CN-117247629-B - PP (polypropylene) base standard sample for detecting ball indentation hardness and preparation method thereof

Abstract

The invention relates to a PP (polypropylene) base standard sample for detecting ball indentation hardness and a preparation method thereof, belonging to the technical field of plastic physical detection. The PP-based standard sample for detecting the indentation hardness of the ball comprises, by weight, 50-80 parts of polypropylene resin, 10-50 parts of polystyrene resin, 5-40 parts of filler, 1-10 parts of compatilizer, 0.1-5 parts of antioxidant and 0.1-1 part of processing aid, wherein the melt flow rate of the polypropylene resin is 14-16g/10min under the test condition of 200 ℃ and 5kg, and the filler is at least one of nano calcium carbonate, barium sulfate or nylon glass fiber mixture. The invention uses polypropylene resin as a base material, and selects specific types and contents of filler and compatilizer, so that the prepared PP standard sample for detecting ball indentation hardness has good uniformity and stability, has wide application range, and can meet the requirements of two load (132N and 358N) test conditions in the standard.

Inventors

• WANG YUQIONG
• PANG CHENGHUAN
• LI GUIYANG
• YUAN TAO
• LI WEILING
• WU BO
• CHEN PINGXU
• NING HONGTAO
• YE NANBIAO

Assignees

• 国高材高分子材料产业创新中心有限公司

Dates

Publication Date

20260505

Application Date

20230922

Claims (9)

1. 1. The PP-based standard sample for detecting the ball indentation hardness is characterized by comprising, by weight, 50-80 parts of polypropylene resin, 10-50 parts of polystyrene resin, 5-40 parts of filler, 1-10 parts of compatilizer, 0.1-5 parts of antioxidant and 0.1-1 part of processing aid, wherein the polypropylene resin has a melt flow rate of 14-16g/10min under the test condition of 200 ℃ and 5kg, the filler is at least one of nano calcium carbonate, barium sulfate or nylon glass fiber mixture, and the polystyrene resin has a melt flow rate of 4.4-9.8 g/10min under the load of 5kg at 200 ℃.
2. 2. The PP-based standard sample for detecting ball indentation hardness of claim 1 wherein the polypropylene resin is a copolymerized polypropylene resin.
3. 3. The PP-based standard sample for detecting ball indentation hardness of claim 1 wherein the nylon glass fiber mixture comprises nylon resin and glass fiber, the nylon resin in the nylon glass fiber mixture having a number average molecular weight of 15000-36000, and the glass fiber having an average length of 0.2-0.6mm.
4. 4. The PP-based standard sample for detecting ball indentation hardness of claim 3, wherein the weight ratio of nylon resin to glass fiber in the nylon glass fiber mixture is 2-4:1.
5. 5. The PP-based standard sample for detecting ball indentation hardness of claim 1 wherein the compatibilizer is maleic anhydride multi-monomer grafted polypropylene.
6. 6. The PP-based standard sample for detecting ball indentation hardness of claim 1 wherein the antioxidant is at least one of a hindered phenolic antioxidant or a phosphite antioxidant.
7. 7. The PP-based standard sample for detecting ball indentation hardness of claim 1 wherein the processing aid comprises a dispersant and a lubricant.
8. 8. The method for preparing a PP-based standard sample for detecting ball indentation hardness according to any one of claims 1 to 7, characterized by comprising the steps of: (1) Sequentially feeding polypropylene resin, polystyrene resin, filler, compatilizer, antioxidant and processing aid into a high-speed mixer for mixing and stirring, extruding and granulating after melt mixing, and drying to obtain PP granules; (2) And (3) carrying out injection molding on the PP granules to obtain the PP standard sample for detecting the indentation hardness of the ball.
9. 9. The method for preparing the PP standard sample for detecting the hardness of the ball indentation according to claim 8, wherein the device for extrusion granulation after melt mixing is a double-screw extruder, the length-diameter ratio of the double-screw extruder is 25-50:1, the rotation speed of a host machine is 300-600rpm, the temperature of a screw cylinder is 170-260 ℃, the temperature of injection molding is 190-260 ℃, the pressure is 55-60Bar, and the speed is 25-30%.

Description

PP (polypropylene) base standard sample for detecting ball indentation hardness and preparation method thereof Technical Field The invention belongs to the technical field of plastic physical detection, and particularly relates to a PP (polypropylene) base standard sample for detecting ball indentation hardness and a preparation method thereof. Background The ball indentation hardness is a magnitude standard for evaluating the plastic hardness, a steel ball indentation with a certain diameter is pressed into the surface of a plastic sample under the sequential action of initial test force and main test force, and after the steel ball indentation is kept for a certain time, the indentation depth is measured so as to determine the whole process of the sample hardness. Ball indentation hardness testing is primarily used to develop, quality control, and provide data for acceptance and rejection by product standards. Provides a reliable magnitude standard for evaluating the hardness of plastics in the industries of chemical industry, light industry, aerospace, automobiles and the like in China, and also provides authoritative arbitration basis for trade settlement and quality certification. The ball indentation hardness tester is a device for evaluating the hardness performance of materials, and in order to obtain accurate test results, it is important to ensure the test accuracy of a tester. Therefore, not only the calibration and period check of the testing machine are required regularly, but also the state of the assessment equipment and the operation of a standardization personnel are required to be supervised at any time. In order to improve the accuracy of the test result, a laboratory generally optimizes the detection equipment or the operation flow, but cannot completely evaluate the accuracy of the test result, and has a certain limitation. The standard substance of the ball indentation hardness is commonly metal at present, for example, a manufacturing process of a plastic ball indentation hardness standard block which can be effectively used for testing the hardness mechanical property of a high polymer material is provided in a patent manufacturing process of a plastic ball indentation hardness standard block, an industrial pure aluminum plate meeting relevant conditions is selected as a base material, and then the metal ball indentation hardness standard block with more uniformity is obtained through smelting and casting. The metal standard substance has higher requirements on the storage environment, is only suitable for one test load, has higher purchase cost of the metal ball indentation hardness standard sample, and has a service life of one year. The ball indentation hardness testing process needs to confirm the equipment state and personnel operation, so that the accuracy of a testing result can be ensured, the laboratory can not identify abnormality in advance at present, and only when abnormal complaints occur, the abnormal complaints are checked and verified step by step through the operation of each part of the equipment and the personnel, so that the steps are complex, and the workload is high. The test sample is tested regularly to verify the equipment and standardize personnel operation, so that the operation is simple, problems existing in the equipment and errors of personnel operation can be found in time, the test sample can be used for tracing reasons of abnormal tests, and the test sample can be used as an effective means for monitoring the state of daily equipment and personnel. However, the existing market lacks plastic ball indentation hardness standard samples, the metal ball indentation hardness standard samples have the defects of high requirements on storage environment, high cost and the like, and the existing market only has standard samples used in one load state, and lacks the standard samples which can be used for checking and verifying equipment in two load states before testing and evaluating the consistency of detection results among laboratories. Therefore, a standard sample with uniform and stable targets needs to be prepared, and the standard sample can be used for capability verification and comparison among laboratories, accuracy verification of a laboratory internal detection method, stability verification of a detection instrument, quality control management, uncertainty assessment, capability assessment of detection personnel and the like. Disclosure of Invention The invention aims to overcome the defects of the prior art and provide a PP (polypropylene) base standard sample for detecting the hardness of ball indentation and a preparation method thereof. The PP standard sample for detecting the ball indentation hardness comprises, by weight, 50-80 parts of polypropylene resin, 10-50 parts of polystyrene resin, 5-40 parts of filler, 1-10 parts of compatilizer, 0.1-5 parts of antioxidant and 0.1-1 part of processing aid, wherein the polypropylene resin has a m