How many types of Blow Moulding are there in your company?
Injection Blow Molding
This process is used for making glass and plastic products, such as single serving bottles and small medical devices, in high volume. The polymer is injected on to what is called a core pin, which is then inflated, cooled, and ejected. To begin with, the polymer is melted down and then fed into a manifold, which injects it into a hollow mold. This preform mold is what makes the outer shape. The internal shape is formed when the preform is clamped around a core rod, or mandrel. Then compressed air is pumped into the preform, inflating it into its final shape. The mold is then allowed to cool before being removed from the core rod, which is known as ejection.
Stretch Blow Molding
This process begins with a preform being made as done in the injection method. The preforms are then heated up, usually with infrared heaters. Then it is blown with high pressure air using metal blow molds. The preform is stretched using a core rod. This process is generally used when making bottles, jars, and other containers.
Extrusion Blow Molding
This process sees plastic melted and extruded into a hollow tube called a parison. The parison is then enclosed in a cooled metal mold. Air is then pumped into the parison, causing it to take the desired shape. After a cooling period, the part can then be ejected from the mold. Extrusion blow molding can be further broken down into two types: continuous extrusion and intermittent extrusion. In continuous extrusion blow molding, the parison is continuously extruded, with individual parts being cut out. With intermittent extrusion blow molding, a machine injects melted plastic into the parison part by part. This process is used for making things like milk and dairy containers, shampoo bottles, and hollow industrial pieces.