Extrusion blow molding and hot runner injection blow molding machines are mainly used for the production of small and medium-sized plastic bottles for medicinal purposes, while "extrusion pull blow" or "injection pull blow" molding machines are used for the production of large bottle bodies.

However, due to the high flatness of the opening of the hot runner injection blow molding bottle, the average wall thickness of the bottle, and the excellent sealing function between the opening and the cap, it can meet the functional requirements of preventing the volatilization of drug gases inside the plastic bottle and the infiltration and leakage of external gases into the bottle, thus making this type of bottle fully meet the special requirements of drug packaging. Additionally, due to the possibility of installing sliding bottom modules on the blow molding mold, the design flexibility of the bottom shape of the bottle body is greater. With the rapid development of the domestic medical industry, the usage of domestic medical bottles will show a significant increase. For this reason, some equipment manufacturers in China are intensifying their research and development on the basis of digesting and absorbing advanced technology from abroad, which can replace domestic and heating billets in two processes. Pharmaceutical manufacturers tend to use one-step "injection pull blow" bottle forming machines. The National Drug Administration proposed the use of hot runner injection blow molding method to produce high-quality plastic drug bottles as early as the Ninth Five Year Plan period. The bottle mouth two-step model refers to the injection and stretching blow molding processes carried out separately by two independent machines.

Extrusion blow molding machine

The most plastic bottle manufacturers use extrusion blow molding and hot runner injection blow molding machines. The one-step model will not cause secondary pollution to the product and has good product uniformity.

Compared to other hollow plastic product molding equipment, plastic bottle molding equipment has small specifications, fast speed, high accuracy, and high efficiency. Three workstations can operate simultaneously, with high production efficiency and short cycle time. It can achieve automatic counting and packaging of all hot runner equipment, resulting in a production efficiency lower than that of three workstations. At present, China has introduced more than 40 production lines for hot runner injection blow molding pharmaceutical bottles from abroad, with a total production capacity of about 700 million units per year. The advantage of the "two-step method" model is its flatness, good sealing, fast variety development, low mold usage and cost. However, due to the step-by-step process of injection tube blank and blow molding, the uniformity of the product is poor; Step 2: Place the tube blank on a honeycomb heater or automatic cycle heating conveyor belt for heating and temperature regulation, and then move it to the bottle blowing process for stretching and blowing molding with compressed air. Extrusion blow molding can form complex, irregular and integral shapes that can produce various strains such as bending and environment, with high performance and good usability. The main difference between the two is that "3-station" refers to the completion of injection molding and heating molding in one process, while "4-station" refers to efficient equipment that can continuously carry out injection molding, molding product demolding, and other processes on a unified equipment. Because the blow molding mold is only composed of a female mold, it can be easily changed by simply adjusting the gap between the machine head and the mold mouth or the extrusion premise, which is also relatively low.

The first station is for injection molding, the second station is for blow molding, and the third station is for bottle removal and cooling.