Abstract: The wrapping film is compactly and fixedly bundled into a unit by means of the superior winding force and retracting property of the film, and the product is free from looseness and separation even under adverse conditions. Therefore, the stretch film should have good puncture performance and transverse tear strength to ensure that the film does not break when it encounters sharp objects at high draw ratio. In this paper, taking the wrapping film as an example, the XLW (EC) intelligent electronic tensile testing machine is used to test the puncture resistance of the wrapping film to verify whether the wrapping film can effectively resist the puncture of the corner of the cargo. At the same time, the principle and test procedure of the test are introduced. The industry provides a reference for monitoring the puncture performance of the stretch film. Key words: stretch film, stretch film, puncture resistance, puncture resistance, puncture strength, electronic tensile testing machine 1 , meaning Stretch film, also known as stretch film, shrink film. The early stretch film is mostly blown film. At present, the stretch film is mainly produced by the casting method. This is because the stretch film produced by the casting line has the advantages of uniform thickness and high transparency, and can be applied to the requirement of high-rate pre-stretching. Since the single-layer casting can not achieve single-sided adhesion, the application field is limited, so its application is not as wide as that of the three-layer casting process, and the high-quality wrapping film should have high transparency, high longitudinal elongation and high yield point. The characteristics of high transverse tear strength and good puncture performance. Puncture resistance is a guiding indicator for assessing the ability of a package to resist the penetration of sharp hard objects. In the long-term contact with the packaging, if the product contains a sharp and hard material, it is easy to produce a strong puncture effect on the wound film. If the puncture resistance of the stretched film is poor, it is easy to be damaged by the puncture of the sharp object, causing the product or the cargo to be loosely separated and unable to play a protective role. This is also the reason why the wrapping film package should have high puncture resistance. Figure 1 Stretch film 2 , the implementation of standards The domestic test method for the puncture resistance of packaging is mainly based on the relevant puncture performance test part of GB/T 21302-2007 "General Rules for Composite Film Bags for Packaging". 3 , test samples Stretch film provided by a company. 4 , test equipment Jinan Languang Electromechanical Technology Co., Ltd. independently developed and designed the XLW (EC) intelligent electronic tensile testing machine. Figure 2 XLW (EC) intelligent electronic tensile testing machine 4.1 Test principle The sample is fixed on the fixture, and the puncture needle attached to the movable chuck punctures the sample, and the force value sensor and the displacement sensor located on the movable chuck are used to test and record the change of the force value during the puncture. 4.2 Scope of application (1) This equipment is specialized in plastic film, composite materials, flexible packaging materials, plastic hoses, adhesives, adhesive tapes, stickers, medical patches, release papers, protective films, composite covers, metal Puncture, tensile, peeling, deformation, tearing, heat sealing, bonding, opening force, low speed unwinding force, peeling force, etc. of foil, separator, back sheet material, non-woven fabric, rubber, paper, etc. The test, such as the puncture force of the infusion bag cover, the tearing force of the oral liquid cover, the puncture/pull force, the puncture/pull force of the soft rubber bottle stopper. (2) This equipment meets many national and international standards, such as GB/T 21302, GB 8808, GB/T 1040.1, GB/T 1040.2, GB/T 1040.3, GB/T 1040. 4, GB/T 1040.5, GB /T 4850, GB/T 12914, GB/T 17200, GB/T 16578.1, GB/T 7122, GB/T 2790, GB/T 2791, GB/T 2792, GB/T 17590, ISO 37, ASTM E4, ASTM D882, ASTM D1938, ASTM D3330, ASTM F88, ASTM F904, JIS P8113, QB/T 2358, QB/T 1130, and the like. 4.3 Equipment parameters 5 , the test process (1) Cut 5 pieces of the sample with a diameter of 100 mm from the wound film sample using a sampler. (2) Fix the specimen to the special jig for the puncture test and fix the clamp on the test equipment. (3) Set test parameters such as test speed and sample thickness. (4) Click the Start Test option and the test begins. The device automatically calculates and displays the test results of the end of the Zui. 6 , test results The average puncture resistance of the wound film samples tested in this paper was 1.46 N. 7 , conclusion XLW (EC) intelligent electronic tensile testing machine is a professional instrument for testing the puncture resistance, tensile strength, peel strength and heat seal strength of plastic flexible packaging. It can truly reflect the puncture resistance of the sample and its operation is simple. High test accuracy. Jinan Languang has been committed to providing professional testing services and testing equipment to customers all over the world. Over the years, it has provided thousands of packaging anti-puncture monitoring solutions to customers around the world, providing customers with reliable data support. Learn more about packaging barrier, mechanical properties and other related testing equipment, Jinan Languang Consulting. Nucleic Acid (DNA/RNA) Extraction Kit
1. Introduction Nucleic Acid Extraction Reagent Kit,Nucleic Acid Extraction Kit,Covid-19 Nucleic Acid Extraction Reagents,Nucleic Acid Test Kits Jilin Sinoscience Technology Co. LTD , https://www.jilinsinoscience.com
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Notice:
1. The carrier RNA solid must be dissolved in Nuclease Free Water to 1µg/µl before use, and vortex to dissolve. Store in aliquots at -70°C. If you need to store it at -20℃ for a long time, please repackage it according to the number of times of use.
2. Dissolve Proteinase K (20mg/ml): Add Proteinase Dissolve Buffer to dissolve Proteinase K to a final concentration of 20mg/ml. Proteinase K dry powder can be stored at 2-8°C for one year, but dissolved Proteinase K must be stored in aliquots at -20°C. Repeated freezing and thawing of Proteinase K can affect its activity.
3. Buffer VHB must be diluted with 14 ml absolute ethanol before use and stored at room temperature.
4. Buffer RW2 must be diluted with 80 ml of absolute ethanol before use and stored at room temperature.
3. Shelf life
Except for Proteinase K and Carrier RNA, other components of this product can be stored at room temperature (15-25°C) for 12 months, and should be stored at 2-8°C for long-term storage. Proteinase K and Carrier RNA dry powder are transported at room temperature. Please store at -20°C after receiving the test product, and store at -20°C after dissolving.
Stretch film anti-puncture performance testing program