It happened to all of us. You pay $4.00 or
more for a bag of chips, pull apart the bag, and are forced to look deep inside
for your tasty treasure. Instead of filling up the entire bag, the chips are
lying innocently at the bottom and the rest of your bag was air…or was it?
Foods such as chips
need a cushion to ensure they’re whole and crispy when you buy them. But
pumping the bag full of air won’t work. Why? When processed foods such as chips
are exposed to oxygen, the food breaks down and becomes rancid.
That’s why nitrogen
is used. “Nitrogen flushing” is a process whereby all the air is removed from
the bag and replaced with nitrogen gas. The nitrogen doesn’t affect the taste
of the food and doesn’t react with it like oxygen does, so the food stays
fresher longer. And, since the nitrogen gas fills up the bag, the contents
inside are protected during shipping.
Therefore, when you
involve in potato chip bags quality testing, you must consider the property of
potato chip bags as below:
u Good
barrier property to Nitrogen
u Proper
seal strength for high pressure inside the bags
u Bag
integrity to prevent oxidation
To improve your
potato chip bags, the first step is to know the current property of your potato
chip bags. And then evaluate what is necessary you need.
Barrier Property to Nitrogen
Potato chip bags are
likely made of laminated films because of their low gas permeability to
nitrogen. Basically, the gas transmission rate of potato chip bags are lower
than 0.1 cm3/m2·24h. When you measure the gas
permeability of potato chip bags, you need choose a precise and high accuracy
testing instrument in this test range, such as VAC-V2 Gas Permeability Tester
from Labthink. VAC-V2 is based on differential pressure method
and with test range 0.05~50,000 cm3/m2·24h·0.1MPa, which
is totally applicable to potato chip bags gas permeability test. VAC-V2 is a
use-friendly and easy-operated instrument.
1. Just
mount the specimen in the gas diffusion cell, the test chamber is divided into
a upper chamber and lower chamber by the specimen.
2. Evacuate
the testing Chamber
3. Flush
the upper chamber using high purity nitrogen and make the test chamber has a
constant pressure difference between upper chamber and lower chamber
4. The
Nitrogen will permeate through the specimen into low chamber because of the
pressure difference
5. Gas
permeability and other barrier properties of the specimen can be obtained by
monitoring the pressure changes in the lower chamber
This Instrument is
controlled by computer and equipped with professional software. All the test
process is intelligent and automatic computer. Test results can be displayed on
the computer screen directly.
Integrity and Seal Strength Test
Actually, there is an
instrument can measure potato chip bag integrity as well as seal strength test.
LSSD-01 Leak and Seal Strength Tester
combines seal strength test and package integrity test in one instrument. It
can be used to conduct burst testing, creep testing and creep to failure test.
Burst Testing
Burst testing determines the overall minimum
seal strength of the bag seals by inflating the bag at a uniform rate until the
seal separates at the point of greatest weakness. The burst test is a peak
inflation pressure test; you can see how the pressure increases to a maximum
pressure at which the pressure drops to zero. This drop represents the rupture
of the seal. The pressure at which the pouch bursts is a variable statistic
that can be utilized to document process development and process control
through the use of tools such as upper and lower control limits, such as those
seen on this control chart segment.
Creep Testing
The Creep Test is a second general type of
whole package inflation seal strength test. In the Creep Test, a filled, sealed
package is inflated to a constant pressure, which is then held for a specified
time, resulting in a pass/fail result. This provides a test for slow shear of
the adhesive bond similar to a dead weight hanging on the seal. A suggested
starting pressure for peelable seals is to begin evaluating your seal with a
creep pressure that is about 80% of the burst value. The inflation rate is not
critical, as long as the initial fill is not so fast as to shock the seal or so
slow as to result in an overly long test time. The shortcomings of this test
are the need for the operator to visually examine the seal at the end of the
test to determine the degree of seal peel, and the lack of a variable statistic
upon which to perform process control analysis.
For more potato chip bags
quality testing, please contact Yarina Gao via trade5@labthink.cn or visit our website www.labthinkinternational.com.cn
