Needling process

N/inm. Composites reinforced with lyocell 6.7 and lyocell 15.0 multilayer webs reached values of 36 N/mm and 28 N/mm respectively. For the needle felt reinforced composites clear reinforcement effects were determined (lyocell 1.3-PLA = 63 N/ mm, lyocell 6.7-PLA = 61 N/mm and lyocell 15.0-PLA = 57 N/mm ). These results lead to the assumption that the kind of the semi-finished product has a clear influence on the mechanical characteristics of the composites produced by the compression molding technique CP-1. This effect could be attributed to a more homogeneous fiber distribution in the PLA matrix due to the additional needling process and the lower thickness of the needle felts compared to the multilayer webs. It is assumed that the lower thickness lead already in the pre-heating phase to a better heat conductivity and drying in the press. 

Felt-fabric filter media (more particularly needle felts) have gained in importance in recent years. In the "needling" process the fibres are intimately matted together by the action of numerous needles with barbed hooks. These felts are often provided with a woven fabric reinforcement to give additional strength and dimensional stability to the felt. Thanks to their closely matted fibre texture with approximately uniform pore structure, felts attain higher collection efficiency in conjunction with lower pressure drop than woven filter fabrics. 

Hearle JWS, Sultan MAJ. A study of needled fabrics. Part 2 effect of needling process. J Text Inst 1968 59 103-16. 

During the needling process, it is possible to produce either a nearly even and streak-free surface or a structured and patterned surface. 

There were a number of traditional aboriginal uses of jack pine (Maries et al., 2000), some of which are inner bark and needles processed to yield poultice to treat wounds and frostbite pitch chewed as a medicinal dried cones used in tanning of hides roots used to make baskets, and fish hooks made from knots. The wood was used for cabins, boat planks, fishnet floats and fiielwood. Though less effective than spruce (Picea) pitch, pine pitch could also be used for caulking. 

H2N-CH2 [CH2j3.CH(NH2) COOH. Colourless needles, m.p. 224 C (decomp.), very soluble in water, insoluble in alcohol. L-(-H)-Lysine is one of the basic amino-acids occurring in particularly large quantities in the protamine and histone classes of proteins. It is an essential amino-acid, which cannot be synthesized by the body and must be present in the food for proper growth. It can be manufactured by various fermentation processes or by synthesis. 

Malic acid crystallizes in colourless needles m.p. lOO C. It o- curs in many acid fruits, such as grapes, apples and gooseberries. It can be prepared by microbiological processes using various moulds or from ( + )-bromosuccinic acid by the action of NaOH. 

Bright yellow needles m.p. 45 C, b.p. 2 4°C. Prepared together with 4-nitrophenol by careful nitration of phenol. Sodium sulphide reduces it to 2-aminophenol which is used in dyestuffs and photographic processes. 

Within the plane of a nonwoven material, the fibers may be either completely isotropic or there may be a preferred fiber orientation or alignment usually with respect to a machine or processing direction. In the case of thicker dry-laid nonwovens, fiber orientation may be randomized in the third dimension, ie, that dimension which is perpendicular to the plane of the fabric, by a process known as needle-punching (7). This process serves to bind the fibers in the nonwoven by mechanical interlocking. 

In the spunbond process, the fiber is spun similarly to conventional melt spinning, but the fibers are attenuated by air drag appHed at a distance from the spinneret. This allows a reasonably high level of filament orientation to be developed. The fibers are directly deposited onto a moving conveyor belt as a web of continuous randomly oriented filaments. As with meltblown webs, the fibers are usually thermal bonded or needled (53). 

When pure needle-like crystals of -aminobenzoyl chloride are polymerized in a high temperature, nonsolvent process, or alow temperature, slurry process, polymer is obtained which maintains the needle-like appearance of monomer. PBA of inherent viscosity, 4.1 dL/g, has been obtained in a hexane slurry with pyridine as the acid acceptor. Therefore PBA of fiber-forming molecular weight can be prepared in the soHd state. 

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