APTECH Fast-Curing Pinhole-free Primer for Polyurea — NK Safety Primer Construction Technology

Introduction

AP Tech has been supplying Spray PU Foam and Polyurea Coat system raw materials for more than 20 years, and has received favorable evaluations not only for providing products with a wide process range, but also for proposing competitive specifications suitable for field applications.

In this article, we introduce a Polyurea specification that can be completed within 7 hours. The key to this time-saving specification is the use of NK Safety Primer (Korean Patent No. 10-1839613), a "Fast-Curing Pinhole-free Primer."

This product is sprayed using Polyurea small equipment (example: Graco E-10) instead of general Primer application tools (Roller, Squeegee, Trowel), which not only reduces working time, but also provides excellent leveling properties without separate leveling work because it is a fast-curing Type with a Pot-Life of approximately 1~2 minutes. In addition, Pinhole occurrence is minimal regardless of thickness, making it possible to dramatically reduce working time.

It is a very effective specification that can be used when rapid repair work is required at night, such as department store parking lots. The APTECH NK Safety Primer is a Fast-Curing Pinhole-free Primer System for Polyurea fast-curing construction.

A. Polyurea Construction Specification Completed Within 7 Hours

Surface Preparation / Primer 1st Coat (0.15mm) / Primer 2nd Coat (0.25mm) / Polyurea (2~3mm)

B. How to Use NK Safety Primer and Its Characteristics

Item	Description
Spray Equipment	Use of Polyurea small equipment such as Graco E-10
Primer Consumption	0.2~0.45 Kg/m²
Primer Recoat Time	30 min ~ 60 min
Pot Life	1~2 min
Cure Time	5 min ~ 60 min (depending on temperature)

Cure Time Conditions

Item	-20°C	0°C	25°C
TFT (min)	40	5	1
Cure (min)	360	45	15

NK Safety Primer Characteristics

• Polyurea Spray is possible after the 1st coating when the substrate condition is good

• Polyurea Spray is possible 30~60 min after Primer application

• Safe against instantaneous ignition due to the use of high-boiling-point solvents

• Since it is low viscosity, good workability can be achieved even without a hose heater

• A solvent-free Type (VOC free) product is also available separately (Product name: NK Primer Coat)

The APTECH NK Safety Primer is a Primer System designed to simultaneously secure fast-curing Type characteristics and excellent leveling properties.

C. NK Safety Primer Effects and 7-Hour Construction Case

NK Safety Primer — Pinhole Prevention, Fire Safety, and 7-Hour Construction Case

7 hours: Completed from 10 PM to 5 AM the next morning.

Refer to Product Catalog P5.

D. Why Polyurea Construction Can Be Completed Within 7 Hours

High-performance leveling properties and Pinhole prevention effect of NK Safety Primer

1) Excellent Leveling and Pinhole Prevention

Although it is a fast-curing Type, the Pot-Life is approximately 1~2 minutes, making it possible to achieve excellent leveling properties with a single Spray application without separate leveling work while preventing Pinhole occurrence, thereby dramatically reducing working time.

2) Enhanced Appearance with 2-Coat Application

Depending on the substrate condition, a more aesthetically pleasing appearance can be achieved with 2-coat application.

3) Stable Curing Regardless of Thickness

It is natural that the Primer thickness varies depending on uneven surface areas, but there are no curing or Pinhole problems at all. Therefore, it is possible to reduce working time by more than 2~3 times, and the difference between general Primer and NK Safety Primer is very significant.

4) Elimination of Repair Processes

Complicated processes requiring repair of Pinhole or Cratering after the 1st Polyurea coating followed by re-application of the 2nd coating can be omitted, reducing working time.

The APTECH NK Safety Primer is a Primer System that can simplify the Polyurea construction process by minimizing the occurrence of Pinhole and Cratering.

E. Excellent Adhesion of NK Safety Primer

1) Chemical Adhesion

Since it is a 2K PU Primer, it forms almost one body with Polyurea through chemical adhesion.

2) Next-Day Construction Possible

Unlike general 2K PU Primer or Epoxy Primer, there is no strict condition requiring Polyurea construction within 24 hours after Primer application. If it has not been exposed to dust, rain, or moisture, excellent adhesion can still be achieved even with next-day construction.

3) No Silica Sand Required

There is no need to scatter silica sand after Primer construction for adhesion reinforcement. Since the troublesome process of removing remaining silica sand after curing is omitted, working time can be reduced.

4) Standard Pretreatment Conditions Apply

The substrate surface must be free of dust, oil components, and moisture, and pretreatment conditions such as maintaining the substrate temperature at least 3°C above the dew point must be applied according to general specifications to achieve the intended adhesion performance.

Conclusion

The APTECH NK Safety Primer is a Fast-Curing Pinhole-free Primer System for Polyurea fast-curing construction that can simultaneously secure reduced working time and excellent leveling properties.

We hope this method will be helpful to your work when necessary.

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