ISSN:0730-6679    

DOI:10.1002/adv.1986.060060201

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1986

数据来源: WILEY

摘要:

AbstractPlastic components can only be competitive if they make use of the material and thereby emerge technically and economically superior to conventional materials. This places, high requirements on designers and presupposes extensive experience. A situation where the optimal version can only be established in expensive prototype molds is unacceptable. Above all, though, the time that this takes is preventing substitution by plastic parts from gaining an increasing market in the industrial component sector. The tasks which companies have to tackle today include increasing performance and making freely available experience that is currently confined to individuals. The establishment of specified work sequences helps to avoid errors. The chief tasks involved in design are compilation of specifications, material selection, and shaping and dimensioning. The designer's work can be broken down into acquisition of information, calculation, decision making, and drawing. The use of computers can help towards rationalization in the design field as well. This rationalization ought not only to give shorter transit times but improved components as well. The following program packages are available: a data bank program for managing design data, a search program with corresponding data file for material selection, a 3D graphic system for compiling drawings, a FE program for dimensioning, and an expert program to aid the designer in decision making. Apart from the conventional free design it is also possible to define individual functional elements or assemblies, such as snap fastenings or ribs, by way of design macros. These macros are designed and calculated in principle and then simply aligned auttomatically when incorporated in a specific part. Computersided dimensioning makes it possible to establish all the factors influencing quality in a specific application and to recognize weak points in simulated tests right at the design stage. The conventional concept of dimensioning (applying a sum of reducing coefficients to make allowance for loading) has thus been dispensed with, and a route is shown which permits precise allowance to be made for all the influences in a particular loading case. This therefore ensures optimum material utilization.

ISSN:0730-6679    

DOI:10.1002/adv.1986.060060202

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1986

数据来源: WILEY

ISSN:0730-6679    

DOI:10.1002/adv.1986.060060203

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1986

数据来源: WILEY

摘要:

AbstractMicrostructural analyses with optical and scanning electron microscopy can identify processing variables that lead to less than optimum mechanical properties of molded and friction welded polymer components. Delineation of the major phase arrangements in blends of polycarbonate (PC) and poly(butylene terephthalate) (PBT) was key to identifying stress concentrations and internal defects. Phase separations, crystalline arrangement, structure refinements, and shear stresses introduced during molding or friction welding were evident and help to explain the unpredictable impact fracture mode and strength. The techniques help identify when the brittle ribbonlike PC phase extends to the surface without being encapsulated or surrounded by the PBT phase.

ISSN:0730-6679    

DOI:10.1002/adv.1986.060060204

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1986

数据来源: WILEY

ISSN:0730-6679    

DOI:10.1002/adv.1986.060060205

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1986

数据来源: WILEY

摘要:

AbstractThe wear rates and friction coefficient of (PEEK/fiber) composites have been measured under various tribological conditions of sliding velocity, fiber fraction, and kinds of fiber (carbon or glass). The measured tribological data were explained by means of wear and friction equation and also correlated with the observed microstructure.

ISSN:0730-6679    

DOI:10.1002/adv.1986.060060206

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1986

数据来源: WILEY

ISSN:0730-6679    

DOI:10.1002/adv.1986.060060207

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1986

数据来源: WILEY

摘要:

AbstractThe effects of processing conditions and extruder scale are examined for a compounding process involving fully intermeshing corotating twin‐screw extruders. A systematic experimental study involving a matrix of two independent variables (extruder throughput rate and screw rotational speed) was conducted on two different size twin‐screw extruders using a styrene copolymer and carbon black. Several process parameters were examined including melt temperature at the die, motor power, residence time distribution, and carbon black concentration in the extrudate. The residence time distribution data were fit to a three‐parameter plug flow/stirred tank model to obtain a time delay, a time constant, and a mean residence time for each extrusion condition. At low screw speeds, as utilized in many compounding processes, the mean residence time dropped only slightly with increasing screw diameter (for comparable screw length/screw diameter ratios). The carbon black concentrations as measured in the extrudate pellets were within ±5% of mean value, indicating that the extruder damped out the high frequency noise caused by feed rate fluctuations in the individual polymer and carbon black f

ISSN:0730-6679    

DOI:10.1002/adv.1986.060060208

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1986

数据来源: WILEY

ISSN:0730-6679    

DOI:10.1002/adv.1986.060060209

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1986

数据来源: WILEY

ISSN:0730-6679    

DOI:10.1002/adv.1986.060060210

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1986

数据来源: WILEY