Analysis of performance appraisal index of anti-skid coating for flight deck

Yang Zhe91404 Troops, Qinhuangdao, Hebei

Abstract: In view of the lack of professionalism in the performance appraisal index of anti-skid coatings for flight decks in my country, insufficient test coverage, and the difficulty of relevant standards to meet the current performance appraisal test requirements, summarize the working characteristics of the use environment of anti-skid coatings for flight decks and the performance requirements of anti-skid coatings; Focus on analyzing the standards of anti-skid coatings for US military flight decks, my country's current industrial level of coatings and the protection requirements of the actual working environment, and propose anti-skid, abrasion resistance, corrosion resistance, impact resistance, high temperature flame retardancy indicators and safety 6 A performance appraisal index.

Keywords: flight deck anti-skid coating; anti-skid property; abrasion resistance; impact resistance; high temperature flame retardancy

0 Preface

As a special coating that protects the hull from corrosion and abrasion, and has the functions of non-slip and flame retardant, the ship coating is widely used in various parts of the ship.

1 Overview of anti-skid coating standards for flight decks

1.

As the country with the largest number of aircraft carriers in the United States, the anti-skid coating system for flight decks has been recognized by most countries in the world that have aircraft carriers.
In recent decades, with the changes in aircraft carrier tonnage and carrier layout, the replacement of carrier aircraft, the change of take-off and landing methods, and a series of technological innovations, the US flight deck anti-skid coating MIL standard has been updated from MILD-23000A (1961) to MIL- P-246667C (2008), involving more than 30 coating performance indicators.
Among them, the performance index requirements such as impact resistance, abrasion resistance, and slip resistance have been greatly improved.
In the US military standard MIL-P-246667C, according to different use occasions, outfitting technology, performance characteristics, anti-skid coatings are divided into 11 categories.
Each category is divided into general type (G) based on different functions, that is, conventional wear-resistant deck coating system and take-off and landing type (L), that is, the deck of non-wear steel cables used in aircraft carrier landing and taxiing areas.
There are two types of coating systems.
In addition to the protective properties of conventional coatings, take-off and landing coatings are also required to have long service life, accelerated corrosion resistance, non-slip properties, flame retardancy, and other typical properties closely related to the environment in which they are used.
After decades of changes and amendments, the United States has formed a set of increasingly perfect performance index system and test methods for anti-skid coatings for flight decks.

1.
2 my country's relevant standards

Due to the lack of accumulated experience in the field of aircraft carrier engineering in my country, there is a lack of systematic research specifically based on anti-skid coatings for the flight deck of carrier-based aircraft, and there is a lack of targeted performance identification indicators.
At present, the main deck coating standards that can be used for reference are HJB285-2003 "Ship Coating Performance Specification", GJB5066-2001 "Helicopter Deck Anti-skid Paint Specification", GB/T9261-2008 "Deck Paint", GB/T1771-2007 "Color Paint and Determination of resistance to neutral salt spray of varnish, GB/T5210-2006 "Determination of Coating Adhesion by Pull-off Method", GB9263-1988 "Determination of Slip Resistance of Anti-skid Deck Paint", GB/T9276-1996 "Coating Natural Climate Exposure Test Method" etc.
The above-mentioned standards mainly stipulate basic indicators such as friction coefficient and adhesion of general deck coatings, and most of them are national standards.
Compared with the US military standards, there are deficiencies in terms of specificity, strictness, practicality, and systemicity.
In the field of anti-skid coatings for flight decks, my country urgently needs to formulate military standards that meet its own development requirements.

2 Performance requirements for anti-skid coatings for flight decks

2.

When a carrier aircraft is parked on the deck, sliding, taking off and landing, there are strict requirements on the deck anti-skid performance, especially the lateral anti-skid performance.

2.
2 Wear resistance requirements

In addition to serving as a take-off and landing platform for carrier-based aircraft, the flight deck is also equipped with multiple aviation support equipment.
It is the main place for carrier-based aircraft's aviation support operations.
It is subjected to various types of wear such as tire rolling, personnel trampling, and blocking cable friction.
Therefore, it is required that the anti-skid coating for the flight deck must have a high degree of abrasion resistance, be resistant to anti-skid particles and paint falling off, and have a long service life.

2.
3 Impact resistance requirements

In the process of frequent takeoff and landing of aircraft, it has brought huge impact to the deck.
With the increase of aircraft tonnage and takeoff and landing speed, the impact strength has also increased correspondingly.
Therefore, anti-skid coatings for flight decks must have reliable impact resistance, and there should be no peeling off of flake or large particle coatings to prevent the occurrence of peeling coatings from damaging aircraft engines.

2.
4 High temperature flame retardancy requirements

During take-off and landing of a carrier-based aircraft, the high-temperature gas emitted by the engine will wash the flight deck, and the anti-skid coating of the flight deck will directly contact the gas flame as a protective coat of the deck.
Therefore, non-slip coatings are required to have high-temperature flame-retardant properties to prevent fire injuries and deaths, and at the same time to avoid problems such as melting, deformation, and peeling of the coating.

3 Performance evaluation index of anti-skid coating for flight deck

The performance of the flight deck anti-skid coating plays a vital role in the take-off and landing of the carrier-based aircraft.

3.
1 Slip resistance index

The slip resistance test of anti-skid coatings for flight decks usually takes the coefficient of friction as the criterion.
At present, there are only specifications for anti-skid paint on the deck of helicopters in China, and there is no standard specification specifically for anti-skid paint on the flight deck of carrier-based aircraft, and the standard only stipulates the static friction coefficient of the paint in the initial state.
Taking into account the taxiing take-off and landing methods of carrier-based aircraft, the US military has specifically put forward dynamic friction coefficient indicators and test methods.
There are also two test tests in the initial state and the abrasion state for the anti-skid coating, and in each state, it is divided into three forms: dry state, wet state and oil state, as shown in Table 1.

In view of the fact that my country's flight deck anti-skid coatings are still in the groping stage, the friction coefficient can be formulated in accordance with its own technical level and slightly lowered with reference to the requirements of the US military.
However, the test under two test conditions and the assessment of the dynamic friction coefficient should be ensured.

3.

Frequent take-off and landing of carrier-based aircraft will cause huge wear and tear to the anti-skid deck coating of the flight deck.
Therefore, the wear resistance of the anti-skid coating needs to be strictly assessed.
my country's existing standard GJB5066-2001 stipulates the abrasion resistance of the anti-skid paint for helicopter decks, requiring the use of (500g)/(1000r) rubber grinding wheels for grinding, and the abrasion quality is not more than 15mg to qualify.
This requirement is an increase of nearly 85% compared to the requirements in GB/T9261-2008, which is currently the highest domestic standard requirement.
In the US military standard, in consideration of the protection of the blocking cable, a special cable wear tester is used for testing, and the mass loss rate of the coating and the diameter of the steel test rod are measured respectively, and the coating mass loss rate is required to be no more than 10% , The difference of steel rod diameter is not more than 0.
025mm.
The wear resistance in the US military standard is closer to actual use requirements, not only taking into account the protection of the aircraft, but also taking into account the protection of the blocking cable.

When my country is formulating the abrasion resistance index of anti-skid coatings for flight decks, it should also consider the abrasion caused by the coatings on the barrier cables, rather than blindly pursuing high abrasion resistance.
During the test, attention should also be paid to the abrasiveness of the coating on the welded part.
Since the surface of the weld is uneven, and there are welding slag or rust, it is easy to cause bubbles in the paint at that place.
Therefore, special tests on similar parts are required.

3.
3 Performance indicators of worn parts

When conducting paint testing, most of the indicators except for slip resistance are based on the initial state of the paint.
In consideration of actual use and improvement of coating technology, it is of great significance to carry out performance testing on the wear parts of the coating.
The performance test of the worn part mainly considers the degree of pulverization and corrosion resistance of the bare surface.

3.
3.
1 Degree of chalking

Generally, resin is the main component of anti-skid coatings for flight decks.
This type of organic material has a tendency to degrade under atmospheric conditions, and the degradation effect is more obvious under strong ultraviolet light, high temperature and high humidity.
Under the effect of degradation, the base material in the non-slip coating will be decomposed into volatile substances or water-soluble substances, which will reduce the base material of the surface coating, causing the coating film to shrink and the thickness to decrease.
When the surface base material is reduced to a certain extent At that time, pulverization began to appear.
Due to the loss of the surface protection of the worn parts, the degradation and chalking of the inner layer of the anti-skid coating accelerates.
In order to ensure the safety of aircraft take-off and landing, the degree of chalking of the anti-skid coating on the wear area should be used as a performance evaluation index.

At present, neither the US Military Standard nor the National Military Standard has any standards regarding the degree of paint chalking after abrasion.
GB/T9261-2008 only mentions the chalking requirements for the unworn paint in the weather resistance, and GB14826-93 is only the evaluation method for the degree of chalking of the colored paint.
This index requires data accumulation in the scientific research and test stage, and full consideration of the particle quantity grade and volume boundary that affect the safe take-off and landing of the carrier-based aircraft, and then develop a quantitative performance appraisal index.

3.
3.
2 Corrosion resistance

During the construction of anti-skid coatings for flight decks, multiple layers of paint are usually applied to achieve the required performance and thickness.
The parts subject to wear, especially the exposed steel plate, the gaps between different paints and the gaps between the paint and the steel plate are susceptible to corrosion by media such as salt spray, mold, and oil.
The US military believes that anti-skid coatings for flight decks need to be tested for corrosion resistance after the second impact of the coatings based on the use environment, ocean atmosphere, sea water, carrier aircraft fuel, deck cleaners, and antifreeze and anti-fog fluids.
The U.
S.
military has also formulated related tests for salt spray resistance, light and water artificial accelerated aging resistance and chemical substance solution resistance according to different coating types in accordance with corresponding standards to make a final assessment of the corrosion resistance of non-slip coatings, see table 2.

my country's GJB5066-2001 and GB/T9261-2008 only set requirements for the initial salt spray resistance, salt water resistance, diesel resistance and artificial weathering resistance of helicopter deck paint and general deck paint.
The requirements are not only It is lower than the US military standard and is not suitable for anti-skid coatings for flight decks.
This part of the performance appraisal index should be formulated by drawing on the testing methods and evaluation standards of the US military.

3.

The flight deck anti-skid coating not only has to withstand the impact of the tires when the plane is landing, but also the impact of the tail hook.

In the US military standard, in addition to the evaluation index of impact resistance, there are also requirements for crack level and crack level.

3.

When a carrier aircraft is taking off and landing, the high temperature wake will cause damage to the flight deck.

3.

As a special material, anti-skid coatings for flight decks affect the health of personnel and the use of equipment.