Influence of Test Temperature on Polyester Chips Viscosity

Influence of Test Temperature on Polyester Chips Viscosity

Abstract: Testing result indicates that polyester chips viscosity are very sensitive to the test temperature. So it requires to control the temperature precision range strictly . Therefore, an ideal constant temperature water bath is necessary to get the reliable result of the viscosity.

Polyester resin in the field of polymer occupy a leading position, it is not only high strength, good heat resistance, non-toxic, and good insulation. By different processing means, it can be made in the film, in the audio and video tapes, lighting film, food packaging, for high-strength composite film, and can be processed into different types of beverage bottles and electrical parts. Polyester chips are also important raw materials for the chemical fiber industry. Spinning polyester chips must maintain a high purity. So the inspection department to each batch of products to conduct a series of performance indicators to ensure the quality of the batch. The viscosity index indirectly represents the size of the molecular weight, which directly affects the quality of the finished polyester yarn, and the test temperature is particularly sensitive to the viscosity, so the required test temperature range must be strictly controlled.

Polyester chips are specified in the relevant standard method by dissolving one or two mixed solvents at a certain temperature to a certain concentration and then measuring the solvent at a specified test temperature by an Ubbelohde viscometer (having a defined capillary diameter) And the time the solution flows, converted into relative viscosity and intrinsic viscosity. ASTMD2857 specified test temperature accuracy of ± 0.01 ~ 0.02 ℃, ISO12228 specified test temperature accuracy of ± 0.05 ℃, China is the national standard in principle to the ISO closer to the set, also set to ± 0.05 ℃

Select the Taiwan polyester chips (contract, the intrinsic viscosity IV0.645 ± 0.015) set the temperature of the thermostat different temperature for the test to observe the changes in viscosity:

1. Test conditions

Solvent: mixed solvent, weight ratio of phenol: tetrachloroethane = 3: 2

Solution concentration: 0.5%

Test temperature: 25.00 ~ 25.08 ℃

2. Accuracy measurement at different temperatures

Table 1 Effect of temperature on the determination of PET slice adhesion

The same time as

Test temperature ° C Relative viscosity Viscosity

25.00  1.363  0.645

25.01  1.363  0.645

25.02  1.360  0.641

25.05  1.355  0.634

25.08  1.350  0.625

From the data of Table 1, the intrinsic viscosity value decreases with increasing temperature, the temperature rises by 0.01 ℃ Viscosity is not affected; the temperature rises 0.02 ℃, the intrinsic viscosity decreases 0.004; when the temperature rises to 0.05 ℃, the intrinsic viscosity decreases 0.011; To 0.08 ℃, the intrinsic viscosity dropped to 0.021, has been outside the scope of the contract. This shows that the temperature parameters directly affect the size of the viscosity, it is necessary to strictly control the temperature accuracy range, the determination of the results can be a reliable guarantee.

3. Need to pay attention to the problem

Determination of viscosity method is not complicated, but in order to ensure the correctness of the test results must be strictly to the various test links, try to avoid errors. This is mainly: ① weighing; ② solution preparation; ③ viscometer cleaning; ④ viscosity determination of the viscosity of the vertical degree; ⑤ visual line when the level of the situation; ⑥ timer press speed; ⑦ constant temperature water bath temperature The

Among them, the constant temperature water bath temperature control accuracy is determined by the thermostat, and the visual line of the error is also determined by the thermostat, especially those observation window for the arc when the marking line blurred, the greater the error. In addition, it is almost entirely determined by the quality of the inspectors. Therefore, the configuration of an ideal precision constant temperature water bath is a guarantee of an important device for viscosity determination.

The same time as

At present, the domestic production of the thermostat groove accuracy is rarely higher than ± 0.05 ℃, roughly, seems to meet some of the international standards and the implementation of the new national standard, but in fact, due to uneven temperature distribution throughout the tank, With the temperature control temperature fluctuations, the overall control accuracy is clearly inferior to 0.05 ℃, especially in the factory application, a number of viscometer placed in different locations, this phenomenon even more directly affect the test data, while , The thermostatic bath with the refrigeration system is far from being extended, and the viscosity test also brings a lot of trouble (generally, there is no cooling system of the thermostat, only when the room temperature is lower than the test temperature of 5 ℃, to ensure that the temperature control Precision).

What is the true 0.01 ° C temperature control accuracy?

The same time as after adjusting the temperature of the thermostat, from today to tomorrow, the temperature changes, not more than 0.01 ℃, and the temperature inside the thermostat tank temperature distribution is poor, not more than 0.01 ℃.

Kent Yuan (Mr.) Hangzhou Zhongwang Technology Co., LTD.

P  /Wahtsapp: +86 15068109723  E lei@zonwon.com

Determination of Molecular Weight of Polyacrylamide by Dilute Solution Viscosity Method

Determination of Molecular Weight of Polyacrylamide by Dilute Solution Viscosity Method

Abstract: To learn and master the Ubbelohde viscometer viscosity measurement method; to understand the statistical significance of the molecular average molecular weight and polymer dilute solution of the intrinsic viscosity of the characterization method; master the determination of polymer dilute solution viscosity experiment Technology and viscosity method to characterize the molecular weight of polymer; the viscosity of polyacrylamide aqueous solution to reflect the molecular weight of polyacrylamide;

Experimental principle

        Liquid flow is due to external force molecules irreversible displacement process. Liquid molecules exist between the interaction force, so when the polymer liquid flow, the polymer molecules to produce internal friction between the performance of the liquid viscosity characteristics.

        According to Newton's law of viscous flow, the viscous resistance of the liquid to the flow is caused by the flow gradient between the two layers of flowing liquid (with A) due to intermolecular friction.

In the Ubbelohde viscometer capillary, it is assumed that the force that causes the polymer dilute solution to flow is all used to overcome the internal friction f:

For most flexible polymer - good dilute solution solvent system, protraction

with c and  with c. Extrapolated intercepts coincide with the value of the point

 , that is, the shape of the polymer is the polymer solution between the chain and the polymer solvent interaction between the molecules of the reaction, the current Mark-Houwink empirical formula:

Can be found in the relevant manual. Therefore, the polymer can be dilute the viscosity of the polymer to calculate the molecular weight.

Instrument: Ubbelohde viscometer constant temperature water bath, electronic scales, stopwatch, pipettes, flasks, ear cleaning ball, glass sand funnel;

Reagents: polyacrylamide samples, sodium chloride, purified water;

Experimental steps:

1. Solution preparation

2. Viscosity meter cleaning and drying

3. Viscometer installation: check the viscometer, with a clamp carefully fixed viscometer, into the constant temperature sink. The viscometer should be kept vertical, and the constant temperature surface should be immersed in the two balls above the capillary and the temperature remains constant.

4. Determine the elution time of the solution: Remove the 10 ml solution from the self-volumetric flask and inject it from the A tube into the viscometer. The clip holds the C tube and draws the solution from the B tube to the top of the a The ball volume of half of the time until the release of the ear ball, release the C tube clip, the air into the C tube, immediately horizontally watching the decline in the liquid level with a stopwatch recorded liquid flow through the a and b line time is Out of time.

5 ml, 5 ml, 10 ml and 10 ml of solvent were added to the same solution for 2/3, 1/2, 1/3, 1/4 of the original solution, and the respective elution times (t2, t3 , T4, t5).

Determination of pure solvent elution time: The solution in the viscometer was poured out and washed several times with solvent to determine the elution time t0 of the pure solvent.

Kent Yuan (Mr.) Hangzhou Zhongwang Technology Co., LTD.

P  /Wahtsapp: +86 15068109723  E lei@zonwon.com

Coyp right by @Hangzhou Zhongwang Technology CO.,LTD

Difference Between Ubbelohde Viscometer and Brookfield Viscometer

Difference Between Ubbelohde Viscometer and Brookfield Viscometer

Abstract：Introducing of Ubbelohde viscometer and Brookfield Viscometer. Concept, difference and advantages of ubbelohde viscometer and Brookfield viscometer.

Brief introduction of Ubbelohde viscometer：

When the fluid is flowing by external force, there is a tangential internal friction between the flowing liquid layers, and if the liquid is to pass through the tube, a portion of the work must be consumed to overcome the resistance of the flow. When the flow rate is low, the liquid in the pipe is advanced in a straight line parallel to the pipe wall. The liquid closest to the pipe wall is actually stationary, and the farther the distance from the tube wall is, the greater the flow rate is. The tangential force f between the flow layers is proportional to the contact area A between the two layers and the velocity difference Δv, and is inversely proportional to the distance Δx between the two layers: where η is the proportional coefficient, called the viscosity coefficient of the liquid, Referred to as viscosity.

The molar mass of the polymer not only reflects the size of the polymer molecule, but also directly related to its physical properties, is an important basic parameter. Unlike conventional inorganic or low molecular organic matter, the polymer is mostly macromolecular mixture of different molar mass, so the measured molar mass of polymer is usually a statistical average. 

Brief introduction of Brookfield Viscometer:

       Brookfield Engineering is an engineering and manufacturing company with headquarters in Middleboro, Massachusetts. Its product line includes laboratory viscometers, rheometers, texture analyzers, and powder flow testers as well as in-line process instrumentation. These instruments are used by research, design, and process control departments. It was suspected of causing one of Massachusetts' most unusual and serious residential toxic waste contamination problems, and settled the claim by paying relocation and cleanup costs without admitting responsibility.       

Classical Brookfield viscometers employ the principle of rotational viscometry - the torque required to turn an object, such as a spindle, in a fluid indicates the viscosity of the fluid. Torque is applied through a calibrated spring to a disk or bob spindle immersed in test fluid and the spring deflection measures the viscous drag of the fluid against the spindle. The amount of viscous drag is proportional to the amount of torque required to rotate the spindle, and thus to the viscosity of a Newtonian fluid.In the case of non-Newtonian fluids, Brookfield viscosities measured under the same conditions (model, spindle, speed, temperature, time of test, container, and any other sample preparation procedures that may affect the behavior of the fluid) can be compared. When developing a new test method, trial and error is often necessary in order to determine the proper spindle and speeds. Successful test methods will deliver a % torque reading between 10 and 100. The rheologicalbehavior of the test fluid can be observed using the same spindle at different speeds, but because the geometry of the fluid around a rotating bob or disk spindle in a large container does not allow a single shear rate to be assigned, proper rheometry is not feasible using this setup.

Apart from its rotating bob viscometers, Brookfield now also produces defined-geometry rheometers which allow complete rheological analysis of fluids.

Difference Between Ubbelohde Viscometer and Brookfield Viscometer

1. Ubbelohde Viscometer：Cheap, suitable for relative measurement, Uptel viscometer itself can not control temperature, with precision thermostat can be accurate measurement of viscosity, in addition to the Ubbelohde viscometer installed in the automatic viscosity test equipment, you can achieve Ubbel's viscosity Automatic measurement, directly to the intrinsic viscosity, than the viscosity, relative viscosity, viscosity, viscosity average molecular weight and other needs of the measurement results.
2. Brookfield Viscometer：Have adopted the well-known viscosity measurement principle, which absorbs the viscosity value by the continuous rotation of the rotor immersed in the liquid to be measured. The torque is proportional to the resistance of the rotor immersed in the sample by sticky dragging, proportion.

Kent Yuan (Mr.) Hangzhou Zhongwang Technology Co., LTD.

P  /Wahtsapp: +86 15068109723  E lei@zonwon.com

Coyp right by @Hangzhou Zhongwang Technology CO.,LTD

IVS800H Automatic（High Temperature）Viscometer

IVS800H Automatic（High Temperature）Viscometer

Introduction：

IVS800H Automatic（High Temperature）Viscometer was designed for testing the intrinsic viscosity and viscosity average molecular weight of PE, PP and their copolymers and ultra-high molecular weight polyethylene at temperature 135 degree. It was applied our company’s new independent innovation Z shape ubbelohde viscometer (Patent No.: ZL 201320467957.8). By adding the sample from below, it can automatically determine the level height, simplified the automatic sampling, automatic cleaning and other operations, easy to achieve full automatic testing.

Features

The Z shape ubbelohde viscometer (Patent No.: ZL 201320467957.8) is IVS800H’s Core components. We are added the sample from below. We use the sample bottle replacing the liquid storage ball. The Z shape ubbelohde viscometer works together with 6 units constant temperature sample tray and sample syringe. This machine can achieve sampling, replacing, washing, drying automatically. It meets the ISO1628-3 and GB/1632-3 stander. It can not only deals with Single Point experiment, but also can do linear extrapolation test. Extrapolation software program is also the first in the country.

Critical Technology：

1）Max temperature up to 150 degree; Temperature fluctuation / uniformity: ± 0.05 degree.

2)  Imported stainless steel optical-fiber system. It will not aging when

Placed in water or oil long time. With this character, it can avoid damages

Causes by long time soak in the water or oil environment, and ensure system

Operation long-term and reliable.

Meanwhile, the system has the intelligent adaptive optics system.

It will auto adjust the fiber strength to ensure the measurement data accuracy

and extend the life of the system, according to the viscometer, Viscosity

tube, solution, water quality, optical fiber transmittance,etc.

3） Automatic injection technology. Put the prepared solvent, dissolution and cleaning agent in the sample tray. Then operate the PC to control single measurement, continuous measurement, and cleaning automatically. It achieves viscometer tube cleaning without taking out the tube.

Easy operation, safe and Environmental protection.

4） The main engine connects the PC by a data line. It’s convenient, quick and reduce the probability of communication failure.

5）IVS800H’s software can provide different viscosity calculation formula based different filed need. Such as Solvent viscosity, dynamic viscosity, Solomon - Hugh tower, serial extrapolation and other formulas. It will work out the result automatically according to user’s selection.

6）Constant temperature sample tray: It reduces the temperature difference between sample and bath. Time saving and more Efficient.

7）New sample can be added while measuring process is working. It can adjust the vacuum pump pressure to fit different sample.

8）All the materials of pipeline are resistant to strong acid, alkali, organic solvent.

9）The machine uses replacing method to clean the tubes. No need to disassemble viscometer and reduce reagent consumption and operation;

10） Automatic injection and online cleaning, drying. drying; Cleaning and drying rapidly.

11）Multi modes for cleaning and dry: single or multi cleaning agent(according to customer sample requirements)optional, cleaning times and speed can be adjusted;

During drying, user can choose to dry under room temperature

or constant temperature. It has the function of cleaning and

drying the viscometer tube. When the machine power off, the tube

can be in the liquid or full air state, ready for the next test.

Performance parameters：

1）          Timing range：0-999.99 S

2）          Timing resolution：0.01 S

3）          Temperature range：Ambient temperature～150℃ 

4）          Temperature fluctuation/uniformity：±0.05℃

5）          Heating power： 1000 W

6）          Tank inner size（L×W×H）：22×16×32 cm

7）          Tank outer size（L×W×H）：37×62×60 cm

8）          Power: AC  220V，50Hz

Standard practice:

Measuring stander：  

GB/T 1632.3-2010 Plastics - Determination of the viscosity of polymers in dilute solutions by capillary viscometer – Section third: polyethylene and polypropylene (HDPE and PP)

Product design standards: GB4457-4460, GB131 mechanical drawing national standards

Dimension standard: GB1800-1804 Tolerance and coordination with national standards

Geometric tolerances: GB1182-1184 National standard for geometric tolerances

Production inspection standards: GB4793.1-2007 - General requirements for the safety of electrical equipment for measurement, control and laboratory use.

Packing list：

Number	Item name	Quantity
1	IVS800H Automatic viscometer	1
2	Sample bottle	At clients request
3	Automatic sample tray	1
4	Waste bottle	1
5	Z shape ubbelohde visometer	1
6	Installation package	1
7	Software	1

Kent Yuan (Mr.) Hangzhou Zhongwang Technology Co., LTD.

P  /Wahtsapp: +86 15068109723  E lei@zonwon.com

Coyp right by @Hangzhou Zhongwang Technology CO.,LTD