A plastic jar making machine is used to manufacture plastic jars and containers through injection molding.
Here are some key points about plastic jar making machines:
- It consists of an injection unit, a clamping unit, mold, and ejection system. The injection unit melts plastic granules and injects the molten plastic into the mold.- The mold has two halves
- a cavity half and a core half. When closed together, they form the shape of the jar. The cavity is usually in the shape of the outer surface of the jar.
- Common molds are single-cavity or multi-cavity molds. Multi-cavity molds allow making multiple jars in one shot.
- Popular plastic materials used are PP, HDPE, PET, etc. The material is fed into a hopper and then conveyed into the injection barrel.
- The molten plastic is injected into the mold at high pressure, usually by an electrically driven screw or plunger.
- After injection, holding pressure is maintained to pack the plastic and compensate for material shrinkage.- The mold opens after cooling time, and the solidified plastic jars are ejected out by ejector pins.- The machine has controls for adjusting injection pressure, speed, temperature, cooling time, etc. This helps get the right material flow and product quality.
- Semi-automatic machines require manual loading/unloading of molds, while automated versions use robots.
- Output capacity depends on shot size, number of cavities, and cycle time. High-end machines can produce over 3000 jars per hour.In summary, plastic jar making machines use injection molding to mass produce plastic jars of different shapes and sizes in an efficient and cost-effective manner.
While injection molding is used to make the preforms and closures for plastic jars, blow molding is another key process used to manufacture the actual jars.In blow molding for jar production:
- The plastic (usually PET) is molten and extruded into a parison (hollow tube).
- The parison is then clamped into a hollow mold cavity and high pressure air blows the parison against the mold walls into the final shape.
- Once cooled and hardened, the mold opens and the blown plastic jar is ejected.Some key points about blow molding machines for jar making:
- Two main types are extrusion blow molding and injection blow molding. In injection blow, the parison is injection molded before blow molding.- Blow molding creates hollow parts like bottles and jars. The parison is stretched and made into the desired shape using air pressure.
- Jars can be made in a single cavity or multiple cavities for mass production.- Machines are equipped with extruders, parison programming, blow pins, and molds on rotating wheels or shuttles.
- Blow molding allows making plastic jars of different shapes, sizes and volume capacities.
- Output depends on number of cavities and cycle time. High capacity machines produce over 2000 jars/hr.So in summary, while injection molding makes preforms and caps, blow molding is essential for mass production of plastic jars of different shapes using the blowing process with molds. Both processes are critical for efficient plastic jar manufacturing.
