Orientation and Mechanical Properties of Extrusion Cast PA 12 Films in Biaxial Stretching Process

2001 ◽  
Vol 16 (4) ◽  
pp. 388-397 ◽  
Author(s):  
S. Rhee ◽  
J. L. White
Keyword(s):  
Mechanical Properties ◽  
Biaxial Stretching ◽  
Stretching Process

scholarly journals Comparison of the Structural Evolution of β Polypropylene During the Sequential and Simultaneous Biaxial Stretching Process

2020 ◽  
Author(s):  
Daoxin Zhang ◽  
Lei Ding ◽  
Feng Yang ◽  
Fang Lan ◽  
Ya Cao ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Structural Evolution ◽  
Deformation Mode ◽  
Microporous Membranes ◽  
Biaxial Stretching ◽  
Coarse Fibers ◽  
Deformation Modes ◽  
Stretching Process

In this paper, the lamellar structural evolution and microvoids variations of β-iPP during the processing of two different stretching methods, sequential biaxial stretching and simultaneous biaxial stretching, were investigated in detail. It was found that different stretching methods led to significantly different lamellae deformation modes, and the microporous membranes obtained from the simultaneous biaxial stretching exhibited better mechanical properties. For the sequential biaxial stretching, abundant coarse fibers originated from the tight accumulation of the lamellae parallel to the longitudinal stretching direction, whereas the lamellae perpendicular to the stretching direction were easily deformed and separated. Those coarse fibers were difficult to be separated to form micropores during the subsequent transverse stretching process, resulting in a poor micropores distribution. However, for the simultaneous biaxial stretching, the β crystal had the same deformation mode, that is, the lamellae distributed in different directions were all destroyed, forming abundant microvoids and little coarse fibers formation.

Physical properties of biaxially oriented PA6 film for simultaneous stretching and sequential processing

2011 ◽  
Vol 31 (1) ◽  
Author(s):  
Masao Takashige ◽  
Toshitaka Kanai
Keyword(s):  
Impact Strength ◽  
Physical Properties ◽  
Physical Property ◽  
High Impact ◽  
Thermal Shrinkage ◽  
Double Bubble ◽  
Biaxial Stretching ◽  
High Impact Strength ◽  
The Difference ◽  
Stretching Process

Abstract There are two different stretching processes that produce the biaxially oriented film, namely the tenter process and double bubble tubular film process. Furthermore, there are two tenter processes, i.e., the sequential biaxial stretching process and simultaneous biaxial stretching process. There is no report describing the difference among film physical properties of the three different processes. The biaxially oriented polyamide film using the double bubble tubular process has good balanced physical property and high impact strength, thus it is used for proper applications utilizing their advantage properties. In this report, the influence of each biaxial stretching process on film physical properties of polyamide, which has hydrogen bond, was studied in detail. As a result, the tentering process film has anisotropic tensile properties between machine direction (MD) and transverse direction (TD). This result was influenced by a later stretching process, namely TD stretching. On the contrary, the double bubble tubular film has good balanced properties, especially thermal shrinkage and impact strength. Tentering simultaneous stretching film has much larger shrinkage in MD than in TD. The sequential stretching film has larger shrinkage in TD than in MD. The double bubble tubular film has high impact strength, because it corresponds to the balanced molecular orientation.

The Sequential Analysis of Film Deformation Behavior during Successive Biaxial Stretching Process

2013 ◽  
Vol 747 ◽  
pp. 611-614 ◽  
Author(s):  
Yoshiyuki Kushizaki ◽  
Masayoshi Tokihisa ◽  
Hideki Tomiyama ◽  
Toshiro Yamada
Keyword(s):  
Constitutive Equation ◽  
Deformation Behavior ◽  
Draw Ratio ◽  
Sequential Analysis ◽  
Machine Direction ◽  
Material Constants ◽  
Biaxial Stretching ◽  
Experimental Deformation ◽  
Stretching Ratio ◽  
Stretching Process

The deformation behavior of Polypropylene (PP) film during successive biaxial stretching process which consists of machine direction (MD) stretching process with a roll drawing and transverse direction (TD) stretching with a tentering was analyzed sequentially by using a finite element method (FEM). In order to analyze it, stress-strain curves of casted PP film and uni-axially oriented PP film in MD were measured and fitted into the constitutive equation that the authors developed previously, respectively, and then, material constants for both films were obtained. Deformation behavior during successive biaxial stretching were calculated by applying the constitutive equation with the material constants of casted PP film for MD stretching and uni-axially oriented PP film in MD for TD stretching, respectively. Analytical conditions were the draw ratio of 5 for MD analysis and the stretching ratio of 9.5 for TD analysis. The authors also experimentally measured the thickness of film during and after MD and TD stretching using a pilot plant under the same conditions as analytical condition. Calculated results were able to express qualitatively the experimental deformation behavior of PP film such as the neck-in phenomena during MD stretching and the change of film thickness during MD and TD stretching.

scholarly journals Orientation Analysis of Polyoxymethylene Films Obtained by Rolling and Successive Biaxial Stretching Process.

1995 ◽  
Vol 51 (2) ◽  
pp. 51-61 ◽  
Author(s):  
Norikazu Miyashita ◽  
Kenji Takasa ◽  
Toshihiko Amano
Keyword(s):  
Orientation Analysis ◽  
Biaxial Stretching ◽  
Stretching Process

Investigation of Relationship between Structural and Crystallographic Condition of some Constructional Materials and their Mechanical Properties

2016 ◽  
Vol 870 ◽  
pp. 207-213
Author(s):  
V.V. Novokreschenov ◽  
R.V. Rodyakina ◽  
M.A. Karimbekov
Keyword(s):  
Mechanical Properties ◽  
Crystal Lattice ◽  
Linear Relationship ◽  
Plastic Flow ◽  
Analytical Study ◽  
Relative Strength ◽  
Plastic Properties ◽  
Face Centered ◽  
The Relationship ◽  
Stretching Process

This paper presents the results of an analytical study into the relationship between the strength and plastic properties of a series of structural materials. For this purpose the behavior of different materials during the stretching process of flat tensile samples with a circular hub was studied. It was found that the criterion of relative strength A depends on the structure and type of the crystal: materials, having a body-centered crystal lattice A < 1, and materials, having face-centered crystal lattice, A > 1. Astable linear relationship, depending on the structure and the type of crystal lattice of the material, between the criterion of relative strength A, geometric parameters of the sample (R and b) with the hub, length of the zone of material’s plastic flow lp and tension δ was found to exist.

Development of a biaxial stretching test machine and its applications

2018 ◽  
Vol 38 (6) ◽  
pp. 605-616 ◽  
Author(s):  
Kentaro Egoshi ◽  
Toshitaka Kanai ◽  
Kazuhiro Tamura
Keyword(s):  
Light Scattering ◽  
Evaluation Method ◽  
Three Dimensional ◽  
Crystalline Polymer ◽  
Stress And Strain ◽  
Test Machine ◽  
Biaxial Stretching ◽  
As Stress ◽  
Stretching Process

Abstract The evaluation method for a biaxially oriented film was developed using in-situ measurement during the stretching process. It can obtain basic data such as stress-strain curves, birefringence, light scattering, three dimensional refractive indexes and birefringence distribution. Stress and strain as functions of stretching speed and stretching temperature, as well as the deformation of spherulite of semi-crystalline polymer can be obtained by measuring the birefringence and light scattering during the biaxial stretching process with a small piece of polymer sample. The experimental results show the stress, retardation and three dimensional molecular orientations behavior during the simultaneous biaxial stretching and the sequential biaxial stretching process. Stretchability, thickness uniformity and spherulite size can be obtained simultaneously. In this paper, advantages and details of the newly developed system will be discussed with some experimental data.

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