VCI Paper
Guidance
Ver. 1ADCOAT CO., LTD.

Preface

This handout gives a brief explanation of VCI paper, “Why do metals rust /corrode?” “How can we use VCI paper to prevent rust / corrosion?” “What are thecautions to take when using VCI paper?” etc. The main purpose is aboutcommonly how to use VCI paper, so our brand “adpack®” is not described, but it isan explanation of VCI paper in commonly, including other companies' products.
“Rust prevention oil”, “rust prevention agent (rust / corrosion inhibitors)”, “rustprevention film”, “desiccant”, etc., which are often compared with VCI paper,
which is a packaging material. However, these do not been explained in thishandout.
ADCOAT CO., LTD.
Technical Division

01

Contents

02

0. Preface ・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・

01

1. Definition ・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・

03

2. Rust / Corrosion ・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・

04

2-1. Saturated Vapor Pressure ・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・

04

2-2. Theory ・･･････・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・

05

2-3. Type of Corrosion ・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・

07

2-4. Type of Dirt ・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・

07

2-5. “Capillary Phenomenon” & “Salts of Sweat etc.” ・・・・・・・・・・・・・・

08

2-6. Others ・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・

08

3. Mechanism of Corrosion Inhibitors ・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・

10

3-1. Oxide Film ・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・

10

3-2. Adsorption Film ・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・

10

3-3. Complex Film ・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・

10

4. VCI Paper ・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・

11

4-1. Constitution ・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・

11

4-2. Type ・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・

11

4-3. Evaluation Test according to JIS (Japanese Industrial Standards)

124-4. Usage ・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・

13

5. Example of Using ・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・

14

6. VCI Paper Trouble Cases and the Solutions ・・・・・・・・・・・・・・・・・・・・・・・・

18

Definition
・ RustOxide or hydroxide of “Iron”

・ Corrosion
Phenomenon that general metal such iron or copper erodes or deteriorates.

・ VCI Paper
Combination of Volatile Corrosion inhibitors and paper such kraft paper.
Alias: anti-corrosion (anti-rust) paper・ Corrosion Inhibitors
The chemicals of “Simple substance” or “Mixture” with protecting of metals
from corrosion/rust, and it may vaporize at room temperature.

・ Moisture-Proof Paper

Packing material of combination with polyethylene (PE) etc. and paper.
Protect from outside moisture.

・ Acid-free Paper
PH of paper is neutral region.
Common kraft paper is acid region, acid paper.

・ Crepe Paper
Wrinkled paper.

Reference）
JIS Z 1535:2014
JIS Z 0103:1996
JIS Z 0108:2012
JIS P 0001:1998

03

Rust / Corrosion
2-1. Saturated Vapor Pressure

Saturated Water Vapor Amount/[g/m 3]

200
175

150
125

100
75

50
25

0
0

5

10

15

20

25

30

35

40

45

50

55

60

65

70

Temperature/ C

Fig 1. Saturated water vapor curve in the atmosphere
Table 1. Saturated water vapor amount in the atmosphere [g/m3]
°
C

0.

1.

2.

3.

4.

5.

6.

7.

8.

9.

0.

4.85

5.20

5.57

5.96

6.37

6.80

7.27

7.76

8.28

8.83

10.

9.41

10.03

10.68

11.37

12.09

12.85

13.65

14.50

15.40

16.33

20.

17.31

18.35

19.45

20.60

21.80

23.07

24.40

25.80

27.24

28.78

30.

30.39

32.08

33.84

35.65

37.58

39.60

41.71

43.91

46.21

48.61

40.

51.12

53.73

56.46

59.36

62.32

65.41

68.89

72.04

75.51

79.13

50.

82.98

86.90

90.96

95.16

99.56

104.23108.94113.98119.07124.3560.

129.81135.62141.50147.56153.85160.53167.53174.22

181.62189.04The upper limit amount of contained water vapor in atmosphere is fixed. For example, in
the air at 30°
C is 30.39 g/m3 is upper limit amount (Saturated water vapor amount).
Humidity of at this condition is 100%. Water vapor amount cannot exceed the upper limit
amount. So, “Temperature 30°
C, Water vapor amount 35.00 g/m3” does not exist.
If temperature 30°
C / Water vapor amount 30.39 g/m3 [Humidity 100%] rises temperature
40°
C, the humidity is 59% [ = “30.39 g/m3” ÷ “51.12 g/m3” × 100] because saturated
water vapor amount at 40°
C is 51.12 g/m3.
On the other hand, if temperature drop to 20°
C, the humidity is 100%. However, 13.08
3
3
3
g/m [ = “30.39 g/m ” － “17.31 g/m ” ] is dew condensation (water) because saturated
water vapor amount at 20°
C is 17.31 g/m3.

04

Rust / Corrosion
2-2. Theory
Main cause of rust / corrosion is oxygen in the air dissolves in the water layer on the metal
surface, and three substances, “metal + water + oxygen”, react. On the other hand, Thereis also corrosion such as silver that is not reacted with water and oxygen. This rust /corrosion reaction is an "electrochemical reaction". As we call "electrochemical”, weakelectricity flows on the metal surface, and formed “battery cell”. The following figure is an
example of iron rust / corrosion. Other reactions may occur depending on the environment
state.
rust
water
OH-

Fe2+

steel

epositive pole

negative pole

1st StepFe

1/2 O2 + H2O + 2 e-

Fe2+ + 2 e- Oxidation Reaction

2 OH-

Reduction Reaction

Fe3+ + e-

Oxidation Reaction

OH-

Reduction Reaction

2nd Step
Fe2+
1/4 O2 + 1/2 H2O + e-

Fe
(Iron)O2+

2H2O(Oxygen)(Water)
Fe2+

+

+

2e-

Fe2+ + 2e(Iron ion) (Electron)
4OH(Hydroxide ion)

2OH-

Fe(OH)2(Iron(II) hydroxide, White color)
4Fe(OH)2 + O2 + 2H2O

4FeO(OH)・nH2O(Iron(III) hydroxide, Red color)Fig 2. Example of iron rust / corrosion reaction
05

Rust / Corrosion
The word “battery” is written on theprevious page, if you have a good
intuition, you will be thinking there
are positive and negative pole(charge). The answer is “Yes”. This
positive and negative pole (charge)
forms a battery on the metal surface,Fig 3. local-action cells on the metal surface
and rust / corrosion occurs whenelectricity flows. The reason why there are positive and negative charge is that common
metal materials are multi-elements, so the charge is generated due to the difference in theproperties of the elements. For example, in the case of stainless steel, the main elements
are iron (Fe), and elements such as chromium (Cr) and nickel (Ni) are also containing. The
positive and negative charge are generated by the difference in the properties of individual
elements.
Following tables 2 and 3 show the relationship between the corrosion resistance of various
metals depending on pH.
Table 2. Corrosion resistance of various metals on pH

+

-

pH

0

Steel

Corrosion (acid)

Stainless

2

4

-

6

+

+

-

10

Corrosion (oxygen)

12

14

Passivation

Passivation

Corrosion (acid)

Aluminum+

8

Corrosion (acid)

Zinc

+

-

Corrosion (acid)

Corrosion

Passivation
Passivation

Corrosion

Table 3. Relationship between various metals and solutions
Concentrated nitricacid or sulfuric acid

Hydrochloric acid
Dilute sulfate

Acidity(pH3 - 5)

Neutral*1

Seawater

Alkalinity

Zinc

Corrosion

Corrosion

Corrosion

Protective
Film

Protective
Film

Corrosion*3

CopperCorrosion

Stability*2

Protective
Film

Protective
Film

Protective
Film

Protective
Film

Aluminum

Passivation

Corrosion

Corrosion

Passivation

Passive Film
(Pitting Corrosion)

Corrosion*4

StainlessPassivation

Corrosion

Passivation

Passivation

Passive Film
(Pitting Corrosion)

Passivation

ChromePassivation

Corrosion

Passivation

Passivation

Passivation

Passivation

Carbon Steel

Passivation

Corrosion

Corrosion

Corrosion

Corrosion

Passivation*1 Trace amount of chloride ion*2 Corrosion: Dissolved oxygen*3 Corrosion: pH13<*4 Corrosion: pH8.5<

Reference）

06

R. Winston Revie; Herbert H. Uhling. Corrosion and Corrosion Control: An
Introduction to Corrosion Science and Engineering, 4th Edition, Wiley InterScience,
2008.
Matsushima; 腐食防食の実務知識, Ohmsha, 2002.

Rust / Corrosion
2-3. Type of Corrosion
There are various types of rust / corrosion depending on the mechanism of rust /corrosion. The differences are occurred by the combination of the type of metal and theusage environmental. Typical corrosions are as follows.
There are different types of rust / corrosion, and the factors that cause them are different,so the prevention methods are also different. For example, "oil staining" is caused byoxidation of oil such as applied rust preventive oil, so is given as this countermeasure"removal and reapply oil regularly", "use no oil, and use another anti-rust wrapping
materials", etc.
1.

General Corrosion

2.

Local Corrosion

3.

Pitting Corrosion

4.

Crevice Corrosion

5.

Galvanic Corrosion

6.

Dealloying

7.

Intergranular Corrosion

8.

Erosion-corrosion

9.

Cavitation Damage

10.

Fretting Corrosion

11.

Stress-Corrosion Cracking [SCC]

11.

Corrosion Fatigue

13.

Scale

12.

Oil Staining

Fig 4. Main Type of Corrosion
2-4. Type of Dirt
The following are listed in the US military handbook as types of dirt that cause rust /corrosion. This dirt are natural enemies of anti-rust /anti-corrosion packaging materials,
containing VCI paper. If metal products are not properly cleaned and dried, this dirt cause
rust / corrosion even if the anti-rust / anti-corrosion packaging material is used properly.
1.

Body secretions [finger prints, sweat, etc.]2.

Residues during soldering, welding / Wax

3.

Cutting or cooling agent

4.

Abrasive

5.

Metal residues of machining, polishing, etc.

6.

Residues of salts for heat treatment

7.

General waste from work place, etc.

8.

Attachment of dust or chemicals in the atmosphere

9.

Residues of ink or etching solution
Fig 5. Main Type of Dirt

Reference）
Technical Order 00-85-3, Corrosion Control for Packaging, 1963.

07

Rust / Corrosion
2-5. “Capillary Phenomenon” & “Salts of Sweat etc.”
When foreign objects adheres to the metal surface, a phenomenon called “capillary
condensation” will occur. This is a phenomenon in which moisture enters a slightinterspace (capillary part) between objects, and the moisture (gas) changes to water(liquid). In addition, when sweat is dried on the metal surface, salts contained in the sweat
remains on the surface. In high humidity environment, these salts may absorb moistureand return to liquid. It makes easier for electric flow of rust / corrosion reactions becauseof salty water conducts electricity well (see pages 5 and 6).
Moisture
Foreign Object
Salts

Metal

Metal
Enlarge
Moisture
Absorption

Condensation

Condensate
Water

Fig 6. Capillary Phenomenon

Fig 7. Salts of Sweat etc.

2-6. Others
Silver (Ag) differ the metal such as copper alloy and steel, and is not corroded by “Water"and “Oxygen". What cause?
As one of the cause, “Hydrogen sulfide (H2S)” is. Silver react with sulfur compounds likehydrogen sulfide. If you bring the silver items at hot spring, the color of items will change toblack. Hydrogen sulfide is produced from exhaust, paper and skin etc. under general life
environmental, because of degradation of sulfur compounds.

2Ag + H2S → Ag2S + H2
[Black]Reference）
V. S. SASTRI. GREEN CORROSION INHIBITORS, Wiley, 2011.
08

Rust / Corrosion
Temperature and Humidity in our factory
The following reference data of temperature and humidity are data in Japan. These data
were in 2017, were recorded every 1 h in our factory. These graphs are “Highest value”
and “Lowest value” in a day.
40
35

Temperature/°C

30
25
20

15
10
5

0
1 Jan. Feb.

Mar. Apr.

May. Jun.

Lowest Temperature in a day

Jul. Aug

Sep. Oct.

Nov. Dec.

Highest Temperature in a day

Fig 8. Highest and Lowest Temperature in a day
100

Humidity/%RH

80

60

40

20

0
1 Jan. Feb.

Mar. Apr.

May. Jun.

Lowest Humidity in a day

Jul. Apr.

Sep. Oct.

Nov. Dec.

Highest Humidity in a day

Fig 9. Highest and Lowest Humidity in a day09

Mechanism of Corrosion Inhibitors
The action of the inhibitors are divided into the following three types in Japan.
3-1. Oxide Film
Oxide film is a film formed by oxidizing the metal surface with oxidant. When a lot of
people hear "oxidation", they may be reminded of "rust / corrosion". However, theoxidation state of the metal produced by the oxidant is different from the state of "rust /corrosion". Examples of oxidant are "sodium nitrite" etc.
Oxide Film
(metallic oxide)

Metal

Oxygen3-2. Adsorption Film
This is a film of “Inhibitor for iron and steel”. A substance having both “hydrophilic group”
and “hydrophobic group” adsorb onto the metal surface, and the film is formed. At thistime, the hydrophilic group contact with the metal surface. The bonding of the inhibitor
and the metal surface is not strong. Therefore, the inhibitor can evaporate naturally or be
wiped off with a solvent. Examples are “amines" etc.
Water [humidity]
Metalhydrophilic grouphydrophobic group

3-3. Complex Film
This is a film of “Inhibitor for copper and copper alloy”. A bonding of the inhibitor and themetal surface is strong. Usually, the film can not be removed unless polishing etc.
Examples are “triazole compounds" etc.
Metal salts
H
N

Cu (I)-BTA

10

N
N

Metal

H
N
N
N

Metal

Cu N

N

N

Cu

N

N
N

Cu

N

N
N

Cu

VCI Paper
4-1. Constitution
The basic construction of VCI paper is "paper + inhibitors".
VCI paper is not “oil paper”. Oil paper is applied oil to paper, and moisture-proof better.
And the oil paper is not contained inhibitors. Popular VCI paper with moisture-proof better
is PE (polyethylene) is coated on the one side. Some companies have been using wax
instead of PE.
Base paper of VCI paper is usually using “acid-free paper / neutral paper”. The acid-free
paper is controlled from neutral to alkaline of pH region. Since normal paper is acid, metal
is easy to rust.
Inhibitors used are 2 type, impregnated type: inhibitors is between paper fibers, coated
type: mixed inhibitors and adhesive and they are coating on the paper surface. Popular
type is “impregnated type”, but DHICAN (Dicyclohexylammonium nitrite) of one of
inhibitors is difficult to dissolve in water. So, it mix with adhesive and water, and coat on
the paper surface.
In the case of steel like cut sheet or coil, the base paper of VCI paper uses paper withcloth sheet of PE. This type of paper is stronger than kraft paper of paper with PE. And,wrinkle processing type is also. This type is called “Crepe paper”. This crepe paper
stretches, can use like bandage.

4-2. Type
Types of VCI paper mainly have “for iron and steel”, “for copper and copper alloys” and “forferrous and non-ferrous” depending on the target metal.
Just as individual metals differ the properties, so compatibility with inhibitors and metals.
Therefore, we have to change the inhibitors depending on the target metal.
For example, sodium nitrite is famous as common inhibitor, this formed oxide film on themetal surface. However, if this was used for copper / copper alloys, the color of copper /copper alloys will change darker, because the thickness of oxide film of copper / copper
alloys increase. On the other hand, in the case of use it for iron, the color is almost
unchanged even if the oxide film becomes thicker.
It is necessary to select VCI paper suitable for use from the combination of "type of VCI" and"type of paper".
For example, if you use VCI paper on the bottom or top of a container, it is not necessary to
use a PE laminated type (moisture-proof type). However, in the case of packaging of heavy
products, if there is no paper strength, such as a type without PE cross sheet, there is a riskof tearing during packaging or transportation.

11

VCI Paper
4-3. Evaluation Test according to JIS (Japanese Industrial Standards)
JIS of VCI paper are the below 2 types (As of 2019).
・ JIS Z 1535 [Review: 2014]: Corrosion inhibitor treated papers for iron and steel
・ JIS Z 0321 [Issue: 1997]: Volatile corrosion inhibitor paper for copper and copper alloys(There are not test about JIS of the other metals like aluminum.)
There are 2 types, “Volatile Test” and “Contact Test”.
In addition to these JIS tests, the products are actually packaged, and using anenvironmental testing machine. The products are promoted rust / corrosion under the
specific temperature and humidity, and we evaluate them.
JIS Z 1535

JIS Z 0321
Copper / Brass /Phosphor bronze [plate]

Steel (SGD3)

Volatile Test

VCI paper:
30 mm×130 mm,
2 sheets

VCI paper:
71.5 mm×280 mm
Temperature cycle:
30°C / R.T. / 5°C / 50°C
/ 5°C / 50°C /Temperature: 20°C
(Using cool water)
Humidity: 90%RH

Contact Test

Humidity: 100%RH

Steel (SPCC)

Evaluation

Temperature
50°C

12

Top

BottomCopper / Brass / Phosphor bronze [plate]
Humidity
100%RH・ Volatile Test (Pass)
Type S: Not Rust
Type H: Not Rust
Type EL: Rust prevention rate, 50%<・ Contact Test (Pass)
Not Rust

Temperature
50°C

Humidity
95%RH

Grade A: Not Change
Grade B: Slightly Discoloration
Grade C: A Little Discoloration
Grade D: Discoloration
Grade E: Terrible Discoloration / Corrosion
Grade A and B are Pass.

VCI Paper
4-4. Usage
1. VCI in VCI paper is finite.
⇒ If keep expose of VCI paper (for days), VCI will gradually vaporize from VCI paper,
reducing the total amount of VCI. As a result, the performance of VCI paper reduce.
When not in use, store it in a plastic bag or container.
2. You can leave VCI paper exposed during working (about half a day).
⇒ Generally used VCI paper is that the VCI contained in VCI paper graduallyvaporizes, but the amount of vaporization loss during working (about half a day) is avery small amount, the performance of VCI paper does not reduce.
3. Use with the printed side or PE laminated side outward.
⇒ VCI is impregnated/coated on the kraft paper side.

4. The storage location is preferably “cold dark place”.
⇒ This is to prevent product deterioration.
5. It is safe to touch the product with bare hands.
⇒ The base material is paper, and the behavior and content of the contained VCI issmall, making it harder to rough skin than rust preventive oil (base material is oil),which is often compared. However, since VCI is often not edible, you should wash
your hands after touching VCI paper.
6. Can be used in combination with rust preventive oil/desiccant/rust preventive film.
⇒ There are no companies that recommend VCI paper and these combinations, butsome customers used in combination. In rare cases, it may cause some chemical
reactions with VCI, and the causes of discoloration and foreign objects.
7. If the packaging form is moisture-proof, the rust-proof period will be extended.
⇒ Moisture is prevented from entering the packaging, and VCI vaporized from VCI
paper hardly become to go outside the packaging.
8. Mainly VCI paper is only effective against dew condensation.
⇒ If there are many corrosive factors (foreign objects) on the metal surface due toinsufficient cleaning, etc., it may be impossible to anti-rust with VCI paper.
9. The rust-proof period is not constant.
⇒ For example, if “The rust-proof period is less than 6 months” is written on the
document, the products do not rust/corrosive reliably even after the storage period 6
months. The rust-proof period change by the condition of the packaging and metal
and the storage environmental.
10. The disposal method is the same as that for general paper (in Japan).
⇒ Follow the relevant laws/ordinances of each country and region.
11. The size of VCI paper used for packaging must be changed according to the situation.
⇒ There is the rough indication size of each company, but it is necessary to change
the size according to the usage environment. If the size is smaller than the roughindication size, it is necessary to test with the actual packaging. There is not
generally formula of the determine size.
13

Example of Using
Conditions for rust-proof packaging with VCI paper are: “Metal products are not rusted”,“Metal product surface are clean”, “VCI paper is properly stored”, “Do not reuse
VCI paper / disposable”, “Type of VCI paper and target metal combination isappropriate”. The most common trouble cases are “Products are already rusted / dirtied
before using VCI paper”.
The required size of VCI paper differs depending on "metal type / surface treatment
method of metal / storage environment / etc.", so it can not be determined with one
formula. Also, even if the metal is the same manufacturer and the same standard, thecorrosion resistance may change if the production lot is different.
Since only VCI paper is effective, "rust prevention oil" and "desiccant" are not required.

Packaging “A”

Wrapping by kraft paper (not moisture-proof) type1

2

It is sufficient if the metal product is packaged, and it is not necessary to seal with tape as
in packaging "B".
Packaging “B”

Wrapping by PE laminated paper (moisture-proof) type1
Close the gap with tape to prevent outside air from entering.

14

2

Example of Using
Packaging “C”

PE bag + kraft paper (not moisture-proof) type1

2

Close the opening of the PE bag to prevent outside air from entering.
It is not necessary to pack the metal product with VCI paper like packaging "A" and "B".

Both of packing "B" and "C" are moisture-proof packaging, andthe evaporated VCI hardly disappaers from in the packaging, so it
becomes a packaging form for long-term storage.
Packaging “D”

Container [VCI paper only on the bottom]

1

2

3
Put another container or a lid on the container containing the products.
The smaller the gap, the better for long-term storage.

15

Example of Using
Packaging “E”

Container [multilayer]

1

2

3

4

5

6

If the board is divided into multiple layers, the vaporized VCI does not diffuse uniformly
into the container with only VCI paper 1 sheet, so it is necessary to place VCI paper ineach layer.
After sandwiching the metal product with VCI paper 2 sheets and making a layer with theboard, put the metal product and VCI paper in the same way.

16

Example of Using
Packaging “F”

Container [interim storage, VCI paper instead of lid]

1

2

When using as a lid, cover whole the products so that they do not get dusty.

Packaging “G”

Big container

Since it is necessary to consider the reach (effective range) of the VCI, it is necessary toplace VCI paper on the top, middle and/or bottom.
Packaging “H”

Crepe paper type of VCI paper

Can use like bandage.

17

VCI Paper Trouble Cases and the Solutions
Problem 1
Metal rusted / corroded / had some foreign objects.
Cause 1・ The products are dirty. [Reusing cleaning solution. The work tools are dirty.]⇒ Use clean cleaning solution and work tools.
・ Cutting solution and cleaning solution remain and on the metal (react with VCI)
⇒ Wash / dry cleanly. Change the cutting solution/cleaning solution to another type.
・ VCI paper size is small.
⇒ Use large size.

・ Sealing is low, Moisture enters the packaging, VCI vaporized goes out of the packaging.
⇒ Increase sealing of the packaging.
・ Rusted before packaging.
⇒ VCI does not have removing rust effect, and not stop rust growth effect also.
・ Mistaking the combination of the VCI paper type and the metal type.
⇒ Package in the correct combination.
・ VCI paper has deteriorated due to reuse and inappropriate storage environment.
⇒ Not reuse VCI paper. Correct storage environmental.
・ There is PE sheet between products and VCI paper.
⇒ VCI paper is required between products and PE because VCI vaporized does notreach onto the product surface.
・ In the case of PE laminated VCI paper type, PE side is touching the products.
⇒ The direction is reversed. PE side is outside.
Problem 2
The plating cracked.
Cause 2・ There are the foreign objects under plating layer, base metal was rusted by them.
⇒ Plating after removing foreign objects. It is the phenomenon in which VCI paper
can not be involved.
Problem 3
Resin, plastic or rubber discolored.
Cause 2
・ Some VCI types have negative effects for them.
⇒ Change VCI paper type.
18

Issue Date:
Revision Date:

Dec. 13, 2019-

ADCOAT CO., LTD.
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