The luminous effect of food-grade silicone key chains has been achieved

To achieve the luminous effect of food-grade silicone key chains, comprehensive considerations need to be made from aspects such as material selection, luminous principle, processing technology and precautions. The following is a detailed introduction:

Material selection

Food-grade silicone: This is a basic material that must comply with food contact safety standards. It is usually made of high-purity siloxane polymers and does not contain harmful substances such as heavy metals and phthalates. It has excellent flexibility, elasticity and temperature resistance, and can withstand stretching, squeezing and temperature changes during daily use.

Luminous materials: Common luminous materials include luminous powder and luminous ink.

Luminous powder: Generally, it is made from alkaline earth aluminates, silicates, etc. activated by rare earth elements. It has the characteristics of high luminous brightness and long afterglow time. When choosing luminous powder, the particle size should be taken into consideration. If the particle size is too large, it will affect the molding and surface smoothness of the silicone rubber. If the particle size is too small, it may affect the luminous effect. At the same time, it is necessary to ensure that the luminous powder has good compatibility with food-grade silicone and will not undergo chemical reactions or stratification during the mixing process.

Luminous ink: It is a liquid material made by mixing luminous powder with organic solvents, resins, etc. It can be directly printed on the surface of silicone and the operation is relatively simple. When choosing luminous ink, attention should be paid to its viscosity, drying speed and adhesion and other properties to ensure the stability of the printing effect and luminous effect.

The principle of night light

Luminous materials usually achieve the luminous effect by absorbing external light energy (such as natural light, artificial light, etc.) and storing it, and then slowly releasing it in a dark environment. Take alkaline earth aluminate luminous powder as an example. It contains a special luminescent center and an activator. When it is excited by light, the electrons in the luminescent center will transition to a higher energy level. When the electrons return from a higher energy level to a lower one, photons will be released, resulting in a luminescent phenomenon.

Processing technology

Mix the luminous powder with silicone

Proportion control: According to the required luminous effect and the performance of the silicone, the mixing ratio of luminous powder and silicone should be reasonably controlled. Generally speaking, the addition amount of luminous powder is between 5% and 30%. The addition amount is too small and the luminous effect is not obvious. Excessive addition may affect the physical properties of silicone, such as hardness and elasticity.

Mixing method: Mechanical stirring or manual mixing can be adopted. Mechanical stirring can make the luminous powder and silicone gel mix more evenly, improving the consistency of the luminous effect. During the stirring process, pay attention to the stirring speed and time to avoid generating too many bubbles. Manual mixing is suitable for small-batch production, but it is important to stir thoroughly to ensure that the luminous powder is evenly dispersed in the silicone.

Forming process

Compression molding: The well-mixed luminous silicone rubber is placed in a pre-designed mold and formed through heating and pressurization. Compression molding can ensure the shape and dimensional accuracy of the key chain, and at the same time, it can fully fill the mold with luminous silicone, improving the quality of the product. During the molding process, parameters such as temperature, pressure and time should be well controlled to ensure that the silicone is fully cured.

Injection molding: Suitable for the production of key chains with relatively complex shapes. After heating and melting the luminous silicone gel, it is injected into the mold through an injection molding machine. After cooling, the finished product is obtained. Injection molding has the advantages of high production efficiency and stable product quality, but it requires professional injection molding equipment and molds.

Luminous ink printing

Printing preparation: Select appropriate printing equipment and screen plates, and make the screen plates according to the design pattern of the key chain. Stir the luminous ink evenly and adjust the viscosity properly to ensure the printing effect.

Printing process: Place the key chain on the printing table and use a squeegee to print the luminous ink onto the silicone surface through the screen. When printing, it is necessary to pay attention to controlling the printing pressure and speed to ensure that the ink is evenly covered on the silicone surface. After the printing is completed, put the key chain into the drying equipment for drying to ensure that the ink is fully cured.

Precautions

Safety and hygiene: Throughout the entire production process, it is essential to strictly adhere to the safety and hygiene standards for food contact materials, ensure the cleanliness and hygiene of the production environment and equipment, and prevent the contamination of luminous materials and silicone.

Luminous effect test: After production is completed, the luminous effect of the key chain needs to be tested. You can place the key chain under light for a period of time, and then observe its luminous intensity and afterglow time in a dark environment to ensure that the night light effect meets the requirements.

Storage conditions: Luminous materials and luminous silicone products should be stored in a dry, cool and dark place, avoiding moisture and direct sunlight to prevent affecting the luminous effect and service life.