XNR 400A Melt Flow Rate Tester

XNR—400A Melt Flow Rate Tester

Instruction Manual

CHENGDE JINHE EQUIPENT MANUFACTURING CO, LTD

1Foreword

2Major Technical Index and Operating Conditions

2.1Major Technical Index

2.1.1Extruding and Discharging Part

2.1.2Test Load

2.1.3Temperature Control

2.1.4Appearance

2.2Working Conditions

3Principles and Structure

3.1Main Principle

3.2Apparatus Structure

3.2.1Testing System

3.2.2Controlling System

3.2.3Automatic Cutting Device

3.2.4Load

4Preparation and Parameters Selection

4.1Equipment Placement

4.2Sample Preparation

4.3Testing Conditions

4.4Cutting Time

5Function of the Keys

5.1Heat

5.2Test

5.3Cut

5.4Setting

5.5Calculation

5.6Query

5.7Delete

5.8Back

5.9Increase/ Upward

5.10Decrease/ Downward

5.11Stop

5.12Confirm

6Usage Directions

6.1Tests Preparation

6.2Starting Up

6.3Set Testing Parameters

6.4MFR Method

6.4.1Heat

6.4.2Test

6.4.3Weigh and Calculate

6.4.4Query and Print out Results

7Indexer Rectification

Temperature Rectification Method

8Attentions

1Foreword

This XNR-400C melt flow rate indexer is designed and manufactured according to standards like GB/T 3682-2000 Determination of the Melt Mass-Flow Rate and the Melt Volume-Flow Rate of Thermoplastics and ISO 1133-2005 Plastics-Determination of the Melt Mass-Flow Rate (MFR) and the Melt Volume-Flow Rate (MVR), the main application of which is to measure mass flow rate. The functions of this instrument are measuring melt-mass flow rate manually, measuring melt mass-flow and volume-flow rate automatically, and measuring melt density. It is equipped with automatic cutting device, a micro printer to print testing results, a FLASH memory which is able to store results of 20 manual tests, 20 automatic tests and density data of 50 kinds of melt at different temperature or of different material.

This indexer is featured as simple structure, accurate measurement, stable and reliable performance and easy to use. It can be applied to tests of not only engineering plastic at high melting temperature like polycarbonate, fluoroplastics and nylon, but that at low melting temperature like polythene,polypropylene, polystyrene and ABS resin. As a result, XNR-400C melt flow rate indexer is widely used in plastic production and petrochemical industry, and related universities, scientific research departments and commodities inspection authorities as well.

2Major Technical Index and Operating Conditions

2.1Major Technical Index

2.1.1Extruding and Discharging Part

Outlet diameter:Φ2.095±0.005 mm

Outlet length: 8.000±0.025mm

Cylinder diameter: Φ9.550±0.025 mm

Cylinder inner length: 152±0.1 mm

Pistonrodheaddiameter：Φ9.475±0.015mm

Piston rod head length: 6.350±0.100mm

2.1.2Test Load

Test load is realized through different combinations of a set of weights and a piston rod. There are eight levels these combinations can provide as nominal load that is necessary for testing:

Level 1: 0.325kg = (piston rod +weight tray +insulation cover +1# weight) =3.187N

Level 2: 1.200kg= (0.325kg +2# 0.875kg weight) =11.77N

Level 3: 2.160kg= (0.325kg +3# 1.835kg weight) =21.18N

Level 4: 3.800kg= (0.325kg +4# 3.475kg weight) =37.26N

Level 5: 5.000kg= (0.325kg +5# 4.675kg weight) =49.03N

Level 6: 10.000kg= (0.325kg +5# 4.675kg weight +6# 5.000kg weight) =98.07N

Level 7: 12.500kg= (0.325kg+5# 4.675kg weight +6# 5.000kg weight+7# 2.500kg weight)=122.58N

Level 8: 21.600kg= (0.325kg +2# 0.875kg weight +3# 1.835kg weight +4# 3.475kg weight +5# 4.675kg weight +6# 5.000 kg weight +7# 2.500kg weight +8# 2.915 kg weight)=211.82N

2.1.3Temperature Control

Controllable range: ambient temperature～400℃

Temperature fluctuation: ≤±0.1℃

8h drift: ≤0.1℃

Temperature gradient: ≤0.5℃

Resolution ratio: 0.1℃

Error correction: two points linear correction

Temperature recovery time: ≤4min

2.1.4Appearance

Length 290×width 410×height 630（mm）

2.2Working Conditions

Ambient temperature 10℃—35℃, no vibration and corrosive media around

Installed correctly on a stable basis and adjusted to level

No influence of strong magnetic field and no strong air convection when working.

Supply voltage: AC220V, frequency 50Hz 5A, fluctuation range of the supply voltage no more than ±10%

3Principles and Structure

3.1Main Principle

Melt flow rate indexer is actually a kind of extrusion plastometer, which first heats the tested object through a high temperature muffle furnace to melt it, and then conduct extrusion test under a certain load through the standard die. The melt’s mass or volume that flows through this standard die in every 10 minutes is exactly the melt flow rate of the tested object.

The Mass-Flow Rate method is abbreviated as MFR.

Measurement unit: gram/10min.

Calculation formula: M

(θ:testing temperature,℃

Mnom: nominal load，kg

tref: reference time（10min），second（600s）

M: average mass of sample bar

t: sample interval, s )

Example: There is a tested object with is cut once every 30 seconds and in total cut five times. The masses of these bars are: 0.0816 g, 0.0862 g, 0.0815 g, 0.0895 g, 0.0825 g. The average mass M: (0.0816 g+0.0862 g+ 0.0815 g+ 0.0895 g+ 0.0825 g) / 5= 0.0843 g

Taking it into the formula: MFR=600×0.0843/30=1.686(g/10min)

3.2Apparatus Structure

This instrument consists of testing system, controlling system, automatic cutting device and load device.

3.2.1Testing System

(1) Cylinder

It is made up of nitriding steel, HV≥700.

(2) Piston rod

This part is made up of nitriding steel, HV≥600. The inner diameter of piston rod head is 0.075±0.015 mm uniformly smaller than that of the cylinder. There is one insulation cover on the piston rod head to insulate the rod with the load. There are two annular marks scribed 30 mm apartand so positioned that the upper one is aligned with the top of the cylinder when the distance between lower edge of the piston head and the top of the die is 20 mm.

(3) Die

Φ2.095±0.005mm, made up of tungsten carbide，HV≥700

3.2.2Controlling System

This system chooses platinum resistance(Pt 100) as temperature sensor, which forms a precision temperature measuring bridge together with a precision resistor, and automatically adjusts the heater’s power through an embedded intelligent system.

3.2.3Automatic Cutting Device

The automatic cutting device is comprised of an electric motor, a decelerator, a position monitoring switch and a blade. It’s controlled by embedded intelligent system and set up at the bottom of the cylinder. Therefore, it is characterized as small and flexible.

3.2.4Load

The load device consists of eight levels of weights. The weight of load is the sum of the mass of weights and piston. It’s shown in the following chart:

4Preparation and Parameters Selection

4.1Equipment Placement

Place the indexer on a stable workbench. Next, put the air level into the cylinder, which should be adjusted to level through the bottom bolts.

Take out the cleaning rod, the compression rod and the die rod from the accessory case. Put them at anywhere convenient for use.

Put the die and the piston into the cylinder. (Before leaving our factory, the piston is already placed in the cylinder, while the die is always placed in the accessory case.)

Plug in the indexer. The electric source needs to be equipped with a reliable grounding device and a leakage protection device.

4.2Sample Preparation

A sample can be of shapes like granules, pieces, thin film, powder, etc. Before tests, please stove the sample according to its corresponding requirements. When a severe random discretion phenomenon appears, it’s important to consider whether it is owing to the sample’s unstable characteristics and if it’s necessary to mix in some stabilizer. (Particularly the powder)

Based on the sample’s expected melt flow rate, weigh it following the chart below. If it’s a national standard sample, then weigh it following the instruction of the sample.

Note: When the material’s density is more than 1.0g/cm, maybe it’s necessary to add more.

4.3Testing Conditions

The national standard GB/T3682-2000 discloses testing conditions in Appendix A and B. Some frequently-used materials’ testing conditions are as follows:

4.4Cutting Time

When testing by a cutting and weighing method, it’s necessary to set up an expected cutting interval no matter it’s automatically or by hand. If the interval is too short, the mass of the sample will be too small, and therefore leads to a larger influence on weighing error and cutting error. However, the interval shouldn’t be too long, because the distance between the two marks is limited, which causes that the mass of the sample is restrained. Besides, we want to realize a parallel comparison among more than two samples. We recommend you to refer to the chart below:

5Function of the Keys

The board of this indexer consists of twelve keys. Their functions are:

5.1Heat

Press this key to let the indexer to heat the tested object. The set temperature will be reached after about 10 to 15 minutes. After that, you can begin testing 15 minutes later.

5.2Test

When using the MFR method, pressing this key leads to the indexer first finishing a pre-cutting procedure to discharge the remains of the previous sample, and beginning timing simultaneously. It will cut once after every intervaluntil the set cutting times is reached, and then stop timing.

When using the automatic method, pressing this key results an automatic cut to discharge the previous remains. Then the indexer will prepare for testing process based on the requirements of its user. If time is set as testing basis, then the indexer will cut another time after this interval and meanwhile it will stop timing and show the testing results. Else if displacement is set as testing basis, then it won’t cut until a set displacement is reached. After that the indexer will still stop timing and show the testing results.

5.3Cut

Press this key and the indexer will automatically cut the sample once. Generally it’s used for discharging previous remains.

5.4Setting

This key is used to set parameters and choose methods available: MFR method, automatic method and melt density measurement. You can set the parameters according to different methods.

5.5Calculation

In MFR method, this key is used for inputting the mass of the bars cut, calculating and storing the testing results. In the measurement of melt’s density, it’s used for inputting the mass of the bars cut, calculating and storing the melt’s density.

5.6Query

Pressing this key you can query the results stored before. When the indexer is at the interface of MFR method, it will display the results of MFR method. It’s also the same case for the automatic method.

5.7Delete

When referred to previous results, pressing this button can delete the record at current location.

5.8Back

This is used to return to the main interface.

5.9Increase/ Upward

This key is for switch options and changing data. When changing data, pressing once allows you to change the number at lowest number. If you want to change the number at the last but one order, please press the key and hold on for some time. When the indexer is waiting for instructions, pressing orderly increase-decrease-increase-decrease and then it begins its temperature revision.

5.10Decrease/ Downward

This key is also for switching options and changing data. When changing data, pressing once allows you to change the number at lowest number. If you want to change the number at the last but one order, please press the key and hold on for some time.

5.11Stop

When testing, pressing this key will stop the whole test.

When heating before testing, pressing this key will stop heating.

5.12Confirm

When setting data, please press this key to order the indexer to receive set values.

6Usage Directions

6.1Tests Preparation

(1) Place the die: Push the handle of the die’s baffle, and then push the baffle to the bottom. Place the die from the top and use the compression rod to push it until it touches the baffle.

(2) Place the piston from the top of the furnace into the cylinder.

(3) If using automatic method and melt density measurement, please install the tie rod for displacement sensor.

(4) Prepare proper ample for testing. (Please refer to the chart in 4.2)

For previous process like drying and stabilizing, please refer to national standards of corresponding materials.

6.2Starting Up

Turing on the indexer, it will go into a corresponding interface according to the method chosen.

If the method used last time before turning off is MFR method, it will go into the MFR method interface like following picture:

Picture 1 Starting Up Interface

On this interface, the first line shows current temperature and current position of displacement sensor. The second line shows set temperature, total cuts and cutting interval. The third line show testing process, including cuts already conducted and timing. The forth line shows whether it’s heating or waiting for instructions.

6.3Set Testing Parameters

Examine current interface and parameters set. If it doesn’t meet practical requirements, please set the parameters again. Press the Set key to enter in the setting interface, as shown in the following picture.

Picture 2: Parameters Setting Interface

After entering, the “Set Temperature” will be underlined after pressing Confirm. If you need to change the temperature, press Confirm. If not, press Downward and the “Total Cuts” will be underlined, followed by circulation. When the underline moves to an item, press Confirm and that item will twinkle. Pressing Increase and Decrease you can change the numbers. Pay attention that when you press once, the lowest order changes, but only when you press and hold on for a while can the last but one order changes. All the changes are either incremental or degressive.

6.4MFR Method

6.4.1Heat

After setting the parameters, press the Heat button and then the indexer begins to heat the tested object. It will reach the preset temperature after 10 to 15 minutes and remain stable with a tiny fluctuation of 0.1 degree centigrade. The whole test can begin 15minutes after the temperature becomes stable.

6.4.2Test

Before tests, take out the piston first and put sample into the cylinder through the charging hopper and the charging rod. Be sure to pack the sample down in order to avoid the emergence of bubbles. After that, put the piston into the cylinder again. The whole procedure should be finished in 1 minute. If the sample already flows out from the die during the process, please press the Cut button to cut this par and scarp it. If the sample melt and flow quickly, please use a copper wire or an aluminum wire that has a diameter of around 2 cm to plug up the die’s outlet, and take it out when compress the sample.

The cylinder’s temperature will decrease when putting in the sample, but will be back to the set one after 2 to 3 minutes. 4 minutes later, put the required load on the piston and place the sample tray below the die’s outlet. If the die is plugged up before, take out the wire first. Then the sample flows from the die and piston begins to descend. In this process, if it’s necessary to cut the extrudate, please press the Cut button.

When the piston descends to the degree that the lower mark is at the same level with the top of guide bushing, press the Test button. Then the system begins timing and cut the extrudate automatically. Please discard this extrudate and the extrudates before.

After every interval, the indexer will cut the sample automatically and buzz. After the total cuts are realized, the indexer will stop. If the total cuts are still not realized, but the mark is already at the same level as the guide bushing, please press the Stop button and discard all subsequent extrudate.

During the process, you can press the Stop button to stop timing. Then the indexer will get back to the temperature controlling state. Press the Timing button again and then the indexer will restart its test and begin timing.

After testing, please keep the indexer extruding in a constant temperature until all the sample are discharged out. Then take out the load as well as the piston, and clean the piston. Pull the handle of the die’s baffle, and take out the die using the charging rod. Use the die cleaning rod to purge the sample remaining in the hole of the die. Then use a strip of cloth to clean the die before it cools down. Bind a piece of clean white gauze to the cleaning rod and wipe the cylinder clean before it cools down.

Attention: the cleaning of the piston, the cylinder and the die is very important. If they are not clean enough, next test will be highly influenced.

(During the cleaning process, the cylinder and its related part are still at high temperature, please be careful.)

6.4.3Weigh and Calculate

Weigh the sample bars without bubbles, and discard those whose mass are more than 15% of average value. Select more than three qualified sample bars and input their data into the indexer to calculate.

On the MFR surface, press the Calculate button to enter the MFR method calculation interface, as shown below:

Picture 3: Mass Inputting Interface

The Test Number is defined by the user through three figures. It would be better to keep an record in case of future use. The Material Number, Temperature, Timing come from those preset parameters and therefore generally there is no need to change. (material number, testing temperature and cutting interval) Move the underline to the position of Mass and then press the Confirm button to input mass. Then press the Confirm button again to let the indexer receive the input number. The number of cuts is changed to 2 automatically and the corresponding calculation results are displayed. (Please refer to 3.1.1 MFR to see the calculation principles.) After inputting the number of mass of all the bars, press the Back button and then the “Yes” at the position of “Store or Not” begins to twinkle. If you want to store it, please press the Confirm button. Else please switch to “No” and press the Confirm button to return to working stage.