How to Prepare Ready to Use Enamel Powder

Ready-to-use enamel powder are basically mixed by several kinds of enamel frits and milling additives after ball milling. It mainly contains frits, clay, electrolytes, refractors and pigments. Ready-to use enamel powder can be divided into two types.


Complete Ready-to use enamel powder: The grinding process for this enamel powder is completely finished. It can be used just by stirring in a mixer.


1. Put sufficient amount of water into the mixing vessel. The mixer with a high shear force is recommended.


2. Add ready-to-use enamel powder gradually into the mixing vessel until the demanded enamel density is reached. Baume can be used instead of a vessel with fix volume, since it is easier to operate.

3. Stir or ball mill for 10 – 15 minutes. If submersion enamel is going to be used, mixing for overnight is recommended to achieve the enamel stability.


4. Sieved the prepared enamel slurry by a 80 mesh sieve and then it becomes ready to use.


Partial Ready-to-use enamel powder: The grinding process of this enamel powder is partially completed. This enamel powder should be grinded by the user in a mill up to the demanded fineness.


1,Put enamel powder into a mill.

2,Add sufficient amount of water into the mill.

3,Grind the enamel powder up to the demanded fineness.

4,Discharge the enamel slurry and after adjusting its suspension feature, the enamel powder is ready to use.

Features of Cadmium Red Pigment from Nolifrit

Cadmium red pigment is the compound of Cadmium Sulfide and Cadmium Selenide(3CdS•2CdSe). Usually, The ratio of Cadmium Sulfide is 55%, Cadmium Selenide 45%.

Chemical Name Cadmium red pigment
Chemical Compositions Cadmium Sulfide, Cadmium Selenide
Pigment Index No. Pigment red 108
CAS No. 12214-12-9
Shape Red powder
Crystal form Hexagonal crystalline, Cubic crystalline.
Temperature resistance(max) 900℃


Cadmium red pigment has very bright color. It’s of high temperature resistance, alkali resistance, light resistance, and atmospheric resistance. With strong coloring power and covering power, the color pattern of Cadmium red pigment can range from yellow, red to purple. The more Cadmium Sulfide(CdSe) contained in Cadmium red pigment, the darker its red color will be.

Cadmium red pigment can be applied in high temperature resistant paint. It also can be used in enamel, ceramic, glass, plastic, art pigment, print ink, paper, leather, colored sand architecture material and electric material, etc…

(Steel enamel cookware in Cadmium red color🙂


(Le Creuset Cast iron enamel cookware in Cadmium red color:)


Hunan Noli Enamel Co., Ltd is the leader manufacturer of Cadmium red pigment in China, Focusing on the production of enamel pigments over 30 years.

As the sense of environmental protection enhanced in recent years, more and more small manufacturers of Cadmium red pigment have to stop their production, which makes Nolifrit the only and best choice for Cadmium red pigment. As our production is based on factories on west border areas in China, so there’s no worries for environmental pollution.

Cadmium red pigment produced in Nolifrit is very cost-effective, the price is half of the current international brand. Much cheaper than Ferro and Pemco(Prince).

Nolifrit once had a meet with the world’s top one brand of colored cast iron enamel cookware Le Creuset in the 24th International Enamellers Congress in Chicago. Le Creuset showed the strong interests in our Cadmium red pigment series. They are quite willing to build up the long term cooperation with us. If you are also one of the enamel cookware manufacturer like them, you can contact with us, we will send you our best offer for our enamel pigments.


Ceramic porcelain frit

An ISO 9001:2001 certified ceramic porcelain frits manufacturer, we follow stringent guidelines for our supplier selection, porcelain frit technology and technical service standards.

We offer both leaded and no lead porcelain frit varieties available as transparent porcelain frits, glossy porcelain frits and matt porcelain frits designed specifically for double fast firing, single-fired monoporosa and porcelain stoneware ceramic coating applications.

Our specialty porcelain frits are ideal for ceramic coatings used in architectural ceramics, building ceramics, dinnerware and ceramic arts.

This article comes from ferro edit released

How to Test Acid Resistance Level for Enamels

The applications of acid resistant enamel coating is more and more widely, especially in mid and high level market. It’s not only applied in industrial area, where chemical resistance and long lasting durability against the elements is key, but also in our daily life, like enamel cookware and enamel water heater tank.

How to test acid resistance level for porcelain enamel coating?

Nolifrit follows a very serious and effective testing method for this.

Testing Reagent:

15% citric acid is used in this test. It’s reacted on the enamel coating surface and the result can be seen by virtual observation.

Testing Step:

1, Place some drops of citric acid liquid on enamel coating surface.

2, Cover the dropped enamel coating surface for 15 minutes.

3, Wash the test plate, to do the follow tests:


A, Visual Inspection

To inspect the two enamel coating areas directly by eyes. If there is obvious difference between the acid applied area and the regular enamel coating surface, the result is negative.

B, Pencil Test( dry)

Two parallel lines are drawn between the acid applied enamel coating area and the regular enamel coating surface by a pencil. Two lines are swabbed by a dry towel. If it is harder to swab the acid applied enamel coating area than the regular enamel coating area, the result is negative.

C, Reflection Test:

A light source is reflected on the acid applied enamel coating area and the regular enamel coating area. If there is a dim reflection on the acid applied enamel coating surface, the result is negative.


D, Pencil Test( wet)

The test in item B is applied by a wet towel. If it is harder to swab the acid applied enamel coating area than the regular enamel coating area, the result is negative.

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

We have many kinds of enamel frit and enamel powder (ready to use powder and electrostatic powder) with high acid resistance level AA. They are widely used in enamel cookware, enamel storage tank, GGH(gas gas heater) and heater exchangers.

How to repair chipped enamel cookware

Porcelain enamel cookware often has a steel or cast iron base coated in a substance called vitreous enamel. Vitreous enamel is made by fusing melted glass to metal at a very high temperature. This smooth enamel coating protects the metal underlying your cookware. In many cases, the enamel chips over years of use or as a result of improper care. It’s possible to repair these chips or to seek a replacement piece if your enamelware is under warranty.

To repair your chipped porcelain enamel from scratch, purchase a food-safe epoxy. Use the epoxy to gently fill in the space left from where the vitreous enamel chipped away. Let the epoxy harden slightly, and then press a piece of waxed paper over it. Apply pressure to the waxed paper and flatten the epoxy against the cookware. Remove the waxed paper, and let the epoxy dry.

Once the epoxy has dried, you can use 400-grit sandpaper to gently sand the edges of the repaired area so they are flush with the surrounding edges. Take great care not to scratch the nearby enamel coating.

Using a food-safe enamel paint and a paintbrush, cover the epoxy area with a pigment as close in color to the original enamel as possible. Let it dry.

Once you’ve finished the repair process, be sure to wash your enamelware extremely thoroughly to remove all sand or other remnants of the repairs.

If you’re temporarily repairing your enamelware using the method outlined above, you should still plan to replace your cookware or get it professionally repaired for long-term use.

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

We can provide very professional vitreous enamel coating solutions for enamel cookware. We have many customers manufacture high level enamel cookware. Their product exported to EU and US market.

Enamel coating for undersea tunnel wall panels

On 23rd OCT, 2018, Hong Kong-Zhuhai-Macau Bridge opening ceremony is hold in Zhuhai, Guangdong. This bridge will be officially opened to traffic. After this, driving from Hong Kong to Zhuhai and Macau will only take 45mins. This provide much convenience for the residents and travelers both in Hong Kong, Zhuhai and Macau.


This bridge has very long undersea tunnel, the side wall of which is all decorated by vitreous enamel panels.

Vitreous enamel panels, also known as porcelain enamel panels, it’s corrosion resistant, fire resistant and high temperature resistant. Enamel coating thickness can be 0.5mm, and it’s of high weather resistance. Which can be kept for more than 100 years, without any fades even exposed to wind and rain.


Enamel coating is widely applied in our daily life. For example: cookware, oven, BBQ, bathtub and so on. Vitreous enamel panels is only one of the applications among these. Including enamel signage, mark, subway or undersea tunnel wall panels and architecture panels etc…

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

We can provide very professional vitreous enamel coating solution for subway and undersea tunnel wall panels. Our ground coat frit A-9, A-10 and super white frit is specially designed for this field. The quality can be almost same with Japanese enamel frit manufacturer Tomatec and with much lower production cost. Which makes us the top one choice to replace them.

Noli Porcelain Enamel Solution for Oven Part

For customers who manufacture gas stove or oven part made by 0.5mm to 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.

Advice for Making Enamel Mug with Rolled Edge

Enamel mug is quite popular in our daily life. It covers all the advantages of a glass or ceramic mug, but it won’t easily be broken like glass or ceramic mugs. And it can be decorated by varies of colors, which makes it colorful and beautiful, looks much better than steel mug. Also, it’s more healthy and environmental friendly than plastic mug.

Nolifrit has many customers who manufacture high quality enamel mugs with very nice appearance.

One of our customer was facing problem to make those enamel mugs. They use 0.3-0.4mm thickness steel plate. Problem comes from the edge. As picture showed, its metal body exposed on the rolled edge. not fully covered by enamel slurry when coating. This problem is very common among most of enamel mug manufacturers.


He asked for our help and we offered our professional technical service and advice to solve this problem.

Our advice is as follows:

1– When casting the steel body, try to make the edge more curving. To make the rim more close to mug wall, like the picture showed:


2–  There are some burrs in edge. Try to grind the burrs from sharp edge. This work should be done before welding.

3– Make mug rabbet upward when drying enamel slurry.

4—By using enamel frit with higher quality, the result could be better.

5—By using steel plate with thickness 0.5-0.6mm, the result could be better.

After taking our advice, our customer solved this problem completely and can make enamel mug with perfect edge:


Classification of Enamel Frit (2)

Cover Coat Frit

Cover coat enamel frit is coated on the surface of enamelware. By appearance, it can be classified into white frit, colored frit, transparent frit. By features, it can be Acid resistant frit, Alkali resistant frit, Abrasion resistant frit, Microcrystal frit, optical luminescent frit. High temperature resistant enamel frit and insulative frit etc…

①White frit:

White frit can make cover coat in a white color with strong covering power. By the opacifiers used in cover coat frit, it can be classified into Titanium cover coat and Antimony cover coat. In Titanium cover coat, when Titanium dioxide is fired, it can make the surface in super white color, And its enamel layer is thin, so it can save material. It’s most widely applied in daily enamel cookware. The opacification of Antimony oxide in Antimony cover coat is not good as Titanium Dioxide, so its enamel layer is thicker. It’s usually used in cast iron bathtub or other enamelware not for food containers.

(Antimony White Frit:)


Colored cover coat frit:

It’s made by white frit with pigment. Pigment can be added when firing or milling. Colored cover coat frit has colored Titanium frit and colored Antimony frit etc…

(Titanium Ivory Frit:)


Transparent frit:

It has no opacifying power, and it’s transparent enamel frit. It’s usually coated on cover coat to enhances glossiness. And it’s also used as a basic frit to mill pigment together, which is called decal transparent frit.


Enamel frit with chemical properties:

This type has Acid resistant and Alkali resistant frit. Acid resistant frit contains more than 65% silicon dioxide, it’s mainly used in chemical industrial enamel product. Alkali resistant frit contains much Zirconium dioxide and it also need silicon carbide and Titanium dioxide to enhance its Alkali resistance.

(Acid Resistant enamel frit for pipe:)


⑤Enamel frit with mechanical properties:

It’s Abrasion resistant frit. There are two ways to improve abrasion resistance of enamel frit. One is to add Silicon Carbide, Boron Nitride worked as milling additives. Other is to micro crystallize enamel frit to gain microcrystallization enamel frit with better abrasion resistance.

⑥Enamel frit with optical properties:

Namely, luminescent enamel frit. Enamel frit with Zinc Sulfide and Cadmium Sulfide added, mainly used in enamel signage and instrument panel etc…

⑦Enamel frit with thermal properties:

High temperature resistant enamel frit can be used in more than 750℃ temperature, can bear sudden change of temperature. It can’t contain any alkali metal oxide, and it contains much (40% or more) Boric oxide and few Beryllium oxide. It also need to add some refractory materials like Aluminum oxide and Chromic oxide. High temperature resistant enamel frit mainly applied in jet parts protection or paint for nuclear power reactor.

⑧Enamel frit with electrical properties:

It’s resistor enamel frit. It has very big electrical resistivity and it’s insulative enamel frit. It’s not allowed to contain any alkali metal oxide. It’s usually used to be wire of insulating material or insulative coating material for printed circuit board.

Edge frit:

Enamel coating for the edge of enamelware. The expansion coefficient is higher than normal cover coat frit. And it has wide firing temperature range, elasticity also better. Edge frit has many colors, usually worked as decorations for the edge.

(Blue Edge Frit: )