GB/T 5472-1985 Test method for flow curing of thermosetting molding compounds

GB/T 5472-1985 Test method for flow curing of thermosetting molding compounds GB/T5472-1985 Standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Test method for, rectangular'tlow cere propertiesof theraosettleg moblding compiundsThis standard is applicable to the determination of flow curing properties of thermosetting molding compounds with a large range of flow length variations. This method can be used to control the inspection of the stability of molding properties of molding compounds. 1 Definition
1.1 Flow length: The length of the sample flowing in the rectangular flow channel cavity under specified conditions. 1.2 Flow time: The time from the sample being subjected to a specified pressure to the loss of fluidity. UDC 678.5/.8.072
GB5472—86
1.3 Flow velocity: The flow velocity is divided into average flow velocity and stage flow velocity. The former is the ratio of the total flow length of the sample to its corresponding flow time, and the latter is the slope of the curve at different stages in the flow curve of the entire process of the sample flow state. Unpreheated samples generally have three stages: melt flow, flow and solidification.
1.4 Residual fluidity: The fluidity of the sample after being preheated under specified conditions or pre-plasticized in a material tube. 2 Principle
This method measures the flow state of thermosetting molding materials in a rectangular flow channel mold cavity under specified temperature and pressure, and simultaneously tracks and depicts the flow curve. In this way, the flow length and flow time of the sample can be measured and the flow velocity can be calculated. 3 Equipment
3.1.1 The mold flow channel size is 4±0.03mm×10±0.05mm×172±1.00mim, and its structure is shown in Figure 1. 3.1.2 The hardness of the mold working surface should be greater than Hc50, and the surface roughness of the mold flow channel is V10. 3.1.8 The mold outer dimensions and its taper should match the tapered hole of the heating sleeve: National Bureau of Standards 19B5-10-17 Issued
1986-07-01 Implementation
.2 Press
GB 5472-8
Figure 1 Mold diagram
3.2.1 The press capacity is 98kN (10000kgf), with two piston hydraulic cylinders, capable of cold pressing and hot pressing. 3.2.2 The press can increase the pressure evenly and can apply the specified pressure to the sample with a deviation of ±0.2MPa. 3.2.8 The sample should withstand a reverse pressure of 1MPa (10.2kgl/cm2) during the flow process. .8 Meter
Partial immersion mercury thermometer with a graduation value of 1K and a measuring range from room temperature to 473K (200℃), or a thermocouple or thermistor thermometer with the same graduation value and measuring range. The thermometer should be calibrated by the metering department. 8.4 Heating device
Use oil bath heating or electric heating that can control the mold temperature deviation to ±1K and can be heated to 473K. 3.5 Recording system
A recording device that can depict the relationship curve between flow length and flow time. 3.6 Day and a half
Weighing 100g, sensitivity 0.1g. wwW.bzxz.Net
.7 Ruler
Measurement length 200mm, graduation value -1mm.
3.8 Stopwatch
4 Sample
4.1 Sampling shall be carried out in accordance with the provisions of Chapters 3, 4 and 5 of GB2547-81 "Plastic Resin Sampling Method". 4.2 The amount of material added to each mold sample is the weight of the sample after filling the mold cavity during molding multiplied by the excess material coefficient 1.1. Note: 10g is taken for each section of phenolic and amino molding plastics. 5 Test conditions
GB B472-8
5.1 The temperature and pressure listed in the following table are recommended for different types of molding plastics. Varieties
Phenolic molding compound
Gum aldehyde molding compound
Melamine plastic
C.2 Selection of test pressure
Mold margin,.()
438 ±1(185 ±1)
423 ±1(150 ±1)
428 ±1(155 ±1)
Test pressure, MP
6.912.7 19.6
6.9 10.8 14,7
6.9 10.8 14.7
Firstly, use the mid-range pressure for the test. If the flow length of the sample exceeds 150Ⅱm, use the low-range pressure for the test. If it is less than 50mm, use the high-range pressure for the test.
Note: ①When the flow length of the sample is still more than 150mm at low pressure, the sample can be preheated or pre-plasticized to measure its residual fluidity. ②When using low pressure, the pressure should be calibrated with a standard dynamometer. @Under special circumstances, the test can be carried out according to the product standard or other overflow and pressure agreed upon by the supplier and the belt. B Test steps
.1 Install the mold according to Figure 2, so that the temperature of the mold and the pressure head is constant within the specified range for at least 15 minutes before the test can be carried out. .2Automatic hot pressing piston cylinder, adjust the pressure to the specified value. Raw class
Recording pen
Material damage rod
Throat screw plate
Punching head
Figure 2 Short-circuit flow diagram
Heating
Protective layer
Pressure
GB 5472-85
6.3·Weigh the sample according to 4.2, start the cold pressing piston cylinder, and preform the sample into a Φ30mm round ingot with a pressure of 15~30MPa. 6.4 Place the net ingot sample accurately on the heated pressing head and immediately start the press. Within 205, increase the pressure to the specified value and observe the flow curve traced by the recording pen.
.8 When the recording pen indicates that the flow performance of the sample disappears, stop the operation of the recording system. 6.6 Before the specimen is demolded, it is necessary to maintain a certain time (generally 0.5~2.0min) before removing the pressure and lowering the pressure head. Use the ejector rod to push the specimen from top to bottom, cool it to room temperature, and measure the length of the rectangular part with a ruler (accurate to 1mm). 6.7 Repeat the operations from 6.3 to 6.6 until the difference between the length of 3 consecutive specimens and their arithmetic mean does not exceed 5%. In the past, it was recommended to use the same type of plastic for each pair of molds. If a pair of molds is used to press molding materials of different types and brands, in order to purify the mold and obtain accurate results, the first few specimens should be discarded. 7 Results display
T.1 Flow length - read from the curve or directly measure the length of the short part of the specimen with a ruler, expressed in m. T.2 Flow time t - read from the curve or use a stopwatch from the time the sample reaches the specified pressure to the time the flow stops, expressed in s. 7.3 Each test result is displayed as the arithmetic mean of 3 measurements; take three significant figures. Note: ①). In order to understand the flow state of the whole release, the following formula can be used to calculate the stage flow velocity, Wi
-stage flow velocity, mm/s
Where: V
1.-Flow length of different slope stages on the curve, mm,-Corresponding flow time of different slope stages on the curve, "②The average moving speed is calculated according to the following formula:
Formula: -
Average fluidity, mf75,
L-Flow length, mm,
t-Flow time, s:
③The residual fluidity of the sample after preheating or preplasticization can be expressed according to the above results. Test report
Indicate the reference to this national standard
The sample name, brand, batch number, production date and other detailed characteristics of the sample, b,
Test temperature and pressure!
Abnormal phenomena during the test, such as demoulding and appearance, individual values ​​and arithmetic mean of the test results, tester and date.
Xie Jia explained:
This standard was proposed by the Ministry of Chemical Industry of the People's Republic of China and is technically managed by the Physical and Mechanical Methods Branch of the National Plastics Standardization Technical Committee.
This standard was drafted by Chongqing Synthetic Chemical Factory. The main drafter of this standard is Chen Guangming
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