Blow molding in the present day

Blow molding in the present day
23 de November de 2022 Sofía Sánchez

There are many products made by blow molding that accompany us in our daily lives. This efficient manufacturing process uses air pressure to expand the plastic (preform) in a mold cavity, producing thin-walled, one-piece hollow parts.

moldeo por soplado

Bottles, containers, containers, jars, etc. These are the most well-known products. However, this flexible process is also used for many fields of industry and in daily life, such as automotive, consumer products, electronics, fuel tanks, furniture, health, security, packaging, toys.

In Gestión de Compras we have the necessary means to produce components by blow molding with great versatility. We work with a wide range of materials and sizes, being able to manufacture from a few pieces or prototypes to high production volumes.


In addition, this technique not only ensures the necessary conditions for the product inside. It also takes care of the finish, appearance and adaptability. However, none of this matters if we do not select the right blow mold. This process is characterized by several advantages, such as:

  • Variety of products
  • Multiple production methods
  • Automation
  • It requires lower pressures than injection molding.
  • Various volumetric capacities.
  • The products obtained have excellent mechanical properties, good resistance to degradation and chemical attack.

Botellas plástico soplado

However, if we do not select the right mold or the right supplier, we may encounter some problems, such as leaks, rocker arm pants, weld line tearing, surface wall defects or uneven radial wall thickness distribution.

That is why for the realization of the mold, Gestión de compras adapts to the needs and guidelines established by each customer. In this way, the customer obtains the exact mold he needs to manufacture his products.

The main materials used in blow molding are:

  • Polyethylene terephthalate (PET): It is the most commonly used to make bottles.
  • Low density polyethylene (LDPE, LLDPE).
  • High density polyethylene (HDPE).
  • Polypropylene (PP).
  • Polyvinyl chloride (PVC).

Piezas moldeo por soplado plástico


There are three types of blow molding, the usefulness of which varies depending mainly on the purpose of the product and its material:

  • Extrusion blow molding (EBM): HDPE, HMWPE, LDPE, PP, PVC, PETG, E-PET. In this process, the plastic is melted and extruded into a tube (preform) which is hermetically sealed at the bottom by the mold. Air is injected into the preform and it acquires the desired shape, is allowed to cool and the part is ejected.
  • Injection blow molding (IBM): HDPE, PP. Injection molding and blow molding are combined. The molten plastic is injection molded around a core to obtain a preform and is introduced into the mold, then air is injected to expand the material and achieve the final shape of the part, cooled and ejected.
  • Stretch blow molding (SBM): It is indicated for the production of multilayer parts. It is a two-stage process similar to injection blow molding. The process begins with the injection (or similar process) of a preform. The preform is heated with infrared heaters and high-pressure air is injected while the preform is stretched using a rod. The preform expands into the desired part shape.

Preforma PET


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