• Scope: The test measures the force value needed to tear a fabric, plastic film, or thin sheeting. It helps evaluate the tear resistance of materials, especially those used in packaging. Depending on the application, either a low or high propagation force may be desirable.
• Procedure:
  • Ten samples are cut from the material, both in the machine direction and the transverse direction.
  • A sample is positioned in the tester and clamped in place.
  • A cutting knife creates a slit in the sample, ending 43 mm from the far edge.
  • The pendulum is released to propagate the slit through the remaining 43 mm.
  • The energy loss by the pendulum is used to calculate an average tearing force.
• Sample Sizes:
  • The preferred test sample for plastic films is the constant radius sample, which provides a constant radius from the start of the tear strength measurement. This is useful for materials where the tear may not propagate directly up the sample as intended.
  • Another common sample shape is a 63 mm x 76 mm rectangle.
  • For textiles, a modified rectangle adds height on the ends of the sample to minimize unraveling of the outside edges.

The results of the Elmendorf Tear Test are presented as tearing force in milli-newtons (or grams-force). Keep in mind that there is no direct relationship between thickness and tearing force, so comparisons should only be made for samples of the same thickness. If you’re curious about material durability, this test provides valuable insights!

Labthink Provide professional elmendorf Tear tester, Click for more details .

Abrasion resistance of ink layer is one important parameter that is used to evaluate the printing quality. If the abrasion resistance of the ink layer is poor, the printed words on the paper or paperboard may become illegible and the part with printed area may be abraded in transportation, storage or in use. As a result, the printed words will be not able to be read by the customers, which cause inconvenience or misunderstanding and thus the product image would be compromised. Therefore, it is necessary for the manufacturers to test the abrasion resistance of the ink layer on the paper or paperboard before use.

This article provides a test method of abrasion resistance of ink layer on paper and paperboard for your reference. The testing instrument we used is Labthink’s MCJ-01A Rub Tester. The specimens we used are paperboards with printed words.

Figure 1. Printings on Paper and Paperboard

Figure 2. MCJ-01A Rub Tester

The tests are performed according to the following procedures.

Cut one piece of specimen from the provided sample and then fix the specimen in the test plane of the instrument. The size of the specimen should be 230mm×50mm.

Use a reflection densitometer to measure the density of the ink layer on the surface of the specimen.

Fix the rubber pad on the test block and then place it onto the specimen.

Set rub times and then start tests. The rubber pad with test block will rub on the specimen surface until the preset rub times are completed.

When tests are finished, the density of ink layer will be measured by reflection densitometer and the abrasion resistance of the specimen will be calculated.

For more details about MCJ-01A Rub Tester, please visit www.labthink.com

About Labthink Instruments Co., Ltd:

Labthink Instruments Co., Ltd is one leading supplier of packaging testing instruments, which is headquartered in Jinan, China and operated in Boston, U.S.A.

Measure Oxygen Permeability of Thin Films, which is important cause it directly affects the shelf life of content in packaging.

Test Device

Labthink OX2/230 Oxygen Transmission Rate Tester

Test Standard

ASTM D3985 — Standard Test Method for Oxygen Gas Transmission Rate Through Plastic Film and Sheeting Using a Coulometric Sensor

Test Procedure

1. Prepare the diamond shaped film specimen according to specific standard. The test specimen should have uniform thickness and be free of wrinkles, creases or other visible defects. Identify the permeating direction of the test and if necessary, mark the permeating direction on the test specimen. Generally the water vapor permeates from the outside in.

2. Place the prepared test specimen on the outer test chamber very carefully

3. Apply a layer of vacuum grease on the flange of the integrated inner test chamber then install the upper test chamber back and tighten it.

4. Set up test parameters. Select specimen type “Film” and start the test

5. Observe the flow of each test cell in process of testing. The flow of Cell A, B, C and Zero should be 10±1 ml/min and the flow of oxygen should be 60±10 ml/min. Otherwise the flow should be adjusted by turning the valves in clockwise or counterclockwise direction. Turn in clockwise direction to decrease the flow, while counterclockwise direction to increase the flow. The flow rate of oxygen would not be displayed in test interface. A rotameter should be inserted into the multi-port to check the flow rate of humidified gas. The rotameter should not stay in the multi-port for a long time.

7. View the test results and reports. If necessary, repeat the above procedures to perform another round of tests.

The principle of volatile corrosion inhibition is by using VCI, volatile corrosion inhibitor which can be evaporated under normal temperature so as to achieve saturation in the closed environment; VCI molecules are absorbed onto the metal surface to form a transparent protection film of several molecules thick after complicated physical and chemical reactions. This transparent protection layer is water proof, difficult to be dissolved and thus, can stop further corrosion. Evaporated VCI molecules can reach anywhere in the package with best anti-rust performance. VCI plastic material is manufactured by polyolefin resin with VCI under processes.

Volatile corrosion inhibiting film testing should adopt US military specification MII.PRF-22019D “Barrier Materials, Transparent, Flexible, Sealable, Volatile Corrosion Inhibitor Treated” and other domestic and international standards.

1.VCI Thickness Testing

Whether the thickness of VCI plastic film is even or not is the basic for VCI film and its performances. Uneven thickness would affect the tensile strength, permeation of different parts of the package; and would affect the following processing. Thickness testing methods are varied. For VCI plastic film thickness measurement, ISO 4593 and GB/T 6672-2001 are applicable.

Labthink PARAM CHY-C2 and CHY-CA Thickness Testers are both high precision thickness testers for VCI plastic film thickness testing with the resolution upto 0.1um. Labthink PARAM CHY-CA Thickness Tester, besides its high precision, high efficiency and other characteristics and functions to similar PARAM CHY-C2, is equipped with automatic feeding system to satisfy the constant and effective testing requirements of the clients with greater testing efficiency.

2. VCI Plastic Film Impact Testing Instruments

VCI (Volatile Corrosion Inhibition) plastic film impact property and its control could avoid package breakage owing to the insufficient toughness, so as to effectively get rid of product rustiness caused by inferior impact or shock resistance of the VCI plastic packages during circulation.

VCI plastic film impact testing is in compliance with ASTM D3420, GB/T 8809-1958 and other international standards. Labthink PARAM FIT-01 Film Impact Tester is in strict compliance with these standards and with more advanced functions. For example, Labthink PARAM FIT-01 Film Impact Tester is of pneumatic specimen clamping and pneumatic pendulum releasing, which is completely different from other products that are manual clamping. Pneumatic clamping is rapid and effective with even clamping force on the four sides of the film, and will not slide during impact with inaccurate results. Besides, the precision of PARAM FIT-01 Film Impact Tester is up to 0.001J, whereas other impact testers are mostly of mechanical type with low precision through reading the graduation on the board.

3. VCI Plastic Film Tear Resistance Testing

The VCI (Volatile Corrosion Inhibition) packaging material may be torn by exterior forces during storage and transportation. Sufficient tear resistance can reduce the transmission of tear and avoid rusting caused by leakage. The testing for tear performances of VCI packaging material is of Elmendorf method; and Labthink PARAM SLY-S1 Tearing Tester can be applied for this test. This tester is computer control, display and horizontal adjustment that guarantees reliable and accurate testing results; the unique ‘3-ring’analysis technology can help the operators with more direct analysis and evaluation.

4. VCI Seal Performance Testing

VCI (Volatile Corrosion Inhibition) packages, owing to strict requirements, its seal performance testing is quite important. Seal performance is defined as the characteristic of avoiding alien substance entering into or contents coming out of the package. Usual testing methods are as follows:

4.1 Underwater Decompression Method:

Labthink PARAM MFY-01 Leak Tester is on underwater decompression method according to GB/T 15171-94 Test Method for Leaks in Sealed Flexible Packages. Put a certain amount of distilled water into the vacuum chamber, and put the sealed vacuum container into the distilled water completely. Then, set the testing pressure and testing time. Usually, the vacuum degrees are 20, 30, 50 and 90 kPa, etc. Start testing. When the leak tester has reached a certain vacuum degree, stop vacuumizing and observe. The inner-out pressure difference of the specimen will cause inferior quality specimen leak so as to test leakage.

4.2 Pressured Testing Method

Labthink PARAM LSSD-01 Leak and Seal Strength Detector is of pressured testing method. Imposing high pressure gas into the vacuum container and test the pressure resistance, sealing degree and leak indexes so as to test integration and seal performance of the vacuum container.

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.

5. Barrier property testing

Barrier property is defined as the barrier performance of packaging material against liquid or gas permeable substances. The entry of oxygen would greatly increase the possibility of oxidization of metal contents, and the water vapor barrier property is of even more importance.

For gas barrier property, Labthink introduces PERME VAC series Gas Permeability Testers and Labthink PERME OX2/230 Oxygen Transmission Rate Test System that comply with relevant ASTM, ISO or GB standards (such as GB 1038 and GB 1037). For water vapor barrier property testing, Labthink PERME TSY-T series Water Vapor Permeability Testers and Labthink PERME W3/330 Water Vapor Transmission Rate Test System are applicable.

Further details please feel free to contact Shirley via:
TEL: 0086-531-85061080
FAX: 0086-531-85062108
EMAIL: trade2@labthink.cn
SKYPE: shirley-labthink
MSN: shirleywu_labthink@hotmail.com

More about Labthink(http://www.labthink.cn/en):
Labthink focusing on the laboratory testing instruments R&D and production and laboratory IT services, is dedicated to provide professional quality control solutions for customers in packaging, food, pharmaceutical, medical, daily chemistry, printing, adhesive, automotive, petrochemistry, bioscience, construction, new energy and other industries.

Customers worldwide(parts):

Labthink, think for you only!

SLY-S1 Tearing Tester complies with Elmendorf method, and is applicable in tearing resistance test of films, laminated films, foils, paper and paper boards.

Further details please feel free to contact Shirley via:
TEL: 0086-531-85061080
FAX: 0086-531-85062108
EMAIL: trade2@labthink.cn
SKYPE: shirley-labthink
MSN: shirleywu_labthink@hotmail.com

More about Labthink(http://www.labthink.cn/en):
Labthink focusing on the laboratory testing instruments R&D and production and laboratory IT services, is dedicated to provide professional quality control solutions for customers in packaging, food, pharmaceutical, medical, daily chemistry, printing, adhesive, automotive, petrochemistry, bioscience, construction, new energy and other industries.

Further details please feel free to contact Shirley via:
TEL: 0086-531-85061080
FAX: 0086-531-85062108
EMAIL: trade2@labthink.cn
SKYPE: shirley-labthink
MSN: shirleywu_labthink@hotmail.com

More about Labthink(http://www.labthink.cn/en):
Labthink focusing on the laboratory testing instruments R&D and production and laboratory IT services, is dedicated to provide professional quality control solutions for customers in packaging, food, pharmaceutical, medical, daily chemistry, printing, adhesive, automotive, petrochemistry, bioscience, construction, new energy and other industries.

More details  about Labthink, please feel free to contact Shirley Wu via:

Keywords: pet food packaging, barrier property, oxygen transmission rate, OTR, water vapor transmission rate, WVTR, mechanical property, differential pressure permeability tester, water vapor permeability tester, tensile tester, leak tester, seal strength, seal performance

With the development of living standards and the change of life styles, there have been great changes in recreation, consumption and emotional commitments. Thus, pet industry is surging. As pets are getting more and more popular, the quality control requirements for pet food are much stricter than before. Besides quality safety of pet food itself, the quality control and testing for its packaging has drawn the attention of pet food manufacturers. Hereafter, Labthink will make an introduction of barrier property, seal property and seal performance of pet food packaging, based on Labthink’s differential pressure gas transmission rate tester, water vapor transmission rate tester, tensile tester and leak tester.

1.Barrier Property Testing for Pet Food Packaging

Barrier property refers to the barrier functioning of vacuum packaging materials against gases and liquids. In other words, barrier property is the transmission performance of gases or liquids through vacuum packaging materials. Thus, barrier property testing includes water vapor transmission rate testing and gas transmission rate testing which can be subdivided into tests for detailed gases, such as oxygen, nitrogen and carbon dioxide, etc. Barrier property is the influential factor for shelf life product quality.

1.1 Oxygen Transmission Quantity of Pet Food Packaging

Pet food contains great amount of fat. If the packaging materials are inferior in oxygen barrier property, the product inside would have more contacts with oxygen. If so, fat of the pet food would be easily oxidized, and led to deterioration. As to pet food with aroma, the entering of air and exiting of aroma would influence the degree of satisfaction. Oxygen transmission rate should be tested according to GB/T 1038-2000, Plastics-Film and Sheeting-Determination of Gas Transmission-Differential-Pressure Method, and ISO 2556, Plastics -Determination of the Gas Transmission Rate of Films and Thin Sheets under Atmospheric Pressure -Manometric Method. Labthink VAC series of differential pressure gas transmission rate testers select best components with stable and reliable performance. The testers are superior to national and international standards. Besides gas transmission quantity measurement, this series of instruments have unique functions for determination of solubility coefficient, diffusion coefficient and permeation coefficient. Thus, fully meet the demands for barrier property analysis and optimization.

1.2Water Vapor Transmission Quantity of Pet Food Packaging

If packaging material has high water vapor transmission rate, the pet food inside would be easily damped and get lump. What’s worse is that germs would grow and endanger pets’ health. Water vapor transmission quantity should be tested according to GB/T 1037-1988, Test Method for Water Vapor Transmission of Plastic Film and Sheet –Cup Method, and ASTM E96-2000, Standard Test Methods for Water Vapor Transmission of Materials. Testing temperature is 38±0.6%, and relative humidity is 90±2%. Labthink PERME series of water vapor transmission rate testers is manufactured with highly precise weighing sensor to improve testing accuracy and shorten the determination period for permeation equilibrium effectively. Correspondingly, the whole testing process can be shortened. Meanwhile, temperature and humidity control technology has been combined with weighing technology, and with the help of computer control technology, automatic measurement can be realized with precise testing results and no external interference. Thus, the water vapor transmission rate testing for aluminum foil or other high barrier materials can be completely satisfied. There are several instrumental options, including single-cell, three-cell, six-cell or twelve-cell water vapor transmission rate testers.

2. Mechanical Property of Pet Food Packaging

The mechanical properties are the fundamental indexes for pet food product during production, transportation, shelf life and usage, etc., which include tensile strength, elongation, heat seal strength and tearing strength, etc.

2.1 Tensile Strength

Tensile strength is termed as the biggest strength value of pet food packaging material before breakage. Through testing, breakage resulting from packaging materials with insufficient tensile strength can be effectively observed. Labthink XLW series of auto tensile testers are specially designed for packaging industry. Main functions, including testing item selection, parameter selection and sampling process after testing are all in compliance with relevant standards. Operators only need to select testing items to complete corresponding tests. Reports with standard testing results can be produced without conversion. One tester can accomplish seven kinds of tests, including tests of tensile strength, elongation, peeling strength, heat seal strength and tearing, etc. With the help of menu interface, corresponding tests can be selected easily. Thus, this series of tensile testers are the most professional of the industry.

2.2 Heat seal strength

Heat seal strength is the analytical index for heat seal performance of the sealed place. Inferior heat seal strength would break to failure at the sealed place and result in leakage and contamination. Labhtink PARAM HST series of heat seal testers are precisely monitored by mini-computers, and are designed with human friendly interface. All the core components are world famous. With the help of the above mentioned tensile testers, precise heat seal measurement of pet food packaging can be accomplished. Several types are for selection.

2.3 Tearing Resistance Property

During storage and transportation, pet food packaging may be torn to breakage by external forces. Sufficient tearing resistance strength can reduce expansion of tearing, so as to avoid breakage. Besides, tearing strength is an important index to evaluate open easiness of pet food packaging for customers. Labthink PARAM SLY-S1 Tearing Tester applies computer control and display, as well as computer horizontal adjusting technologies, so as to guarantee accurate and reliable testing results. The innovative Three Circle technology can help users better analyze and evaluate. It’s of the highest automatic standard and precision globally.

3. Leak Testing of Pet Food Packaging

Leak and Seal performance of pet food package refers to the sealing reliability of such packaging. Through testing, the sealing performance of the whole package can be confirmed. There are several methods for seal performance testing, and the most common practice is by leak tester. For example, Labthink PARAM MFY-01 Leak Tester applies vacuum method to ,according to national standards, keep 0.5 min. at -30kpa, -50kpa, -70kpa and -90kpa respectively. As to vacuum package, it’s necessary to observe the recovery of sample after testing.

This method is a qualitative eye observation. As to quantitative leak and seal testing, positive method instrument can be applied, such as Labthink PARAM LSSD-01 Leak and Seal Strength Tester.

When the abovementioned properties are qualified, there are other necessary indexes to guarantee product quality within shelf life period. For more information, please visit: www.labthink.cn, or contact Shirley Wu via:

TEL: 0086-531-85061080

FAX: 0086-531-85062108

EMAIL: trade2@labthink.cn

SKYPE: shirley-labthink

MSN: shirleywu_labthink@hotmail.com

• Labthink at CHINAPLAS 2011: Booth S21, Hall 1.1

Labthink will participate Chinaplas 2011 at Booth S21 Hall 1.1 during 17~20, May in Guangzhou (China Import & Export Fair Pazhou Complex). We will bring new technology and products of Packaging Quality Control Testing Techniques to each visitor.

Labthink is willing to further strengthen exchanges with professionals of the plastic and rubber industry, and brings more professional information and services with her profound testing control techniques. Labthink(Booth S21, Hall 1.1), inviting and await for your presence respectfully.

For more details, please feel free to visit http://www.labthink.cn

or contact Shirley Wu via:
EMAIL: trade2@labthink.cn
SKYPE: shirley-labthink
MSN: shirleywu_labthink@hotmail.com

More about Labthink:

Labthink focusing on the laboratory testing instruments R&D and production and laboratory IT services, is dedicated to provide professional quality control solutions for customers in packaging, food, pharmaceutical, medical, daily chemistry, printing, adhesive, automotive, petrochemistry, bioscience, construction, new energy and other industries.

Labthink is an international enterprise headquartered in Jinan, China with administrative, sales and service branches in Shanghai, Guangzhou,Brussels and etc.,covering over 40 countries and regions.

More about CHINAPLAS:

CHINAPLAS –Asia’s No.1 International Plastics and Rubber Trade Fair

Accompanying the growth of China’s plastics and rubber industries for nearly 30 years, CHINAPLAS has become a distinguished meeting and business platform for these industries and has also largely contributed to their prosperous development. At present, CHINAPLAS is not only the largest plastics and rubber trade fair in Asia, but also widely recognized by the industry as the 3rd most influential exhibition in the world. Its significance is surpassed only by K Fair in Germany, the world’s premier plastics and rubber trade fair, and NPE in USA, the second largest plastics fair in the world.