Interesting Facts about Blow Moulding as an Industrial Process

From man-made to technological machineries, the industrial industry, indeed, has been taking pride of how its processes move ahead for a more efficient and profitable production. In general, to meet every manufacturing, construction, forestry and all other related objectives, the industrial industry engages with three types of procedures or industrial processes including the physical, chemical and mechanical steps to achieve better and higher volume of output. An excelling example of these is called as blow moulding or blow molding.
Originally, the blow molding machine itself and its process were developed in 1800s. However, it only became popular when plastic bottles were manufactured through blow molding in 1940’s. Since then, a number of manufacturing companies started using blow molding as their mechanical partner for creating several products out of plastic which both welfare of the society and economy profits.

The blow molding typically uses substances such as the polypropylene (PP), polyethylene (PE), polyethylene terephthalate (PET) and polyvinyl chloride (PVC). It’s advantageous for crafting a variety of products, having multiple methods, one piece construction, precise end products and more.
Meanwhile, as a manufacturing process, the blow molding machine fundamentally produces hollow plastic shapes by means of inflating the abovementioned liquid plastic forms.

A standard blow molding machine consists of three major parts namely the extruder, accumulator die and molds from which containers with different shapes and sizes are processed. As of today, the manufacturing companies could choose between the extrusion blow molding, injection blow molding and stretch blow molding as three methods of this specific industrial process.

The extrusion blow molding (EBM)

To begin with, EBM is considered as the simplest type among the three. A manufacturing company could benefit from this method because it only requires a small capital investment and is suitable for small production. By using an extruder, die, press and mould, an EBM machine directly produces bottles that are characterized as rich in color, printable and impact resistant. Also, this method produces plastic products that could withstand a varying weather condition.

So how does EBM works? Well, this blow moulding method starts with dropping a hot tube made of plastic from an extruder to water cooled mold. This mold would close and the air would start to be injected through the top or neck of the container. Then it has to touch the walls of this mold and freeze. After that, the container would maintain its rigid shape and therefore it’s ready for use.

The injection blow molding (IBM)

This blow molding method is selected by manufacturing companies who would like to produce containers with no handles. IBM is divided into three stages: first, the melted plastic is injected into a split-type steel mold from a screw extruder. Then, the mold would create a test-tube like parison with a screw finish on top. When it has been transferred on a core rod and placed inside another cold mold, air would then be injected until the substance takes its shape.

IBM is preferred by the manufacturing companies who would like to trade plastic containers with the distinctions of threaded necks, wide mouth openings, creative shapes and solid handles. Also, they benefit from IBM because these end products do not necessitate any trimming or reaming before it could be distributed to the public.

The stretch blow molding (SBM)

Last but not the least, the end products made through the SBM method popularly includes PRT bottles used for storing water, juices and all other beverages. Also, SBM could be used for packing detergent products and more. What makes SBM the front-runner among the three methods of blow moulding is its ability to stretch materials in hoop and axial directions. SBM also creates plastic bottles which are lighter than the others because of the aforesaid merit.