Moisture Regain Research Articles

Studies of Formaldehyde-Crosslinked Cellulose

Moisture sorption data of Form C samples have been obtained using a McBain-Bakr sorption balance and these were used to calculate effective area of molecular contact of the cross-linked samples with the Brunauer-Emmet-Teller (BET) equation. A probable explanation is advanced for the maxima and minima in moisture regains of cross-linked in the swollen state samples and the effective area/HCHO relationship. Attempts have been made to infer the distribution of cross-links trom the moisture sorption data of the cross-linked samples. Iodine accessibility values of formaldehyde-crosslinked fibre and dye pickup studies of formaldehyde-crosslinked fabric support an earlier assumption that the primary wall is ruptured under Form W conditions.

Temperature and Moisture Regain Changes of Textiles During Vacuum-Steaming

A report is given of temperature and regain changes which occur during steaming of a mass of hygroscopic textile fibers held in an initially evacuated chamber. The experimental measurements for wool are compared with values of temperature and regain calculated by Nordon and Haly. Similar calculations are carried out for cotton and are compared with experimental measurements. When the initial regain of the textile is low, the temperature of the mass of fibers during steaming rose to a value considerably in excess of the steam temperature (because of the effect of heat of sorption). At higher initial regains, the fiber temperature during steaming was equal to the steam temperature. The accuracy of the theoretical calculations is discussed in terms of the accuracy of the data used, viz, sorption isotherms for wool and cotton at elevated temperatures, specific heats, and differential heats of sorption for these fibers.

WET SPINNING OF NYLON 6: EFFECT OF SOLVENT ON FIBER PROPERTIES

Wet spinning of nylon 6 with molecular weight of 3×104 was studied by using five solvent systems of phenol (Ph), o-chlorophenol (OCP), sulfuric acid (SA), formic acid (FA) and dichloroacetic acid (DCA). Each of the solvent systems except OCP contained 10% water.It is supposed from the data of solubility parameter, intrinsic viscosity, and Huggins' constant that FA, SA and Ph are very good, OCP is fairly good, and DCA is rather poor solvent for nylon 6. Coagulating behaviors of phenolic solvent systems (Ph and OCP) differ from those of other solvent systems, and it is expected that phenolic solvent systems results in the homogeneous and dense fiber structure, and other solvent systems results in the inhomogeneous and sponge-like coarse fiber structure.The results of wet spinning are as follows; Fibers from Ph and OCP solvent systems have the homogeneous structure and good mechanical properties at lower alkali concentration in coagulating bath. Fibers from FA solvent system have the skin-core structure similar to viscose rayon, and have extraordinary low densities probably due to the presence of many voids. But when they are drawn, their fiber structure turns to homogeneous and their densities increase remarkably. The mechanical properties of drawn fibers from FA solvent system are best among five solvent systems. Fibers from DCA and SA solvent systems have the coarse fiber structure with macro-voids, and poor mechanical properties.Moisture regains of wet spun fibers are generally greater than those of melt spun fibers, but vary considerably depending on solvent systems. Moisture regains of fibers from DCA and FA solvent system depend remarkably upon relative humidity, and that from FA solvent system decrease with drawing, while that from Ph solvent system depend slightly upon relative humidity, and increase with drawing. These intresting hygroscopic behaviors are probably due to the finestructural characteristics such as micro-voids which may be influenced by the type of solvent and the drawing ratio.

Salt‐catalyzed reaction of phenyl glycidyl ether with silk fibroin

AbstractThe addition reaction of phenyl glycidyl ether (PGE) with silk fibroin was investigated in the presence of various salts in different solvents at 40–130°C. Some water was required to make the epoxide react with silk padded with various salt solutions. The reaction rate increased with the salt and PGE concentrations and reached a maximum value at a certain concentration of the salt or PGE. Padding with solutions of thiosulfate, stannate, thiocyanate, bicarbonate, and cyanide resulted in large weight gains to 12%, dry crease angles of 138°, little moisture regains and low solubilities (up to 15%) in 3 N HCl and 1 N NaOH aqueous solutions at 65°C (1 hr). Histidine, lysine, arginine, aspartic and glutamic acids, serine, and tyrosine reacted. The weight gains decreased with increasing solubility parameter of the solvents used, reached a minimum value at about 10 or at the solubility parameter of the epoxide, and then increased with the parameter. The epoxide‐silk reaction may depend on the distribution of PGE between aqueous salt and an organic solvent phases, and on the swelling of the silk fibroin in aqueous salt solution or in various organic solvents. The mechanism for this epoxide‐silk reaction was discussed in the light of the observed phenomena.

Influence of Temperature and Moisture Regain Changes on the Wrinkling of Wool Fabrics

Influence of Temperature and Moisture Regain Changes on the Wrinkling of Wool Fabrics

Determination of Temperature and Moisture Regain Changes in Wool Fabrics Wrinkled during Wear

Determination of Temperature and Moisture Regain Changes in Wool Fabrics Wrinkled during Wear

Molecular Weight and Moisture Regain of Polyacrylonitrile Cellulose Graft Copolymers

Molecular Weight and Moisture Regain of Polyacrylonitrile Cellulose Graft Copolymers

Temperature and Moisture Regain of Wool Fabrics During Steam Pressing

Temperature and Moisture Regain of Wool Fabrics During Steam Pressing

Cross-Linked Cotton of High Moisture Regain

Two general methods for retaining the high moisture regain of cotton after resin- finishing to improve wash-wear properties have been studied. The first method was the use of hydrophilic cross-linking agents, and the second method was the use of hydrophilic additives with conventional resins. The hydrophilic cross-linking agents included methylolated derivatives of N,N'-di hydroxyethylenebisamides, dimethylaminoethyltriazone, trimethylammoniumethyltriazone iodide, and bis( 2-carbamoylethyl)dimethylammonium iodide. Several mixtures of di methylolethyleneurea and one of these agents gave better combinations of high moisture regain and crease-recovery angles than either component alone. The best combination of these properties was obtained with methylolated dimethylaminoethyltriazone. It is believed that agents of this type are effective because of the formation of hydrophilic derivatives of cellulose. The hydrophilic additives included polyethylene glycols and simple quaternary ammonium salts. These were added to trimethylolmelamine and dimethylolethyleneurea resins. Best results, on the basis indicated above, were obtained with benzyltrimethyl ammonium chloride and dimethylolethyleneurea. It is believed that these additives, like the salts and the polyethylene glycol ethers studied by other workers, function by preventing fiber collapse during curing. The polyethylene glycol that was retained in the fabric by coreaction with the trimethylolmelamine did not appear to have any effect on the moisture absorptivity.

The Timing of Moisture Regain Changes and Fabric Deformation in Wrinkle Recovery Tests

The Timing of Moisture Regain Changes and Fabric Deformation in Wrinkle Recovery Tests

The Timing of Moisture Regain Changes and Fabric Deformation in Wrinkle Recovery Tests

The Timing of Moisture Regain Changes and Fabric Deformation in Wrinkle Recovery Tests

Grafting of acrylate monomers in cotton fabrics

AbstractThe graft copolymerization of acrylate monomers, methyl, ethyl, n‐propyl, and n‐ or isobutyl, in cotton fabrics was carried out in the aqueous emulsion system by the ceric ion method. The rate of grafting decreases with increasing length of the ester group. The maximum improvement of dry crease recovery, thus raising its value, increases with increasing graft‐on shifts towards the higher extents of grafting, and with decreasing second‐order transition temperature of graft polymer. The improvement of wet crease recovery, equilibrated in the presence of a wetting agent, is always greater than that in the dry crease recovery even when the hydrophobic propyl or butyl acrylate‐grafted cotton levels off with increasing graft‐on. The improvement of crease recovery was explained by the stabilization of the opened fiber structures by grafting with acrylates, especially those having bulky ester groups, the entangled crosslinking between the graft polymers or the graft polymers and cellulose chains, and the consequently developed elastomeric or swelling, elastomeric behaviors due to the segmental movements in the amorphous regions of graft copolymer. Furthermore, from the measurements of water imbibition and repellency, moisture regains, tensile properties, stiffness, flex abrasion, and thermosetting properties, it has been concluded that the improvements of physical properties are remarkable in the propyl or butyl acrylate‐grafted cotton.

Retention of Swelling Ability in Cotton Cross-Linked with High-Temperature Curing

The cross-linking of cotton fabric with several N-methylol finishing agents in combi nation with an additive, the dimethyl ether of tetraethylene glycol, was investigated in an effort to obtain wrinkle-resistant and wash-wear cotton fabrics that retain an ability to swell with water. By proper adjustment of the concentration of this additive in the pad bath, it is possible to obtain finished fabrics with moisture regains equal to or even greater than untreated cotton, while maintaining good wrinkle resistance and wash-wear appearance. Wet crease recovery is slightly increased and dry crease recovery is slightly decreased by the use of the additive. Chlorine resistance and the relationship of breaking strength to crease recovery are unaffected. The inclusion of this additive in the treating bath formulation appears to alter hoth the length and distribution of the cross-links formed.

The amorphous fraction of cellulose and its relation to moisture sorption

The OH OD exchange reaction between deuterium oxide vapor and cellulose has been studied for thirteen different types of cellulose; the extent of exchange in a cellulose was determined by measuring the increase in the dry weight of the sample. With each cellulose the deuteration reaction was in two stages, a rapid stage followed by a slow stage; the material that exchanges during the rapid stage is the infrared-amorphous fraction of the cellulose, and therefore values for the amorphous fractions of the thirteen samples could be obtained. These amorphous fractions were found to be linearly related to the moisture regains of the samples. There is tentative evidence that the cellulose II samples absorb slightly more water into a unit amount of amorphous material than cellulose I samples.

Heat Setting of Protein and Cellulosic Fibers

It is shown in this paper that protein and cellulosic fibers can be heat set at tempera tures above 100° C and moisture regains varying from that corresponding to 65% RH to the saturated value providing the moisture regain is kept constant during the treatment. No chemicals need to be added before or during the treatment.

Heating, Cleaning, and Mechanical Processing Effects on Cotton: Part II: Equilibrium Moisture and Density

Several series of cottons were dried by gin and laboratory methods to secure ranges in levels of drying. Moisture regain and density were determined after drying and after several types of mechanical working. The lower moisture regains for cottons excessively dried at the gin persist for long periods following drying but storage for several years essentially eliminates the influences of initial drying. Repeated exposure to high and low relative humidities at normal temperatures reduces but does not eliminate the drying effects. Cellulose density increases as lint moisture is reduced by gin drying. The changes in moisture and density suggest changes in cellulose structure but their direct influences on spinning behavior are inconclusive. Gin drying has a greater influence on moisture of cotton lint at opening and carding than in the second drawing sliver. By the latter stage, moisture differences caused by drying have been essentially eliminated, but the initial stages of mechanical processing take place when the maximum differences exist in moisture level of the lint.

31—Changes in the Dimensions of Plain-Knitted Wool Fabrics with Variation of Moisture Regain

Changes in area of a plain-knitted wool fabric as a result of changes in regain (r.h. movement) are shown to be dependent upon fabric stiffness and the previous treatments of the fabric. A suggested mechanism is also put forward to account for the shrinkage in area which occurs when a dry-relaxed fabric is placed in water.

Effects of Gin Drying and Cleaning Practices on Properties of Bleached and Resin Treated Fabrics'

Fabrics made from lint cotton subjected to twelve combinations of ginning practices —seed cotton cleaning, lint cleaning, and drying levels—were tested as gray, bleached, and resin treated fabrics. The seed cottons dried to the lowest moisture level before ginning produced the weakest gray fabrics. Bleaching caused no accentuation of their differences in breaking and tearing strengths which could be associated with the ginning practice since strengths of all twelve fabrics were reduced about the same amounts. Resin treatment and laundering decreased the differences in strengths among fabrics. Density of cellulose was slightly higher for the three lots dried to the lowest moisture level. Moisture regains of the bleached fabrics were essentially equal. Alkali centri fuge swelling values were more closely associated with fiber fineness than with the ginning practices. Among the fabrics, differential dyeing detected differences asso ciated with fiber fineness but not with ginning practices. Degree of polymerization was reduced by bleaching but showed no consistent relation to seed cotton treatment. Inconsistencies among samples within groups do not permit conclusions to be reached as to effects of seed cotton cleaning or lint cleaning.

Moisture Regain of Specialty Hair and Fur Fibers

Moisture Regain of Specialty Hair and Fur Fibers

Correspondence Regarding "Moisture Regain of Tightly Woven Fabrics"

Correspondence Regarding "Moisture Regain of Tightly Woven Fabrics"