1. MECHANICAL BONDING -STITCH BONDING -NEEDLE PUNCHING -HYDROENTANGLEMENT 2. STITCH BONDING 3. NEEDLE PUNCHING 4. INTRODUCTION Needlepunched nonwovens are created by mechanically orienting and interlocking the fibers of a spunbonded or carded web. This mechanical interlocking is achieved with thousands of barbed felting needles repeatedly passing into and out of the web. 5. THE PROCESS 6. PRINCIPLE OF NEEDLE PUNCHING Source: textileapex.blogspot.com 7. COMPONENT OF NEEDLE LOOM 1. Needle Loom 2. Felting Needle 8. THE NEEDLE LOOM The needle board : The needle board is the base unit into which the needles are inserted and held. The needle board then fits into the needle beam that holds the needle board into place. The feed roll and exit roll. These are typically driven rolls and they facilitate the web motion as it passes through the needle loom. 9. THE NEEDLE LOOM..cont The bed plate and stripper plate. The web passes through two plates, a bed plate on the bottom and a stripper plate on the top. Corresponding holes are located in each plate and it is through these holes the needles pass in and out. The bed plate is the surface the fabric passes over which the web passes through the loom. The needles carry bundles of fiber through the bed plate holes. The stripper plate does what the name implies, it strips the fibers from the needle so the material can advance through the needle loom. 10. THE NEEDLE LOOM..cont 11. THE NEEDLE LOOM..cont 12. THE FELTING NEEDLE The correct felting needle can make or break the needle punched product. The proper selection of gauge, barb, point type and blade shape (pinch blade, star blade, conical) can often give the needlepuncher the added edge needed in this competitive industry. 13. THE FELTING NEEDLE (Needle Gauge) The gauge of the needles is defined as the number of needles that can be fitted in a square inch area. Thus finer the needles, higher the gauge of the needles. Coarse fibers and crude products use the lower gauge needles, and fine fibers and delicate fibers use the higher gauge needls. For example, a sisal fiber product may use a 12 to 16 gauge needle and fine synthetics may use 25 to 40 gauge needle 14. THE FELTING NEEDLE (Components) Crank Shank Intermediate blade Blade Barbs Point 15. THE FELTING NEEDLE (Components) Crank The crank is the 90 degree bend on the top of the needle. It seats the needle when inserted into the needle board. 16. THE FELTING NEEDLE (Components) Shank The shank is the thickest part of the needle. The shank is that part of the needle that fits directly in the needle board itself. 17. THE FELTING NEEDLE (Components) Intermediate blade The intermediate blade is put on fine gauge needles to make them more flexible and somewhat easier to put inside the needle board. This is typically put on 32 gauge needles and finer. 18. THE FELTING NEEDLE (Components) Blade The blade is the working part of the needle. The blade is what passes into the web and is where the all important barbs are placed. 19. THE FELTING NEEDLE (Components) Barbs The barbs are the most important part of the needle. It is the barb that carries and interlocks the fibers The shape and sized of the barbs can dramatically affect the needled product 20. THE FELTING NEEDLE (Components) Point The point is the very tip of the needle. It is important that the point is of correct proportion and design to ensure minimal needle breakage and maximize surface appearance. 21. THE FELTING NEEDLE (Needle Reduction) Single reduction:- has two sections, the shank and the blade. Much stiffer Only for coarse gauge needle Used to punch stiff fibers including ceramic materials, waste fiber blend and shoddy where needle force are high 22. THE FELTING NEEDLE (Needle Reduction) Double reduction:- has three sections, the shank, the intermediate blade and the blade. Less stiffer compare to single reduction Suitable for finer gauge needle, 32 gauge needle and finer Used to punch less stiff fibers 23. THE FELTING NEEDLE (Barb shape) Rounded Barb Styles Conventional cut barb needle 24. THE FELTING NEEDLE (Barb angle) Fiber compaction is greater with higher barb angles because the fibers do not slip off the barb face during penetration through the fiber batt. As a result, fabrics can be made stronger and more dense than if the barb angle had been lower. Fabric made with lower barb angles will be more lofty and thick; they will generally have a better hand and be of lesser strength than if barb angles had been higher. 25. THE FELTING NEEDLE (Needle types) The Pinch Blade The Fork Needle 26. THE NEEDLE ACTION As the needleloom beam moves up and down the blades of the needles penetrate the fiber batting. Barbs on the blade of the needle pick up fibers on the downward movement and carry these fibers the depth of the penetration. 27. TYPES OF LOOMS 1. The Felting Loom 2. The Structuring Loom- use what are called fork needles 3. The Random Velour Loom - Special crown type needles or fork needles are used. 28. MACHINE VARIABLE Depth of penetration Puncture density 29. MACHINE VARIABLE..cont Depth of penetration The maximum penetration is fixed by the needle of the machine and depends on the length of the three sided shank, the distance between the needle plates, the height of stroke, and the angle of penetration. The greater the depth of penetration, greater is the entanglement of fibers within the fabric because more barbs are employed. 30. MACHINE VARIABLE..cont The puncture density number of punches on the surface of the feed in the web is a complex factor and depends on the density of needles in the needle board (Nd) the rate of material feed the frequency of punching the effective width of the needle board (Nb T) the number of runs 31. Tennis Court Surfaces Space Shuttle Exterior Tiles Marine Hulls, Headliners Shoe Felts Blankets Automotive Carpeting Automotive Insulation Filters Vinyl Substrate 10.Insulator Primary Carpet Backing Fiberglass Insulation Felts APPLICATIONS OF NEEDLE PUNCHING Fiberglass Mats Wall coverings Composites Blood Filters Tennis Ball Covers Synthetic Leather Carpet Underlay Pads Auto Trunk Liners Interlinings Papermaker Felts Felts Padding Shoulder Padding Ceramic Insulation Kevlar Bullet Proof Vests 32. HYDROENTANGLEMENT 33. INTRODUCTION Spunlacing uses high-speed jets of water to strike a web so that the fibers knot about one another. Japan is the major producer of hydroentangled nonwovens in the world. The biggest producers of spunlaced fabrics in the U.S. are DuPont, Chicopee and Kendall corporations. 34. INTRODUCTION..cont Was officially introduced by DuPont in 1973 (Sontara). Many different specific terms for spunlaced nonwoven like jet entangled, water entangled, and hydroentangled or hydraulically needled. The term, spunlace, is used more popularly in the nonwoven industry. Softness, drape, conformability, and relatively high strength are the major characteristics that make spunlace nonwoven unique among nonwovens. 35. PROCESS Spunlacing is a process of entangling a web of loose fibers on a porous belt or moving perforated or patterned screen to form a sheet structure by subjecting the fibers to multiple rows of fine high-pressure jets of water. 36. MATERIALS USED IN SPUNLACE TECHNOLOGY Could be carried out using dry-laid (carded or air-laid) or wet- laid webs as a precursor. Mixtures of cellulose and man-made fibers (PET, nylon, acrylics, Kevlar Cellulosic fibers are preferred for their high strength, pliability, plastic deformation resistance and water insolubility. Cellulosic fibers are hydrophilic, chemically stable and relatively colorless. 37. ENTANGLEMENT UNIT the energy is delivered to the web by the water needles produced by the injector. Therefore, we can calculate the energy from the combination of the water velocity (related to the water pressure) and the water flow rate (related to the diameter of the needles). 38. PROCESS..cont Various steps are of importance in the hydroentangling process. Precursor web formation Web entanglement Water circulation Web drying 39. PROCESS..cont The formed web (usually air-laid or wet-laid, but sometimes spun bond or melt-blown, etc.) is first compacted and prewetted to eliminate air pockets and then water-needled. The water pressure generally increases from the first to the last injectors. Pressures as high as 2200 psi are used to direct the water jets onto the web. 40. PROCESS..cont Why need pre-wetting? to prevent uncontrolled disturbance of the fiber arrangement to minimise changes in the MD/CD ratio of the web minimise jet marking when the web is impacted by the main jets Enable the web to pass between the first injector and the support surface Lightly adhere the web to the conveyor to prevent slippage 41. PROCESS..cont (pre-wetting) 42. PROCESS (support wire) The conveyor surface may be a permeable, continuosly woven mesh of metal or polymeric construction, a solid metal roll, or a sleeve, which is normally perforated. Small open area --- formation of dense fabrics Larger open are --- lower tensile strength The pattern of the final fabric is a direct function of the conveyor wire. 43. Spunlace support wire details PROCESS (support wire) 44. Spunlace support wire and the product PROCESS (support wire) 45. WEB SUPPORT SYSTEM (CONVEYOR WIRE) Plastic wire Metal wire Good flex resistance Light weight Easy to install Corrosion resistant Difficult seams Prone to shower damage Difficult to control knuckle height Moderate temperature Poor flex resistance Heavy weight Difficult to install Prone to corrosion Invisible seam Shower damage resistance Easier to control knuckle height High temperature 46. PROCESS (Injector operation) It has been argued that 10 rows of injectors (five from each side of the fabric) should achieve complete fabric bonding . Injector hole diameters range from 4-10mm and the holes are arranged in rows with 3-5 mm spacing, with one row containing 30-80 holes per 25 mm 47. PROCESS..cont Hydroentanglement is applied on both sides First entanglement roll acts on the first side a number of times in order to impart to the web the desired amount of bonding and strength A second entanglement roll in a reverse direction in order to treat and, thereby, consolidate the other side of the fabric. The hydroentangled product is then passed through a dewatering device where excess water is removed and the fabric is dried. 48. WATER SYSTEM Water is most critical part in spunlace process. Therefore, there are some requirements for the water as follows: Large amount of water about 606 m3/hr/m/injector Nearly neutral pH Low in metallic ions such as Ca No bacteria or other organic materials 49. Water circuit and filtration Filtration system is a major cost in a hydroentanglement installation and water quality affects process efficiency. The quantity of water in the circuit is about 40-100 m3/h The waste water produced in hydroentanglement is recycled and circulated back to the main high-pressure pumps. All impurities must be removed to ensure efficiency. 50. FILTRATION SYSTEM Due to the large amount of water consumed, the spunlace process requires that it be recycled. Therefore, a high quality filtration system is necessary for the spunlace process. Some of special filters are listed as following: Bag filter Cartridge filter Sand filter 51. WEB DRYING When the fabric leaves the entanglement zone the web, it is completely saturated with water. There are a few steps to remove water from the fabric. The include: Vacuum dewatering system Drying system 52. PROCESS (De-watering) Suction is used to remove excess water from the support surface during hydroentanglement to prevent flooding. Flooding leads to energy losses that can caused reduced fabric strength and interference with the bonding process. It also produces defects in the fabric. De-watering can be done using squeeze rollers too. 53. APPLICATIONS OF HYDROENTANGLED FABRICS The largest US market for spunlaced fabrics spans from surgical packs and gowns, protective clothing as chemical barriers to wipes, towels and sponges for industrial, medical, food service and consumer applications. The main reason for wide use of these fabrics in medical applications is based on relatively high absorption abilities. Another important criterion is absence of a binder in the fabric allowing sterilization of the fabric at high temperatures. 54. APPLICATIONS OF HYDROENTANGLED FABRICS Wipes The earliest applications was a replacements for woven gauze in products such as laparatomy and x- ray detectable sponges. Now, diverse hygiene product such as baby wipes, personal care, facial cleansing, make-up removal, food service, industrial and household cleaning products. 55. APPLICATIONS OF HYDROENTANGLED FABRICS Washable domestic fabrics hydroentangled cotton fabrics for semi-durable bedsheets, napkins and tablecloths can be washed up to ten times before disposal. High-temperature protective clothing hydroentangled aramids, are well established as protective liners and moisture barrier substrates in fire fighting garments. 56. APPLICATIONS OF HYDROENTANGLED FABRICS Artificial leather widely used as backings for PU coated synthetic leather. Surgical fabrics surgical gowns, scrub suits, sheets and drapes for excellent comfort and softness. In surgical gowns, infection control is paramount and spunmelt and composites containing breathable films are favoured over hydroentangled fabrics where there is a need for improved barrier protection 57. APPLICATIONS OF HYDROENTANGLED FABRICS Medical gauze Lining and clothing Filtration Automotive