Characteristics and precautions of hollow blow molding machine

1. Features of Fully Automatic Blow Molding Machines:

Blow molding machine molds differ from injection molding molds and possess their own unique characteristics. The key mold for fully automatic blow molding machines is the mold for the injection molded parison. The mold material has specific performance requirements, requiring minimal thermal expansion and contraction, and high heat transfer efficiency.

The mold structure utilizes a hot runner design, which has high thermal conductivity. Given China's current mold technology, it is still difficult to develop and manufacture molds that meet quality standards for fully automatic blow molding machines. Some mold companies are reportedly unclear about the materials used for fully automatic blow molding molds. How can they develop these molds? These are fundamental issues; resolving them will facilitate other challenges. The blow molding machine's screw and barrel are manufactured from high-quality nitrided steel using advanced technology, resulting in excellent wear resistance and a long service life. The blow molding machine utilizes a light-controlled material metering system, effectively aligning extrusion speed with die speed. A low-speed, high-torque motor with variable frequency speed regulation directly drives the screw for pre-molding.

The blow molding machine's screw utilizes a mixing head for uniform plasticization and excellent coloring, meeting the process requirements of various plastic products. The wide range of mold thickness and mold opening and closing stroke adjustments makes it suitable for the production of a wide range of products. The mold clamping mechanism utilizes a single toggle, three-link, and three-hinge mechanism, providing a high force multiplier, reliable locking, and smooth operation. The mechanical components also feature excellent repeatability in their working positions.

Second, the following six key operating points should be mastered when operating a fully automatic blow molding machine:

First: To reduce the weight of the parison, the blow molding machine should extrusion speed, where possible, to reduce mold waiting time. This is crucial for future machine maintenance.

Second: While ensuring adequate cooling of the product, minimize the molding cycle time. I'm sure you'll find more solutions.

Third: Ensure sufficient inflation pressure and a fast blowing rate during operation.

Fourth: Ensure the extruder temperature, speed, and melt P value are carefully controlled during operation.

Fifth Point: Ensure sufficient venting during the blow molding process.

Sixth Point: Operators must be familiar with the molding properties of plastic materials to better utilize their inherent advantages.

III. Preliminary Analysis of Processing Temperatures for Fully Automatic Blow Molding Machines:

It is well known that many substances in nature exist in three states: gas, liquid, and solid. However, this is limited to crystalline substances. The plastics we encounter daily are all amorphous substances, or rather, exist as mixtures. Today, the editors from Apollo Blow Molding Machine will explain the "three states" of plastic molding.

During the blow molding process, the temperature rises slowly. When the processing temperature is relatively low, the polymer is in a rigid solid state, exhibiting only minimal deformation under external forces, similar to glass. This state is therefore called the glassy state.

If the ambient temperature is raised to a certain level, the polymer will undergo significant changes in shape under external forces. Within a certain temperature range, the shape change is relatively stable, and this state is called the highly elastic state.

If the temperature continues to rise, the deformation gradually increases with the temperature until it becomes a viscous fluid, at which point its shape cannot be restored. This state is called the viscous flow state. The transition from the glassy state to the elastic state is generally called the glass transition, and the temperature range during this morphological transformation is called the glass transition temperature. The temperature range during which the elastic state transitions to the viscous flow state is called the viscous flow temperature. The processing and molding of plastic products are all completed in the viscous flow state.

The glass transition temperature of a blow molding machine refers to the temperature at which a polymer transitions from the elastic state to the glassy state. It refers to the temperature at which amorphous polymers (including the non-crystalline portion of crystalline polymers) transition from the glassy state to the elastic state, or vice versa. It is the lowest temperature at which macromolecular segments of amorphous polymers can move freely. It varies depending on the measurement method and conditions. It is an important processing parameter for polymers. Above this temperature, polymers exhibit elasticity; below this temperature, polymers exhibit brittleness, which must be considered when used as plastics, rubbers, synthetic fibers, etc. For example, the glass transition temperature of polyvinyl chloride is 80°C. However, it is not the upper limit of the product's operating temperature. For example, the operating temperature of rubber must be above its glass transition temperature; otherwise, it loses its high elasticity.

Blow molding machine viscosity temperature: The temperature at which a polymer transitions from a highly elastic state to a viscous flow state is called the viscosity temperature. This fluid polymer is called a melt. The macromolecules in the melt are in a disordered state, with chain segments entangled with each other. This generates internal friction during flow, causing viscous flow. This viscous flow state is typically the processing state of a material, and the viscosity temperature is the minimum processing temperature for hot-melt materials. Therefore, understanding the viscosity temperature and viscous flow patterns of polymers is crucial for polymer processing and molding.

Blow molding machine decomposition temperature: The temperature at which a polymer in a viscous flow state degrades its molecular chains as the temperature rises. The decomposition temperature is the temperature at which this degradation is evident.