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Insert molding technologyis a common production method in our daily life. Whether it’s the smartphones we use every day or the electronic components that power our homes, many of these daily necessities are made through a manufacturing process called insert molding. Insert molding technology allows manufacturers to fuse plastic and metal components into one long-lasting and durable part. In this article, Longsheng will explore with you how theinsert molding processis performed?
What is insert molding？
Insert molding is a subset ofinjection molding technology, similar to overmolding, in which metal parts are placed into a mold cavity before the plastic is actually injected. The insert is precisely positioned within the mold by hand or robotic arm. The mold then closes and the plastic is molded over the insert to form a single part. Common inserts include pins, blades, threaded nuts and knobs, sockets, bushings and metal handles of tools such as screwdrivers. For encapsulating metal parts in plastic products, insert injection molding is more suitable. Manufacturers in the automotive, medical, electrical, consumer goods, cosmetics and other industries are increasingly using insert injection molding technology.
How Does insert molding work？
Insert molding is a sophisticated and complex manufacturing process that involves multiple steps to create complex components with enhanced structural integrity. Here's an overview of how it works:
1.Put the embedded parts into the mold
In the insert molding process, the first step is the loading of inserts, which can be completed manually or automatically. In an automated loading environment, specialized machinery accurately and quickly places embedded parts inside the mold. The outstanding feature of this automation technology is its high efficiency and accuracy, which is especially suitable for large-scale production occasions. In contrast, the manual loading process relies more on skilled operators. Although this method shows certain advantages in cost management, due to its low work efficiency, it is usually more suitable for the production of small parts.
2.Mold injection after melted plastic
During this process, we use injection equipment to inject pre-melted plastic into the interior of the mold. When there is a pressure difference between the injection device and the mold cavity, the plastic will enter the mold cavity through the injection hole and finally solidify. Injection equipment ensures that plastic can be filled accurately and directly into every part of the mold. Then, during the cooling and solidification stages, pressure is applied to the plastic and it interacts with the inner walls of the mold. In order to ensure that every channel in the mold can be completely filled with plastic, this process must be completed under high temperature and high pressure conditions. Therefore, plastic can be effectively prevented from flowing out of each channel and causing pollution. In addition, the high temperature and high pressure environmental conditions can also effectively promote the smooth removal of excess air in the mold through the exhaust port, thus ensuring that all components inserted into the mold can be tightly adhered to the surface of the mold, thereby constructing a complete product structure.
3.Start that mold
Once the molten material has experienced sufficient cooling and solidification within the mold, the mold can be opened. For some products with complex structures, a robot specially designed for injection molding can be used to achieve the above actions. This operation can be done manually or by automated tools. Before opening the mold, it must be ensured that all parts can be fully heated to the required temperature and that the entire structure can work properly. When the mold is opened, it is necessary to confirm whether the insert has been perfectly integrated with other parts of the mold to form a complete system.
4.Separate molding components from gates
During the mold formation process, the gate serves as the main supporting part, ensuring the integrity and stability of each part of the mold. If the gate design is unreasonable or defective, it may cause the entire mold to fail to work properly. It is a common situation during the molding process that the first molded part often forms a tight connection with the gate.
Next, this step becomes particularly critical, as it involves separating the gate from the molded part to facilitate subsequent operations and handling. During this process, special attention should be paid to the cleaning of the gating system and the removal of surface defects. In this critical step, the operation process must be very delicate to prevent improper operation from causing cracks or damage to the molded parts, which will have a negative impact on the quality of the final product.
5.post- processing
The specific steps for insert molding are determined based on the type of product you wish to achieve. When post-processing becomes an integral part of the production process, surface treatment and final quality inspection become routine operations.
What are the applications of insert molding?
1.Automotive industry
Insert molding can be used to produce automotive interior parts(such as dashboards, door panels, seats, etc.), exterior decorative parts (such as bumpers, light housings, car logos, etc.) and functional parts (such as water tanks, pipes, fuel tank, etc.). With the rapid development of new energy vehicles, insert molding also plays an important role in the application of lightweight materials.
2.Home appliance industry
Insert molding is widely used in the manufacture of casings and internal components of household appliances, such as casings and internal structural parts of televisions, refrigerators, washing machines, air conditioners, etc. These plastic products not only look beautiful, but also have good durability and insulation properties.
3.Medical device industry
Insert molding technology is widely used in the production of disposable medical devices(such as syringes, infusion sets, blood collection devices, etc.) and medical device casings. These products need to meet strict hygiene and safety standards, and insert molding technology can provide high-precision, high-cleanliness manufacturing solutions.
4.Electronic device industry
Insert molding technology plays a key role in the production of casings for electronic productssuch as mobile phones, computer accessories, keyboards, mice and MP3 players. At present, the production of electronic components mainly uses plastic injection molding technology, including injection mold design, material selection and processing methods. This batch of products needs to have a refined appearance and a high degree of structural strength, and injection molding technology not only meets these standards, but also provides excellent electromagnetic shielding and insulation properties.
5.Packaging industry
Insert molding technology is also widely used to produce various types of packaging containers, including but not limited to bottles, caps, and food packaging boxes. For example, plastic bottles used for the production of beverages and dairy products and bottle caps used for the production of cosmetics and pharmaceuticals are manufactured using injection molding technology. This batch of packaging products must meet food safety, moisture-proof and impact-resistant standards, and insert molding technology can provide us with high-precision and lower-cost production solutions.
6.Toy and model industry
Insert molding technology has the ability to produce children's toys and models of various shapes and colors to meet the diverse needs of the market. At present, it is mainly used in automobile, electronics, machinery, construction and other industries, such as children's cars, children's airplanes, toys and other similar plastic products. Such products generally require exquisite appearance, long-lasting durability, and safety and non-toxic properties, and injection molding technology can provide high-quality production solutions for these products.
7.Building materials industry
Insert molding technology is also widely used in the manufacture of building materials, such as door and window frames, various pipes and decorations, etc. Plastic pipes are mainly used for indoor decoration and outdoor laying in construction. Their advantages are light weight, high strength, corrosion resistance and not easy to deform. This batch of products not only looks elegant and durable, but also helps improve construction efficiency.
8.Industrial parts
Insert molding technology can produce a variety of industrial parts, such as gears, valves and connecting parts. These parts are widely used in mechanical equipment and machinery, and their manufacturing requirements are high precision and high-quality mechanical properties.
9.Aerospace industry
Insert molding technology has been applied to manufacture parts with precise structures and high precision requirements, such as aircraft interiors, sensor casings, and various connectors. In order to meet the standards of high strength, high temperature resistance and light weight, these components must be met. Insert molding methods provide a solution for high-quality manufacturing.
10.Furniture Industry
We have always relied resolutely on insert molding technology to create furniturebecause this method is unique in terms of durability, aesthetics and design innovation. This technology helps to perfectly combine functionality and design style, making it a leading product in the furniture manufacturing industry. For example, the following structures can be listed: chair bases and armrests, table legs and support mechanisms, chairs and tables placed in the open air, office furniture combinations, and modular shelf modules.
11.Agricultural tools and equipment
Insert molding has revolutionized the agricultural industry, providing strong, weather-resistant components essential to modern agriculture. The technology excels at efficiently producing large quantities of durable items, making it ideal for agricultural applications. Such as: dashboard housings, knobs and levers for tractors and harvesters, sprinkler heads and connectors for irrigation systems, containers and storage boxes, shovels and rakes, etc.
What materials are used in insert molding?
Insert molding uses a variety of materials, mainly including the following categories:
1. Metal materials
Metal materials are one of the most commonly used materials in insert molding and are favored for their high strength, high hardness and good electrical and magnetic conductivity. Common metal materials include:
| Material | Feature |
| Aluminum | Offers excellent machinability, high strength-to-weight ratio, and superior corrosion resistance, making it perfect for lightweight, durable machined parts. |
| Stainless steel | Stainless steel offers superior corrosion resistance, high strength, excellent toughness and ease of fabrication, ideal for demanding machining operations. |
| Copper | Copper displays excellent thermal conductivity, electrical conductivity and plasticity. It is also highly ductile, corrosion resistant and can be easily welded. |
| Titanium | Titanium It’s a metal with excellent strength-to-weight ratio, low thermal expansion, high corrosion resistance; sterilizable and biocompatible for machining. |
| Brass | Brass has desirable properties for a number of applications. It is low friction, has excellent electrical conductivity and has a golden (brass) appearance. |
2. Plastic materials
Plastic materials are also commonly used in insert molding, especially when part weight needs to be reduced, corrosion resistance improved, or specific functionality required. Common plastic materials include:
ABS:ABS is one of the most commonly used materials in injection molding. It is widely used in the manufacturing of casings and components for automobiles, home appliances, and electronic products due to its good mechanical properties, impact resistance, chemical resistance, and easy processability.
PC:PC has excellent transparency, impact resistance, heat resistance and dimensional stability. It is often used to make products that require high transparency and high strength, such as optical discs, eyeglass lenses, safety helmets, displays for electronic equipment, etc.
PA:Nylon material has high strength, wear resistance, oil resistance and good self-lubricating properties. It is often used to manufacture bearings, gears, pipes, cable sheaths and other parts that need to withstand mechanical stress and wear resistance.
POM:POM is known for its high hardness, high rigidity and excellent wear resistance. It is often used to manufacture precision parts, gears, bearings, sliding parts, etc.
PMMA:Also known as organic glass, it is often used to make lenses, display boxes, signs, etc. due to its good optical properties, transparency and weather resistance.
PET:PET is mainly used to make beverage bottles, food packaging, etc., but in injection molding, it is also used to make some products that require high transparency and good barrier properties.
PBT and PETG:These materials have good heat resistance, chemical resistance and mechanical properties and are commonly used in the automotive, electronics and home appliance industries.
PPSU and PEEK:These high-performance plastics are used in the manufacture of parts in extreme environments, such as medical devices, aerospace and automotive parts, because of their high temperature resistance, chemical resistance and high strength.
TPE/TPR:This type of material combines the elasticity of rubber with the processability of plastic. It is often used to manufacture seals, hoses, handles and other products that require soft touch and good sealing.
List of plastic materials
| Thermoplastics | Thermosets |
| ABS | Epoxy Resin |
| PPE/PS | Silicone Rubber |
| PETG | PTFE |
| Nylon | Polyester Resin |
| Polypropylene | Phenolic Resin |
| PMMA (Acrylic, Plexiglas) | Glass-Fiber Reinforced Plastics |
FAQs
1.What is the insert molding process?
The insert molding process is a molding method in which pre-prepared inserts of different materials are put into the mold, and then resin or molten material is injected to join and solidify the material and the insert, and finally an integrated product is made. This process is widely used where it is necessary to enhance the strength of components, achieve specific functions, or simplify the assembly process.
2.What materials are used in insert molding?
There are various materials used in the insert molding process, mainly including metal materials (such as copper, iron, aluminum, stainless steel, etc.), plastic materials (such as thermoplastics and thermosetting plastics), and non-metallic materials (such as ceramics, glass, wood, etc.) ) and special materials (such as magnetic materials, conductive materials, etc.). The specific choice of material depends on factors such as product performance requirements, production cost, and processing difficulty.
3.What is inset molding?
Insert molding is a molding process that involves placing a pre-prepared insert (usually metal or other high-strength material) in a mold and then injecting plastic or other molten material. These materials are joined to the inserts and solidified within the mold to form an integral product. The insert molding process can significantly improve the local strength, hardness and wear resistance of the product while meeting specific functional requirements.
4.What is the process of film insert molding?
The process flow of film insert molding usually includes the following steps: First, inserts that meet the requirements need to be prepared. These inserts can be made of metal, plastic or other materials. According to the design requirements of the product, prepare the corresponding mold. Place the pre-processed insert in the corresponding position of the mold according to the design requirements, and ensure that it is stable and reliable. Molten plastic or other material is injected into the mold, allowing it to engage with the insert and solidify. After the injection molding material is completely solidified, cool the mold to the appropriate temperature and then take out the product. It should be noted that the process flow of film insert molding may vary depending on specific products and application scenarios. In actual operation, it needs to be adjusted and optimized according to specific conditions.
Summary
The insert molding process is divided into five main steps: Loading the insert into the mold, mold injection of molten plastic, opening the mold, separating the molded parts from the gate and post-processing., the workflow of insert molding is a complex and delicate process, which requires strict control of parameters and conditions in each link to obtain high-quality products.
Disclaimer
The content on this page is for reference only.LSdoes not make any express or implied representation or warranty as to the accuracy, completeness or validity of the information. No performance parameters, geometric tolerances, specific design features, material quality and type or workmanship should be inferred as to what a third party supplier or manufacturer will deliver through the Longsheng Network. It is the responsibility of the buyerseeking a quote for partsto determine the specific requirements for those parts.Pleasecontact usfor moreinformation.
LS Team
This article was written by multiple LS contributors. LS is a leading resource in the manufacturing sector, withCNC machining,sheet metal fabrication,3D printing,injection molding,metal stamping, and more.
