Spray enamel coating in wet process

Spray enamel coating is to compress air to spray enamel slurry or powder to body metal. Spray enamel coating in wet process is prevented first, then in the mid of 20th century, dry powder spray is prevented, it’s to use electrostatic adsorption to let enamel powder adhere on body metal. There’re mainly 2 ways of spray enamel coating in wet process: handwork spraying and automatic machine spraying.

1, Handwork spraying

Handwork spraying can be applied to almost all product, especially for those which has very elaborate line and pattern for decorations and with very complex shape. The weakness for handwork spraying is low efficiency, high labor strength for the workers. And the quality of final products depends much on workers’operation proficiency

For spray enamel coating in wet process, the caliber of spray gun can be adjusted according to types of enamelware and property of enamel slurry. Enamel slurry can be supplied by cup on spray gun or peripheral express tank. For product with little usage amount and need to change frequently, the cup on spray gun is suitable. For example, enamel cookware which always need to coated with patterns in many colors for decorations. When the using amount of enamel slurry is very huge and with single type, peripheral express tank will be better. For example, stove grill, cast iron cookware with single color and big architecture panels. For these, enamel slurry in express tank will easily sink, so the enamel slurry inside need to be swigged constantly to keep its balance, to prevent any bad effects due to the sink of enamel slurry.

To achieve better atomization effect, enamel slurry for spray enamel coating in wet process should be finer, but also need to pay enough attention to the quality after drying and firing. To prevent cracking and shrink of enamel surface. The specific gravity of enamel slurry better be higher. As with higher specific gravity, spraying time can be reduced. For single faced coating, required coating thickness can be attained as long as spray gun passed it for few times.

2, Automatic machine spraying

For big objects, automatic machine spraying should be applied.

The products will be horizontally hanged and pass through a channel with many spray gun around. Spraying can be done automatically when the product passed through.

Enamel pots should be placed on the transmit line and sprayed with many spray guns. Every spray gun should be adjusted with suitable anger and be fixed. To coating every face of product with required standard. When product pass through the scope that the spray gun can reach, except to go forward, it should also turn around, to ensure full coating. Enamel slurry supply system of automatic spraying machine usually include express tank, tube, liquid level control, and filter sieve etc…supply system will transport enamel slurry to spray gun. Traditional supply system is express tank, it can be used for store and also offer high express to transport. Then develop to store tank with diaphragm pump together. This makes it more convenient for continuous enamel slurry supply or change enamel slurry types and easy to clean after work.

Dipping enamel coating in wet process

Wet process enameling is to coat enamel slurry to metal body. There are mainly 3 ways for wet process enameling: dipping, spraying and flow coating. First, let’s know about dipping enamel coating.

Dipping is the most primitive and easy way in enamel coating. It’s fit for product in single color. If metal body is small and with simple shape, we just need to dip it in enamel slurry and take it out after it adsorb enough enamel slurry, then wipe off redundant enamel slurry. If metal body is complicated, we will need turn it in enamel slurry and swing, turn or hook it to wipe off redundant enamel slurry. To achieve a uniform enamel coating .


The specific gravity and stop flow of enamel slurry is of crucial importance. Need to be measured constantly. When the stop flow of enamel slurry is low, it will need stop flow additive to adjust. For metal body with different sizes and complexities, there’re also different requirements for its specific gravity and stop flow.

1, For small product with complex shape. Specific gravity and stop flow of enamel slurry should be higher. The quality of enamel coatingdepends more on the worker’s operant level

2, For big product with simple shape. specific gravity and stop flow of enamel slurry can be lower. For the production of this product, dipping and swing can be done by one worker and other assistant works done by another operator. By this, enamel coating process is dispersed by specific workers, which makes enamel coating with high quality and more stable and the physical exhaustions of workers is also divided.

3, For product with multiple coating and firing, ground coat thickness need to be as thin as possible, to reduce the problems that happen in subsequent process. Especially for the product with decal, as the problem will mostly appear in decal firing. Traditional tools and facilities for enamel dipping is very simple, mainly include jar, pliers, grill. For products need special handle on the edge, there’re also special tools, such as: side wipe rubber, rolling case and plate. Those tools are all customized without any standard model for it.


In reasonable enamel coating process, enamel slurry should be coated on metal body with uniform thickness. It will make big difference to final product’s property. Also will affect the quality and appearance of enamelware.

Noli Porcelain Enamel Solution for Oven Part

For customers who manufacture gas stove or oven part made by 0.5mm to 1.mm thickness high quality low carbon steel, Nolifrit can supply them with high quality porcelain enamel frit meet with Europe RoHS and US FDA standard. Also with very nice heat resistance and thermal shock resistance. Effectively solved fish scale problem and at the same time, it has very strong adherence.

We also have one-stop solution service to supply you with suitable products, include our porcelain enamel frit, enamel pigment, milling additives, degreasant and adherence promoters. Those product can be purchased all together from Hunan Noli Enamel Co., Ltd.

We can offer technical guidance and after-sales service. Simultaneously, we can also customize the color and porcelain enamel coating for our customers. To satisfied the personalized requirements.


Typical Case:

One of the top 10 manufacturers of home appliance in Egypt.


Weak adherence of oven part

Nolifrit Solution:

Use three types of porcelain enamel frits (high+ mid+ low temperature) mixed,to expand the firing temperature range.

And prolong the firing time.


Problem solved after customer take our advice:


     Before(Weak adherence)                   After(Strong adherence)

Hunan Noli Enamel Co,. Ltd is the leader manufacturer of porcelain enamel frit and enamel powder in China. Focused on enamel coating for almost 30 years.

We can offer very professional technical guidance and product solutions. To solve the problems our customers will likely face in their production. We have successfully solved most of the problem of our customers, which makes us with very good reputation and build up the profound trust between us and our customers.

How to Test Adherence Level for Enamel Coating

The adherence level of enamel coating can not be directly judged by its surface appearance. As the combination of enamel coating layer with steel is hidden inside. While Nolifrit has a very professional method to test adhesion of enamel coating.
20181013074523_16391Test Principle
Test weight generates a cavity on the enamel coating surface as the result of free fall. The enamel in this region breaks and the effect of the impact visually examined. The impact effect is scored in accordance with the following graduation scale. This result is recorded as adhesion value of the enamel.
Test Method
Impact testing instrument on the picture is used. The impact apparatus has a specific diameter with specific weight and spherical tip. The plate with enamel coating is placed on the annular metal mould.
Structural Specifications
A pipe with a length of 1 meter and an inner diameter of 21 mm is positioned fully vertically on an appropriate chassis. A channel is opened on one side of the pipe. There are various sections positioned on various heights of the pipe in order to fix the weight.
The weight of impact apparatus inside the pipe is 2kg. The tip of this apparatus is designed to be a hemisphere with a diameter 10 mm. The distance between the end of the pipe and the metal mould is adjusted in a manner so that the power of the vertical load weight will not decline.
Distance between the impact weight and metal plate to be tested is 0.75 m. The impact part is released from this position, so the impact energy is determined as 15 kj. Impact energy = Falling height X Impact weight X Gravitational constant.

The result can show the adhesion level of enamel coating with steel plate. There are mainly 5 levels as follows:QQ截图20190619101809

Hunan Noli Enamel Co,. Ltd is the leader manufacturer of enamel frit and enamel powder in China. Focused on enamel coating solutions for almost 30 years.

We have very professional laboratory and engineer to test enamel plate. Our ground coat all meet with the standard of Excellent level. Which make the quality of our enamel frit supreme and stable.

Efcolor cold enamel coating

Efcolor enamel powders are fired at just 150ºC, so there is no need for a specialist kiln. They can be baked in your home oven, or use the specially designed Efcolor Tea Light Stove (If you have a fan assisted oven you might need to check where you place your pieces, so that the fan doesn’t blow the powder off before it has had a chance to set).

Efcolor enamel coating can be used on a wide range of surfaces inlcuding wood, porcelain, glass, silver, copper, bronze, brass, stone, ceramic or any other surface that can be fired at 150ºC… including our great range of copper blanks which can be found here.

You can get some great effects by sifting through stencils or shapes, or by adding elements to the powder and then baking in place. We recommend you get a sifter/sieve top to make it easier to spread the colour over your surface.

This article comes from metalclay edit released

Safety and Benefits of Using Enamel Coating Cast Iron Cookware

While traditional cast iron cookware is still an essential part of any kitchen the majority of cooks and chefs prefer the enameled version. Enamel coating cast iron is much easier to clean and there are no seasoning issues. The inner coating provides non-stick properties and prevents iron leaching into your food. This cookware pieces come in a variety of vibrant colors to meet customer expectations and to match existing colors in kitchen design.

Is Enameled Cast Iron Cookware Safe?

lt in iron rising to toxic levels. Excess iron levels in the body can lead to serious health problems.This, of course, isn’t a problem with enamel coating iron. The main benefit of enamel coating pieces over traditional cast iron vessels is their inertness. The enamel coating is non-reactive, so you can cook all types of foods in those pots. Once the enamel coating has been removed from the interior surface, it may no longer be inert, and cast iron in the pot’s core will leech into the food.

Enamel coating iron cookware is considered safe, according to the FDA’s Center for Food Safety and Applied Nutrition. The lines of cookware imported from abroad must meet the FDA safety standards. The importation of products that contain potentially toxic substance cadmium in their glazes is prohibited and manufacturers have discontinued use of cadmium-based and lead-based pigments.

To ensure the safety of your cookware buy only good quality enamel products from a trusted brands. The coating must be thick enough that it won’t easily chip. Avoid bringing in glazed cast iron vessels from abroad.


The following are some advantages that enamel coating cookware offers:

Enamel cast iron cookware is healthy and safe to use. Unlike pure cast iron, this utensils don’t interact with your food, so you can cook any type of food in them including tomatoes and other acidic foods.

Enamel coating provides a non-stick surface that makes cooking easy without food sticking to the bottom.

Enameled cast iron pieces are extremely durable. The products last for many years and can be passed from parent to child.

The pans and pots can be heated to high temperatures, which makes them a popular choice for searing and braising foods.

Cast Iron construction conducts and holds heat very well, providing an even consistent temperature throughout the entire pot, which is perfect for cooking soups, stews and chili.

Superior heat retention is helpful in keeping the food warm when serving. These pans only need a low to medium heat, which makes this type of cookware energy efficient.

This cookware is suitable for all heat sources and any type of stove top. It is also acceptable for refrigerated food storage and can be used as a serving dish on the table.

The enamel glazed surface does not need any kind of seasoning, so it requires very little maintenance. Enamel glaze also prevents rusting and comes in various colors for visual appeal.

This article comes from healthy-cookware edit released

What is Enamel Coated Cast Iron?

20180426What is EnamIt’s like regular cast iron, but… Wait for it… It’s coated by enameled paint.

It’s safe to use with acidic foods, like tomato based sauces or chilis, and has a high heat retention due to its thickness and generally awesome cast iron qualities. Additionally, these skillets are also safe to use in the oven, on all stoves and on the grill.

I would slightly hesitate to use the really ornate, pricy cast iron out on the barbie due to the risk of damaging the somewhat delicate, glossy coating. I am talking about something like Le Creuset or a comparable brand. Like this one on Amazon:el Coated Cast Iron?

Enamel coating iron is also heavy which may be a positive or a negative depending on if you have other plans for the cookware such as protection against an intruder.

If you don’t have a sandwich or panini press you can use a preheated dutch oven or skillet.

Enamel coating iron also has a lower thermal conductivity when compared to simple cast iron; many chefs use the time it will take to heat up an enamel coating iron Dutch oven and complete other tasks in the meantime.

These skillets are also more expensive than traditional cast iron, particularly when you compare well-known brand names, like Le Creuset. However, if you can find these skillets at flea markets, thrift stores or from an aging relative, you may be able to save some money.

But, thankfully well known names like Lodge and other cookware brands have gotten into the enamel coating iron game. Which is great considering the high prices of some of the imported pieces.

This article comes from thekitchenprofessor edit released