ISSN:0730-6679    

DOI:10.1002/adv.1984.060040301

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

年代:1984

数据来源: WILEY

ISSN:0730-6679    

DOI:10.1002/adv.1984.060040302

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

年代:1984

数据来源: WILEY

摘要:

AbstractMolds used for low pressure forming of rubbery polymeric sheet have certain design constraints. The choice of mold material depends upon the severity of service and the number of parts required. Specifications for wood, plaster, aluminum, thermosetting resins, sprayed metal, and steel are discussed. Design criteria for vent hole diameter and number of vent holes are presented. Frictional aspects of mold surfaces and ancillary aspects of mold design, such as clamping mechanisms and sheet supports, are discussed.

ISSN:0730-6679    

DOI:10.1002/adv.1984.060040303

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

年代:1984

数据来源: WILEY

摘要:

AbstractBecause the expansion of expandable polystyrene beads (EPS) results in a reduction in bulk density of more than one‐thirtieth, the beads require a pre‐expansion step prior to the final molding operation. Hence, the pre‐expansion process has become an important unit operation for foamed bead molders. This article presents some of the design concepts used for EPS pre‐expansion processing. Included are the characteristics of startup, temperature control and agitation during operation, and shutdown procedures. By following the suggestions outlined, the pre‐expansion process should deliver a uniform product, regardless of the raw bead supplier, and thereby help eliminate waste due to poor foam

ISSN:0730-6679    

DOI:10.1002/adv.1984.060040304

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

年代:1984

数据来源: WILEY

摘要:

AbstractConductive fillers are currently being evaluated for their ability to produce conductive plastic parts which shield electromagnetic interference (EMI). These fillers all have a geometrical characteristic to them which makes them susceptible to damage during compounding and processing. In this paper the effects of compounding and processing on the electrical properties of compounds produced from a variety of conductive fillers are presented. These fillers include carbon black, carbon fibers, aluminum‐coated glass fibers, stainless steel fibers, and aluminum flakes. Thermoplastic polymers were used as matrices in the preparation of the conductive compounds. This study shows that a balance must be reached between dispersive mixing requirements and minimizing damage to the filler particle

ISSN:0730-6679    

DOI:10.1002/adv.1984.060040305

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

年代:1984

数据来源: WILEY

摘要:

AbstractButadiene–acrylonitrile copolymers were prepared with such variations in molecular structure as molecular weight, degree of long branching, and gel. The acrylonitrile content was varied from 28% to 44%. Viscoelastic behavior of gum elastomers, uncured compounds, and vulcanizates were characterized. Thus, the effects of molecular architecture on the properties were followed through the processing steps of compounding and vulcanization. Also, the effects of molecular parameters on the large deformation of vulcanizates were examined by the tensile stress–strain behaviour. The fracture toughness was examined with the tensile failure characteristics and De Mattia Flex

ISSN:0730-6679    

DOI:10.1002/adv.1984.060040306

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

年代:1984

数据来源: WILEY

ISSN:0730-6679    

DOI:10.1002/adv.1984.060040307

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

年代:1984

数据来源: WILEY

ISSN:0730-6679    

DOI:10.1002/adv.1984.060040308

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

年代:1984

数据来源: WILEY

ISSN:0730-6679    

DOI:10.1002/adv.1984.060040309

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

年代:1984

数据来源: WILEY

摘要:

AbstractPlastic bottles for carbonated beverages have many advantages over glass and metal containers. However, plastic bottles are also known to be imperfect barriers for gaseous fluids; i.e., they are semipermeable. This characteristic results in serious carbon dioxide transmission losses, particularly on the ½‐L or smaller single‐service bottles which have high area‐to‐volume ratios. Shelf life of these smaller beverage containers is therefore reduced. This article combines literature data and a simple diffusion model to predict shelf life for PET beverage bottles. As anticipated, the model shows that the smaller bottles have an unacceptable shelf life based on industrial standards. Moreover, while refrigerated temperatures increase shelf life to acceptable levels, temperatures for storage above 100°F can also reduce the 2‐L bottle to less than acceptable levels. The shelf life predictions developed with the model are close to those observed in practice. Further manipulation with the model shows that a hypothetical multilayered barrier wall could be constructed which would give an acceptable shelf life at any reasonable

ISSN:0730-6679    

DOI:10.1002/adv.1984.060040310

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

年代:1984

数据来源: WILEY