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structural reaction injection molding

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Series: ASM Handbook
Volume: 11B
Publisher: ASM International
Published: 15 May 2022
DOI: 10.31399/asm.hb.v11B.a0006945
EISBN: 978-1-62708-395-9
...-styrene size-exclusion chromatography scanning electron microscope short ber reinforced polymer secondary ion mass spectroscopy styrene-maleic anhydride sheet molding compound Society of Plastics Engineers superplastic forming structural reaction injection molding scanning transmission electron...
Series: ASM Handbook
Volume: 11B
Publisher: ASM International
Published: 15 May 2022
DOI: 10.31399/asm.hb.v11B.a0006935
EISBN: 978-1-62708-395-9
... the heating cycle (as in the sheet molding compound process), by gas formation during the reaction (as in polyurethane reaction injection molding), or by adding a blowing agent. Addition of Fillers The addition of fillers can significantly reduce the apparent shrinkage of both thermoplastic...
Series: ASM Handbook
Volume: 11B
Publisher: ASM International
Published: 15 May 2022
DOI: 10.31399/asm.hb.v11B.a0006916
EISBN: 978-1-62708-395-9
... applications, two-part systems are used. For example, in resin transfer molding (RTM), reaction injection molding (RIM), and vacuum assisted resin transfer molding (VARTM), a meter mixer is used to precisely mix parts A and B prior to injecting it into the mold cavity. If the mix ratio is not carefully...
Series: ASM Handbook
Volume: 11B
Publisher: ASM International
Published: 15 May 2022
DOI: 10.31399/asm.hb.v11B.9781627083959
EISBN: 978-1-62708-395-9
Series: ASM Handbook
Volume: 11B
Publisher: ASM International
Published: 15 May 2022
DOI: 10.31399/asm.hb.v11B.a0006864
EISBN: 978-1-62708-395-9
... Abstract This article discusses technologies focused on processing plastic materials or producing direct tools used in plastics processing. The article focuses on extrusion and injection molding, covering applications, materials and their properties, equipment, processing details, part design...
Series: ASM Handbook
Volume: 11B
Publisher: ASM International
Published: 15 May 2022
DOI: 10.31399/asm.hb.v11B.a0006925
EISBN: 978-1-62708-395-9
... be reduced to a single curve when weight-average molecular weight is used. Plastics with narrow molecular weights are preferred for low warpage in thin-wall injection molding, film extrusion, and rotational molding. Plastics with moderately low molecular weights are suitable for high-speed processing...
Series: ASM Handbook
Volume: 11B
Publisher: ASM International
Published: 15 May 2022
DOI: 10.31399/asm.hb.v11B.a0006915
EISBN: 978-1-62708-395-9
... with various regions of the viscosity curve. It discusses the concept of shear sensitivity, the nature of viscoelastic properties, and the electrical, chemical, and optical properties of different plastics. It also reviews plastic processing operations, including extrusion, injection molding, and thermoforming...
Series: ASM Handbook
Volume: 11B
Publisher: ASM International
Published: 15 May 2022
DOI: 10.31399/asm.hb.v11B.a0006927
EISBN: 978-1-62708-395-9
... for quality assurance fixturing, for example three small bosses with a coplanar surface, can provide the necessary consistent part-to-part fixturing means necessary for precise part measurement. Structural Foam Molded Parts Structural foam molding is a variation of injection molding that incorporates...
Series: ASM Handbook
Volume: 11B
Publisher: ASM International
Published: 15 May 2022
DOI: 10.31399/asm.hb.v11B.a0006922
EISBN: 978-1-62708-395-9
... to the chemical reaction Fewer joining options Thermosets come in a wide range of colors/finishes, can be injection and compression molded, can be recycled, and generally have attractive pricing. This article focuses primarily on thermoset materials that at room temperature are below their glass...
Series: ASM Handbook Archive
Volume: 11
Publisher: ASM International
Published: 01 January 2002
DOI: 10.31399/asm.hb.v11.a0003525
EISBN: 978-1-62708-180-1
... center on the techniques used to evaluate the composition and structure of the material. Unlike metals, polymers have a molecular structure that includes characteristics such as molecular weight, crystallinity, and orientation, and this has a significant impact on the properties of the molded article...
Series: ASM Handbook
Volume: 11B
Publisher: ASM International
Published: 15 May 2022
DOI: 10.31399/asm.hb.v11B.a0006933
EISBN: 978-1-62708-395-9
... is important because it impacts the mechanical, physical, and chemical resistance properties of the molded article. In general, rapid or quench cooling results in a lower crystalline state. This is the result of the formation of frozen-in amorphous regions within the preferentially crystalline structure...
Series: ASM Handbook
Volume: 11B
Publisher: ASM International
Published: 15 May 2022
DOI: 10.31399/asm.hb.v11B.a0006923
EISBN: 978-1-62708-395-9
... properties. For these materials, properties such as tensile strength and modulus can be correlated with density, which in turn is related to crystallinity. One primary example is PE, which in the commercial market is classified according to density. Hydraulic stress during injection molding flow...
Series: ASM Handbook
Volume: 11B
Publisher: ASM International
Published: 15 May 2022
DOI: 10.31399/asm.hb.v11B.a0006912
EISBN: 978-1-62708-395-9
... representations of a molded part if the material in the machined part is similar to that in the injection-molded part, the machined sample is annealed, and the geometry of the machined part closely matches that of the injection-molded part. The following differences between a machined plastic part and a molded...
Series: ASM Handbook Archive
Volume: 11
Publisher: ASM International
Published: 01 January 2002
DOI: 10.31399/asm.hb.v11.a0003508
EISBN: 978-1-62708-180-1
..., mold creep, springback F 233 Casting deformed with respect to drawing; pattern and mold conform to drawing Casting distortion F 234 Casting deformed with respect to drawing after storage, annealing, machining Warped casting Inclusions or Structural Anomalies G 100...
Series: ASM Handbook
Volume: 11B
Publisher: ASM International
Published: 15 May 2022
DOI: 10.31399/asm.hb.v11B.a0006924
EISBN: 978-1-62708-395-9
... and oligomers) and, as a result of chemical reactions, polymerize into a network structure ( Ref 1 – 5 ). Figure 1 illustrates the distinction between the processing of thermoplastics and thermosets. In Fig. 1(a) , a thermoplastic polymer may be heated above the glass transition or the melting...
Series: ASM Handbook
Volume: 11A
Publisher: ASM International
Published: 30 August 2021
DOI: 10.31399/asm.hb.v11A.a0006831
EISBN: 978-1-62708-329-4
... (cast steel) Flow marks, crow’s feet D 134 Casting surface entirely pitted or pock-marked Orange peel, metal mold reaction, alligator skin D 135 Grooves and roughness in the vicinity of re-entrant angles on die castings Soldering, die erosion D 140 Depressions in the casting...
Series: ASM Handbook
Volume: 11B
Publisher: ASM International
Published: 15 May 2022
DOI: 10.31399/asm.hb.v11B.a0006913
EISBN: 978-1-62708-395-9
... of properties in high-humidity environments; have among the highest volume and surface resistivity in thermosets; low dissipation factor Compression moldings, extrusions, injection moldings, transfer moldings, laminates Epoxies Good electrical properties, useful over a wide range of environments Castings...
Series: ASM Handbook Archive
Volume: 11
Publisher: ASM International
Published: 01 January 2002
DOI: 10.31399/asm.hb.v11.a0003550
EISBN: 978-1-62708-180-1
... effect. However, at conditions of either low (>4) or high (<10) pH, the rate of hydrolysis may become perceptible and result in molecular weight reduction and mechanical property diminution. These polymer types can also degrade during processing (i.e., extrusion or injection molding...
Series: ASM Handbook
Volume: 11B
Publisher: ASM International
Published: 15 May 2022
DOI: 10.31399/asm.hb.v11B.a0006917
EISBN: 978-1-62708-395-9
... to reduce the crystallinity has enhanced the ESC resistance ( Ref 14 ), but others show better ESC resistance with higher levels of crystallinity, as achieved through slow cooling during injection molding ( Ref 15 ). It appears likely that the phenomenon is coupled in these studies. The presence...
Series: ASM Handbook
Volume: 11A
Publisher: ASM International
Published: 30 August 2021
DOI: 10.31399/asm.hb.v11A.9781627083294
EISBN: 978-1-62708-329-4