MRE (Meal-Ready-to-Eat) is an important field of food research. Owing to its specialty, there are more strict requirements for MRE processing, nutrition and packaging. MRE requires long-term safe and clean storage as well as good packaging seal performance. Those characteristics determine the strict packaging requirements for MRE.

Further details please feel free to contact Shirley via email: trade2@labthink.cn, (tel)0086-531-85811021 or visit our web: http://www.labthink.cn/en

1. MRE Package Heat Seal Strength Testing

MRE package heat seal strength testing tests the heat seal parts of the MRE package such as the top, bottom and back sides of the package. Cut specimen in the vertical direction from the heat seal places, as the heat seal specimens for top, bottom and back parts. The specimens are required to be 15+/-0.1mm, and spread length of 100+/-1mm. If the length can not be reached, cellophane can be applied to connect the same material to reach the length.

Take the heat seal place as the centre line, and spread the package flat, clamp the specimen onto the clamps of Labthink PARAM (PC) -500 Auto Tensile Tester. The ordinate axis of the specimen should be in compliance with the centre line of the clamps with proper tightness. The initial distance between clamps should be 50mm. The testing speed is 300mm/min. Start testing and calculate the heat seal strength with the average of 10 specimens in the unit of N/15mm with 3 significant figures. One thing should be cautious is that if the specimen is broken during testing, it should be replaced by a new one.

HST-H3 Heat Seal Tester can simulate the testing conditions for MRE packaging line in lab research. The above two testers can achieve specimen preparation and testing.

2. MRE (Meal-Ready-to-Eat) Package Permeation Testing

Permeation testing of MRE package is of vital importance to MRE quality, since MRE contains fat and its oxidization would affect storage and shelf life. Thus, excellent oxygen and gas barrier property should be guaranteed. Besides, some dried goods as dehydrated vegetables require better storage performance. Those products can be stored for a long time provided moisture permeation and gas permeation are avoided. Therefore, permeation testing of MRE is of great importance.

Permeation testing includes moisture permeation testing and gas permeation testing. Labthink PERME VAC series of differential pressure gas permeation testers or Labthink PERME OX2/230 Oxygen Transmission Rate Test System are applicable for gas permeation testing. For moisture permeation or WVTR (water vapor transmission rate), Labthink PERME TSY-T series of moisture permeation testers and Labthink PERME W3/330 series of moisture permeation (WVTR) testers are applicable.

3. MRE Package Peeling Testing

MRE package are mostly laminated pouches such as plastic-aluminum packages. The laminated films used for MRE should take mechanical strength under normal temperature as well as mechanical strength under heat seal temperature. During packaging, MRE package materials meet various forces, especially the force during heat seal process to separate the layers of materials. In order to guarantee reliable composition, laminated material peeling test of MRE package should be applied. Labthink PARAM XLW series Auto Tensile Testers are the exact testers for peeling testing.

Flexible laminated plastic material peeling test methods (GB 8808) can be the reference for testing method. Firstly, cut 50mm at each end in widthways. And then, prepare 5 same specimens along the width. The composed direction is the vertical direction. Peel along the length of the specimen for 50mm without obvious injuries between the laminated layer and the basic layer. If the specimen is not easy to be peeled off, put 20mm of one specimen end into the solvent, and wait until complete evaporation of the solvent.

When testing, clamp the peeled ends onto XLW (PC) Auto Tensile Tester. Be careful the vertical line should in compliance with the central line of the clamps, and adjust for proper tightness. Set the testing speed of auto tensile tester at 300mm/min and start testing. The un-peeled part and the tensile direction form a T.

4. MRE Package Friction

Friction in MRE packaging process is both a driving force and resistant force, and it should be restricted within a certain scope. The roll material for automatic packaging requires little inner friction coefficient and proper outer friction coefficient. High outer friction coefficient would cause great resistance during packaging and material deformation. Insufficient friction would lead to skidding of drag system with inaccurate trace of electronic eye and inaccurate cut position. However, the inner friction coefficient sometimes should not be too low, some packaging machine would occur unstable piling and wrong siding. Therefore, the testing for coefficient of friction is of great importance. Labthink PARAM MXD-02 Coefficient of Friction Tester works according to international standards. Besides, temperature has great influence on coefficient of friction. Therefore, coefficient of friction at normal temperature and ambient temperature should both be tested. As to testing of coefficient of friction at specially required temperatures, Labthink PARAM FPT-F1 Friction/Peel Tester is available.

5. The Leakage of MRE Package Heat Seal

The leakage of MRE packages is the failed heat seal owing to the existence of certain factors. The failed heat seal is usually caused as follows:

A. Insufficient heat seal temperature. Different temperatures are required for different parts of one package as well as for different packaging speed. The horizontal heat seal and vertical heat seal requires different heat seal temperatures, which has to be considered during packaging process. Besides, for heat seal instruments, temperature control accuracy is another concern.

B. Contaminated seal places. During inserting process, the seal places of packages are usually contaminated by the contents; including liquid contamination and dust contamination.

C. Issues related to equipments and operations, such as foreign body in the heat seal mold, inferior heat seal pressure and unparallel heat seal mold, etc.

D. Issues related to packaging materials, such as inferior heat seal caused by extra corona discharge or excessive slipping agent.

The above-mentioned issues can be resolved by online inspection, as well as laboratory testing by Labthink PARAM MFY-01 Leak Tester and LSSD-01 Leak and Seal Strength Detector for leak testing.

Further details please feel free to contact Shirley via email: trade2@labthink.cn, (tel)0086-531-85811021 or visit our web: http://www.labthink.cn/en

About Labthink:

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