塑料技术手册:Volume 1:吹塑成型:Blow molding 内容简介

《塑料技术手册》是大型综合性手册，通过阅读、学习本手册，无论是专业人员还是非专业人员，都会很快熟悉和掌握塑料制品的设计和制造方法。本册内容包括：吹塑过程，挤出吹塑成型，注射吹塑，拉伸吹塑成型，模具，塑料材料，设计。

塑料技术手册:Volume 1:吹塑成型:Blow molding 目录

LIST OF FIGURES
LIST OF TABLES
PREFACE
ABOUT THE EDITORS
6.BLOW MOLDING
INTRODUCTION
Container
Industry Size
BLOW MOLDING PROCESS
Blowing Requirements
Airflow Control
Extrusion versus Injection Blow Molding
BASICS IN PROCESSING
EXTRUSION BLOW MOLDING
Extruder
Melt Flow
Parison Sag
Parison Head
Parison Wall Thickness
Machine Design
Single—Stage Design
Two—Stage Design
Continuous Extrusion Design
Intermittent Extrusion Design
INJECTION BLOW MOLDING
STRETCH BLOW MOLDING
Injection Stretch Blow Molding
Spe Machines
Extrusion Stretch Blow Molding
Dip Blow Molding
Multibloc Blow Molding
Other Blow—Molding Processes
Blow Molding with Rotation
MOLD
Basic Features
Materials of Construction
Pinch— Off Zone
Flash Control
Blowing and Calibrating Device
Venting and Surface Finish
Cooling
PLASTIC MATERIAL
Blow Molding and Plastic
Behavior of Plastics
Barrier Plastic
Barrier Material Type
Blow Molding Reinforced Plastic
DESIGN
Bottle Design
Industrial Products
Complex Irregular Shape
Oriented 3—D Parison
Other Design Approaches
SUMMARY
History

塑料技术手册:Volume 1:吹塑成型:Blow molding 节选

　　《塑料技术手册 吹塑成型（1 影印版）》：　　Parison Swell The die flow influences parison behavior through molecular orientation， which manifests itself at the die exit as extrudate swell.Flow at the inlet of a die， where the streamlines are converging rapidly， involves a high rate of stretching in the flow direction.This produces a high degree of molecular orientation， and if the melt is permitted to exit immediately， as for flow through an orifice plate， there would be a very high degree of swell.However， if a long straight section，for example a capillary or straight annular die， follows the entrance， then molecular relaxation processes will lead to a disappearance of the orientation generated at the entrance， and as the die is made longer， the degree of swell is reduced.At the same time， however， the shearing in the die produces some axial orientation， and for a very long die， there is still significant swell resulting from this shear flow.If the die has an expansion or contraction section， this will introduce stretching， and this willintroduce orientation whose direction depends on the details of the die design.For these reasons， parison swellis very sensitive to die design.　　The melt leaving the die may exhibit sharkskin or melt fracture， which are irregularities in the surface of the extrudate that can affect the surface finish of an extrusion blow—molded container.This effect occurs above a critical shear stress in the die and is often the factor that limits the speed of an extrusion process.Extrudate distortion is most severe in the case of narrow molecular weight distribution （MWD） （chapter 1） high—viscosity plastics.Increasing the temperature or reducing the extrusion rate can sometimes eliminate it， but either of these actions will increase the cycle time.The use of an internal heater in the mandrelis a method to reduce the tendency toward melt fracture on the inside of the parison.The detailed origins of this phenomenon are not fully understood， but the shape and material of construction of the die and the formulation of the plastic are known to be contributing factors.　　……

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