Blow molding technology offers a number of advantages over other high-volume production processes, such as injection. And it presents, at the same time, favorable cost factors. The process uses plastics with a higher molecular weight, making it possible to obtain thinner walls and higher strengths at equal weight.
In general, all blow molding processes consist of obtaining a preform, which is a tubular element or in the form of a test tube, fixing it inside a blow mold and, at a specific temperature of each material so that it has sufficient consistency. Next is to inject air into the tube to adapt to the walls of the mold, allowing it to cool under pressure and open the mold to extract it when it has reached sufficient consistency.
Basic concepts of the process
Blow molding offers a series of advantages over other large series processes, such as injection, as it allows counter-leaks, the possibility of varying the wall thickness and, depending on the low pressures used (0.2-1.0 MPa), low residual stresses. At the same time, it presents favorable cost factors.
The process allows the use of plastics with a higher molecular weight than, for example, injection, making it possible to obtain thinner walls and higher strengths with equal weight, and better performance against environmental agents and chemical products that produce cracking.
Basically, the process consists of obtaining a preform (which has the appearance of a test tube or a length of tube), placing it in a two-part hollow mold that clamps one or both ends or not, injecting pressurized air into the hot preform to connect with the walls of the mold and take its shape, allow it to cool and open the mold to remove the piece.
Factors influencing the selection of different usable materials or possible blow molding processes are performance requirements, part size and shape, quantity to be manufactured, and cost considerations. Each process has advantages and disadvantages that must be taken into account, while the suitability of each material to the process to be used must be considered.
Thermoplastic extrusion and blowing
We incorporate the latest technological advances for blowing hollow bodies with thermoplastic materials. Our products are designed and manufactured in accordance with the construction criteria and technical dictates of our engineering department which has extensive knowledge in the construction of machinery and equipment for the transformation of thermoplastic materials.
In the new and current version, the previous CPU has been replaced by a new state-of-the-art microprocessor that provides greater capacity and speed to the multithreaded routine, also allowing us a better and more precise control of temperatures and any other parameters, in particular, the movements controlled by position transducers strain gauges, all this, constitutes a real improvement of ace and excellent performance of this equipment.
Our plastic extrusion machinery consist of the following;
This is the tool that is assembled and disassembled to clean and obtain an optimal extruded material for product design. The type of material is laminated. There are several types of heads, among them there is a pinhead, accumulator, torpedo etc.
This tool can also be moved, it is used so that the material gets the shape you want, in the blowing machine a container and in other machines another type of product. The mold works by a hydraulic system.
This tool can be moved to coincide with the entrance to the mold, it serves to blow the material that is inside the mold and this in turn of the shape of the mold. The pin works by a pneumatic system.
The function of this tool, which can also be moved, is to cut the material that grips the mold so that in this way the pin can enter the mold and do its job.