FIELD OF THE INVENTION

The present the invention describes largely to an apparatus configuration and technique for manufacturing five different hybrid nonwoven fabric using hydro entanglement technology, primarily due to the unique configuration for web formation and the hydro-entanglement unit. Thus the developed cost-effective and high-performance hybrid hydro-entangled nonwoven fabric can cater to the widest range of applications. The resultant hybrid nonwoven fabrics exhibit superior strength, absorbency, thickness and can be tailored for unlimited applications in the medical, hygiene and industrial sector.

BACKGROUND OF THE INVENTION

The current COVID-19 pandemic has become an eye-opener for our lack of preparedness for single-use items of PPEs (personal protection equipment) and associated solutions for eluding the shortcomings of single-use items. Products, such as disposable & reusable surgical gowns, drapes, gloves, wipes and instrument wraps are widely used in hospitals. Several government initiatives to control HAIs (Hospital Acquired Infections) promote the use of nonwoven based medical products, such as disposable patient gowns, drapes, and linens that help reduce the spread of HAIs. Due to the spread of the COVID-19 pandemic, speedy and effective sanitization has become a vital necessity for everybody - personal, household, workplaces, hospitals, industries and wipes are proving a godsend. Further, for critical industries like food, beverages and pharma, wipes are highly beneficial due to their properties “to absorb, retain or release dust, dirt or liquid on demand”. When you use a clean wipe every time, there is no need to worry about cross contamination.

Globally there are numerous production lines producing the hydro-entangled nonwoven fabrics, but these lines due to their apparatus configuration are capable of producing limited variants of hydro-entangled nonwoven fabrics focusing wipes or hygiene or drapes and gowns or industrial applications. Thus during the crisis phase of the COVID19 pandemic, there was a surge in demand for nonwovens for isolation gowns and coveralls and majority of the producers were unable to produce the right nonwovens due to their technology limitations, which led to massive scarcity and unrealistic price increase.

SUMMARY OF THE INVENTION

The present invention is focused on an apparatus configuration for web formation and the hydro-entanglement unit, as it facilitates to manufacture of hydro- entangled hybrid nonwovens of five physically and functionally dissimilar variants, which can use cheapest of raw materials like the fluff pulp cellulose and also use natural and man-made staples fibers and long synthetic man-made filaments. Three dissimilar fibrous web layers can be created as per the requirement; the innovative design of the apparatus aids to position any of the fibrous web layers either on top, bottom or middle or inactive position such that a wide range of dissimilar hydro-entangled hybrid nonwoven fabrics can be developed. The hydro-entanglement unit involving the water jet heads are designed in such a way that it can successfully entangle various layers (single or double or triple layers) in all 5 dissimilar nonwoven variants.

The current invention provides a massive benefit to the manufacturer as due to the unique configuration of the web formation and hydro -entanglement unit, all possible variants of hydro-entangled nonwoven fabrics can be produced in a single production line, otherwise 2-3 production lines may have been required to produce all 5 dissimilar variants. Thus the single production line with inventive apparatus configuration can produce hydro-entangled hybrid nonwoven fabrics for wide applications like low lint dry wipes, wet wipes, nonwoven fabrics for medical disposables like drapes and isolation gowns, surgical masks, gauze and bandages, nonwoven fabrics for hygiene products like femcare, baby care, adult incontinence and tampons, cosmetic facial masks and can also be tailored for numerous industrial applications.

It is to be implicit that both the previous general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

Non-woven Fabrics

Nonwovens are a unique class of textile material formed from fibers, or Continuous filaments or Chopped Yarns - are of any nature or origin that are bonded together through various means to form a coherent structure. Nonwoven materials are not really fabrics though they give us a feel of being fabrics. Non woven fabric is formed which does not require spinning (yarn mfg.) and weaving/knitting process, but the short fibers or filaments of textile or random orientation support column structure formed web, and mechanical, thermal or chemical methods such as reinforcement made. Simply say is this: it is not a one interweaved by the yarn, woven/knit together, but the fibers are bonded together by direct physical methods. Nonwovens breaking the traditional textile principle, and has a short process, production speed, high output, low cost, versatile, sources of raw materials and more features.

Nonwoven fabrics are engineered fabrics that may be single-use, have a limited life, or be very durable. Nonwoven fabrics provide specific functions such as absorbency, liquid repellence, resilience, stretch, softness, strength, flame retardancy, wash ability, cushioning, thermal insulation, acoustic insulation, filtration, use as a bacterial barrier and sterility. These properties are often combined to create fabrics suited for specific jobs, while achieving a good balance between product use-life and cost. They can mimic the appearance, texture and strength of a woven fabric and can be as bulky as the thickest paddings. In combination with other materials they provide a spectrum of products with diverse properties, and are used alone or as components of apparel, home furnishings, health care, engineering, industrial and consumer goods. Nonwovens can be classified in more than one way: on time scale, by employed technology or by the area of application. The application areas of nonwoven fabrics include following segments: hygiene, wipes, apparel, medical, healthcare, personal care, automotive, electronics, filtration, agriculture, horticulture, furnishings, construction, and packaging. ED ANA identified hygiene (31.8%), construction (18.5%), wipes (15.4%) and filtration (4.0%) as the key segments with market share in roll goods products. Disposable to durable nonwovens products can be placed on a time scale with few products perishing after seconds (wipes) to some products with a lifespan of decades (geotextiles).

The classification on the basis of technology can be challenging as numerous combinations of raw materials, web formation, web bonding and finishing treatments lead to nonwoven products for a countless of applications. Essentially, this degree of freedom is the key to engineer nonwovens with unique properties to cater a wide range of application areas. The production of nonwovens takes place in three stages, although modern technology allows an overlapping of some stages, and in some cases all three stages can take place at the same time. The three stages are:

Below are globally popular nonwoven technologies (web bonding based):

Thermal bonding: This method uses thermoplastic properties of certain synthetic fibres to form bonds under controlled heating. In some cases, the web fibre itself can be used, but more often a low melt or bicomponent fibre are part of the blend composition to perform the binding function later in the process. There are several thermal bonding systems in use:

• Calendering uses heat and high pressure is applied through rollers to bond the fibre webs together at high speed.

• Through-air thermal bonding makes bulkier products by the overall bonding of a web containing low melt and bicomponent fibres. This take place in a controlled hot air stream. Drum and blanket systems apply pressure and heat to make products of the average bulk. • Ultrasonic bonding is a technology in which molecules of the fibres are being excited under a patterned roller by high frequency movement of a “sonotrode’ which produces internal heating and softening of the fibres.

Mechanical bonding: In this the strengthening of the web is achieved by inter fibre friction as a result of the physical entanglement of the fibres. There are two main types of mechanical bonding:

• Needle punching, specially designed needles are pushed and pulled through the web to entangle the fibres. Webs of different characteristics can be needled together to produce a gradation of properties difficult to achieve by other means. Needle punching can be used with most fibre types but, because of the nature of the process, not with very fine fibres.

• Hydro entanglement is commonly applied to carded or wetlaid webs and uses fine, high pressure water jets to cause the fibres to interlace. Hydro entangling is sometimes referred to as spunlacing, as the arrangement of jets can also be used to give a wide variety of aesthetically pleasing effects. The water jet pressure used has a direct bearing on the strength of the web. This method uses thermoplastic properties of certain synthetic fibres to form bonds under controlled heating. In some cases, the web fibre itself can be used, but more often a low melt or bicomponent fibre are part of the blend composition to perform the binding function later in the process. Every technology has advantages and disadvantages and none of the technologies have universal applications. Meltspun technologies have achieved speeds closer to 1200m/min and have gsm range of 8-120gsm, higher production and lower gsm is good to lower the prices of the single use and mass volume disposable medical and hygiene based products. However, such products are made from 100% synthetic materials and being non-biodegradable polluting the environment and creating issues. Needle punch nonwovens have gsm range of 80-2000gms, they have isotropic properties and fibrous in feel, thus mostly used for durable and industrial applications like geotextiles, automotive, artificial leather substrates. Needle punch again due to the end application requirements are made from coarser staple fibres (Polyester, Polypropylene and Polyamides). Thermal bonded nonwovens are again synthetic fibre based nonwovens and depending upon their technology their gsm range is 30-200gms. Such nonwovens are used for hygiene and home textile applications and due to their production and application limitation are losing popularity. Spunmelt, needle punch and thermal bonded nonwovens all are plastic fibre based, thus variations possible mainly through gsm change, their physical structure can’t be altered. Hydro-entangled nonwovens are getting popular because of their versatility, the technology can handle wide range of fibres with varying fineness and staple length, they can use fluff pulp, staple fibres (natural, regenerated and synthetic), even aramid, carbon, splittable bi- component fibres. Physical structures of hydro-entangled nonwovens can be plain (similar in appearance to woven), perforated (similar to gauze fabrics), online hydro-embossed and thermos-embossed so that chemical free pictures can be developed on the fabrics, recently 3D embossed nonwovens are developed using hydro-entangled technology. The technology can handle cheapest of raw materials (fluff pulp) and natural & green fibres, with speeds catching up to 300 m/min, cost effective and eco- friendly disposable nonwoven can be developed for wipes, medical, hygiene, PPE and industrial applications. It all started with baby’s bums (wet wipes) and with continuous innovations newer applications like Aerospace wipes are added by hydro-entangled nonwoven manufactures. Hydro-entangled technology is the cleanest and hygienic, thus good for medical and skin touching applications. Still there are issues on cross direction strength and thickness for hydro-entangled nonwoven fabrics, if same can be improved, numerous applications of hydro-entangled nonwoven fabrics can be identified.

Continuous technological advancements are happening in the hydro-entangled based nonwovens manufacturing for functional properties improvement purposes and cost reductions and below are few examples: Spunbond-Pulp (SP) Composites are developed using the wet-laid + Spun melt + hydro entanglement technologies, such products are getting popular as they are stronger, less linting and equally good for dry and wet applications.

Polyester Cellulose (CP) Composites are developed using the card+ Wet laid + hydro entanglement technologies, such products are getting for high (no lint) dry wipes for pharma and semi-conductor industries, such products have also been successfully qualified for aerospace cleaning applications.

Wet laid Spunlace are developed using the wet-laid (Pulp + Staple Fibres) + hydro entanglement technologies, using the paper technology of web formation the dispersible and flushable nonwovens are developed which are good for moist toilet tissue applications. Spunlace developed using the wet-laid technology qualify global standards on flush ability.

Further to improve strength of the spunlace, CSC (Card-Spunbond-Card) are developed using the spunbond layer in the middle, with such configurations the CD strength can be doubled when compared to basic Card-Card (CC) technology products and they have MD: CD ratio of 2.5-3: 1. However to develop each of above composite products, there are dedicated lines focusing each product, which makes limitation for investor or manufacturer is handicapped to develop basic commodity spunlace with very few variants. To handle different raw materials like short cut length fluff pulp (up to 3mm), staple fibres (up to 12mm-51mm of various deniers and cut length (natural, regenerated and man-made) and melt spun webs, the web formation unit needs to be designed accordingly, also the aqua jet and filtration system should be capable to support such web layers and successful hydro entanglement the fibres which will lead to appropriate fabric formation. If aqua jet is incompetent, all pulp fibres will be flushed to filtration system and if filtration system is in competent, filtration system will fail and finally hydro entanglement unit will stop working.

The current invention describes an apparatus, method and appropriate machinery layout for web formation and hydro-entanglement unit which will help to produce pantemerous variants of high performance hydro-entangled nonwoven fabrics, thus single production line can cater to all possible applications of spunlace nonwovens and multiple line investments are not required.

Fig 2 explains the configuration of the apparatus manufacturing P-S-C based hybrid spunlace nonwovens (Pulp web + Spun bond web + Carded web), the position of the wet-laid equipment is closer to the hydro-entanglement section (cellulose fluff pulp around 2-5mm), which is capable to deliver web ranging 8gsm-100gsm, subsequent wet-laid is the spunbond un-winder device, which is capable to deliver web ranging 8gsm-200gsm, after un-winder is the high performance card, which can handle any staple fibres with length of 12-5 lmm, which is capable to deliver web ranging 8gsm-80gsm. Further the hydro entanglement section is equipped with water jet stations on both belt and drums and designed to entangle the webs from both sides (entanglement from top and entanglement from bottom of web, water jet stations are flexible to handle pressure ranging 40-400 bars) successfully and efficiently. Minimum 6 jet head are placed each on belt and drum, such that entire range of plain, perforated/aperture and embossed nonwovens are manufactured ranging 20gsm- 400gsm.

Fig 3 explains the configuration of the apparatus manufacturing P-C based hybrid spunlace nonwovens (Pulp web + Spun bond web + Carded web), the position of the wet-laid equipment is closer to the hydro-entanglement section (cellulose fluff pulp around 2-5mm), which is capable to deliver web ranging 8gsm-100gsm, subsequent wet-laid is the spunbond un-winder device which is not required, so it is non-active position. The high performance card is in active position, which can handle any staple fibres with length of 12-5 lmm, which is capable to deliver web ranging 8gsm-80gsm. Further the hydro-entanglement section is equipped with water jet stations on both belt and drums and designed to entangle the webs from both sides (entanglement from top and entanglement from bottom of web, water jet stations are flexible to handle pressure ranging 40-400 bars) successfully and efficiently. Minimum 6 jet head are placed each on belt and drum, such that entire range of plain, perforated/aperture and embossed nonwovens are manufactured ranging 16gsm-200gsm.

Fig 4 explains the configuration of the apparatus manufacturing P-S based hybrid spunlace nonwovens (Pulp web + Spun bond web), the position of the wet-laid equipment is closer to the hydro-entanglement section (cellulose fluff pulp around 2-5mm), which is capable to deliver web ranging 8gsm-100gsm, subsequent wet-laid is the spunbond un-winder device, which is capable to deliver web ranging 8gsm-200gsm, after un- winder is the high performance card, which is not active while manufacturing P-S based hybrid spunlace. Further the hydro-entanglement section is equipped with water jet stations on both belt and drums and designed to entangle the webs from both sides (entanglement from top and entanglement from bottom of web, water jet stations are flexible to handle pressure ranging 40-400 bars) successfully and efficiently. Minimum 6 jet head are placed each on belt and drum, such that entire range of plain, perforated/aperture and embossed nonwovens are manufactured ranging 16gsm- 300gsm.

Fig 5 explains the configuration of the apparatus manufacturing S-P-C based hybrid spunlace nonwovens (Spunbond web + Pulp web + Spun bond web), this is a critical product to manufacture and requires the spunbond web on top of the pulp layer, so an alternate path is created using the guide rollers such the spunbond web is transported above the wet-laid unit and placed above the wet- laid layer before the entry into the hydro-entanglement section, the position of the wet-laid equipment is closer to the hydro-entanglement section (cellulose fluff pulp around 2-5mm), which is capable to deliver web ranging 8gsm-100gsm, subsequent is the high performance card, which can handle any staple fibres with length of 12-5 lmm, which is capable to deliver web ranging 8gsm-80gsm. Further the hydro-entanglement section is equipped with water jet stations on both belt and drums and designed to entangle the webs from both sides (entanglement from top and entanglement from bottom of web, water jet stations are flexible to handle pressure ranging 40-400 bars) successfully and efficiently. Minimum 6 jet head are placed each on belt and drum, such that entire range of plain, perforated/aperture and embossed nonwovens are manufactured ranging 20gsm-400gsm.

Fig 6 explains the configuration of the apparatus manufacturing S-C based hybrid spunlace nonwovens (Spun bond web + Carded web), for manufacturing S-C products the wet-laid equipment is non-active, Subsequent wet-laid is the spunbond un-winder device, which is capable to deliver web ranging 8gsm- 200gsm, after un-winder is the high performance card, which can handle any staple fibres with length of 12-5 lmm, which is capable to deliver web ranging 8gsm-80gsm. Further the hydro-entanglement section is equipped with water water jet stations on both belt and drums and designed to entangle the webs from both sides (entanglement from top and entanglement from bottom of web, water jet stations are flexible to handle pressure ranging 40-400 bars) successfully and efficiently. MinimumMinimum 6 jet head are placed each on belt and drum, such that entire range of plain, perforated/aperture and embossed nonwovens are manufactured ranging 16gsm-300gsm. Figl explains the process route to manufacture pentamerous variants of hybrid spunlace nonwoven fabrics; 102 explains on possible raw materials can be considered are (i) Wet-laid: Cellulose Fluff Pulp fibers and cellulosic staple fibres with length ranging 2mm-5mm; (ii) Spunbond Un-winder is a device which has automatic splicing arrangements and can unwind spunbond layer as per the requirements with gsm ranging 8-200gms, spunbond can be of any polymer like Polypropylene, Polyester, PLA and also from Bi-component fibres like Polyester/Polyethylene, Polyester/Polyamide etc.; (iii) Carding: Natural staple fibres are like Cotton, Silk, Wool, Jute, Hemp, Ramie, regenerated man-made staple fibres like viscose, tencel, modal, cellulose acetate, polylactic acid (PLA), Poly vinyl alcohol and synthetic man-made staple fibres like polyester, polypropylene, nylon and bi-component fibres. Staple fibres with length of 12- 51mm and denier can be about 0.8 to about 4. When cotton fibers are used, the cotton fibers have a staple length of about 12 millimeters (mm) to about 30 mm. The cotton fibers can generally have a fiber size of about 150 microns to about 280 microns. The cotton fibers can also be bleached if desired. For synthetic man-made fibres like polyester, polypropylene, Nylon, cellulose acetate, PLA, PYA etc. the lengths are about 12 mm to about 51 mm.

In the exemplary method fig 1, 104, explains on raw material preparation step. In case of wet-laid process is similar to paper manufacturing. A dilute slurry of water and fluff pulp fibres is mixed in tank to be deposited on a moving wire screen, where the water is drained and the fibres form a web. In case of carded and air- laid, the preparation area starts with bales of staple fibres which can be from natural materials such as cotton or regenerated or synthetic man-made materials such as polyester. The bales are opened and the fibre conveyed to equipment that open the tufts of fibres into individual fibres. Various fibres may be blended together as per pre-defined blend composition or 100% composite. In case of natural fibres like cotton, the fibres are cleaned for natural contaminants like leaves or seed cots etc. Further the opened, cleaned and blended fibres are pneumatically conveyed to web forming devices.

In the exemplary method fig 1, 106, wherein the nonwoven fabric web formations can be done using (i) wet-laid (ii) Un- winder and (iii) carded layers. The configuration is designed in such a way that all 5 variants of hybrid spunlace can be developed.

In the exemplary method fig 1, 108, a hybrid web is developed at 106, wherein the nonwoven web structure can be any of 5 variants like P-S-C based hybrid spunlace nonwovens (Pulp web + Spun bond web + Carded web); or P-C based hybrid spunlace nonwovens (Pulp web + Spun bond web + Carded web); or P-S based hybrid spunlace nonwovens (Pulp web + Spun bond web); or S-P-C based hybrid spunlace nonwovens (Spunbond web + Pulp web + Spun bond web); or S-C based hybrid spunlace nonwovens (Spun bond web + Carded web) enters the hydro-entanglement section is equipped with water jet stations on both belt and drums and designed to entangle the webs from both sides (entanglement from top and entanglement from bottom of web, water jet stations are flexible to handle pressure ranging 40-400 bars) ;minimum 6 jet head are placed each on belt and drum, such that entire range of plain, perforated/aperture and embossed nonwovens are manufactured ranging 20gsm-400gsm.

In the exemplary method fig 1, 110, nonwoven web is further dried using non- contact type through air-driers, without disturbing the hybrid nonwoven properties.

In the exemplary method fig 1, 112, the dried hybrid nonwoven fabrics are wound on paper core (3” or 6”) on high speed winding systems into (parent rolls) jumbo rolls of width 3400mm and Out diameter of rolls of 2000mm. Further these jumbo rolls (parent rolls) are off-line silted on wide with slitting machines of width 3400mm, into small slits rolls ranging 60mm to 1600mm and with rolls of outer diameter ranging 600mm to 1300m. Final slit widths depend on the end applications, it can be for medical disposables, cosmetic face masks, bandages, medical gauze, sanitary napkins, diapers, panti-liners, dry and wet wipes for personal care, home and industrial applications.