It is the injection of melted plastic material under extreme pressure into the die or mold cavity. s the material cools, it forms the desired shape. The time-lapsed of the injection molding cycle may range from a few seconds to 2 or more minutes, and it is up to the magnitude, design, complexity, and material of the parts.
Injection-molded materials manufacturing in the First Part:
First Part China Limited manufactures high volume and low-quality injection molded parts professionally. Many experienced and professional workers of the First Part produce rich quality plastic molded parts for defense, medical, aerospace, and automotive.
Plastic injection process in the First Part:
The First Part of China uses the following steps for plastic injection molding.
- Material preparation
1. Material Preparation:
Dry plastic pellets are used to be blended with color additives or fillers.
Molding machines carry pellets into their hopper, and then these pellets are sent to the mold cavity in the barrel with the help of a screw.
In the barrel, the pellets undergo a heating process to melt them. It also warms the mold cavity.
The heated mold or die cavity is filled with molten liquid or resin through an opening called a gate. The molten material, after filling into the cavity, converts into the mold shape.
The molten material in the mold and the mold itself are allowed to be cooled to take a solid form.
The cooled and solidified material is got out into the loading cabin through the gate of the mold cavity. Ejector removes from the mold cavity, and a new injection molding cycle can be started now.
What are the types of injection molding technology?
The types of injection molding technology are as follows.
- Thin wall molding
- Gas-assisted injection molding
- Metal injection molding
- Liquid silicone injection molding
- 3D printing
- Unique material formulations
1. Thin wall molding:
It is an injection molding technology that produces very thin-walled plastic products. Test apparatus (test tubes, beakers, and flasks), electronic materials (back covers of mobiles and body of laptops), and tubes are manufactured with the help of this technology.
2. Gas-assisted injection molding:
Thick plastic injection molded parts can be deformed after cooling. This process eliminates this issue by defusing gas into the mold cavity filled with molten plastic material. The outer surface of the mold retains its smooth look and the internal of the mold remains porous or vacuumed with this technique. This process assists in maintaining a good appearance and reduce costs.
3. Metal injection molding:
Metals can be injection molded like plastic. This technique is much more costly than plastic injection molding. It is used in some industries like the cell phone industry. It protects cellular electronic devices from harmful radio or microwaves.
4. Liquid silicone injection molding:
Thermoset has vast applications in plastic injection molding. In this technique, cold material is poured into a highly heated mold cavity. This process protects the mold parts from melting again. This technique is used to produce medical devices, car parts, etc. that can undergo extreme temperature and chemical reactions by using liquid silicone.
5. 3D printing:
It is a very important technique because it plays a vital role to produce many plastic and metal molded parts like prototyped models. It is also used to make many engineering models, such as buildings, roads, houses, and automotive models.
6. Unique material formulations:
Though it is not considered a plastic injection molding technique, yet it enhances the molding capabilities of the molding machines. Many injection developers and industries use a carbon filter, mineral filter, and a blowing reagent to increase the properties of the mold parts.
Types of injection molding in the First Part:
The following types of injection molding are done in the First Part. Here we will explain the first two of them.
- Over molding
- Insert molding
- Thermoplastic injection molding
- Cold runner molding
- Hot runner molding
1. Over molding:
It is also known as two-shot molding, and this process helps to embrace an injection mold over another material like metal. It increases the duration of the product. A thermoplastic elastomer is the most commonly used material for over-molding. It is used to manufacture various substances such as grip handle of the toothbrushes, grips of the hammers, and rubber grips over steel steering wheels of the vehicles. It is also used for sealing the injection mold product parts.
2. Insert molding:
This method is similar to over-molding and mixes two or more components into a final product. In this process, the injection mold component is poured into the mold, cavity and molten plastic material is filled around the inserted component. Inserted material provides extra strength to the product and reduces the unnecessary mass of the product.