β-Crystal Development of Isotactic Polypropylene during Sheet Extrusion Process

Kerddonfag, Noppadon; Chinsirikul, Wannee; Hararak, Bongkot; Winotapun, Charinee; Kumsang, Pramote

doi:10.4028/www.scientific.net/amr.93-94.655

Cited by 3 publications

(2 citation statements)

References 4 publications

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“…Melt temperature during extrusion was 230 °C, and chilled roll temperature was maintained at 120 °C. On the basis of our previous findings, the chilled roll temperature was an important controlling parameter in producing a high relative beta‐crystal content of 80%–90% as calculated by the K value (Turner‐Jones equation) based on wide angle x‐ray diffraction . Beta‐PP sheet was cut into a dimension of 96 × 96 mm with an effective draw area of 75 × 75 mm.…”

Section: Methodsmentioning

confidence: 94%

Porous Ultrahigh Gas-Permeable Polypropylene Film and Application in Controlling In-pack Atmosphere for Asparagus

Chinsirikul

Klintham

Kerddonfag

et al. 2013

Packag. Technol. Sci.

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Porous polypropylene (PP) films with greater gas permeability and lower permeability ratios (β) than existing commercial films were developed for fresh produce packaging. PP containing high content of beta‐form crystal was biaxially stretched under controlled conditions. Resulting porous films with uniquely high oxygen transmission rate (OTR) of 2 659 000 cm3⋅m−2⋅d−1, water vapor transmission rate of 67 g⋅m−2⋅d−1, and β value of 0.76 was used as a “breathable window” attached to the less permeable commercial BOPP (biaxially oriented PP) lidding film. Various sizes/areas of the breathable windows were designed and tested on packaging asparagus of 400 g, at 5°C. Results demonstrated that in‐pack O2 and CO2 concentrations could be practically controlled and modified by changing areas of the breathable windows. Altered porous high OTR area directly affected total gas permeation of the package. Optimum gas composition of Ο2 and CΟ2 within the recommended controlled atmosphere for asparagus, stored at 5°C, was effectively created and maintained in the package containing 25 cm2 breathable window (15% of total film lid's area). The shelf life of asparagus under optimum modified atmosphere was extended to 29 days, as compared with <3 days in the normal, low OTR tray sealed with BOPP lidding film. Clearly, these developed porous ultrahigh permeable PP films can be useful materials in designing high OTR package with desirable in‐pack O2 and CO2 concentrations. Copyright © 2013 John Wiley & Sons, Ltd.

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Section: Methodsmentioning

confidence: 94%

Porous Ultrahigh Gas-Permeable Polypropylene Film and Application in Controlling In-pack Atmosphere for Asparagus

Chinsirikul

Klintham

Kerddonfag

et al. 2013

Packag. Technol. Sci.

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“…The relative content of β-phase crystal or K-value of β-nucleated PP sample is about 0.84, calculated using the Turner-Jones equation (K value = H β / [H β + H α1 + H α2 + H α3 ], whereas H is peak height). This should be signified to the efficiency of β-cystal nucleator to promote a β-phase crystallization during sheet extrusion process [3]. The neat PP and β-nucleated PP precursor sheets were analyzed by DSC technique to determine the thermal characteristics of different crystalline morphology.…”

Section: Crystalline Structure Of Precursor Sheetmentioning

confidence: 99%

Biaxially Drawn Behavior of α- and β-Polypropylene Films under Simultaneous Stretching

Kerddonfag

Saravari

Chinsirikul

2011

AMR

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This study investigated the biaxially drawn behavior of polypropylene (PP) containing different crystalline structure in between of either α-monoclinic or β-hexagonal crystal form or a combination of both. The precursor sheet with α-crystalline PP was prepared from neat resin using the sheet extrusion process. The high content of β-crystalline phase (K-value of about 84%) was developed in the polypropylene sheet using a proprietary type and concentration of β-crystal nucleator. Biaxial film stretching was carried out using a laboratory stretching machine at the temperature of 145°C. Stretching speed and stretch ratio were kept relatively constant at 400 %/sec and 5.5 x 5.5, respectively. β-PP sample demonstrated a distinct biaxially drawn behavior as compared to that of the neat-PP sample, in particular, biaxial yield stress of neat PP (α-PP) was 3.55 MPa, where a much lower biaxial yield stress value was apparent for β-PP (~1.69 MPa). Interestingly, the total calculated area under stretching curves of the β-nucleated PP sample was about 34.8 % lower than that of the neat PP sample. These findings indicate the less energy required for stretching process of β-nucleated PP. Moreover, the drawn β-PP films also showed comparable mechanical properties to the α-PP sample as well as a good optical property, evidenced by low haze values of <1% which was close to that for the normal BOPP films.

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Effect of acrylonitrile–butadiene–styrene copolymer (ABS) on β-nucleation in β-nucleated polypropylene/ABS blends

Wang

Zhang

et al. 2012

Polym. Bull.

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β-Crystal Development of Isotactic Polypropylene during Sheet Extrusion Process

Cited by 3 publications

References 4 publications

Porous Ultrahigh Gas-Permeable Polypropylene Film and Application in Controlling In-pack Atmosphere for Asparagus

Porous Ultrahigh Gas-Permeable Polypropylene Film and Application in Controlling In-pack Atmosphere for Asparagus

Biaxially Drawn Behavior of α- and β-Polypropylene Films under Simultaneous Stretching

Effect of acrylonitrile–butadiene–styrene copolymer (ABS) on β-nucleation in β-nucleated polypropylene/ABS blends

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