ISO 812 Low Temperature Brittleness Multifunctional Testing Machine Brittleness Temperature Tester for Rubber and Plastic ASTM D 746

• Customization: Available
• After-sales Service: Online
• Warranty: 1 Year
• Model NO.: DWB-80
• Display: Digital
• Control: Computer Control
• Weight: 0-100Kg
• Power Source: AC220V
• Transport Package: Wooden Package
• Trademark: Lonroy
• Origin: China
• HS Code: 9024800000
• Production Capacity: 200

Product Description

ISO 812 Low temperature Brittleness multifunctional testing machine Brittleness Temperature Tester for Rubber and Plastic ASTM D 746
1. Application
The low temperature embrittlement tester for plastics and rubber is used to measure the highest temperature when the rubber sample is damaged by impact under specified conditions, that is, the brittle temperature. It can make comparative identification of the performance of non-rigid plastics and other elastic materials under low temperature conditions. The advantages and disadvantages of temperature and low temperature performance. Therefore, it is indispensable in scientific research materials and production process control. This instrument is designed according to national standards such as GB/T 15256-2014 "Determination of Low Temperature Brittleness of Vulcanized Rubber (Multiple Sample Method)" and GB/T 5470-2008 Plastic Impact Brittleness Temperature Test Method. It is the latest developed compressor refrigeration equipment. This equipment adopts cascade compressor refrigeration technology, uses the principle of heat balance and circulating stirring method to achieve automatic uniform cooling and constant temperature of the sample.

ISO 812 Low temperature Brittleness multifunctional testing machine Brittleness Temperature Tester for Rubber and Plastic ASTM D 746
2. Meet the following standards
2.1. GB/T 5470-2008 Plastics - Determination of brittle temperature by impact method
2.2. GB/T 15256-2014 Determination of low temperature brittleness of vulcanized rubber (multiple specimen method)
2.3. HG/T 2-162-1965 Plastics low temperature impact compression test method
2.4. ISO 812-2006 Determination of low temperature brittleness of vulcanized rubber or thermoplastic rubber
2.5. ASTM D 746-2007 Test method for determination of brittle temperature of plastics and elastic materials by impact method
2.6. ASTM D 2137-1994 Test method for rubber properties. Brittle point of flexible polymers and coated fabrics
2.7. JIS K 7216-1980 Test method for brittle temperature of plastics
ISO 812 Low temperature Brittleness multifunctional testing machine Brittleness Temperature Tester for Rubber and Plastic ASTM D 746
3. Technical parameters

Temperature control range	-80ºC (room temperature ≤25ºC)(ethanol is generally used as heat transfer medium)
Impact speed	2m/s±0.2m/s

ISO 812 Low temperature Brittleness multifunctional testing machine Brittleness Temperature Tester for Rubber and Plastic ASTM D 746
4. Structural principle
This equipment consists of the main body of the refrigeration compressor, heating device, electronic control box, cooling tank, cooling medium circulation system, automatic alarm device and other parts. After starting the refrigeration switch, the compressor starts to work and the refrigeration system enters the formal working state. The refrigeration compressor works continuously. When it approaches the set temperature, the heating device in the cooling tank starts to provide heat in proportion to balance the excess cold generated by the refrigeration system to achieve the purpose of constant temperature. Stirring can make the cooling medium in the cooling tank circulate continuously to make the temperature uniform.
Plastic low temperature brittleness test
4.1. Sample holder
A sample can hold 15 pieces at a time
4.2. Impact device
The impact device consists of an impact hammer and a self-locking mechanism.
4.3. Impact device
A sample:
a) The punch radius is 1.6±0.1mm;
b) The jaw radius is 4.0±0.1mm;
c) The gap between the punch centerline and the fixture is 3.6±0.1mm;
d) The gap between the outer side of the punch and the fixture is 2.0±0.1mm
B sample:
a) The radius of the punch is 1.6±0.1mm;
b) The gap between the center line of the punch and the fixture is 7.87±0.25mm;
c) The gap between the outer side of the punch and the fixture is 6.35±0.25mm
4.4 Rubber low temperature brittleness test
The sample holder should be hard and designed to clamp the sample in a cantilever beam style. Each sample should be clamped stably and securely without deformation of the holder. The impact head moves in a direction perpendicular to the upper surface of the sample and impacts the sample at a test line speed of 2.0±0.2m/s. The moving speed after impact remains unchanged within a range of at least 6mm. In order to achieve the specified impact speed during and after the impact, care should be taken to ensure sufficient impact energy. Each sample requires at least 3.0J impact energy. Therefore, it is necessary to limit the number of impact samples for each test.
4.2. Sample holder
Five samples can be clamped at a time.
4.3. Impact device
The impact device consists of an impact hammer and a self-locking mechanism.
4.4. Impactor
a) The radius of the punch is 1.6±0.1mm;
b) The gap between the center line of the punch and the fixture is 8±0.3mm;
c) The gap between the outer side of the punch and the fixture is 6.4±0.3mm
ISO 812 Low temperature Brittleness multifunctional testing machine Brittleness Temperature Tester for Rubber and Plastic ASTM D 746
5. Usage
5.1. Inject the freezing medium (generally industrial ethanol with a purity of 99.7%) into the cold well. The injection amount should ensure that the distance from the lower end of the clamp to the liquid surface is 75±10mm.
5.2. Turn on the power, and the temperature controller and timer display lights will light up. Set the digital temperature control to the required temperature value; (Press the temperature setting key (set) for 0.5 seconds and release it to enter the temperature setting state. Press the plus or minus key and the movement key to set the temperature. After setting the required temperature, press the set key for 0.5 seconds to return to the normal operating state and memorize the parameter value. At this time, the equipment starts working;)
5.3. Clamp the sample vertically on the clamp. The clamp should not be too tight or too loose to prevent the sample from deforming or falling off.
5.4. Press the clamp to start freezing the sample, and start the timing control switch at the same time. When the temperature reaches the test temperature, keep the temperature constant for 15 minutes. The sample freezing time is specified as 5.0±0.5min. During the freezing of the sample, the temperature fluctuation of the freezing medium shall not exceed ±0.5ºC.
5.5. Pull the self-locking handle of the impact hammer, and the impact hammer falls freely under the action of gravity to impact the sample.
5.6. Remove the sample, bend the sample to 180° in the impact direction, and carefully observe whether there is any damage.
5.7. After the sample is impacted (each sample is only allowed to be impacted once), if there is any damage, the temperature of the freezing medium should be increased, otherwise its temperature should be lowered and the test should continue. Through repeated tests, determine the lowest temperature at which at least two samples are not damaged and the highest temperature at which at least one sample is damaged. If the difference between these two results is no more than 1ºC, the test is over.
ISO 812 Low temperature Brittleness multifunctional testing machine Brittleness Temperature Tester for Rubber and Plastic ASTM D 746
6. Test standards
6.1. Specifications
The length of the sample is 31.75±6.35mm, the width is 6.35±0.51mm, and the thickness is 1.91±0.13mm
6.2. Requirements
The surface of the sample should be smooth, free of foreign impurities and damage. The finished product should be cut to the corresponding size after grinding.
ISO 812 Low temperature Brittleness multifunctional testing machine Brittleness Temperature Tester for Rubber and Plastic ASTM D 746
7. Precautions
1. The cooling cycle cannot be cut off during the test, otherwise it will produce a non-refrigeration effect.
2. The thrust has been adjusted before leaving the factory and cannot be changed arbitrarily.
8. Quality assurance
The three-guarantee period of the equipment is one year from the date of formal delivery. During the three-guarantee period, the supplier will provide free repair services for all kinds of equipment failures in a timely manner. For all kinds of parts damaged by non-human factors, they will be replaced free of charge in a timely manner. If the equipment fails during use outside the warranty period, the supplier will promptly provide service to the ordering party and actively assist the ordering party to complete the maintenance task.
ISO 812 Low temperature Brittleness multifunctional testing machine Brittleness Temperature Tester for Rubber and Plastic ASTM D 746
8.Daily maintenance and precautions
1. Keep the equipment clean, strictly prohibit violent vibration and collision, and do not disassemble it at will. The tilt during transportation shall not exceed 45°.
2. The equipment must not be placed near high temperature or sunlight.
3. The electric control box must be moisture-proof and no liquid is allowed to enter.
4. Before starting the machine, make sure that the ground wire is properly connected to ensure safety; the power plug must be firmly plugged in to prevent looseness and cause instant shutdown and burn the compressor.
5. In the event of a power outage or failure causing shutdown, the restart interval must be greater than 30 minutes; when the room temperature exceeds 25°C, the restart interval must be greater than 60 minutes.
6. If the compressor cannot be started, works intermittently, or suddenly stops after working for a period of time, please shut down immediately and first check whether the power supply voltage is between 220V and 240V. If not, please repair the grid voltage or configure an AC voltage stabilizer to make it reach the normal working voltage value of this instrument.
7. Secondly, pay attention to the ambient temperature. This cryostat is recommended to be used at an ambient temperature below 25°C. Because the ambient temperature is too high, the pressure in the compressor system is too high. If the power grid capacity is insufficient or the voltage is low, it is difficult to start at this time, and the interval between two starts is much longer.
8. The sample loaded in the cooling tank should be wiped clean, and foreign objects such as iron filings should not be brought into the cooling tank to avoid blocking the circulation pipeline.
9. Before using again, the amount of cooling medium in the tank should be checked. The appropriate amount of cooling medium should be enough to cover the evaporator copper tube (otherwise, the evaporator is prone to frost, which increases the water content of the cooling medium) and reach the height of the stirring circulation top (otherwise the circulation is not smooth). If the operating temperature is low, please pay attention to the change in the volume of the cooling medium caused by the temperature, and the cooling medium should be replenished in time.
10. The cooling medium can be released after each use.
11. The cooling medium should be replaced regularly to reduce the impurity content and water content as much as possible, otherwise the circulation is poor and affects the refrigeration effect and temperature accuracy.
12. When pressing the "cooling" switch, make sure that the cooling tank is filled with cooling medium, and do not take the temperature sensor out of the cooling tank.

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