Using the heat bonding technology is best mode by identification.In a best approach of the present invention, the heat bonding of core net and which floor core net and cementing layer combine in the heat embossing operation with the heat bonding of core net to be finished.Ultrasonic wave or machine printed roller system with heating and pressurization function all are available.For purposes of the invention, the machine printed system is adopted in suggestion, and one of them is positioned at the surface of the cylinder of cloth one side engraves, and the surface that is positioned at the cylinder of cloth opposite side is flat, obtains the bonding effect of multiple spot with this." pin hole " occur on cloth, it is comparatively desirable to leave 0.01 to 0.02 mm clearance between upper and lower cylinder.For the purposes that cloth of the present invention is considered, the gross area of embossing should be between 5% to 30%, preferably between 10% to 20% on the cloth charge level.In the example of an explanation this programme, the area of embossing is 18%, and the pattern of embossing is 0.76 millimeter * 0.76 millimeter a rhombus, has 31 Argyles on every square centimeter the rolling drum surface.The concrete pattern that embossing is used is also non-key, and any pattern that accounts for cloth cover 5% to 30% area all can use.

Principle of the present invention can be used for any commercially available resin, such as the polymer of polypropylene, polyethylene, polyamide, polyester or any polymer or mixing, as long as they can be meltblown into fiber, can use.Find to use polyamide, especially nylon-6 (polycaprolactam) to be particularly conducive to obtain outward appearance good, be subjected to that the cobalt radiation exposure is not perishable, advantage such as balance is good and easy to process between the characteristic.

Before mention, the basis weight of best cloth of the present invention is 14 to 85 gram/rice ²Cementing layer separately forms in this way, and its basis weight is about 6 gram/rice ²About, form simultaneously in this way, then its basis weight is about 3 gram/rice ²About.The basis weight of general cementing layer should not surpass 10 to 15 gram/rice ², because the basis weight of cementing layer is big, the basis weight that must reduce the core net is to keep desired cloth basis weight.The minimum of this cloth is grabbed the ratio of sample tensile strength and weight greater than 0.8 newton/grammeter ², the ratio of its minimum Erichsen tear resistance and weight is greater than 0.04 newton/grammeter ², its hygrometric state and dry state surface abrasion resistance fastness are greater than 15 Zhou Qituan.For the medical cloth that requires high strength and high abrasion fastness, the basis weight of best cloth is not more than 60 gram/rice ², minimum is grabbed sample tensile strength and is not less than 65 newton, and minimum Erichsen tear resistance is not less than 6 newton, and dry state surface abrasion resistance fastness reaches 40 all groups of rising at least and the wet surfaces wear resistance reaches 30 Zhou Qituan at least.

Should understand fiber, net or the cloth of using manufacturing of the present invention can combine with multiple mode, can be with other fibers with different performance, net, cloth in conjunction with the product that has specially appointed performance with formation.

Some examples are provided below, and purpose is to further specify the present invention; Under any circumstance they do not represent in the present invention the perhaps limit of scope.

Example 1

In following example, the 1st, 2, No. 3 net of enumerating in the table is to produce under the listed condition of table I.

The table I

Production melts and sprays the process conditions of nylon wire

Network No.

Process conditions 123

Extruder temperature-porch ℃ 260 232 260

Extruder temperature-exit ℃ 275 275 300

Filter screen/agitator temperature ℃ 275 275 287

Mold temperature ℃ 287 265 300

Primary air temperature ℃ 287 287 335

Primary air flow velocity meter per second 290 255 221

Polymer flow rate Grams Per Minute hole ^-10.14 0.14 0.28

Mould air gap millimeter 1.14 1.14 1.14

Mould dislocation distance-negative dislocation millimeter 1.02 1.02 1.02

Auxiliary air flow velocity meter per second 30 30 30

Basis weight gram/rice ²52 44 6

Fiber diameter micron 3.6 4.1 9.8

Listed similar in the working condition of No. 1 net and the common pending application (JSU 58), in the hope of obtain on the cloth of moulding stop and strength character between optimal coordination.The working condition of No. 2 nets has been done a little modifications, can produce to have high strength more but stop the cloth that performance has reduction slightly, and this effect is to obtain than No. 1 lower mold temperature and the primary air flow velocity of net by adopting.Producing that No. 3 nets the time have improved the flow of polymer and further reduced the primary air flow velocity is 9.8 microns to obtain fiber diameter, and wherein 80% fibre diameter is greater than 7 microns stratum reticulare.In addition, mold temperature has also improved so that the bondability between No. 3 network fibers increases.The table II has been enumerated the physical characteristic of the cloth of producing with 1,2, No. 3 net that passes through embossing.The table III has been listed and has been produced the employed process conditions of cloth with the listed physical characteristic of table II.

The table II

The explanation that melts and sprays nylon and the physical characteristic thereof of heat embossing

The cloth item number

Characteristic 4567

No. 3 nets of No. 3 nets of No. 2 nets of No. 1 net of stratum reticulare combination-Di 1 floor

No. 2 nets of-Di 2 floor--No. 2 net

-Di 3 floor---No. 3 net

Total basis weight (gram/rice ²) 52 44 50 56

Grab sample tensile strength and weight ratio

(newton/grammeter ²)

Warp direction 2.06 2.77 2.55 2.48

Weft direction 1.53 1.94 1.95 1.90

Hydrostatic head (centimeter water column) 49 36 39 39

Wear resistance (all numbers)

First dry state-group of rising 15 15 40 50

-worn out hole 100 100 100 100

Hygrometric state-the group of rising 15 15 30 35

-worn out hole 100 100 100 100

Second dry state-group of rising 15 15 15 50

-worn out hole 100 100 100 100

Hygrometric state-the group of rising 15 15 15 35

-worn out hole 100 100 100 100

The table III

Melt and spray the process conditions of nylon heat embossing

The cloth item number

Process conditions 4567

The ratio that the embossing area accounts for (%) 18 18 18 18

The oil temperature (℃)

Cylinder 126 122 12 121 is engraved at the top

Bottom light surface roller 126 122 122 122

Thrust between cylinder (newton/centimetre) 685 685 685 685

The translational speed of net (rice/minute) 15 999

From the table II as can be known, No. 5 clothes grab sample tensile strength than No. 4 cloth height, but it stops performance and decreases, this on the data of hydrostatic head as can be seen; Wear resistance does not then change.No. 6 and No. 7 clothes improve to some extent their wear resistance owing to having added cementing layer (No. 3 nets).But No. 6 and No. 7 clothes are owing to close with No. 3 anastomoses of cementing layer, and its standardized sample tensile strength of grabbing decreases successively, and this is because cementing layer has increased the weight of cloth, but does not have No. 2 nets like that many by the tensile strength that Unit Weight increases.The cementing layer of No. 3 net formations slightly improves the hydrostatic head data of No. 6 and No. 7 clothes, and it is remarkable that the surface abrasion resistance fastness is then carried nice and high.

The measuring method of dry state surface abrasion resistance fastness is as follows: tested cloth sample places on the foam pad on the testing machine base plate, the emery cloth of standard Li Telong (Lytron) face that one 7.6 cm x is 12.7 centimetres is contained on the top board of testing machine and with the test cloth specimen and contacts, and the warp direction of cloth specimen is parallel with the warp direction of emery cloth.Press one 1.1 kilograms weight on top board, with 1.25 rev/min the rotational speed of base plate to fix, whenever turning around is called " 1 week " then.Changeed the first round 5 circle and inspected the surface of sample cloth later on magnifying glass, later revolution 5 circles are inspected once, note to reach sample cloth has been ground the required all numbers of group, and it is ground all numbers that the hole is come." group of rising " is defined as the fibre shedding on the cloth cover and begins and form round and round or pearl.Altogether 4 cloth specimens are tested, got its average all number that reach the group of mill and grind the hole as the data in the report.

Similar methods is adopted in wet surfaces wear resistance test, and it does not exist together and is: cloth specimen drips 5 pure water, only 0.2 kilogram of the weight of pressing on the top board after being fixed on the base plate of testing machine on its face.

Example 2

In the example below, what the table IV was listed as is the working condition of the 8th, 9,10 and No. 11 net.

The table IV

Production melts and sprays the process conditions of nylon base net

Extruder temperature-porch ℃ 246 232 232 260

Extruder temperature-exit ℃ 274 274 274 301

Network No.

Process conditions 89 10 11

Filter screen/agitator temperature ℃ 274 274 274 301

Mold temperature ℃ 274 265 265 301

Primary air temperature ℃ 309 285 285 331

Primary air flow velocity meter per second 299 252 191 299

Polymer flow rate Grams Per Minute hole ^-10.14 0.14 0.28 0.28

Mould air gap millimeter 1.14 1.14 1.14 1.14

Mould dislocation distance-negative dislocation millimeter 1.02 1.02 1.02 1.02

Auxiliary air flow velocity meter per second 30 30 30 0

(being right after the page table IV)

Basis weight gram/rice ²52 42 66

Fiber diameter micron 8.2 8.8

8th, 9,10 conform to listed process conditions in the common pending application (JSU58) with the process conditions of No. 11 nets.The process conditions of No. 8 nets are in order to obtain the optimal coordination that stops between characteristic and the intensity on the cloth of moulding.The working condition of No. 9 nets has been done a little modifications, and it is higher but stop the poor slightly cloth of characteristic to produce intensity that it has reduced mold temperature and primary air flow velocity than No. 8 nets.No. 10 nets are to produce average fibre diameter to be about 9 microns under increase polymer flow rate and further reduction primary air flow velocity condition, and wherein 80% fibre diameter is greater than 7 microns.No. 9 is the same with No. 10 used mold temperatures of net.No. 11 the net working condition basically with No. 3 nets similar, but without auxiliary air to improve its interfibrous initial adhesion degree.No. 11 the used mold temperature of net has also improved to improve its interfibrous initial adhesion degree than No. 10 nets.

Below the table V listed with the 8th, 9,10 and No. 11 net physical characteristic at the embossing cloth of showing to make under the listed condition of VI.No. 13 clothes are that No. 12 clothes add 3 gram/rice at every face ²Primacor 4990 adhesives of producing by The Dow Chemical Co. (US) 2030 Dow Center, Abbott Road, Midland, Michigan 48640, (DOW Chemical Co), the latter is a kind of ethene and acrylic acid common polymer of 80/20 ratio.

The table V

The cloth item number

Characteristic 12 13 14 15

No. 11 nets of No. 10 nets of No. 8 net adhesive of stratum reticulare combination-Di 1 floor

No. 9 nets of No. 9 nets of-Di 2 floor-No. 8 net

(being right after the page table V)

-Di 3 floor-No. 11 nets of No. 10 nets of adhesive

Total basis weight (gram/rice ²) 52 58 54 54

Grab sample tensile strength (newton)

Warp direction 94.1 103 94.0 108

Weft direction 71.7 71.9 58.9 69.1

Hydrostatic head (centimeter water column) 41 38 37 38

Wear resistance (all numbers)

First dry state-group of rising 5 15 40 45

-worn out hole 100 100 100 100

Hygrometric state-the group of rising 5 15 30 40

-worn out hole 100 100 100 100

Ku Shi suspended coefficient (%) 46 65 45 44

The table VI

Melt and spray the process conditions of nylon wire heat embossing

The cloth item number

Process conditions 12 14 15

The ratio that the embossing area accounts for (%) 18 18 18

The oil temperature (℃)

Cylinder 104 106 93 is engraved at the top

Bottom light surface roller 97 99 95

Thrust between cylinder (newton/centimetre) 685 685 685

The translational speed of net (rice/minute) 999

As show shown in the V, the surface abrasion resistance fastness of No. 13 clothes increases, and its Ku Shi coefficient that dangles has increased substantially.The addition that increases adhesive again will further improve its wear resistance, but will further have a negative impact to its drapability.

The surface abrasion resistance fastness of No. 14 clothes than No. 13 is much higher, but is not accompanied by the forfeiture of drapability.No. 15 cloth is having more improvement again than No. 14 aspect the surface abrasion resistance fastness.It is believed that this raising is because the cause that the initial adhesion degree has improved between the fiber in No. 11 nets.

Therefore, can clearly find out, the invention provides a kind of melt-blown micro-fiber cloth novel, that do not strengthen, it has the surface abrasion resistance fastness that improved to satisfy purpose, target and the advantage that proposes above.Though the present invention describes in conjunction with specific embodiment, many alternative other schemes, improvement and modification obviously also can be arranged, they will be open-and-shut later on for the explanation of the people who is familiar with the industry on read.Therefore, all meet the spirit of back claim and alternative plan, improvement and the modification of broad range, all belong to the category of the claim of being applied for.

Claims

1, a kind of improved enhancing melts and sprays cloth, described cloth has improved wear resistance, its feature comprises: one deck does not strengthen the thermoplastic core net at least, wherein at least 80% fiber directly is 7 microns or littler, the share that self adhesive effect of its fiber offers the galley proof tensile strength of this cloth is no more than 30%, with do not strengthen surface gummed stratum reticulare at the online one deck at least of described core, described surface gummed stratum reticulare is formed by the thermoplasticity meltblown fibers, this average fibre diameter is greater than 8 microns, wherein 75% fibre diameter is at least 7 microns, and its basis weight is at 3 gram/rice ²To 10 gram/rice ²In the scope, described cloth is in the discrete bond district pressure sintering embossing that is interrupted, and bonding zone accounts for 5% to 30% of cloth surface, and the minimum of this core net is grabbed the ratio of sample tensile strength and weight greater than 0.8 newton/grammeter ², the ratio of its Elmendorf tear resistance and weight is greater than 0.04 newton/grammeter ², having and the hygrometric state wear resistance and at least 40 weeks of playing group at least 30 weeks play the dry state wear resistance of group, the average length of fiber is between 10 to 50 centimetres in the core net, the described gummed of one deck at least stratum reticulare directly is connected with the described core of one deck at least net.

2, improved enhancing the according to claim 1 melts and sprays cloth, it is characterized in that the average diameter of described surface gummed stratum reticulare fiber is about 9 microns.

3, the method that a kind of manufacturing does not strengthen with the microfiber cloth that improves the surface abrasion resistance fastness, wherein, a kind of thermoplastic polymerization resin that can form fiber is forced through the row's aperture that is arranged in the heating shower nozzle and enters stream of inert gas under molten condition, make this resin be scattering into fiber, this fiber is collected and forms one deck net on a receiver, to form cloth, the feature of this method comprises this net by heat bonding:

(1) at first heating shower nozzle place, the polymer that keeps fusion is at temperature levels certain, molecular degradation degree minimum, flow velocity, volume and the temperature of control primary air, the flow of polymer resin and outlet temperature are to make the ground floor thermoplastic fibre, the average diameter of this fiber is greater than 8 microns, and wherein there is 75% fibre diameter to be at least 7 microns, collect described fiber on the receiver outside certain distance and do not strengthen surface gummed stratum reticulare to form the high ground floor of self bondability, described fiber basis weight is at 3 gram/rice ²To 10 gram/rice ²In the scope, and its wet surfaces wear resistance and dry state surface abrasion resistance fastness are greater than 15 Zhou Qituan;

(2) at second heating shower nozzle place, the polymer that keeps fusion is certain, the temperature levels of molecular degradation degree minimum, the flow velocity of control primary air, volume and temperature are to make thermoplastic fibre, at least 80% diameter is 7 microns or littler in this fiber, its average length is more than 10 centimetres, import one its flow in addition and be enough to the uniform high speed auxiliary air of height that cools off and keep described fiber to separate, collecting described fiber in certain moulding distance makes it form one deck core net, interfibrous bondability is very low in this net before further this net embossing being made the formation cloth, the fiber of this described core net is to be collected in described ground floor surface to glue together on the face of stratum reticulare, and described gummed stratum reticulare directly is connected with described core net.

4, method according to claim 3, its feature also comprises:

According to claim 3 or 4 described methods, it is characterized in that 5, the average diameter of the fiber of described gummed stratum reticulare is about 9 microns.

6, according to claim 3 or 4 described methods, its feature also comprises described which floor net bonding with the heat embossing method.