The most common luminous plastic products on the market usually have a light yellow or milky white body color during the day, with a yellowish green light during the dark place. However, more and more customers expect their products to present colorful colors both in bright places dark places. So how can we get this effect?

Currently, there are two common dying production methods on the market:

Method 1：Use dyed colored glow in the dark powder, it can be directly used into transparent plastic production.
Method 2: Use unstained, natural color glow in the dark powder with transparent plastic, and customers can add colorant during the production process by themselves.

We recommend the Method 2, because of the following reasons:

• Accuracy of color matching:

The colors of the dyed glow in the dark powder we provide now may not be exactly the same as the colors required by customers, and we are also unable to accurately match colors according to Pantone or RAL color codes. For specific reasons, please refer to the article: Can Glow in the Dark Masterbatches be Customized Based on The RAL Color?

• The body color will affect the luminous effect:

The proportion of colorant will affect the luminous effect. If you use the dyed color powder directly, it will be hard to adjust the luminous brightness effect again. However, if customers add colorant by themselves, the proportion can be adjusted according to specific needs, which can be better to balance body color and luminous brightness.

• The layering phenomenon between fluorescent powder and luminescent powder:

The dyed color powder we provide is a mixture, which use the natural color luminescent powder as the base and added with fluorescent powder. But the specific gravity of fluorescent powder and luminescent powder is different. The specific gravity of luminescent powder is 3.6g/cm ³, while the specific gravity of fluorescent dye pigments is generally 1.2-1.5g/cm ³. Fluorescent powder is lighter. So, if you use the dyed luminous powder directly during injection molding or extrusion processing, delamination may occur, which may affect the quality of the final product.

Adding colorant into glow in the dark products will definitely reduce the luminescent effect. Therefore, it is necessary to choose dyeing materials that minimize the coverage of luminescent effects as much as possible. At present, fluorescent powders are an ideal choice.

Compared with other colorants, fluorescent powder has a special characteristic: it can reflect light to a certain extent. When fluorescent powder and luminous powder are mixed, the fluorescent powder will display colored body colors in bright areas, while in dark areas, the fluorescent powder will also reflect some of the light emitted by the luminous powder, providing a certain auxiliary effect to the luminous effect.

In terms of color selection, it is recommended to choose colorant with weak color coverage, low concentration, light color, and high transparency, which can reduce the impact on the glow effect and make the product glow brighter and last longer.

The higher the proportion of colorant, the more will cover the luminous effect. Therefore, we suggest that the addition ratio of colorants should be around 0.5% -1%.

The lower the addition ratio, the better the luminous effect can be maintained, but at the same time, the body color of the product will also be lighter. Therefore, when adding colorants, it should find a balance point based on the needs for brightness and body color concentration.

The dyeing of luminous products is different from that of ordinary products. The body color and luminous color of luminous powder are different, so when add colorant, the luminous color of the product may be different with the body color.

• The body color of natural glow in the dark powder is usually milky white, close to white, So, after adding colorant, the body color is the basically the same as the colorant.
• There are three glow color types of natural powder: Yellow-Green, Blue-Green, and Sky-Blue. When the colorant is combined with three different luminescent colors, the luminescent color may have a deviation, or even has a complete difference from the body color.

For example, there are two kinds of dyed color powder – Pink-Red & Magenta. Both exhibit a pink body color but have different luminescent colors because they use different luminescent powders as their base colors. Like attached picture:

Therefore, if you want to dye your own luminous products and also have specific requirements for the luminous color, you should pay attention to the problem of light color superposition when choosing the luminous powder substrate.

For example, if you need blue or purple luminous effects, you should choose blue-green or sky-blue luminous powder as the base luminous powder; And if you want to have yellow, orange, and green luminous effects, you need to use yellow-green as the base luminous powder.