胶圈装订机打孔刀的工作性能研究

基于实验设计方法,进行了胶圈装订机几种打孔刀的打孔性能试验。通过对剪力及剪力随各参数的变化情况进行比较分析,结果表明,胶圈装订机打孔刀的刃口深度越浅,剪力越大;剪力随纸张数的增加基本呈线性增加;随剪纸速度的增加基本呈线性下降或变化不大。在打孔过程中表现出了剪切曲线呈双波峰特性,最后根据剪力在打孔过程中的变化情况,分析得出了打孔刀的打孔机理。     

PUNCTURE TESTING OF TIOGA STRAWBERRIES*

Forces required to puncture firm ripe Tioga strawberries were dependent on the shape and physical dimensions of the punch used. They increased as the area, circumference or total contact surface area of the punch increased. The physical dimensions of the punch were responsible for 83 to 85% of variations in puncture forces. Punch circumference, punch area, and punch total contact surface area were equally effective in estimating the force required to puncture Tioga strawberries.     

DELINEATION OF PUNCTURE FORCES FOR EXOCARP AND MESOCARP TISSUES IN CUCUMBER FRUIT 1

A puncture test was used to differentiate exocarp (skin) and mesocarp tissues of fresh cucumbers for resistance to penetration. Optimum instrumental test conditions were a punch size of 3.15 mm diameter and crosshead speed of 5 cm/min. The force required to penetrate the exocarp of whole fruit was determined and was deemed to represent a composite of the exocarp and the underlying tissue. By placing 7 mm thick, longitudinal slices skin down on a die plate, failure forces representing the mesocarp and exocarp tissues were determined in fruit ranging from 2.5–5.5 cm diameter. Exocarp force measurements were not influenced by slice thicknesses greater than 1 mm. Mesocarp measurements were lower with thicker slices, and required uniformity of thickness to maximize precision. The exocarp was found to represent about 60% of the composite force required to penetrate whole cucumbers, regardless of fruit size. Toughness of both exocarp and mesocarp increased with fruit size. The relative contributions of exocarp to penetration of seven other fruits varied from 58 to 88%.     

Method to Measure the Force to Pull and to Break Pin Bones of Fish

A texture measurement device was modified to measure the force required to pull pin bones from King salmon (Oncorhynchus tshawytscha), snapper (Pagrus auratus), and kahawai (Arripis trutta). Pulled bones were also subjected to tension to measure the breaking force. For all fish, the pulling force depended on the size of the fish, and on the length of the pin bone (P < 0.05). In general, larger fish required greater pulling force to remove pin bones. For example, fresh small salmon (about 1500 g whole) required 600 g on average to pull pin bones, and large fish (about 3700 g whole) required 850 g. Longer bones required greater pulling force. The breaking force followed the same trend. In general, the breaking force was greater than the pulling force. This allows the removal of the bones without breaking them. There was no statistically significant (P > 0.05) difference between the forces (both pulling and breaking) from fresh and frozen/thawed samples, although in general frozen/thawed samples required less force to pull. With the quantification of pulling and breaking forces for pin bones, it is possible to design and build better, “more intelligent” pin bone removal equipment.     

Texture and mechanical properties of prok backfat

A puncture test for measuring the firmness of backfat is described for use in studies of the effects of changes in animal production, and meat processing on the quality of fatty tissue. The operating and recording conditions were chosen from sensory deformation characteristics used in firmness evaluation when pressing fat with the index finger. On average, assessors exerted aaaximum force of about 30 N and caused a deformation of 4 mm in 2 sec and the best predictor of firmness was the maximum deformation they applied. Mechanical properties of the fats were determined by stress relaxation and the modulus 2.5 sec after compression was about 80 × 10⁴ for hard and < 3 × 10⁴ N/m² for soft fat at 3°C and the logarithm of the modulus was linearly related to the subjective firmness rating.
In the puncture test, the forces required to drive a stainless steel punch (3.5 mm in diameter) 2.5 or 4.0 mm into backfat at 3°C at 2 mm/sec correlated well (r > 0.8) with firmness rating and five replicate determinations using the punch proved more discriminating than a panel of four assessors. A combination of the forces required on inner and outer layers of fat accounted for 93% of variation in firmness assessments.     

PEA TEXTURE STUDIES USING A SINGLE PUNCTURE MATUROMETER*

The operation of the single puncture maturometer is described. A linear regression relationship was established between single puncture maturometer readings (SPMR) and commercial maturometer readings. Various parameters of the force distance curve obtained during puncturing of individual peas were found to be related to gross chemical composition and maturity. Maximum force showed the highest and a positive correlation with alcohol insoluble solids (AIS). The force required to puncture peas was independent of the hole size used but increased with increasing pin diameter; it was related to AIS and to total solids by linear regressions. SPMR of peas in a single peapod showed that all were of similar maturity.     

Comparison of instrumental and sensory evaluation of texture of cured and cooked beef meat

The instrumental and sensory texture attributes of beef muscles (M. longissimus dorsi and M. semimembranosus) were compared after curing and thermal treatments. Shear, compression and puncture tests were carried out with an UTM Instron 4301 and the sensory evaluation was made with the score method. The force values obtained for puncture test gave a greater degree of correlation with the sensory tenderness, hardness and elasticity than the shear test forces. The shear test forces were found to significantly correlate with sensory tenderness only for muscles with perpendicular orientation of fibres to the direction of shear blade movement. The evaluation of beef texture with compression test was dependent on the level of sample deformation degree. The force values of compression were found to correlate significantly with elasticity and juiciness of meat up to 60% deformation levels, but at deformation levels higher than 60% appeared significant correlation with tenderness and hardness. The obtained results showed the usefulness of puncture test with proposed parameters for the instrumental measurements of beef texture.     

SENSORY AND MECHANICAL ATTRIBUTES OF GEL TEXTURE

Eighteen experienced judges evaluated the texture of gels varying in gelatin concentration (22-45 g/L) in terms of firmness by oral and manual shear and compression, cohesiveness, and extent of breakdown in the mouth. Manual compression and biting with the front teeth discriminated well across gel concentrations. All sensory measures except extent of breakdown increased with gelatin concentration. Instron (IUTM) measurements showed that increasing gelatin concentration resulted in an increase in maximum force and force/deformation, but had little effect on deformation at yield and rupture or in elasticity and cohesiveness. Results from mechanical measurements varied with the type of force applied (compression, shear or puncture), the loading rate (50 or 200 mm/min), and the extent of deformation attained (40–90%). The highest discrimination across gel concentrations was achieved with shear force at a rate of 200 mm/min and at greater deformations. Sensory responses correlated most highly with the following IUTM measurements: (1) Compression forces at yield and at deformations of 70 and 85% at the higher crosshead speed; (2) Compression forces below the yield point at the lower crosshead speed; and (3) Shear forces measured at maximum deformation (90%) at 200 mm/min.     

细纱机主轴系统支承动反力的识别

细纱机主轴系统是一个多盘多支承系统,滚动轴承作为主轴的支承被安装在墙板上,即使滚盘和主轴系统的动平衡比较好,轴的原始弯曲,支承、滚盘和联轴节的安装误差,残余不平衡量也会引起支承动反力和细纱机的振动,支承动反力通常可用应变测量技术直接测量,但应变片的粘结和系统的标定比较困难,而且在一般情况下信噪比较低,本议事 提出了一个间接方法,利用线性转子模型,分别用理论分析和试验方法确定系统的频响函数矩阵,运转     

Chocolate at a Sliding Interface

The tribological properties of a chocolate‐lubricated tribo‐system have been measured with a pin‐on‐disk tribometer employing poly(tetrafluoroethylene) (PTFE)/zirconia (ZrO₂) as the tribo‐pair. For this study, a series of test chocolate samples was prepared by systematic variation of conching type, particle‐size distribution, milk fat/cocoa butter ratio, and lecithin content. Tribological measurements were found to be sensitive to lecithin content for all particle sizes investigated, while only being sensitive to particle size at high lecithin content. Rheological measurements were found to be sensitive to lecithin content in the case of small particle size, and sensitive to particle size in the case of low lecithin content.     

AREA- AND PERIMETER-DEPENDENT PROPERTIES AND FAILURE OF MATURE-GREEN AND RED-RIPE TOMATO PERICARP TISSUE

The influence of tomato fruit ripeness on area- and perimeter-dependent properties and dominant failure mechanisms of pericarp tissue were investigated. Tissue discs from mature-green and red-ripe fruit were punctured with a flat-ended cylindrical probe and compressed with a flat plate at a constant rate of deformation. Approximately linear force-deformation curves were obtained to tissue failure by both puncture and flat plate compression, interrupted by a region of pseudoplastic deformation at a relatively low initial bioyield force. Based on estimated area- and perimeter-dependent coefficients and firmness (force/deformation) values, initial bioyielding of tissue appeared to be associated with an abrupt increase in cell-to-cell compaction. Puncture of mature-green tissue led to premature failure induced by shearing or rupture of tissue at the probe perimeter. The contribution to puncture of perimeter-dependent or shear-associated forces and a putative "zone of influence" increased markedly with ripening, while the contribution of area-dependent or compression associated forces generally decreased. A concomitant decrease in failure force and firmness with ripening reflected a general loss of both tissue compression and shear strengths. These results suggested that the dominant mode of tissue failure changed with ripening, from cell relaxation and rupture to cell debonding. The data obtained in this study emphasize the need to exercise caution in the interpretation of force-deformation parameters derived from puncture tests alone.     

CHANGES IN GRAPE FIRMNESS DURING MATURATION

Puncture force with skin on, puncture force with skin off, deformability, and ˚Brix were measured on six cultivars of grapes grown in northeastern USA as they matured over a six week period. Deformability increased steadily throughout the maturation period. ˚Brix increased rapidly following veraison and then continued to increase at a slow rate. Both puncture forces decreased rapidly at veraison and then continued to decrease at a slower rate. The puncture force with skin on was always much higher than puncture force with skin off. All the physical properties correlated well with each other and with ˚Brix (with a few exceptions). The puncture test with skin on usually gave the highest correlation with ˚Brix. It could probably be used as an alternative test to ˚Brix or as a confirmatory test to supplement the ˚Brix reading.     

RELATIONSHIP BETWEEN THE PHYSICAL PROPERTIES OF DRIED BEANS AND THEIR TEXTURAL CHARACTERISTICS AFTER PROCESSING

Baked beans in brine and in tomato sauce were prepared using samples from six different uarieties of bean. The dry unprocessed-beans were tested by means of compression and puncture, shearing, back extrusion and compression tests, as well as to sensory evaluation of texture .
For canned beans in brine, the maximum forces for compression and back extrusion were found to be linearly dependent on the maximum force for compression of the dry beans. In the case of beans canned in tomato sauce, only the maximum force for back extrusion exhibited linear dependence. When tomato sauce was used, some softening was observed. The maximum force for back extrusion was correlated to sensory firmness, and the energy for back extrusion to sensory chewiness .     

Frozen Hake Fillets Quality as Related to Texture and Viscosity By Mechanical Methods

This work aimed to develop a textural quality classification function for frozen hake fillets using instrumental measurements. Frozen hake fillets were stored to provide a wide range of textures. Raw and cooked fillets were analyzed for texture using Kramer and Warner-Bratzler shear cells and a puncture device. Apparent viscosity, dimethylamine and protein solubility were also measured. Principal Component Analysis indicated three factors accounted for 86.5% of the variance. Four clusters were found, ranging from excellent quality (low texture, high viscosity) to very poor (high texture, low viscosity). Parameters required for classification were viscosity, maximum force from Kramer and maximum force and energy from the puncture test.     

METHOD FOR DETERMINATION OF FIRMNESS IN CUCUMBER SLICES1

A punch and die assembly was adapted to the Instron UTM for deter-mination of firmness of mesocarp and endocarp tissues in cucumber slices. A cylindricalpunch 0.315 cm diameter (0.200 to 0.635 cm diameter tested) and a cucumber slice thickness of at least 0.48 cm were found to be suitable for the method developed. Penetration force was about five times greater for mesocarp than endocarp in 4 to 5 cm diameter cucumbers. Mesocarp and endocarp were firmer near the stem end than near the blossom end of cucumbers. Force readings also declined for both tissues with increase in fruit diameter from about 2 to 6 em. Single slices taken from the center of 20 cucumbers and punched once each at specified locations in the mesocarp and endocarp provided sufficient sampling to limit the coefficient of variation to about 5%. The correlation coefficient between sensory analysis for firmness and puncture force readings of fermented cucumber slices was 0.88.     

Effect of Storage Conditions of Dry Bean Seeds (Phaseolus vulgaris L.) on Texture Profile Parameters After Cooking

Red kidney beans were stored at constant moisture and high and low temperature for 6 months. Instrumentally measured parameters of hardness, fracturabihty, gumminess, chewiness, springiness and cohesiveness were higher in samples stored at elevated temperatures than the control (2°C). The sensory panel found the stored beans had higher hardness, fracturability, lumpiness, chewiness, and skin toughness and less starchiness, gumminess, pastiness and moisture absorption than the control. Puncture forces followed approximately a normal distribution curve, and there was always some overlap between stored and control beans even when the stored beans had a much higher mean puncture force than the control. All textural parameters of cooked bean cotyledons changed substantially during storage of the seeds at elevated temperatures and high relative humidity.     

TEXTURE MEASUREMENT OF INDIVIDUAL COOKED DRY BEANS BY THE PUNCTURE TEST

TEXTURE MEASUREMENT OF INDIVIDUAL COOKED DRY BEANS BY THE PUNCTURE TEST. M.C. BOURNE. J. Food Sci. 37, 751–753 (1972)-The Instron Universal Testing Machine was set up to puncture test a large number of cooked dry beans, one bean at a time, by using the distance cycling controls on the machine. The punch is caused to cycle between two preset distance limits at a predetermined speed, permitting the operator to devote full attention to placing and removing beans in the puncture cup. 10 beans per minute can be conveniently tested by this procedure. The number of peak force heights in 20 selected force ranges are counted off from the chart, making for rapid retrieval of data. Tests on cooked dry beans show that the number of beans in each texture range follows approximately a normal distribution pattern, except for the presence of a few exceptionally hard beans which cause the distribution curve to tail off into the high puncture-force range.     

A Puncture Testing Method for Monitoring Solid Substrate Fermentation

Meitauza, an indigenous Chinese food made from fermented okara (soymilk residue), was used as a model system for monitoring solid substrate fermentations. The Instron Universal Testing machine and Chatillon hand operated force gauge were used to measure the force to penetrate meitauza as an estimation of mycelial binding. Increased firmness during fermentation was caused by fungal growth and not by water loss and surface crusting. Puncture force readings with the Instron were werll correlated (r = 0.86) with Chatillon measurements. The results of this study indicate that textural measurements using puncture force may have valuable application in monitoring the degree of mycelial growth or fermentation in a solid substrate.     

Frictional behaviors during applications of lotions by use of a novel friction meter and evaluation of tactile feeling

Vol. 43 , No.3 (2009) pp.171–176 A novel friction meter that allows us to measure normal force and friction force at the same time was developed, and the frictional behavior of cosmetics during application was investigated for an evaluation of a tactile feeling, permeability. As a result of measurements of four lotion samples by 15 panels, time courses of normal forces, friction forces and friction coefficients were different among the panels though they used the same samples. It was also found that the maximum value of differentiation in friction coefficient with better permeability feeling was larger than those with less permeability feeling. This suggests that relative changes in the time course of friction coefficients have an important influence on a tactile feeling, permeability.     

地毯簇绒过程针梁受力测试与工艺分析

为分析地毯簇绒机主轴执行机构的受载情况,提出一种间接测试主轴系统末端执行机构受力的方法,完成主轴1转内针梁推杆的受力和不同主轴转速下针梁的受力测试。测试结果表明,随着主轴转速的提高,针梁推杆受到的冲击越加明显,针梁推杆受到的拉力随之变大,并且拉力的变化也趋于激烈,而针梁受到的最大压力随主轴转速变化不大。为此,提出在工艺上采用将喂纱时刻逐次提前、适当减小底布张紧程度的方法来改善主轴系统的受载情况。测试结果也为进一步计算分析主轴等效力矩提供实验依据。