Blow molding: It is a method of clamping molten thermoplastic raw materials extruded from an extruder into a mold, and then blowing air into the raw materials. The molten raw materials expand under the action of air pressure, adhere to the wall of the mold cavity, and finally cool and solidify into the desired product shape.
Wednesday, June 19, 2024
Saturday, June 8, 2024
Compression injection molding is a relatively traditional injection molding method
Principle:
First, inject the molten material into the mold cavity, and when the molten material enters the mold lung. The mold opens slightly under its pressure blade; After the molten material fills the mold cavity, use a high-pressure locking mold to obtain the required product. The second step is compression molding. Due to the fact that the molten material enters the mold cavity when the mold has been slightly opened, the required allowable mold labor is relatively small.
During the molding process, the screw no longer injects material into the mold cavity, but relies on high-pressure locking of the mold to force Lf against the plastic, resulting in a smaller product orientation and lower internal stress. This method is particularly suitable for products with high transparency requirements that are formed and have a small volume;
Advantages:
It can increase the flow length ratio of injection molded parts; Adopting smaller locking force and injection pressure; Reduce internal stress of materials; And improve processing productivity.
Injection compression molding is suitable for products made of various thermoplastic engineering plastics; Such as large-sized curved parts, thin-walled, miniaturized parts, optical lenses, and parts with good impact resistance requirements
Low pressure molding is a process that injects packaging materials into molds at very low injection pressures and rapidly solidifies them into shape.
Low pressure molding process is a packaging process that injects packaging materials into molds at a very low injection pressure (2-20 bar) and rapidly solidifies (5-50 seconds) to achieve insulation, temperature resistance, impact resistance, vibration reduction, moisture resistance, waterproof, dustproof, and chemical corrosion resistance.
This process is currently mainly applied to the packaging and protection of precision and sensitive electronic components, including printed circuit boards (PCBs), automotive electronic products, mobile phone batteries, wire harnesses, waterproof connectors, sensors, microswitches, inductors, antennas, and so on.
Low pressure molding is a process method that falls between high-pressure injection molding and sealing.
Features and advantages
The traditional injection molding process has defects due to high pressure, as low-pressure molding only requires a small amount of pressure to allow the melt to flow into a small mold space, thus not damaging the fragile components that need to be packaged, greatly reducing the scrap rate.
The low-pressure forming process can effectively seal, moisture-proof, waterproof, dust-proof, and chemically resistant the encapsulated components. In addition, it can also balance performance including high and low temperature resistance, impact resistance, insulation, and flame retardancy.
Shorten product development cycle
Low pressure forming molds can use cast aluminum molds instead of steel, making them very easy to design, develop, and manufacture, which can shorten the development cycle. In addition, compared to the time-consuming two-component sealing process, the process cycle of low-pressure hot melt injection molding can be reduced to a few seconds to tens of seconds, greatly promoting production efficiency.
Save total production costs
Firstly, the equipment cost of low-pressure injection molding process is low. Traditional injection molding equipment systems generally have higher costs, including purchasing high-pressure injection molding machines, as well as having a water-cooling system and expensive steel molds. The low-pressure injection molding process equipment system is generally relatively simple, consisting only of three parts: a hot melt glue machine, a work console, and a mold.
Secondly, due to the extremely low injection pressure, aluminum molds can be used for mold design, development, and manufacturing, which can save material costs and development cycles. If low-pressure injection molding technology is used to replace traditional sealing technology, it can also save the cost of sealing the shell and post heating curing.
Finally, due to low pressure and low temperature, the scrap rate of finished products can be greatly reduced, avoiding unnecessary waste.
Therefore, choosing low-pressure injection molding technology can not only significantly improve production efficiency and reduce the defect rate of finished products, but also help production enterprises establish cost advantages overall
Thursday, June 6, 2024
Gas assisted injection molding, also known as gas injection molding, is a new injection molding process. It is one of the most important developments in the injection molding industry since the introduction of reciprocating screw injection machines.
Gas assisted injection molding is an extension of injection molding, which is developed on the basis of injection molding technology and structural foam injection molding; It can also be considered as a combination of injection molding and hollow molding, in this sense, it can also be called "hollow injection molding". The principle is to use relatively low pressure gas to replace the resin in the mold cavity during the pressure holding stage of the original injection molding.
Gas assisted injection molding can be achieved by adding a gas supply device to the existing injection molding machine. The gas supply device consists of an air pump, a high-pressure gas generation device, a gas control device, and a gas nozzle. The gas control device uses a special compressor for continuous gas supply, and is controlled by an electric control valve to maintain a constant pressure. Pressure usually has three levels. A gas control device can be equipped with multiple injection molding machines.
The gas commonly used in gas assisted injection molding is nitrogen. The gas pressure and gas purity are determined by the shape of the molding material and the product. The pressure is generally between 5~32MPa, with a maximum of 40MPa. High pressure gas is injected from the gas nozzle at a set pressure timing during each injection. One or more gas nozzles, located on the injection molding machine nozzle, mold runner or cavity.
Advantages:
Gas assisted injection molding technology has many incomparable advantages. It not only reduces the manufacturing cost of plastic products, but also improves certain properties; When the parts can meet the same usage requirements, using gas assisted injection molding can greatly save plastic raw materials, with a savings rate of up to 50%. On the one hand, the reduction in plastic raw material consumption leads to a reduction in the time of each link in the entire molding cycle
Water-assisted injection molding technology is an advanced injection molding process that injects part of the melt into the mold cavity, then injects high-pressure water into the melt through equipment to finally shape the workpiece.
Advantages:
Due to the incompressibility of water, the front end of the water forms a solid interface, squeezing the inner wall of the product into a cavity. The front end of the water also plays a role in rapid cooling. Therefore, water-assisted has many advantages that gas-assisted cannot match. Research and application show that water-assisted can generate thinner and more uniform cavity walls, and the inner wall surface of the flow channel is very smooth. Especially for thick-walled workpieces, the cooling time of water-assisted can be greatly reduced compared with gas-assisted.
Sunday, June 2, 2024
LSR injection molding as liquid silicone rubber injection molding. LSR, also known as liquid silicone rubber, is fluid, colorless, odorless, safe and environmentally friendly compared to solid silicone.
LSR injection molding: Liquid silicone (Liquid silicone rubber) is divided into two components, A and B. The quantitative device is used to control the two to a 1:1 ratio, and then fully mixed through a static mixer and injected into the barrel of the liquid silicone injection molding machine, and then accurately injected into the heated mold for molding.
Thursday, May 30, 2024
Injection molding, also known as injection molding, is a molding method that combines injection and molding. The advantages of injection molding are fast production speed, high efficiency, automated operation, a wide variety of colors, shapes from simple to complex, sizes from large to small, and precise product size. The product is easy to update and can be made into parts with complex shapes. Injection molding is suitable for mass production and molding processing fields such as complex-shaped products.
At a certain temperature, the completely molten plastic material is stirred by a screw, injected into the mold cavity with high pressure, and cooled and solidified to obtain a molded product. This method is suitable for mass production of parts with complex shapes and is one of the important processing methods.