MXPA98007561A - Process and apparatus improved to produce non-teji bands - Google Patents

Abstract

The present invention relates to a process for producing a nonwoven polymeric web, such as a spunbonded web, having filaments of 0.1 to 5 weight units with equivalent production rates. A plurality of continuous polymeric filaments (F) of an extruder (22) are squeezed and attenuated by a stretching unit (31) including a longitudinal elongated slot (32) strategically placed at an optimum distance very close to the spinner (26) . A strip-forming board (90) is placed under the stretching unit to collect the filaments and form the filaments in a nonwoven web. At the beginning, the production is nominal, the air pressure is below 1,406 kg / cmýmn, and the spinner is placed more than 100 cm away from the stretching unit. Gradually, production increases greatly by simultaneously increasing the air pressure while reducing the distance between the spinner and the stretching unit. The coordination of production adjustment with air pressure and the distance reduction of the spinner and stretch unit produce the finest filaments to equivalent production or the same filament size at the highest production speed and lowest cost.

Description

^ IMPROVED PROCESS AND.APARATO TO PRODUCE NON-WOVEN BANDS BACKGROUND PE INVENTION 5 1. FIELD OF THE INVENTION __ This invention relates generally to an apparatus, process and the product produced therefrom to build a non-band.

Spunbond woven of thermoplastic polymers that produce filaments of reduced diameter and improved uniformity at an increased production rate, and specifically, to an apparatus and process for heating and squeezing thermoplastic materials through a spinner, forming filaments of weight units finest to strategically place the stretching unit under the spinner at a critical distance to produce a finer filament of a desired diameter and with an improved production speed, and the resulting spin-bonded product. Water spray can also be used to cool. 20 2. DESCRIPTION OF THE PREVIOUS TECHNIQUE Devices for producing non-woven thermoplastic teat bands from polymers squeezed through a spinner that form a vertically oriented curtain with downwardly advancing filaments and which air-extinguish the filaments together with a suction-type air stretch or attenuation slot, are well known in the art. The Patent of E. U.A. No. 5,292,239, describes a device that reduces significant turbulence in the air flow to uniformly and consistently apply the stretching force to the filaments, resulting in a uniform and predictable stretching of the filaments. The Patent of E. U.A. No. 3,802,817, discloses a suction apparatus placed at a selected distance below the spinner when using injection streams having turbulent flow rate velocity to produce fine nonwoven fleeces. The Patent of E.U.A. No. 4,064,605, and European Patent Application No. 0230541 discloses examples of the formation of non-woven fabrics. Conventionally, thermoplastic polymers such as polypropylene, polyethylene, polyester, nylon and mixtures thereof are used. In the first step, the polymer melts and squeezes through a spinner to form the vertically oriented curtain of downwardly advancing filaments. The filaments then pass through the extinguishing chamber where they are cooled by cold air, reaching a temperature at which the crystallization of the filament begins, resulting in the solidification of the filaments. A stretching unit located in a fixed position under the extinguishing chamber acts as a suction having an air slot into which compressed air is introduced into the slot, urging air into the upper open end of the slot, forming a current of air that moves quickly in the slot. This air stream creates a stretching force on the filaments, causing them to dim or stretch out of the bottom of the groove where they are deposited on a moving conveyor belt to form a continuous band of filaments. The filaments of the band are then joined together by conventional techniques. By providing conventional construction of the filaments, filaments were typically produced from 1.5 to 6 weight units or more. By using conventional methods, the hot filaments leaving the spinner were immediately cooled to room temperature and solidified and then subjected to the stretching unit. According to an earlier proposal, when the length of the filament traveling through the air is shorter than a specific value selected based on the production (gram per hole per minute) used, the squeezed filaments will make contact with solid constituent of the stretch unit before the solidification of the filaments, resulting in the development of rupture or damage of the filament. In other words, although the prior art produces suitable nonwoven webs, its production is limited by the ability to cool and solidify the filaments in a predetermined length to proper production. The filament spinning speed achieved in the prior art is in the range of 3,000 to 3,500 meters per minute. Although the conventional method and apparatus produce suitable nonwoven webs, the final product can be greatly improved and better web can be produced which consists of filaments with smaller weight unit (weight in grams of 9,000 meters of yarn). A thinner filament produces more surface area and more length per unit weight. A polypropylene spinning unit fabric with filaments of 0.1 to 2.0 weight units would be desirable. When evaluating thickness, different types of thermoplastic polymers may require some adjustment in thickness. Diameters that vary slightly in other thermoplastic polymers such as potietiteno or polyester may require an adjustment also to consider the speed of production. It is also desired that a unit uniformity of weight and tension properties be constant so that the resulting fabric web has a uniform quality. Examples of end uses for the cloth web would be filtration materials, diaper covers and medical and personal hygiene products that require liquid vapor barriers that can breathe and have air permeability. With the present invention, a process for producing a non-woven web of superior quality at much higher production and lower cost can be achieved. The core of the invention is found in the use of a technique comprising mainly adjusting the processing variables such as production, air pressure, and volume at the same time moving the stretch unit vertically over the spinning line to the spinner, resulting in the reduction of air suction associated with the length of the filaments traveling at high speed and causing an increase in the extraction force exerted on the shorter length filaments. The increased extraction force not only produces thinner filaments at higher speed for spinning? filaments, but also creates effect of stronger crystallization induced by tension, causing that the crystallization in line of filaments occurs earlier on the spinning line at higher temperatures and speeds. Correspondingly, the filaments are solidified earlier at a higher temperature, thus resulting in less required extinguishing capacity or higher mass production with the same extinguishing capacity can be used. It can achieve 90 to 95 percent reduction of associated air extraction # with the length of the filaments between the stretch unit and the spinner by moving the stretch unit from a conventional distance of 3 to 5 meters from the spinner to 0.2 to 0.5 meters, giving rise to the possibility of producing finer filaments at higher production speed. When changing the position of the stretch unit and when using steam, the diameter of ios filaments can be controlled in such a way that at sticking between the filaments in contact can be avoided, the temperature of the filaments remains as high as possible before being extracted and consequently facilitating the attenuation of the filaments, resulting in filaments that they have diameters much smaller. The position of the strip-forming board corresponding to the stretching unit can also be adjusted so as to form a non-woven web having desired uniformity with other mechanical properties. You can add water vapor to interact in the process to improve the uniformity and production of the filaments. Water vapor improves the process, but the basic apparatus and process will work without water vapor only by the reduced separation of the spinner and the stretching unit. In terms of the speed for spinning filaments, 4500 meters per minute can be achieved for polyethylene terephthalate (PET) and 5 3500 meters per minute for polypropylene (PP), in the prior art and in current commercial production. With the invention of the applicant, it is believed that 8000 meters per minute have been achieved for PET and 6400 meters per minute for PP. The applicant has been able # produce meltblown grade filaments (5 to 10) micronometers at production speeds joined by spinning from 70 to 150 kg / H / M wide), which is more than the capacity of conventional production technology. In accordance with the invention, a correct start procedure is needed to establish (finally) the conditions optimum with the highest speeds to stamp filaments to corresponding higher productions. For example, a process of producing a spunbonded fabric of 4.5 unit weight of PET filament at 4.0 gram per hole per minute (ghm) summing 8000 meters per minute of filament velocity can not be establish if the process starts with the stretch unit placed near the spinner to less than 50 cm. The correct start of the process is to begin first with the stretch unit placed at least 100 to 150 cm below the spinner and with a much lower production, less than 1.0 gh and at use lower air pressure, between 0.703 to 1.406 kg / cm2mn so that soon the filaments can be screwed through the groove of the stretching unit. Once the initial start is established under these conditions, the air pressure and production are then coordinated in a coordinated manner to a desired condition, while the stretching unit is raised closer to the spinner. A stable process can be obtained where filaments of 4.5 unit weight to 4.0 ghm are produced with the stretch unit placed 25 cm below the spinner when using 5.2725 kg / cm2mn air pressure. It has been found that the applicant can use distances between the spinner and the stretching unit between 5 and 150 cm and optimally between 20 and 90 cm between the spinner and the stretching unit. However, these small distances are only achieved after the start procedure mentioned above. There are two distinct changes that occur for the inline diameter profile as the speed increases for spinning filaments. First, the speed of reduction in diameter of the fused thread increases in the upper region of the spinning line. In other words, the cast thread thins faster at speed to spin higher, creating more surface area to cool. Second, the position where the filament begins to solidify due to the so-called stress-induced crystallization moves towards the spinner. As the filament speed is higher, less cooling is required (shorter extinguishing chamber), and the stretching unit can be lifted above the spinning line without causing interruption of the process as the filaments solidify well before entering. to the slot of the # unit where contacts are made between the filaments. When the distance between the spinner and the stretching unit decreases, the pulling force Fa, which is associated with the length of the filaments (dZ) traveling at high speed between the spinner and the stretching unit will be reduced in proportion, resulting in increasing inertial force F¡nßr <; .ß, which leads to even higher filament velocity, thinner filaments and higher solidification temperature. This in turn allows the stretching unit to be elevated higher. The results show that Depending on the material to be processed and the production to be used (gram per hole per minute, referred to as ghm from now on), the stretch unit can be raised as close as 5 to 40 cm to the spinner to a production of up to 4 ghm, compared to 2 to 4 meters being used in production Current commercial, which is more than 90 to 95 percent reduction in air drag force that has significant impact on the performance of the process in terms of fineness of the filaments that can be produced at production speed that can be achieved. As the stretch unit is closer to the spinner, the temperature at which the filaments are stretched will be higher and the elongated viscosity will be lower, which is inversely proportional to the elongation speed. That is, with lower elongation viscosity, higher elongation speed (higher filament velocity) can be achieved under the same force of extraction.

^ BRIEF DESCRIPTION OF THE INVENTION A process and apparatus for producing a spunbonded nonwoven web consisting of filaments of reduced diameter and improved uniformity from thermoplastic materials at an increased production rate, comprising a spinning machine having an extruder for heating and squeezing materials thermoplastics through a spinner, to substantially form a plurality of oriented polymer filaments vertically and a filament stretching unit having a longitudinal elongated slot substantially equal in length to the spinner, said stretching unit being strategically placed under the spinner at a critical distance to receive the filaments therein. The stretching unit is movably connects to the spinner and can be moved manually or by motor at a desired distance from the spinner before and during the operation of the machine to produce spunbond filaments. The distance between the elongated slot of the stretch unit and the spinner is critically determined to provide a finer filament of a desired diameter, resulting in a filament of better size in diameter and an improved production speed. The important distance between the elongated slot in the stretch unit and the base of the spinner where plastic materials are squeezed is substantially about 0.2-0.9 meters. When placing the stretch unit relatively close to the base of the spinner after initial start. You oe a fiiamen.o gives unit of weight as fln. Since the process of stretching occurs as the hot melted rings come out of the spinner, allowing them to cool sufficiently to not stick while simultaneously being sufficiently hot (soft) to stretch into a finer filament of more uniform weight unit. In conventional devices where there is a large gap between the base of the spinner and the stretching unit, typically the hot melt threads are first cooled to room temperature and solidified and then reach the stretch unit where it is more difficult to achieve the finer or thinner type of filaments obtained from the present invention. The filaments, when hot, can be stretched or attenuated to a finer diameter when using the present invention. The result is a better product as it has more area surface and length by unit weight and more effort. The stretching unit has a groove in the form of the letter V on the upper portion with an elongated open end directed horizontally at the top and opposite side walls depending on the open upper end, one towards the other, for form a narrow cavity at the end of the upper portion of the slot. An adjacent nozzle supplies a directed stream of air introduced into the groove over the entire length of the groove so that a turbulent flow pattern is formed in the area where two directed air streams merge with each other. Slot also includes a lower portion that is configured to improve the randomness of the spreading of the filaments for uniformity of the resulting web. A strip-like board is placed under the stretch unit to receive the filament sheet, forming the same in a nonwoven web. The machine is constructed so that the position and location of the stretching unit and the strip-forming board can be independently adjusted vertically on the spinning line, as well as horizontally perpendicular to the spinning line. The apparatus includes two air supply nozzles communicating with the stretching groove on both sides to form an angle of 15 ° to 30 ° each, adapted to a curved air passage to introduce a directed air stream. A turbulent flow pattern is triggered when air currents leaving both nozzles contact the filaments as well as each other so that an intense "flutter" or "wavy" movement of the filaments is established. This interaction of air and filaments drastically increases the drag force exerted on the filaments, resulting in increased attenuation of the filaments. In order to operate the stretch unit placed 0.2 to 0.9 meters from the spinner as described above, a start procedure must be followed, starting with the stretch unit placed at least 100 cm or further from the spinner at a location In this connection, a suitable polymerization and nominal pressure and volume of air are established so that P can be achieved by screwing the filaments through the groove of the stretching unit. Once the spinning line is established in this condition, the air pressure and the production can increase gradually in a coordinated manner while raising the stretch unit to the spinner. Through this starting procedure and these distance adjustments between the spinner and the stretching unit that becomes smaller »a stable process can be obtained where the finest filaments can be produced at an equivalent or higher production. Therefore, once After completion of the spinning line initiation and once the spinning line has been established, the stretching unit can then be manually or powerfully raised manually to the spinner while simultaneously appropriately increasing the polymer production and the pressure of the spinning line. air up reach a position between the spinner and the stretching unit to produce the finest filament (smallest weight unit) and the most uniform band at the increased production speed. The band-forming board in relation to the air stretch unit must also be adjusted for desired band properties, such as uniformity and elevation of the band. An object of this invention is to provide a machine that produces a spunbonded nonwoven web comprised of filaments having a smaller diameter than conventionally produced filaments with a better uniformity to the filaments. from thermoplastic materials at a higher production rate.

Another object of this invention is to produce a spin-bonded nonwoven web composed of thermoplastic filaments having an optimum small weight unit to create filaments with more surface area and more length per unit weight to be used as a non-woven web. And still another object of this invention is to provide a method for producing finer filaments with better uniformity from thermoplastic materials to be used as non-woven webs spun at a higher production rate. In accordance with these and other objects that will be apparent hereinafter, the present invention will now be described with particular reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE INVENTION Figure 1 shows a perspective view of the apparatus according to the present invention. Figure 2 shows a side elevation view of the cross section stretch unit used in the present invention, Figure 3 is an exploded perspective view showing a stretch unit in accordance with the present invention.

W DESCRIPTION OF THE PREFERRED MODALITY Referring now to the drawings and in particular to Figure 1, the present invention is generally shown in which it includes an improved spinning machine including an extruder 22, a teat rod 25, and the stretching unit 31. The extruder 22 and loom rod 25 are fixedly mounted to a floor support above the movable stretch unit 31. The stretching unit 31 is movably supported above a movable mesh wire web conveyor 92 which is a component of the band-forming board 90. The band-forming board further comprises an adjustable base 93 (vertically) that can be used to vertically adjust the distance between the upper part of the table 90 and the spinner 26 in a scale of approximately 30 to 150 cm. Wheels 94 are mounted below the base 93 on a pair of tracks 95 so that the band-forming board 90 can be moved back and forth horizontally to allow some space to change the spinner 26. 20 Polymer is fed from the supply of polymer 20 in the hopper 21 where the polymer is heated and melted in the extruder 22, pushed through the filter 23 and measuring pump 24 to the loom rod 25, where it is then squeezed through a spinner 26 which has a plurality of holes in multiple rows, together forming a curtain of filaments F that move vertically downwards.

* The stretching unit 31, which acts to attenuate the filaments, includes an elongated longitudinal slot 32 that is strategically aligned below the spinner to receive the curtain of filaments that move by gravity and air pressure. The most important distance with respect to the size and volume of production of the filament after establishing the initial start is the distance between the base of the spinner 26 and the upper part of the stretch unit 31. The filaments F, before being # sucked in and taken out by stretch unit 31, They cool and partially solidify by a fast moving stream of air mixture (and optionally atomized water) which enters by suction of the ambient air stretch unit 31 with steam produced by the water spray unit 28. Referring now to figure 2, the unit Stretch 31 includes a slot 32 having an elongated, horizontally directed open top slot segment 33 that includes a pair of side walls 35 and 36 projecting from the top surface S of the stretch unit 31 at an angle of up to 90 °. The stretching unit 31 also includes a upper slot segment 34 composed of a pair of side walls 37 and 38 depending on the upper slot segment 33 at an angle of substantially between 15 ° to 60 ° and preferably 30 ° to 45%. The slot 32 further comprises a lower slot segment 44 having lower side walls of a pair of lower blocks 50 and 51. Transverse shors 41 are positioned between the upper and lower slot members 34 and 44 on each side of the slot 32. A pair of air nozzles 42 and 43 on each side of the slot 32 extends over the entire longitudinal length of the slot 32 and formed between inner surfaces of the lower end of the upper slot side walls 37 and 38 and the opposed surfaces 54 and 55 of the lower blocks 50 and 51. An air passage 56 extends over the entire longitudinal length of the slot 32 of the stretching unit 31 and is defined by the separation plate 57 at the bottom of the air chamber 58, which has two fixed sectional plates 59, and a curved surface of the lower blocks 50 and 51. The air passage 56 is divided into two segments, a discharge segment 60 connected with nozzles 42 and 43 having a width in gradual reduction in the direction towards the associated nozzle and a unification segment 82 containing four parallel vertical sections in an arc curve section of the air passage 62 is connected to the air chamber 58 through an air window 64 which is a brake plate Located on the edge of the separation plate 57 adjacent to the side walls 70 and 71 of the stretching unit 31. Air is supplied to the air chamber 58 through a fold 65 connected to a suitable air supply unit 66 (see figure 1). The air chamber 58 comprises a number of air lines 68 which enter the air chamber 58 of the fold 65 and having an open end 69 that faces upwards and closes towards the side walls 37 and 38 of the upper slot segment. The arc curve section of the air passage in the? ß segment. Unification creates an air pressure drop that serves to equalize the air volume flow rate and speed over the entire longitudinal length of the $ 2 slot, especially at the outlet of the nozzles 42 and 43. The area for the passage of air 5 decreases gradually over the passage of air from the air window 64, to the outlet of the nozzles 42 and 43, which also serve to unify the air pressure. As a result, the air flow at the outlet of the nozzles 42 and 43 will be uniform in volume and velocity over the entire longitudinal length of the slot 32. The air chamber 58 further includes a number of water spray heads 76 (FIG. optional) installed and in fluid communication with a water inlet pipe 72 connected to a water supply unit 74. For example, steam from the water spray heads serves to cool the air entering from the water supply unit. air 66v that facilitates the solidification of the filaments that make contact with the air stream. The lower blocks 50 and 51 of the stretching unit are constructed in such a way that the upper surfaces of the blocks, which define the air passage with the separation plates 57 and two plates in vertical section 59, are composed of two curved edges in a downward arc and one in an upward arc curve. The two edges curving downwards have different depths. The edge closest to the air window 64 is 2 to 10 mm longer than the other edge. The lower blocks 50 and 51 of the stretching unit are connected with side walls 73 and 71 of the stretching unit by a plurality of bolts 75 through holes extended in the upper walls 71 and 73 so that the positions of the blocks can be adjusted up or down to change the cavity of the nozzles 42 and 43 and therefore the volume and velocity of the air flow in accordance with the needs of the process. Referring now to Figure 3, the stretching unit 31 includes on each side the side cover plate 80 connected by a number of bolts 89 through horizontally corresponding extended holes 81, 82 and 83, through which it can be adjust the width of the slots 34 and 44. A rubber gasket 84 is used between the body of the stretch unit 31 and the side cover plate to seal the unit. The distance between the stretching unit 31 and the band-forming board 90 can be adjusted with male screws 86 fixed vertically to the side cover plate 80 through equivalent female screws 85 and driven by a motor with a gearbox system 87 fixed to the table forming band 90 (see figure 1). By turning the screws 86, the position of the stretching unit 31 can be adjusted correspondingly with respect to the strip-forming board 90. Figure 3 also shows the air supply 66 and the water supply conduit 74 fixed to the input conduits 65, 88 and 72, respectively. Referring again to Figure 1, a very important element of the invention is shown. The band-forming board 90 is placed below the slot 32 of the stretching unit 31 to receive the filaments F and form the filaments in a band. non-woven The band-forming board 90 comprises a vacuum suction box for pulling filaments on a moving wire mesh belt conveyor 92 that transports the strip as it is formed to the next stage of the process to strengthen the band by conventional techniques to produce the final nonwoven web band. The band-forming board 90 includes the adjustable base 93 which is used to vertically adjust the vertical distance between the top of the table 90 and the spinner 26 on a scale of about 30 to 180 cm. The critical distance between the stretching unit 31 (on the upper slot 32) and the lower portion or surface of the spinner 26 is a critical setting and critical distance to achieve the invention. The distance between the bottom of the spinner and the top of the stretch unit can be adjusted, preferably between 10 to 90 cm during normal production. The following is an example of an apparatus constructed in accordance with the present invention when using polypropylene as the polymer.

EXAMPLE 1 A correct starting procedure is needed in order to finally establish the optimum conditions where the highest speed is reached to spin filaments to a corresponding production. Therefore, at the initial start, (distance from the top of the stretch unit to the spinner is on the conventional scale of 100 to 150 cm separation distance or more.) A lower production, less than 1.0 ghm, a An air pressure lower than 0.703 to 1.406 kg / cm2mn, is established so that the coiling of the filaments through the groove can be achieved.A established continuous line of teta filaments to these conditions, air pressure gradually increases , which increases the speed to hitar.Simultaneously, the stretching unit is placed closer to the spinner, at the same time adjusting the production and therefore the air pressure.The final distance from the top of the unit Stretching at the taper is about 5 to 150 cm, preferably 20 to 90 cm, during normal production, The width at ta upper part of the upper slot segment 33 of the stretch unit is approx. Approximately 10 to 20 cm. The width at the top of the upper slot segment 34 is approximately 5 to 15 cm. The width between the opposite edge of the slot 32 in the shoulder 41 is approximately 0.3 to 2.0 cm. The outlet cavity of the nozzles 42, 43 is approximately 0.1 to 0.6 mm. The air streams introduced from the air supply unit 66 on both sides of the slot have a velocity of approximately 100 to 350 m / second at the outlet outlet of the nozzles 42, 43 and form a turbulent flow as they join. Air and steam must be sucked from the upper open end 33 by the air streams coming out from the nozzles 42, 43 and this stream of air sucked with steam cools and pulls filaments on the upper slot segment 44 to the nozzles 42, 43 where it joins the turbulent flow air stream. The filaments thus introduced form an intense "flutter" or "wavy" pattern as they move over the air stream below the nozzle according to the pattern of the air flow. This movement of "intense flutter", coupled with the proximity of the 5 stretch unit to the spinner, creates an ideal situation, where a significantly increased air extraction force produced by "form drag" due to the movement of Flapping is exerted on filaments that are still "hot" and therefore will stretch soon, resulting in filaments that have a unit of weight of about 0.1 to 2.5 for polypropylene at a production rate of about 70 to 360 kilograms per meter machine width, then referred to as a dimension corresponding to the width of the spinner, per hour and 0.3 to 4.5 units of weight for polyethylene terephthalate to one production speed of approximately 100 to 540 kilograms per meter machine width per hour.

EXAMPLE 2 The width of the upper part of the upper slot segment 33 of the stretching unit is 10 cm. The width at the top of the upper slot segment 34 is 5 cm. The width between the opposite edge of the slot 32 in the shoulder 41 is 3 mm. The outlet cavity of the nozzles 42, 43 is 0.1 mm.

The width of the spinner is 10 cm. The number of holes in the spinner is 144 with hole diameter of 0.35 m. The extinguishing chamber located on the right below the loom rod is 15 by 28 (cm x cm), supplying cold air of 7.2 to 15.5 &C. The raw material used is 35 MFR polypropylene. The processing temperature used is 230 * 0. The production used is 2.5 grams per hole per minute. The distance from the top of the stretch unit to the spinner is 40 cm. The supplied air The stretch unit is at 3.0 NM / min with a pressure of 3.8665 kg / cm2mn. The distance from the bottom of the stretching unit to the surface of the table forming band 90 is 40 cm. A uniform sheet of fine filament curtain is seen emerging from the groove of the stretching unit after being stretched by the downward turbulent air stream fused by two air streams from a to b. sides of Sa filament curtain. The nonwoven fabric thus obtained has an excellent uniformity with filament size of 3, 5 weight units. The speed to spin filaments in this case is 6,400 meters per minute. The processing has to go through the start procedures in the following way. The initial polymer production is 0.5 gram per hole per minute. The stretching unit is placed 150 cm below the spinning machine. The air pressure of 1.0545 kg / cm2mn is used for the stretching unit. Light extinguishing is supplied. The threading of filaments through the stretch unit is completed soon under this condition. Then, the stretching unit moves gradually while increasing the air pressure and production accordingly and then a certain quantity of extinguished air is supplied until reaching the final processing condition mentioned above. It should be noted that there is a scale of conditions under which the beginning can be achieved. The only purpose of the beginning is to thread the filaments through the groove of the stretching unit to establish a stable weaving line. Without a proper start procedure, the final processing condition can not be achieved as described above. In other words, it is impossible to screw filaments squeezed at a rate of 2.5 grams per hole per minute through a stretch unit placed 40 cm below the spinner without facing a problem of non-solidified filaments making contact with the solid constituent of the stretching unit, causing severe blockage of the groove and the process must be interrupted.

EXAMPLE 3 The same equipment is used as in example 2 with the raw material being PET (potietflene terephthalate). The processing temperature used is 290 ° C. As a start, the production of 0.5 gram per hole per minute is used and the stretching unit is placed 120 cm from the spinner. No extinguished air is needed. The air pressure of 1,406 kg / cm2mn with volume velocity of 2.0 Nly? / Min is supplied to the stretching unit. The threading of the filaments through the slot can be achieved soon. Then, gradually increase the air pressure and production at the same time by moving the stretching unit as described in example 2. Finally, the production processing condition of 4.0 grams per hole per minute and air pressure of 4,921 kg / cm2mn with the stretching unit placed 25 cm from the spinner and the forming board 40 cm below the slot. The band thus obtained has an excellent uniformity with a filament size of 4.5 weight units. The speed for spinning filaments is 8,000 meters per minute. 10 EXAMPLE 4 As in Example 2 with 35 MFR polypropylene, when smaller production is used, the nonwoven web thus obtained has better uniformity with different filament sizes. For the production of 1.0 gram per hole per minute, the air pressure for the stretch unit is 3.1635 kg / cm2mn and the stretching unit is 30 cm away from the spinner, the strip with filament size of 1.8 units is produced of weight. For the production of 0.5 gram per hole per minute, air pressure of 2.4605 kg / cm2mn with stretch unit 30 cm below the spinner, the band with filament size of 1.0 unit weight is produced. As production is reduced to 0.1 gram per hole per minute at air pressure of 1.7575 kg / cm2mn and the unit of stretch 20 cm below the spinner, we obtain extremely uniform W ^ band with filament size of 0.25 weight units. During the beginning, the filaments are squeezed through a spinner in a vertical curtain form downward to nominal production and the stretch unit is placed away from the spinner with nominal air pressure and volume. With this adjustment, the filament curtain can still be cooled by ambient air only to avoid adhesion between the filaments before being • sucked into the stretching unit. When it is established by After completing the weaving line and stabilizing, the stretching unit moves toward the spinner gradually while simultaneously increasing the pressure and volume of the air supply to the stretching unit and the polymer production. As the stretch unit moves closer to the spinner and they are used higher air pressure and volume, the temperature at which the filaments are stretched and the extraction force on the filaments increase correspondingly, resulting in filaments of smaller size. The reduction in the size of the filament facilitates the cooling of the filaments so that the unit of The stretch can be moved further towards the spinner without causing the filaments to adhere to each other before entering the stretch unit. By repeating those steps of alternatively adjusting the position of the stretch unit, the volume and pressure of the air supply and the production of the polymer melt, it can be achieve a desired production where the finest filaments (smallest weight unit) are produced at maximum production for the given process condition. By adjusting the processing condition described above, the position of the band-forming board is accordingly adjusted to achieve the best uniformity of the resulting band. The band thus formed can then be subjected to one of many conventional techniques for joining or entangling to form the web of cloth joined by final spinning, or joined as is without any additional process, depending on the end uses of the band. # The preferred modality includes the stretching unit that is can raise a distance of about S to 50 cm from the spinner during normal production. Filaments of 0.1 to 2.5 units of weight can be produced for polypropylene at a production speed of 70 to 260 kilograms per meter of machine width per hour and 0.3 to 4.5 units of weight for terephthalate of polyethylene at a production speed of 100 to 540 kilograms per meter machine width per hour. The preferred embodiment further includes a band-forming board that is capable of adjusting its position both horizontally and vertically in accordance with the positions of the spinner and the stretching unit to achieve a uniform nonwoven web that can then be joined by one of many known techniques to produce the final spunbonded webs. In this way, it is evident that the present invention has provided an apparatus and a process for producing nonwoven webs. joined by spinning that completely satisfies the objects, purposes and advantages stated above.

The present invention has been shown and described herein in that it is considered as the most practical and preferred embodiment. However, it is recognized that departures from the same can be made within the scope of the invention and that obvious modifications will occur to one skilled in the art. #

Claims (25)

1. An apparatus for forming a non-woven web from crushed polymer filaments, comprising: means for squeezing polymer including spinning means, having a spinner with a plurality of multiple rows of closely spaced orifices, vertically oriented, to squeeze a plurality of continuous polymer filaments; means for stretching filament including a longitudinally disposed elongated slot positioned below said spinner at a predetermined distance adjustable to less than 50 centimeters to achieve a desired pulling force and filament thickness; air nozzle means for supplying air under pressure, said nozzle means having an outlet communicating said groove of stretching means over substantially the entire longitudinal length of said groove of stretching means, said nozzle means being arranged in a predetermined direction away from the center line of said groove, for introducing an air stream directed downwardly in said groove; and web forming means positioned below said groove of stretching means to collect the filaments for formation in a nonwoven teat band.

2. An apparatus for forming a non-woven web according to claim 1, including water spraying means * placed adjacent to and surrounding the spinner to cool said filaments.

3. An apparatus for forming a non-woven web according to claim 1, which includes means for movably adjusting the distance between said spinner and said stretching means, so that the distances between the spinner and the means of Stretch and web-forming means can be adjusted to achieve the thickness of the desired filament diameter and the uniformity of the strip.

4. An apparatus for forming a nonwoven web according to claim 2, wherein said water spraying means includes a water tube adjacent to and surrounding said spinner with water heads installed downward, spaced at predetermined distances a of the other.

5. An apparatus for forming a non-woven web according to claim 1, including placing said nozzle means adjacent said groove and positioned relative to said groove to form a turbulent flow over the vertical length of said groove to exert a drag force on the filaments to

As they enter vertically through said groove in said stretching means, said driving force exerts on said filaments passing vertically through said groove causing a "flutter" or "wavy" movement pattern under said means nozzle

6. An apparatus for forming a non-woven web according to claim 1, wherein the distance between said spinner and said stretching means is between about 5 centimeters and less than 50 centimeters to produce filaments of 0.1 to 2.5 units. weight for polypropylene at a production speed of 70 to 360 kilograms per meter machine width per hour and 0.3 to 4.5 weight units for polyethylene terephthalate at a production speed of 100 to 540 kilograms per meter machine width per hour .

7. An apparatus for forming a nonwoven web according to claim 3, wherein said means for positioning said stretching means relative to said band forming means includes at least one male screw vertically fixed to said stretching means and said band forming means and including an equivalent female screw fixed to said stretching means and motor means fixed to said male screw to move said stretching means with respect to said band forming means.

8. A process for forming a non-woven polyimide fabric spun-bonded from a plurality of squeezed polymer filaments, comprising the steps of; (a) squeezing a plurality of filaments vertically oriented by spinning through a spinner from a thermoplastic polymer; (b) stretching said filaments by means of stretching positioned below said spinner when using air pressure, applying said stretching means a predetermined distance from said spinner; and i '(c) forming a web in web forming media positioned beneath said stretching means, said stretching means placed less than 50 centimeters below said spinning machine, so the size of each

5 one of the filaments can be controlled by the distance of the stretching means from (to spinner 9, - A process according to claim 8, which includes the step of adjusting the distance between the spinner and the means of stretch between 5 centimeters and less than 50 centimeters,

10. A plurality of filaments comprising a spun-bonded non-woven teat band produced by the process comprising the steps of: (a) squeezing a plurality of filaments vertically oriented by spinning through a spinner to

15 from a thermoplastic polymer; (b) stretching said filaments by means of stretching positioned below said spinner when using air pressure, applying said stretching means a predetermined distance away from said spinner; and (c) forming a band of non-woven polymeric cloth spunbonded into web-forming means placed below diodes of stretch means, said stretch means placed less than 50 centimeters below said spinner, so the size of the diameter from

The filaments can be controlled by the distance of the stretching means from the spinner.

11. - A plurality of filaments according to claim 10, having a weight unit of approximately 0.1-2.5 for polypropylene.

12. A process for forming a non-woven polymeric fabric unit by spinning from a plurality of pressed ceramic filaments, comprising the steps of: (a) at the beginning, squeezing a plurality of filaments vertically oriented by spinning through a spinning of a thermoplastic polymer; (b) at the beginning, screwing the filaments through a groove with means of stretching placed at least 1 or 0 of said spinner, using reduced production and nominal air pressure, 0.703 to 1,406 kg / cm2mn; (c) increasing the air pressure and production in a coordinated manner, at the same time simultaneously reducing the distance between said spinner and said stretching means until said distance between said spinner and said stretching means is between 5 to 150 cm because the size of the filaments can be controlled by the distance between the stretching means and the spinner; (d) forming a web of a spunbonded nonwoven fabric in web forming means optimally positioned below said stretching means, whereby the size of the filaments can be controlled by the distance between the stretching means and the spinner tF to form a uniform band with desired properties.

13. The process according to claim 12, wherein the distance adjusted after the start between the spinner and the stretching means is between 5 cm and 150 cm.

14. The process according to claim 12, when using polyethylene terephthalate which reaches 8000 meters per minute of speed for spinning filaments, • 15.- A process for forming a non-woven polymeric fabric 10 unit by spinning from a plurality of polymeric filaments crushed, comprising the steps of: (a) squeezing a plurality of filaments vertically oriented by spinning through a spinner of a thermoplastic polymer forming a non-polymeric teat

15 knitted together by spinning; (b) at the beginning, stretching said filaments by means of stretching positioned below said spinner when using nominal air pressure that apply an extraction force at a distance of at least 100 cm away

20 of said spinner and a nominal production; (c) increasing the air pressure from a nominal air pressure to 3.8665 kg / cm2mn, at the same time simultaneously reducing the distance between said stretch means and said spinner to less than 50 cm to

25 greatly increase the production.

16. - An apparatus for forming a nonwoven web from crushed polymer filaments, comprising: means for squeezing polymer including means for hiting, having a spinner with a plurality of vertically oriented multiple rows of 5 holes closely, for squeeze a plurality of continuous polymer filaments; means for stretching filament including a longitudinally disposed elongated slot positioned below said spinner at a predetermined distance adjustable to less than 50 centimeters to achieve a desired pulling force and filament thickness; air nozzle means for supplying air under pressure, said nozzle means having an outlet communicating with said groove of stretching means over substantially the entire longitudinal length of said groove of stretching means,

Said nozzle means being arranged in a predetermined direction away from the center line of said slot, for introducing an air stream directed downwardly in said slot; band forming means positioned below said groove of stretching means to collect the filaments for ta

20 formation in a non-woven fabric band; means connected to said stretching means and said spinner to changeably adjust the separation distance between said spinner and said stretching means; and means for adjusting the air pressure of said means of

Nozzle simultaneously with the adjustment of said distance enters said

. spinner and said stretching means, whereby said air pressure and said distance from said spinner to said stretching means can simultaneously change to increase the production of the apparatus at the same time reducing the distance between the spinner and the stretching means unless 150 cm

17. A process for forming a spunbond nonwoven polymeric fabric from a plurality of crimped filaments to increase production, comprising the steps of: (a) squeezing a plurality of filaments vertically oriented by spinning through a spinner of a thermoplastic polymer forming a spunbonded nonwoven polymeric fabric; (b) stretching said filaments by stretching means initially placed at least 100 cm from said spinner, by using air pressure of less than 1,406 kg / cm2mn; (c) simultaneously changing and increasing the air pressure for said stretching means, at the same time correspondingly reducing the distance between said spinner and said stretching means and increasing the production of said filaments until the production reaches a desired amount at predetermined values of simultaneous air pressure and separation of spinner and stretching means; and (d) forming a filament band of a spunbonded nonwoven polymeric web by depositing said squeezed filaments into weblike media placed beneath said stretch means.

18, - A process according to claim 17, wherein the size of the filaments is selected by controlling the distance between the stretching and spinning means and the air pressure.

19. A plurality of filaments according to claim 10, having a weight unit of about 0.3-4.5 for polyester.

W RE U E

A process for producing a nonwoven, nonwoven fabric web, such as a spunbonded web, having filaments of 0.1 to 5 weight units with equivalent production speeds is disclosed. One & plurality of continuous polymeric filaments (F) of an extruder (22) and attenuated by a stretching unit (31) including a longitudinal elongated slot (32) strategically placed at an optimum distance

10 very close to the spinner (26). A band-forming board (90) is placed under the stretching unit to collect the filaments and form filaments in a non-woven teat band. At the beginning, the production is nominal, the air pressure is below 1,406 kg / cm2mn, and the spinner is placed more than 100 cm away from

15 ta stretching unit. Gradually, production increases greatly by simultaneously increasing the air pressure while reducing the distance between the spinner and the stretching unit.

Coordination of the adjustment of production to air pressure and reduction of distance of the spinner and stretch unit

20 produce finer filaments to equivalent production or the same filament size at the highest production speed and cost is low.