In a world where everyone is trying to outdo each other and make their product stand out, there’s a reason why some products are magnetic. Sometimes, the secret to this magnetic allure is luminescence. Luminescent materials, commonly referred to as glow-in-the-dark materials, can add a captivating charm to everyday items. Think of the toy stars on a child’s bedroom ceiling or the luminescent hands on a watch.

The cool thing about these cool applications is that they use a cool technology. It’s called adding glow-in-the-dark powder to plastic that’s been injection molded. But how do you actually get plastic to glow in the dark? And how do you do it without messing up the way the plastic looks or works?

In this article, we’re going to show you how to add glow-in-the-dark powder to plastic injection molding. We’ll cover the types of glow powders, the injection molding process, and some tips to make sure your injection molded parts glow without any production problems.

Ⅰ. Characteristics of Luminescent Powder Injection Molding

Before we get into the nitty-gritty of plastic injection molding, it’s important to understand what luminescent powder is. Luminescent powder is a type of photoluminescent pigment that absorbs and stores light energy. When the surrounding light gets dim, this pigment slowly releases the stored energy in the form of visible light. This process can happen over and over again, which makes luminescent materials a useful and cool addition to all sorts of products.

When you’re picking out glow powder, you need to think about things like color, particle size, and the kind of glow you want. Glow powders come in different colors, like the classic green and blue. Particle size affects how long and how bright the glow is. Smaller particles make a glow that lasts longer and is clearer, while bigger particles make a glow that’s brighter but doesn’t last as long.

Glow powder is a powder that glows in the dark. It is widely used in the injection molding industry to make products like glow-in-the-dark toys, shoes, watches, and more. Here are some features of glow powder injection molding:

1. The glow effect is strong, so the product can glow in the dark in different colors like green, blue, and yellow.

2. The surface of the product is still smooth after adding glow powder, so it won’t have defects.

3. It has strong UV resistance, so the product can be used for a long time.

Ⅱ. Methods of Adding Luminescent Powder in Injection Molding

There are two ways to add glow powder to injection molding: dry and wet.

1. Dry Addition

To add luminescent powder directly to the hopper of the injection molding machine, mix it, melt it, and then inject it is called dry addition. The advantage of dry addition is that it is easy to control the amount added. You can adjust the amount of luminescent powder added according to the desired glow-in-the-dark effect. However, dry addition requires attention to the following points:

(1) The particle size of the luminescent powder and the raw material must be consistent to ensure uniform mixing.

(2) If you add too much luminescent powder, it may affect the flowability of the raw material, making it difficult to inject.

2. Wet Addition

Wet addition is to mix the luminescent powder and flow agent evenly in the hopper of the injection molding machine, and then add them to the raw materials for mixing, melting, and injection molding. The advantage of wet addition is that the mixing is uniform and the luminescent effect is better. However, the following points should be noted:

(1) The ratio of luminescent powder to flow agent must be strictly controlled to avoid affecting the quality of the injection molded products.

(2) After mixing the luminescent powder and flow agent, they should be used in time to prevent the luminescent effect from decreasing.
The above is the characteristic and method of adding luminescent powder in injection molding. I hope it can help you to add luminescent powder in your injection molding production.

Ⅲ. Precautions for Adding Luminescent Materials in Injection Molding

Luminous powder is a kind of photoluminescent material that can emit light by absorbing various visible lights. It has a strong absorption capacity for short-wave visible light below 450 nanometers and can be used indefinitely in various industries. Here are some usage methods of this product in injection molding:

1. Material Selection

Special powder for injection molding is suitable for various performance rubbers (PP, ABS, PC, PVC, etc.). Transparent plastics have better luminescent effect, and semi-transparent plastics can also have good luminescent effect. If color adjustment is needed, do not add too much color powder, so as not to significantly reduce the brightness of the luminescence. The brightness of luminescence in products with darker colors can be increased by increasing the proportion of powder. The use of mica color powder can be directly mixed with transparent rubber materials without adding color powder.

2. Proportion

Plastic material: luminescent powder = 1kg: (20g～200g). The more powder you add within this range, the brighter it will glow; too little powder will make the glow uneven, and it won’t glow as well. Adjust according to your needs.

3. Material

If you use recycled material for injection molding with luminescent powder, it may turn black, so it’s better to use new material. If there is moisture in the rubber material, it may turn black, so you need to dry it moderately before injection molding.

4. Injection Molding Machine Selection

Make sure to clean the injection molding machine really well. Use a short barrel to make the injection molding time shorter. This will help you go fast and not burn or blacken the plastic. Different injection molding machines will give you different results. If it doesn’t work, try another machine. Keep trying until you get what you want.

5. Mixing Method

Mix luminescent powder with plastic resin in a dry and stirred environment. Use a mixer or a roller mixer to mix it evenly. Use the correct resin material. Luminescent powder can be mixed with various resins, from polyethylene and polypropylene to acrylic resins or polycarbonates, but each resin requires specific mixing and molding considerations. Mix it evenly with an appropriate amount of white oil (the viscosity of white oil prevents the powder from settling), then add it in proportion to mix uniformly. (Note: Avoid vigorous stirring with metal objects, as it may cause blackening). (Try to reduce injection molding temperature, select a lower molding temperature for product formation, and avoid blackening of luminescent products). After injection molding, the luminescent plastic products are ready.

6. Mold Design

When you design your mold, you want to make sure it doesn’t mess up the glow. That means no sharp corners or thin walls that could cause stress. Usually, you want to make the thicker parts of your design stepped. That way, you get a stronger, more reliable glow.

7. Parameter Settings

The temperature and pressure when you make the plastic parts will affect how well the glow powder is mixed in. If you use the right settings for the plastic and the mold, like how hot the plastic gets and how hot the mold gets, how hard you push the plastic into the mold, and how long you let it cool down, you can make sure the plastic doesn’t get messed up and the glow powder still works.

Ⅳ. Process of Adding Luminescent Powder in Plastic Injection Molding

First, you need to know what luminescent powder is in injection molding. Luminescent powder for injection molding is mainly composed of photoluminescent pigments excited by visible light and special carriers. It absorbs energy under light and emits light spontaneously in the dark. This luminescent effect only needs a short period of light exposure to maintain a long-lasting glow.

1. Material Preparation

First, you need to prepare the luminescent powder for injection molding and the right carrier materials. Luminescent powder usually comes in powder form, so you can choose the color and particle size you want. You can choose carrier materials from suitable plastic granules like polyethylene (PE) or polypropylene (PP). You need to choose luminescent powders that are specifically designed for plastic injection molding. Look for powders that work with the type of plastic you’re using and the level of luminescence you want. You also need the right injection molding machines and molds.

2. Injection Molding

Mix the glow powder with the carrier materials in the ratio you want, either by hand or with a mixer. Then put the mixed stuff into the hopper of the injection molding machine and set the machine’s processing parameters like temperature and pressure according to what you need. Start the injection molding machine and inject the mixed stuff into the mold. The injection molding machine heats and presses the stuff so it takes the shape of the product you want inside the mold. Once the product cools and hardens, you can take it out of the mold.

3. Light Source Excitation

Injection molded products will glow in the dark on their own, but to make them glow brighter, you need to expose them to a light source to excite them. Common light sources include daylight, incandescent lamps, and LED lights. If you put the molded products under a light source for a while, they will absorb enough light energy to glow in the dark on their own. Different luminescent materials have different requirements for how long you need to expose them to light.

When using luminescent powder in injection molding, there are a few things to keep in mind:

(1) Make sure you mix it up good so the luminescent pigment is spread out evenly in the carrier material.

(2) Adjust the settings on your injection molding machine as needed to make sure you get good parts.

(3) Luminescent materials can get messed up if they’re exposed to bright light for a long time, so don’t leave them out in the sun or anything.

(4) Different kinds of luminescent powders for injection molding might need different amounts of light, so you might have to play around with it a little.

To sum up, using luminescent powder in injection molding involves preparing the material, molding it, and then exciting it with a light source. When you excite it with light, the products you mold with injection molding will glow in the dark. To make sure your products look good and glow well, you need to mix it up good, adjust your machine, and don’t let it sit in the sun too long.

Ⅴ. Advantages of Adding Luminescent Materials in Injection Molding

1. Colorful Selection

Color is super important in product design. Luminescent powder lets you get exact shades that regular pigments can’t do. Luminescent powder has a huge range, from soft pastels to bright neon lights, so you can make your brand look better or make your products stand out in a crowded market.

Luminescent powder can create colors with special effects, like glow-in-the-dark, in addition to the standard visual spectrum. These unique colors are great for emergency tools, consumer electronics, and safety equipment, where visibility is important. They attract attention and enhance user experience.

2. Functional Luminescence

Luminescent powder can do more than just look good. It can also be engineered to serve a purpose in injection-molded parts, making them work better and do more. For example, you can get custom UV-resistant luminescent powders that won’t fade or change color even if they’re exposed to harsh lighting conditions.

You can also use glow-in-the-dark powders that can handle high temperatures. This is great for things like car lights. These tough guys can handle the heat and keep your parts working longer.

3. Environmental Emission Control

In a world where we all have to be green, luminescent powder is a greener way to make things. By using light-stable annealed luminescent powder technology, products can last longer and not break down from light, so you don’t have to replace them as often.

This indirect contribution to sustainability complements the shift from heavy metal luminescent powders to safer, more eco-friendly formulations, aligning with regulatory trends and consumer preferences for eco-conscious products.

4. Illuminating Brand Assets and Product Innovation

When it comes to products, how they look is often the first thing people notice. By using glow powder in their branding, companies can create looks that people will remember and that will resonate with their customers.

Plus, using glow powder can help companies come up with new ideas. When brands use glow powder to make things that glow in the dark, they can create new products that people will think are cool and that will start trends instead of following them.

5. Optimizing Quality through Light and Lifespan Testing

Luminescent powder’s ability to maintain its color and luminescent properties under adverse conditions not only shows how tough it is, but also makes it easy to test for quality. Since luminescent parts give off light after they’ve been exposed to light, they can be tested for light and lifespan (standard tests for making sure a product is good).

This means you can get real-time, non-intrusive indicators of how well your product is doing and how long it’s going to last, so you can make changes to your design before you start selling it.

Ⅵ. Conclusion

Using glow-in-the-dark materials in plastic products is a cool new thing in making stuff. It’s not just about safety or looking cool, it’s about making things that people want. If you know what you’re doing, you can make things that people will love.

If you can keep up with the new stuff and use the new technology, you can make plastic products that people will want to buy. That’s what it’s all about. You want to make things that people will want to buy. That’s what makes you money.