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Atomic Performance Products - XR6T High Performance Conrods

MRE (Meal-Ready-to-Eat) Package Heat Seal Strength Testing

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. As to the quality control and testing items, Labthink Instruments Co. Ltd. (www.labthink.cn) introduces as follows

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.

Labthink, the excellent provider of testing instruments and testing services, is devoted to provide most excellent and complete quality control solutions for pharmaceutical, foodstuff, cosmetics, packaging, printing, adhesive, automotive, petrochemistry, environment, biology, new energy, construction, aviation and electronic industries worldwide.

Labthink Instruments Co., Ltd.

No. 144 Wuyingshan Road, Jinan 250031, China

Tracy Bao info@labthink.cn

Tel: 0086 531 85061153 fax:0086 531 85812140

Labthink is devoted to share excellent quality testing and control techniques with global clients and is known for wide coverage of international testing standards. Labthink participates in the drafting of several important standards of food, pharmaceutical and packaging industries, and is the excellent partner of national certification institutes.

Labthink has also established cooperation with IGT, Rycobel, Metrotec, Chilton, Moroka and other renowned distributors to provide attentive and prompt technical services for her customers in more than 40 countries and regions.

Labthink aims at creating satisfactory value and professional services for her customers.

Labthink, think for you only!

About the Author

Which material to use and why?

Piano strings are made of a fibre which is pulled taut. When the string is tapped in the centre by a striker the resonance produces the note. The bending of the string causes a strain of up to 0.2% and a stress of up to 100 MPa. Based on the function and requirements of a piano string and the properties listed (E = tensile modulus, σy = yield stress, εf = failure strain, ρ = density), which of the following materials would you choose?

1. silica glass (E = 94GPa, σy =7,000 MPa, εf = 0.1%, ρ = 2.6 g/cm3)
2. polypropylene (E = 1.5GPa, σy = 40MPa, ε 3. steel (E = 210GPa, σy = 680MPa, εf = 5%, ρ = 7.8 g/cm3)
4. polyethylene (E = 1GPa, σy = 20MPa, εf = 200%, ρ = 0.9g/cm3)
5. aluminium (E = 70GPa, σy = 40MPa, εf = 50%, ρ = 2.7 g/cm3)

Please help meee!!!
Thanks!

Required parameters :

ε = 0.2%
σ = 100 MPa

Then we need elasticity modulus of

E = σ / ε = 100 MPa / 0.002 = 50 GPa.

Some choices can be "ignored" due to small E,

we only have now:

> silica glass (E = 94GPa, σy =7,000 MPa, εf = 0.1%, ρ = 2.6 g/cm3)
> steel (E = 210GPa, σy = 680MPa, εf = 5%, ρ = 7.8 g/cm3)
> aluminium (E = 70GPa, σy = 40MPa, εf = 50%, ρ = 2.7 g/cm3)

Aluminuim is ignored due to low yield strength σy = 40MPa

silica glass is ignored due to low strain εf = 0.1%

Then we 'confidently choose' : "Steel".
steel (E = 210GPa, σy = 680MPa, εf = 5%, ρ = 7.8 g/cm3)

Good luck