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FAQ

Q What tips are needed to filter contact angle meters on the more than ten models?

A
 
The first thing to note is your solid sample size.
If your sample is bigger than any of our listed models, please contact us for a solution.
If you can prepare any size of sample, any model can be chosen. The next step is to see what options are available to meet your needs.
Temperature control and a sliding system are available for limited models.
 

Q What sizes of needles are provided for the contact angle meter?

A
 
Luer lock -type needles have a two-digit number on their adapter section that indicates the needle gauge (indicated as G). The diameters of the tips are:
Gauge Int. dia. Ext. dia.  
32G 0.10mm 0.23mm    
28G 0.15mm 0.35mm    
22G 0.4mm 0.7mm    
18G 0.8mm 1.2mm    
15G 1.4mm 1.8mm    

*The 32G needle is Luer taper type and is used on a special syringe.

*The outer diameter of Teflon- coated needles are slightly larger than the above since the thickness of the coating is about 20 to 30µm.

 

Q What is the difference between Goniometer and Contact Angle Meter?

A
 
They are the same in the respect specifying an instrument in the field of surface science. There are varieties of Goniometers that play active rolls in the fields for example physical therapy, crystallography, spatial distribution of light, etc. Therefore, we are using the name “Contact Angle Meter” that name and natures agree.

 

Q How can I purchase Kyowa's products?

A
 
Kyowa has local agents in several countries. Assistance with sales and technical support can be found at our website on the "Where to buy" page. Contact the local agent in your region. If there is no one available, contact us directly or through your local distributor of scientific instruments.

 

Q How can I receive technical support from Kyowa after I make a purchase?

A
 
If you buy Kyowa's product through local agents listed on our webpage "Where to buy", they will provide technical support and parts with necessary instructions. For more details, please contact your local agents.
For customers who have purchased Kyowa's products directly from the company, we will support and provide necessary information directly through e-mails or phone calls. We provide services and support for at least seven years after purchase even if the product is discontinued.

 

Q I have lost the operation manual. Is it possible to obtain a new one?

A
 
A PDF file of the latest operation manual is available free of charge. If you are a user of the software FAMAS or DYNALYZER, please proceed to your user registration at "Registration" and obtain the access keys necexxary to enter the download site, where PDF files of the operation manual and the latest version of the software are available.
If you are not a user of the above software, contact us or our agents found at  "Where to buy".  Give us the model and serial number of your product.
Operation manuals for some older products may no longer be available.  Hard copies of operation manuals are provided for value.

 

Q Is there a proper droplet volume for measuring contact angle? Is there any official standard to define the droplet volume?

A
 

Larger droplets tend to be rather flattened due to gravity's effect. This may causes errors of measurement. On the other hand, smaller droplets may be difficulties to measure deu to quick evaporation.  In general, a droplet volume around 1 to 2 µL is used.

For example, JIS R3257 “Testing method of wettability of glass substrate” indicates “1µL or larger, 4µL or smaller”. ASTM D5946 “Corona-treated polymer films using water contact angle measurements” indicates 5 - 8µL”. In our opinion, these volumes are rather larger.

 

Q Is it OK to use the liquid remaining in the syringe the next day?

A
 
We recommend replacing the liquid sample every day to avoid problems caused by accidental contamination or deterioration of the liquid.

 

Q What is the recommendable cleaning method for glass syringe?

A
 

An ultrasonic cleaner with solvents or surfactant solutions is recommended.

Syringes used for oily samples are better handled under separate process than for cleaning syringes used for water soluble samples.

 

Q What kinds of liquid are used as “standard liquid” for contact angle measurement?

A
 
The major objective of contact angle is to evaluate combinations of liquid and solid. Another objective is to compare solids using a liquid as standard. In the later objective, water is the liquid most commonly used.
Purified water such as DI water, distilled water, and pure water are recommended. City tap water is not recommended because it may include some elements that will negatively affect the results.
In addition, the papers for surface free energy analysis stipulate typical probe liquids for analysis. Those include diiodomethane, formamide, ethylene glycol, and so on as well as water.

 

Q Is it possible to conduct periodic calibration and inspection on contact angle meters?

A
 
A standard droplet sample that prints three droplet images and a circular calibration images on a glass block is provided with any Kyowa contact angle meter. It allows for periodic calibration and inspection.

 

Q Is it possible to conduct periodic calibration and inspection on surface tensiometers?

A
 
Surface tensiometers are classified within the following three categories:
DyneMaster series: The built-in electric balance is calibrated by the weight(s) provided with each model. Inspection can be performed with liquid of pure substance of which surface tension is published.  Purified water and ethanol are recommended.
DropMaster series (by pendant drop): Standard pendant drop similar to the standard droplet sample for contact angle is available as an option.
BP-D5: Calibration is done using purified water.

 

Q Why do Kyowa's DyneMaster series (Tensiometers) attach the Wilhelmy Plates as a standard accessory, but not the du Noüy Ring?

A
 
Kyowa recommends the Wilhelmy Plate method rather than du Noüy Ring method for measuring surface tension because of the following advantages offered by the Wilhelmy Plate method:
- Variations over time can be measured, which is essential for solutions including surfactant that lowers surface tension.
- The plate is simple shape and comparatively durable whereas the ring is complex shape and need very careful handling so as not to bend its thin and soft wires. Change of ring diameter and circularity make a big difference in measurement results.
- Correction by liquid density is not required if the density is within 0.6 – 1.4 g/cm3. du Noüy Ring method needs to input liquid density of every range for correction.
However, Kyowa respects the du Noüy Ring method for its long history and extra function in measuring Lamella length. In response to the demand for only the du Noüy Ring, it is possible to obtain a du Noüy Ring and a Ring reformer instead of two Wilhelmy plates as a standard accessory for the DyneMaster series.

  For further questions, please contact us through the webpage Contact us or to the e-mail address at overseas-sales@face-kyowa.co.jp   

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