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The objective of this research was to survey the effects of starch quaternization and sulfosuccinylation on the adhesion of cold starch paste to raw cotton fibers for cotton warp sizing at low temperature. Acid-thinned cornstarch (ATS) was quaternized and then sulfosuccinylated to introduce 3-(trimethylammonium chloride)-2-hydroxypropyl and sulfosuccinate substituents onto its backbones. The electroneutrality of starch samples prepared was achieved by maintaining a constant mole ratio (5.3:1) of the two substituents. A series of electroneutral cornstarch (ECS) samples with different levels of the substituents were derived by altering the feed ratio of the modifying reagents to starch for determining desirable level of starch modification. Adverse influences of cotton wax and starch retrogradation on the adhesion of cold starch paste to raw cotton fibers were evaluated to illustrate the effectiveness of starch quaternization and sulfosuccinylation. It was found that the modification was able to alleviate the adverse influence of starch retrogradation and ameliorate the adhesion to the fibers at low temperature. Higher level of the modification led to less retrogradation and resulted in strong adhesion. Furthermore, the adverse influence of cotton wax on the adhesion could be eliminated after a pre-wetting treatment of raw cotton warps with hot water. The adhesion of ECS paste to raw cotton at 60 °C was statically the same as that of ATS at 95 °C when total DS of ECS was 0.0443 or higher.

We present a methodology to predict the storage modulus ( G ’ ) of starch paste due to granule swelling, given the physical properties of the starch granule and temperature history. This was tested on experimental measurements of granule size distribution and G ’ for 8% w/w suspensions of waxy maize, normal maize, waxy rice, normal rice, and cross linked normal maize – all heated to different temperatures (65–90 °C) with holding times between 2 and 60 min. Experimental data of storage modulus G ′ vs volume fraction φ fall onto a master curve when G ′ is normalized by a multiple of γ / R ‾ , where γ is the granule-solvent interfacial energy, and R ‾ is the average granule size. We show that one can combine this master curve with starch swelling theories to forecast the time-dependent rheology of starches. This work also demonstrates that granule-solvent interfacial energy is a key physical parameter in controlling starch rheology.

The effect of concentration and temperature on viscoelastic properties of chestnut starch is discussed in the paper. The starch structure was estimated using the fractional standard linear solid model FSLSM. Rheological parameters of the FSLSM model were determined and their changes for different concentrations and temperatures of chestnut starch paste were discussed. High values of the viscoelastic modulus of plateau allow us to state that in all the analyzed cases, the medium with a structure typical of viscoelastic quasi-solid bodies is formed. The values of the rheological parameters of FSLSM model provide useful information concerning the structure of chestnut starch paste, such as the total elasticity of the networks, network oscillations, gel stiffness, and structure of cross-linking. The proposed method of discussion of the results of rheological measurements allow to present a comprehensive evaluation of the analyzed medium structure.

The α-amylase enzyme has been reported during the last decade to be used for removal of the excess starch adhesive paste, which is usually used to fix textiles on paper, textiles, wood panels, or other rigid support materials. The final aim of this work was the application of α-amylase in order to remove the old starch from historical textiles in an attempt to conserve them under mild conditions. An extensive study was undertaken using various types of textiles in order to identify the optimum condition for the use of the enzyme, in relation to time, concentration, temperature and pH, before any other attempt. The first step was to simulate the textile ageing. The fabrics were coated with starch paste adhesive, and then a process of artificial thermal ageing was made on samples for different periods of time. After that the enzyme was applied to the samples, at different concentrations and at different intervals. This study also presents interesting results concerning the effect of the enzymatic treatment on the mechanical and optical parameters of linen, silk and cotton, dyed with madder or turmeric dye mordanted with CuSO4 or ferric citrate. Finally, the removal of enzymatic residues from textiles after the treatment has been studied. The application section has been fulfilled by using the whole process in a piece of a historical carpet from fabric adhered with starch. This piece of carpet is in the museum of the Faculty of Applied Arts, Helwan University in Egypt.

Acid-thinned cornstarch was monophosphorylated by reaction with orthophosphates to obtain an agent for sizing heat-sensitive viscose warp yarns under reduced temperature. Influences of the modification and sizing temperature on paste behavior, adhesion to viscose fibers, and properties of sized viscose yarns were studied for a range of substitution of 0.021-0.082 and temperatures from 60°C to 95°C. The modification resulted in an increase in viscosity stability of the starch paste, enhancement of the adhesion to the viscose fibers, improvement of mechanical properties of the sized viscose yarns, and a decrease in hairiness of sized yarns even if the temperature of the starch paste was lowered to 60°C. The modification is capable of improving the sizing properties of starch for viscose yarns at 60-80°C when the degree of substitution with phosphate groups is about 0.05.

“Yuzen” is a traditional but still popular method of dyeing fabrics in Japan. The products using the Yuzen method and manufactured in Kyoto city are called “Kyo-Yuzen.” The dyeing method of Yuzen can be dividing into 10 procedures. A specialized craftsman is in charge of each procedure. During the paste application (Nori-oki) procedure, the expert applies a starch paste or a rubber paste to a fabric in order to resist dyeing. The two resist pastes create different effect on the dyed fabric. At market, the fabric with a starch paste application is perceived to have a higher value than that with a rubber paste. In this study, the difference of the viscosity between two materials was clarified, and specimens which craftsman dyed were observed. Then how two materials put on fabrics, and the structures of them were measured. As a result of this research, it was clarified that rubber paste penetrated into fabrics rather than starch paste.

The removal of old glue from paper artworks is of paramount importance for the preservation of its integrity during the restoration process. Wet cleaning is one of the traditional methods, although it may cause damages on artworks. In this work, an advantageous alternative method, based on the use of a rigid hydrogel, for a simple and localized removal of starch paste from paper supports is presented. The use of an appropriate hydrogel allows to overcome many of the problems faced by restorers minimizing damages, through a controlled release of water to the artwork, and a simple and not invasive application and removal. At the same time, the specific and targeted enzyme activity leads to a significant reduction in the application time of the cleaning procedure. In this context, experiments were carried out applying Gellan hydrogel carrying α-amylase enzyme on several paper samples soiled with starch paste. To assess the cleaning efficacy of the proposed hydrogel, we have used a multidisciplinary approach, by means of spectroscopic techniques, scanning electron microscopy, chromatographic analysis, and pH investigations.

A method of producing alumina fibres has been developed. The process used a water-based alumina and rice starch paste. An initial feed-rod was made from a central cylindrical rod of alumina paste surrounded by a square shaped section of starch paste. This feed rod was subsequently extruded so that it is reduced in size by a determined ratio. The extrudate was cut into short lengths and re-assembled to the exact dimensions of the initial feed rod so that it contained many smaller alumina rods. This latter specimen was re-extruded and the steps repeated as many times as required to obtain a large amount of small diameter fibres. By selecting the die diameter and the number of extrusions the diameter of the fibres was easily controlled. Since all the fibres were in one easily handleable bunch, the bottleneck associated with sintering could be avoided. Hence an economic method of fibre production can be envisaged.

The dynamic viscoelasticity and stress relaxation often types of starch pastes were measured. The dynamic moduli increased with increasing frequency, and were different for each starch paste, changes in tan δ for cassava and potato starch pastes being about 0.5-0. 6. The stress relaxation behaviour of all the samples tested could be represented by a four-element mechanical model. The relationship between spinnability and stress relaxation was determined, the spinning distance increasing with increased relaxation time (T 2 ). No satisfactory linear relationship between spinning distance and relaxation time (T 2 ) was apparent with the 10 starch paste samples.

A fundamental rheological method was used to study the freeze-thaw stability of hydroxypropyl potato starch pastes. The effect of the number of freeze-thaw cycles on the changes in complex modulus (G*) and phase angle (δ) during heating of the thawed starch pastes was evaluated by comparing the rheological measurements with the measurements of syneresis at different centrifugal forces. The centrifugal forces influenced the detection of the first syneresis as well as the extent of syneresis, with regard to the number of freeze-thaw cycles. When starch pastes exhibited syneresis, the G* formed a distinctive peak during heating at 52.5–53.8C. The magnitude of the peak became bigger with number of freeze-thaw cycles. Furthermore, the results of this rheological method give information on the destabilization process and provide a simple method for detection and prediction of the extent of freeze-thaw stability of starch paste. With this method, the effect of the storage period at –20C, and the freezing rate, on the extent of freeze-damage of starch pastes could be investigated successfully.

Two methods are described for storing starch paste adhesive that allow it tobe kept mold-free for up to six months at room temperature without fungicidal additives. The preferred method, using sterile syringes, has the further advantage that small quantities of starch paste can be used without opening the container and risking contamination with microorganisms. Paste stored in a syringe for eight weeks is smooth, free of lumps, and ideal for use when extruded from the syringe. An alternative method for inhibiting fungal growth in paste pots without the use of chemical fungicides involves exposing the starch paste to ultraviolet light. The gelatinization process of starch as it relates to paste preparation and storage is discussed, as is the microwave oven method of preparing starch paste.

Starch paste is used in cooking and processing as a viscosity enhancer and viscosity stabilizer.1,2 But few studies have been conducted on its spinnability, which is a visco-elastic phenomenon. We have jointly developed a Rheoner RE-33005 with Yamaden Co.3 to assess spinnability. The area of the tip of the rod in this equipment is a very small cross-sectional area to minimize the effects of surface tension. The spinnability of various starch pastes was compared with this apparatus, and the results suggest that the characteristics of spinnability are important indicators of viscoelastic behavior. The relationship between spinnability and dynamic viscoelasticity was developed, and the stress relaxation was investigated.

Unmodified cassava starch paste was characterized on the basis of its paste viscosity as affected by drying, cooking, and paste temperatures at different paste concentrations The paste exhibited plastic fluid flow with high hot-paste peak viscosity. The temperature of the peak viscosity decreased with increasing concentration. Drying temperature had statistically significant effects on the paste viscosity; the higher the temperature at which the starch was dried, the lower was the paste viscosity over the levels of concentration and cooking temperature. Starch drying temperature and paste concentration significantly affected the paste stability as measured by freeze-thaw tests and paste retrogradation tendencies.

The dynamic mechanical behaviour of starch pastes has been investigated over a frequency range of 0.02 to 5.0 radian sec−1. The influence of concentration of starch, source of starch and method of paste preparation on rheological properties have been studied. The results suggest that under the conditions examined differences in the dynamic rigidity and viscosity of pastes may be attributed to differences in the number fraction of large granules and the volume fraction of swollen starch particles they contain.

1 THE PROBLEM 1.1 Description of the textile A regimental silk banner, measuring 90cm x 125cm, handmade in December 1814,was to be prepared for exhibit (Fig. 1).. The banner was composed of a silk ground*, ornately decorated with many colors of silk embroidery. Ribbon decoration was painted with a blue pigment. Lettering was applied in gold leaf onto the painted areas. A 7.5cm twisted fringe was sewn to three-edges. The flag was finished on both sides.

On Determination of Shearing Stability of Starch Pastes. Test conditions for the shearing stability test of starch pastes are not sufficiently outlined in existing publications. In the present paper, first of all a determination of optimum parameters (type of paste production, type of stirrer, stirring time, stirrer revolutions, viscosity measurement etc.) for a shearing stability test was attempted. It became apparent that shearing treatment of 5 min by means of a blade stirrer at a number of stirrer revolutions of 1800 r.p.m. with a 5% paste concentration is sufficient to determine shearing stability of a starch paste. For viscosity measurement which as well as pasting and shearing stress is carried out a 95 °C, a Brookfield viscosimeter is used. Provided measuring conditions (type of spindle, spindle revolutions) are kept constant before and after shearing stress, shearing stability can be expressed as remaining viscosity as a percentage of the initial viscosity. Furthermore, reproducibility of paste production as well as that of the whole shearing stability test were determined. Finally, a test was carried out as to wether there is a connection between shearing and heat stability of paste. Values obtained from 11 commercial products made such a connection between the two criteria apparent.

Two studies on the effects of paper conservation treatments. Study I: The effect of various adhesives used in paper conservation on the stability of water colors and inks. Testing was done on both sized and unsized papers, using methyl cellulose, carboxy-methyl cellulose, rice starch paste, PVA and acrylic resins. Carboxy-methyl cellulose proved to be the most satisfactory adhesive tested, being both workable and safe for use with inks tested. Study 2: The effects of various methods of dry cleaning on paper were studied using scanning electron microscopy. All papers showed residual particles of eraser after treatment.

Some aspects of mechanical finishing processes for cotton textiles, mainly calendering, have been examined, and the influences of heat, pressure, moisture content, and starch content on the resultant finish investigated. An increase in moisture content of the fabric during calendering produces the following effects on the finished samplesndashincrease in stiffness and lustre, decrease in thickness, loss in textile qualities, and increase in resistance to abrasion. On storage, both the stiffness and the lustre of the calendered fabric show a gradual fall, With softening agents, the stage at which they are added to the starch paste determines the viscosity of the paste and the stiffness of the fabric. Studies on soluble starches show that for pastes of the same viscosity the stiffness of the fabric depends on the amount of the starch taken up and on the concentration of the starch.

Paper consists essentially of cellulose and, as such, is susceptible to deterioration when exposed to adverse conditions such as high relative humidity, which encourages mould growth of cellulytic organisms, and acidity, which causes hydrolytic breakdown of the cellulose molecules. This type of degradation causes a loss of mechanical strength with the result that paper becomes brittle and fragile. It is, moreover, an irreversible process so that the intrinsic strength of paper cannot be restored by any known means, and, therefore, some form of lamination will have to be adopted in which the fragile paper documents are sandwiched between two sheets of a supporting material. The classical method of lamination is that of ‘silking’—a process in which both sides of the document are covered with fine silk having an open weave which is attached by an adhesive such as starch paste or dextrin. This process has been used for a long time for the repair of valuable books and manuscripts, but it does suffer from the disadvantage that deterioration of the silk will inevitably occur unless care is taken in the choice of the quality of the silk and of the adhesive, and also the conditions of storage must be carefully controlled.

1. A study was made of the structuromechanical properties of plastic powder mixtures containing 20% starch paste. It is demonstrated that the powder particles are joined to the plasticizer by adsorption bonds, while bonding between the particles themselves is effected by the van der Waals-London forces through plasticizer layers in areas with a disturbed structure, which possess free surface energy. 2. The effects of the amount of plasticizer and the specific surface area, particle shape, and material of the powder on the structuromechanical properties of plastic powder mixtures have been examined.

1. 1. Measurement of the flow properties of starch pastes with the precision and accuracy required for industrial purposes is feasible. The methods described utilize the Corn Industries viscometer and a modified Stormer viscometer. The former provides a continuous record of the change in flow properties during pasting at a controlled cooking temperature; the latter supplements the data obtained during pasting with a rate of shear-shearing stress curve from which the apparent viscosity, expressed in poises, can be computed at any given rate of shear. 2. 2. Rheological data on a variety of commercial starches were obtained. The effect of rate of shear, concentration of the starch, and other factors are discussed. In all cases a curve typical of pseudoplastic flow was obtained. 3. 3. Continuous decrease in apparent viscosity occurs during the pasting process with the greatest change in the first hour; for many starches a fairly level viscosity is obtained after one hour cooking at 90–92°C. Vigorous agitation, in contrast to that obtained with low-speed sweep agitators, produces a more rapid decrease in viscosity, but differences in agitation apparently do not alter the nature of the pasting process. 4. 4. The effect of rate of shear on the computed values for apparent viscosity is great. Satisfactory measurements can be made only when the rate of shear is constant or when the magnitude can be determined and specified. The measuring methods described are reproducible and characterize the starches with respect both to rate of pasting and the flow properties of a given paste at different rates of shear. Industrial measurements can be made more precise by these means, and discrepancies in standardization and grading can be largely eliminated.

(1923). XXIII.—THE FLOW OF STARCH PASTE THROUGH CAPILLARY TUBES. Journal of the Textile Institute Transactions: Vol. 14, No. 11, pp. T414-T440.

An unusual occurrence of decreasing tablet disintegration time with increasing tablet hardness was explored. Tablets were made with varying ratios of starch disintegrant to starch paste and compressed with eight different forces. This unusual disintegration pattern is modified by changes in the starch ratios. The reason for this phenomenon is ascribed to grain swelling as the mechanism by which starch acts as a disintegrant.

A method is presented for determining the porosity of tablet granulations in which two different density measurements are employed. They are (a) the “true” or maximum density of the granules obtained by high pressure compression of samples of the granulations, and (b) the apparent density, determined by mercury displacement. The values resulting from these two measurements on a given granulation were used to calculate the per cent void space in the granules. This report includes data from applying the experimental procedures to four test granulations, potassium bromide crystals (10-20 mesh), and glass beads. The results indicate that granulations prepared by the wet granulation method, using starch paste, had approximately 30% void space, while aspirin granulation, prepared by the slugging process, had approximately 3% void space.