Plastic crayons are made through a process that involves melting raw materials and molding them into the desired crayon shape. Here’s a breakdown:
Manufacturing Process
The process generally follows these steps:
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Raw Material Preparation:
- The necessary raw materials, which include colored pigments and plastic base materials, are gathered. The type of plastic may vary, but often involves a polymer like polyethylene or polypropylene.
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Melting and Mixing:
- The raw materials are added into a reaction kettle.
- The mixture is heated to 150°C.
- The materials are stirred and melted for about 6 hours. This process ensures the colored pigment is evenly dispersed into the melted plastic, creating the colored plastic crayon material.
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Injection Molding:
- The melted crayon material is then transferred to an injection molding machine.
- The material is injected into molds of the desired crayon shape.
- The molds are cooled, and the solid plastic crayons are ejected.
Key Points
- Heating: The crucial step of heating the mixture to 150°C ensures the plastic base materials melt properly so they can blend with color pigments.
- Mixing Time: Stirring for about 6 hours is crucial for creating a homogeneous material to make a crayon with uniform color.
- Molding: Injection molding ensures that the crayons have a consistent shape and size.
- Raw Materials: The specific type of plastic and pigment used can vary, which affects the crayon’s properties.
Summary
In essence, plastic crayons are made by melting plastic with coloring agents in a reaction kettle, then injecting the melted material into molds to create the crayon shapes. The controlled heating, mixing, and molding are key to creating a usable and effective crayon. The process described in the reference mentions that the heating process takes approximately 6 hours at 150°C, which is key to obtaining the color plastic crayon material.
