How to Improve Barrier Performance of PET Bottle Base?

June 11, 2009 - PRLog -- Nowadays, PET bottle has found its wide applications in beverage, dairy, pharmaceuticals and chemistry, etc. This mainly relies on the development of its barrier performance development. In order to achieve better barrier performance, the research and control of PET bottle base barrier property is a must. At present, the following four techniques are commonly applied so as to improve the barrier property of PET bottle base barrier property.
1. PET Bottle Base Barrier Property Solution: Multi-layer
Multi-layer method is also defined as complex injection method. Inject PET backings, and then, inject barrier material through hot mold core to form central barrier layer. This method requires high skills of the operator and strict quality control.  
2. PET Bottle Base Barrier Property Solution: Raw Material Blending
Input barrier material directly into the PET raw materials, which is favorable for standard bottle base process systematically with the prepared materials. This method requires no other processing measures, and requires little of the operator. However, the blended barrier material would reduce the transparency of the PET bottles and result in turbidity.
3. PET Bottle Base Barrier Property Solution: Coating
Coating is to plasma coat on the inner and outer sides of the molded bottle base, this processing is usually quite complicated.
4. PET Bottle Base Barrier Property Solution: Multi-molding
This method starts from the interior molding, and makes multi-layer molding during equal processing period. Multi-molding method is quite complicated since it requires every layer to be very thin; however, in actual application, mold core may be deviated by the pressure differences and failed to realize even thickness. Besides, when the first molding period finishes, the bottle base has to be transmitted to another molding chamber for further molding. This process is accomplished through rotation, and would easily lead to peel of layers. This problem has been resolved by some companies: when changing molding chamber, several lines of mold cores moves in the parallel way which replaces the rotation and avoids layer peeling.
The above-mentioned progress and applications on PET bottle base barrier performances and technologies have paved the way for carrying out of various barrier performance solutions. High barrier performance is closely linked to barrier performance testing. When testing the barrier performances of PET packages and PET bottle bases, Oxygen Permeability Rate Tester is a useful tool. Labthink introduces Labthink PERME OX2/230 Oxygen Transmission Rate Test System for PET bottle and PET bottle base barrier property testing.
Oxygen transmission rate (OTR) is the most common testing for barrier property testing of PET bottle and PET bottle base. ASTM F1307, GB/T 19789 and other equal pressure testing methods are applicable. Isolate the transmission chamber with the pre-conditioned specimen to form two separated gas flow system: the testing gas flows outside the PET bottle or the bottle base (testing gas can be pure oxygen, or the gas mixture with oxygen); high pure carrying gas flows inside the bottle or bottle base. Though the two sides are of the same pressure, the oxygen partial pressures are different. Due to the oxygen concentration differences, oxygen transmits through the package, and is carried to the sensor which would bring forward accurate oxygen quantity in the carrier gas flow so as to calculate oxygen transmission rate.
Labthink PERME OX2/230 Oxygen Transmission Rate Test System can provide thorough oxygen testing means for barrier property of PET bottle and PET bottle base. Besides, this instrument is of master-satellite mode, a master base can support nine satellite modules; thus, 30 specimens can be tested at the same time. Its testing accuracy and technology have both achieved world advanced standard.  
Those are the brief introduction for PET bottle base barrier property technology improvement and relevant testing. Labthink Instruments Co., Ltd. (www.labthink.cn) and her Permeability Lab, are wiling to have more cooperation with you.

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