1. Questions When We Process Photosensitive Pigments.
Q1: What should pay attention to when we use Photosensitive powder?
Description:How can we avoid color difference due to improper operation of photosensitive powder?
Answer:
1. Avoid processing such powder above 280 degrees centigrade.
2. Avoid using it together with UV absorber.
3. Be careful with additives and base materials, as the photosensitive powder is highly sensitive to polarity, different additive or base material may cause color difference.
4. Storage: Store such powder in a sealed, dry, and dark place, without direct sunlight.
5. Toxicity and safety: Photosensitive powder is non-irritating to skin, and safe for handling and operation. It does not contain any substance harmful to human body, and therefore, it is consistent with safe toys and food packaging specifications.
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Q2: How can I dissolve the photochromic pigment powders?
Description:When using photochromic pigment powder, we need to dissolve it and mix it into various pigments before we can use it. What is the method of dissolving photochromic pigments?
Answer: Photochromic pigment powders can be dissolved. When photochromic pigment powders lose ultraviolet irradiation or when the temperature rises above 45ºC, the photoreceptor molecular bond closes, i.e., they return to their original color. Various solvents, polarities and substrates of photochromic pigment powders will affect the color change of OP powder, so the same dye will have different color performance in different solvents, polarities and different substrates.
2. Problems When We Use Photosensitive Pigments in Different Applications.
Q1: How do you apply photosensitive pigments to an umbrella?
Description: For all the time, we are using umbrella of unchangeable color. Can we add photosensitive pigment to the umbrella pigment so that the color can change under different outdoor lighting conditions?
Answer: The answer is yes. Sun umbrellas applying photosensitive pigments will change in color when exposed to sunlight/UV radiation, and return to its original color when the sunlight/UV is lost. Color-changing sun umbrella is one that fully utilizes the color changing principle of such powder to change its color from being “colorless to colored” under sunlight exposure.
The use of photosensitive pigments in umbrellas is a breakthrough for the traditionally unchanged color and pattern of umbrellas. When exposed to sunlight, the umbrella surface can gradually show a colorful appearance, and return to its original color when sunlight is blocked. The color change can be cyclic, performing the magic of color variation in light, bringing more surprises to life.
Q2: How can photochromic powder not fade on fabric?
Description: It is often reported that fabric applied with photochromic powder will fade after washing, thus affecting the product quality. So, how to make the powder stay put? Here is a good way to do this for everyone.
Answer:
- To apply the photochromic powder on fabric, the first step is to choose proper ink and coating adhesive. The applicable ink should be transparent; otherwise, it will largely affect the photosensitive effect;
- Photochromic powder will decompose and go lumpy when soaked in water-based coating for a long time. So, it is necessary to use it timely after mixing in water-based coating, or, use bright powder.
- Mixing proportion: Ink: photochromic powder = 100: 20~100 (weight ratio). Generally, the more the powder is added, the thicker it is applied, the more obvious the color will be.
- Mixing method: Put the prepared powder in a small container, add 80% transparent oil-based ink, and stir evenly with a three roller machine to fully mix the powder and remove air from the surface of powder particles to avoid affecting powder dispersion. After mixing, pour the prepared ink in proportion and stir evenly to form photochromic ink.
- Screen print (or print) the photosensitive ink on the surface of product. For screen printing, 80-150 mesh is suggested (It is best to print the ink on white base material, as the photochromic powder itself has variable color, which will not change as expected when printed on dark base material. The thickness should be 0.1~1.0 mm.)
- After printing, let it dry naturally for 40 to 60 minutes, or dry it in a forced way.
Q3: How to use photosensitive powder in injection molding?
Description: What are the steps of photosensitive powder injection molding? What is the mixing ratio? Are there any precautions?
Answer: Photosensitive powder for injection molding: The ratio of such powder to plastic material is generally around 0.4% – 10%, depending on the color shade of product. Add less powder for light color, and more for dark color.
- Mixing: First, add diffusion oil to the raw material and stir for one minute. Then, add Kingchroma photosensitive powder and stir for another one minute. The stirring time should not be too long.
- Injection molding machine: The injection molding machine should be fully clean, with a lowest temperature just enough to support the process. Do not leave the material in machine for too long to avoid burning. The molding output also varies with the state of machine, whether being new or old, domestic or imported. You need to constantly test and adjust the machine to get optimal result.
Q4: How to use photochromic powders in printing?
Usage instruction:
- It depends on the color and type of base material. The lighter the color, the less the usage. PU and acrylic bonding agent are preferred for water-based ink base material; PLASTISOL bonding agent for oil-based material; and SILICON agent for dyeing.
- Photochromic powders must be used with light stabilizer and antioxidant, whose usages are 1/5 of the powder or 1% – 2% of the base material.
- For screen printing, 80-150 mesh is suggested. You can also use rotary machine for printing. Lithographic printing has poor effect.
Q5: What do I need to be aware of when applying photochromic powders to clothing?
Description: Photochromic powders are special material that can change color with light. There will be some difficulties when using it on clothing. What precautions are there?
Answer: You need to do the following before using photochromic powders on clothes:
1. Choose proper material: Photochromic powders usually applies to natural or synthetic fibers such as cotton, silk, and nylon. Make sure your clothing material is suitable for this kind of powder.
2. Mix the powder: Before using it on clothes, it is often necessary to mix it with certain adhesive or other medium. Make sure to mix it correctly according to instruction.
3. Ensure ventilation: Ensure that the operating environment is airy enough to use this powder. Sufficient ventilation can reduce the potential harm to human body, and help distribute the powder more evenly on clothing.
4. Evenly apply: You need to brush or spray the powder evenly on clothes. It must be evenly applied to avoid uneven color changes.
5. Prevent pollution: Do not touch substances such as food or beverage when using the photochromic powders, as it will dye them to cause pollution or damage.
6. Pay attention to cleaning and maintenance: Select proper washing method and temperature as instructed. You need to follow the instruction so that the photosensitive effect can last longer.
Q6: How about the washing fastness of photosensitive powder used in yarn?
Description: Can the photosensitive powder be used on sand yarn and washed in water, and will it have an effect on the color change?
Answer: Photosensitive powder can be printed on yarn with coating, but the water washing fastness is not good, because the printing surface of yarn is too small, the water fastness will be poor once washed, so water washing is not recommended.
Q7: What are the recommended proportions of photochromic powder added to coatings, inks, and plastic products?
Description:
Coatings: It is recommended to add photochromic powders at a proportion of 6-20%, suitable for various surface coating products, including PMMA spray paint, ABS spray paint, PVC spray paint, water-based spray paint, etc.
Inks: It is recommended to add photochromic pigment powders at a proportion of 15-30%, suitable for printing on various materials, including fabric, paper, synthetic film, glass, etc.
Plastic Products: It is recommended to add photochromic powders at a proportion of around 0.8%, suitable for various plastic materials in injection molding, extrusion molding, and products with high color concentration, such as photochromic PE masterbatch and photochromic PMMA masterbatch.
3. Problems About Price of photosensitive pigment powders
Q1: What are the price differences in photosensitive pigment powders?
Description: Photosensitive pigment powder is sold at variable prices in the market, but with similar powder. Why are some particularly expensive and others relatively low? There is also a significant difference in quality, some are good and some are bad. What are the differences specifically?
Answer: Quality photosensitive pigment powder has better printing result. It is completely different from poor one. Different country and manufacturer will also lead to a big difference in quality. Kingchroma is an advanced color-changing powder manufacturer. It is also an agent for well-known foreign manufacturers of such powder. Our powder has microcapsule characteristics such as good resistance to high temperature and oxidation.
Q2: How much is one kilogram of photosensitive powder?
Description: How about your photosensitive powder quality and prices? Why is there price difference?
Answer: Photosensitive powder of different quality is sold at different prices, ranging from 172 to 258/kgs. Quality photosensitive powder has better printing effect, which is totally different from poor one. KingChroma photosensitive powder has microcapsule characteristics such as good resistance to high temperature and oxidation, and thus can meet the needs of customers.
4. Safty and Store Problems When We Use Photosensitive Pigment.
Q1: What do I need to pay attention to during the storage and production of photochromic powders?
Description: Photochromic powder is reversible photochromic substance in microcapsule, which is a spherical and transparent outer shell that neither dissolves nor melts. It is this shell that protects the photochromic substance from other chemical factors. What requires our attention when producing and storing it?
Answer: During production or storage, we should store photochromic powders in dry and dark place to avoid light fatigue. We should also ensure there is no corrosive substance such as strong acid or alkali in the environment. We should not use it with UV absorber. Different additive or base material may cause unexpected effect of the product. Due to the variety of types, usage status, and application environment of photosensitive materials, it is not possible to list them all.
Q2: Is photosensitive powder okay for skin contact, is animal fur okay?
Description: We want to use the photosensitive powder on animal or human hair, but the local government needs a certificate to verify whether the powder can be used on humans or animals.
Answer: Please rest assured that Kingchroma’s photosensitive powder contains SGS, Rohs and other certificates, and is non-toxic to skin and animals. We also have customers to make coloring paste for human or animal hair.
5. Other Problems about Photosensitive Pigment
Q1: What if the photosensitive pigment does not change color when exposed to light?
Description: Recently, we are consulted that photosensitive pigment purchased from other manufacturer doesn’t change color in the sunlight, which is actually very rare. But, how to deal with it when it happens?
Answer: Usually, when the color doesn’t change, there is a great possibility of improper operation or fabric sublimation. So, we should strictly follow relevant requirements when using photosensitive pigment. Here are the complete usage precautions on photosensitive pigment:
Usage precautions:
- Avoid processing such powder above 280 degrees centigrade.
- Avoid using it together with UV absorber.
- Be careful with additives and base materials, as the photosensitive pigment is highly sensitive to polarity, different additive or base material may cause color difference.
- Storage: Store such powder in a sealed, dry, and dark place, without direct sunlight.
Q2: How to use photochromic powder?
Description: Improper operation of photochromic powder in the process of use will cause color differences, how can we avoid these problems?
Answer: 1, should avoid photochromic powder processing above 280 degrees Celsius.
2, should avoid photochromic powder and ultraviolet absorber used at the same time.
3, photochromic powder is highly sensitive to polarity, adding different additives or using different substrates may cause color differences.
4, Storage: Photochromic powder should be sealed and stored in a closed, dry, dark place, avoid direct sunlight.
5, toxicity and safety: photochromic powder is non-irritating to the skin, safe and error-free handling and operation, and does not contain harmful substances to the human body, composite safety toys and food packaging specifications benchmark.
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