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Home / Flat Brushes / Dyne Pens – Letianqi Corona Test Pens, Surface Tension Testing Pens, Also Known as Daying or Dayin Pens

Attributes

Brand -
Category Stationery, Educational Electronics & Office Supplies / Flat Brushes
Origin -
Brand Letianqi
Product Type Dyne Test Pen
Application Surface Tension Testing
Target Materials Plastic, Film, Foil, Paper
Pack Size Single Unit
Ink Color Blue
Shelf Life 12 Months (Unopened)
Storage Temperature 5°C to 25°C
Country of Origin China
Item Weight 15 grams

6 reviews

A

Anonymous

Mar 21, 2026

Rating: 4/5

Reliable for routine checks

We keep a set of different dyne values in our lab. These pens are easy to use and the markings are clear. Delivery was also very quick.

A

Anonymous

Mar 15, 2026

Rating: 5/5

Accurate and fast

These Letianqi pens provide instant results. We tested them against more expensive brands and found no difference in accuracy. Great for our packaging department.

A

Anonymous

Mar 13, 2026

Rating: 3/5

Decent but dries out if left open

The pen works well when fresh, but you must be very careful to cap it immediately after use. I left it open for a few minutes and the tip dried out faster than others I have used.

A

Anonymous

Mar 06, 2026

Rating: 5/5

Essential for our printing line

We use these pens daily to check the treat level on our polyethylene films before printing. The ink flow is consistent and the results are reliable. Highly recommended for quality control.

A

Anonymous

Mar 04, 2026

Rating: 4/5

Good value for money

Works exactly as expected for surface tension testing. The only reason I didn't give 5 stars is that the cap can be a bit tight sometimes, but the performance is solid.

A

Anonymous

Mar 03, 2026

Rating: 5/5

Standard industry tool

If you work in flexography or coating, you need these. This specific brand offers good consistency across batches. No complaints from our technical team.

5 FAQ

Q: Can these pens be used on metal surfaces?

A: Dyne pens are primarily designed for non-porous polymer surfaces like plastics and films. They are generally not suitable for testing untreated metal surfaces.

Q: Do you offer a kit with multiple dyne levels?

A: Yes, we sell individual pens as well as complete sets ranging from 30 to 72 dynes/cm. Please check our store listings for bundle options.

Q: How do I know if the surface tension is sufficient?

A: If the ink bead remains intact for 2 seconds, the surface tension is lower than the pen's value. If it spreads evenly within 2 seconds, the surface tension is equal to or higher than the pen's value.

Q: Is the ink toxic or hazardous?

A: The ink contains formamide and other solvents. It should be used in a well-ventilated area and kept away from eyes and skin. Please refer to the SDS sheet for detailed safety information.

Q: What is the shelf life of these pens once opened?

A: Once opened, we recommend using the pen within 3 to 6 months for optimal accuracy, provided the cap is sealed tightly after every use.

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