Viscose fibers modified

In another study by Sdrobis et al. [57], the effect of modification on cellulose pulp fibers in LDPE was reported. They used unbleached and bleached kraft cellulose pulp fibers modified with oleic acid in cold plasma conditions as reinforcements. The melt-mixed composites contain up to 10 wt% of untreated and modified cellulose pulp fibers with LDPE. They reported that interfacial adhesion between cellulose and matrix could be improved through modification and most of the properties have been improved when the modified pulp fibers were incorporated into composite matrix. Variation of complex viscosity function of angular frequency for composites is shown in Fig. 11.11. 

Modified viscose fibers are characterized by very particular properties. By the addition of suitable chemicals, fade-resistant spin-dyed fibers, X-ray contrast fibers, or even flame-retardant fibers can be manufactured. 

The stmcture and properties of viscose fibers can be controlled by selectively modifying the viscos process conditions. Fibers can be made with a symmetrical cross-section or a variety of cross-sectional shapes. By controlling the spinning conditions, the fibers can be spun in a form of skin-core stmcture. By using additives either in the viscose solution and/or in the coagulation bath, high-wet modulus fibers can be produced. 

Various modified viscose fibers, micromodal, and modal, for example, produced from beech were not studies for biostability. Information on biostability of artificial fibers produced from lactic casein, soybean protein, maize, peanut, and com is absent. 

It is possible to add modifiers or delustrants at the dissolving stage. However, modem viscose dope plants feed several spinning machines which are often expected to make different grades of fiber. It is therefore now more common to add the materials needed to make special fibers by injection close to the spinning machines. 

Cellulose is sometimes used in its original or native form as fibers for textile and paper, but is often modified through dissolving and reprecipitation or through chemical reaction. The xanthate viscose process, which is used for the production of rayon and cellophane, is the most widely used regeneration process. The cellulose obtained by the removal of lignin from wood pulp is converted to alkali cellulose. The addition of carbon disulfide to the latter produces cellulose xanthate. 

Regenerated proteins from casein (lanital), peanuts (ardil), soybeans (aralac), and zine (vicara) are used as specialty fibers. Regenerated and modified cellulose products, including acetate, are still widely used today and the production of fibers is similar to that described above for synthetic fiber production. Most regenerated cellulose (rayon) is produced by the viscose process where an aqueous solution of the sodium salt of cellulose xanthate is precipitated in an acid bath. The relatively weak fibers produced by this wet spinning process are stretched to produce strong rayon. 

In the in situ consolidation model of Liu [26], the Lee-Springer intimate contact model was modified to account for the effects of shear rate-dependent viscosity of the non-Newtonian matrix resin and included a contact model to estimate the size of the contact area between the roller and the composite. The authors also considered lateral expansion of the composite tow, which can lead to gaps and/or laps between adjacent tows. For constant temperature and loading conditions, their analysis can be integrated exactly to give the expression developed by Wang and Gutowski [27]. In fact, the expression for lateral expansion was used to fit tow compression data to determine the temperature dependent non-Newtonian viscosity and the power law exponent of the fiber-matrix mixture. 

Poly(vinyl alcohol) is used in films, coatings, fibers, and as a viscosity modifier of a variety of aqueous systems such as certain cosmetics. Its films, formulated with dichromate salts, may be cross-linked by exposure to ultraviolet light. This property has found application in photoengraving and related fields [6],... 

The cure reactions, the viscosity-time-temperature profile, the processing conditions, the resultant epoxy chemical and physical structure, and the mechanical response of a C-fiber/TGDDM-DDS cured epoxy composite are modified by the presence of a BF3-amine complex catalyst within the prepreg. These factors also will be modified... 

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