Blow moulding how does it work

After achieving the dimensions of the mold, the plastic is then cooled for ejection. The last phase is the ejection phase where the die is opened to release the product. Some injection molding machines can have extra phases. The additional phases are used for additional heating or cooling cycles, preform conditioning, coating, and other secondary processes. Stretch Blow Molding: Stretch blow molding, also known as injection stretch blow molding, is basically a modification of the injection blow molding process.

This process also includes the three main phases with an additional step in the blow molding phase. In stretch blow molding, the preform is created by injecting the plastic melt into a die with a metal road at the center.

The developed preform is then transferred to the product mold in preparation for the blow molding phase. Before inflating the preform, it is first stretched to a specific length by a stretch rod. After stretching, the plastic melt is then inflated to the shape of the final product.

After molding, the product is then cooled and ejected. Stretch blow molding is not limited to plastic injection. Stretching can also be achieved in an extrusion blow molding machine. This is done by partially extruding the parison and stretching it with a pull rod. It is then enclosed by a die and is inflated to shape. The main objective of stretch blow molding is to create a product with a biaxially oriented plastic.

Biaxial orientation is the process in which the plastic is stretched in two directions. In the longitudinal direction, the plastic is stretched by the stretch rod while in the lateral direction, the plastic is stretched by inflation. A biaxially oriented plastic has many desirable qualities including high impact, tensile, and tear strength, improved barrier properties, and excellent transparency. With the increased mechanical properties, bottles and packaging materials can be made with thinner walls.

Note that not all plastics can be biaxially oriented. Moreover, the plastic resin must have the right properties and quality for it to stretch without tearing or producing specks or other defects. PET is a common biaxially oriented plastic that is used to produce clear plastic bottles. There is a wide array of raw materials that can be used for blow molding. Blow molding materials are commonly thermoplastics that do not easily degrade upon heating.

Blow molding is extensively used in the manufacture of plastic bottles which is why most raw materials have properties suitable for such application. Currently, blow molding is gaining momentum in the transportation, construction, and consumer goods industries.

This makes engineering plastics such as polyamides and polycarbonates viable to be blown molded as well. Plastic containers are material storage products made of a variety of plastics. Plastics are an ideal material for creating containers. They are known for their excellent formability, degradation resistance, durability, lightweight, recyclability, and controllable mechanical properties A plastic tank is a large capacity liquid or granular storage unit that can be vertical, horizontal, below or above ground, as well as movable.

Plastics make our lives easier and help us produce things more cost-effectively. This process can be used to manufacture plastic products. The process involves heating a plastic tube known as a preform or parison to its melting point and then putting that into the cavity of a mold. They then use compressed air to inflate the molten plastic like a balloon so that it takes the shape of the mold but is hollow inside.

The amount of plastic used and the air pressure determines how thick the final product is. Blow molding has its roots in glass blowing, where a craftsman would heat the glass to its melting point and then blow through a tube to inflate the glass. This process has been around since as far back as the s. A patent from the time shows the process being used with celluloid polymer.

These early methods were not suited for mass production. In the s, they developed commercial machines to manufacture blow-molded bottles and made mass production possible.

The materials available were too brittle and took too long to produce to effectively utilize the process to make large quantities. Blow molding exploded into industrial prevalence with the creation of low and high-density polyethylene. This revolutionized many industries including the soft drink bottling industry and the automotive industry. Here are some commonly blow-molded products:. Blow molding is also widely used in the automotive industry and makes the design and mass production of auto parts simple and cost-effective.

Here are some commonly blow-molded automotive parts:. To sum up, blow molding has a wide variety of uses and is a great way to produce a large number of parts inexpensively. There are a few different types of blow molding. Plastic injection molding is ideal for high-volume orders and mass production in projects requiring thousands or even millions of the same part. Injection molds must have a high precision match between mold halves, so material flow is perfectly controlled.

With injection molding, creating the mold is the key to building a perfect, precision part. When the production mold is finalized, and the machine is prepped, manufacturing begins. An initial run will be thoroughly examined for any part defects. If none are found, full production can begin. Depending on the part and the agreement with the molder, quality checks can take place on a regular basis.

They will check for strength, color correctness, and any common defects that can occur like flash or warping. The precision of an injection mold generally makes it more expensive than a blow mold. At Rodon , we s pecialize in close-tolerance injection molding of small plastic parts, and provide a total concept solution from design and tooling to production, fulfillment, and packaging.

The combined effort of our designers and toolmakers results in molds that ensure quality, precision tolerances, and optimized cycle times. We have the capacity to mold parts with complex geometries and variations in wall thickness. When sourcing for a molder, we often recommend ThomasNet as an excellent platform for supplier and product searching. With over , suppliers, you'll easily be able to find one that matches your needs and requirements.