Hot melt extruded materials are widely used in polymer materials, pharmaceuticals (especially solid dispersions), food, and plastic industries, and the subsequent crushing of extruded materials is a key step in determining the final product performance (such as particle size, flowability, stability).

1、 Due to the following characteristics of hot melt extruded materials, their crushing faces unique challenges and is very difficult:

1High toughness and viscoelasticity:

At the glass transition temperature（Tg）After processing above the melting point, the extruded material often remains in a high elastic state rather than a brittle state, making it difficult to effectively fracture and pulverize.

2Thermal sensitivity:

The mechanical energy generated during the crushing process will be converted into thermal energy, which may cause the material to soften, melt, or adhere, especially for lowTgPolymers or systems containing low melting point drugs.

3Adhesion:

Polymers in a molten state are prone to adhere to the medium and inner walls of crushing equipment, resulting in decreased efficiency and product loss.

4Target particle size requirement:

In the pharmaceutical field, it is usually necessary to crush the extruded material into fine powder (such as150-500Microns are used for subsequent capsule filling or compression, which places high demands on crushing efficiency and particle size control ability.

2、 Design concept of crushing process:

1Low temperature crushing:

Glass transition temperature of hot melt extruded material（Tg）This is the most important parameter. It is best to crush at a level much lower than the materialTgAt this point, the material is in a glassy state and exhibits brittleness. Therefore, the crushing system must be equipped with a low-temperature refrigeration system.

2Properties of polymer carrier:

The molecular weight, chain structure, crystallinity, etc. of polymers can affect their mechanical strength and fracture behavior. Therefore, it is necessary to adopt a model structure that meets this characteristic.

3Drug loading capacity:

high concentrationAPIIt may alter the mechanical properties of the entire system, making it more brittle or tough.

4Shape of extruded material:

Strip, stick or sheet? The initial size and shape affect the type and method of crushing.

3、 The current situation of hot melt extruder crushers on the market:

1Liquid nitrogen low-temperature crusher:

The equipment cost is high, the usage cost is high, and it has a certain degree of danger.

2Hammer crusher:

Low efficiency and high energy consumption. It needs to be crushed multiple times（15Only then can the requirements be met.

3Airflow crusher:

Cannot be crushed.

4、 Beijing has pioneered Tonghe's ultra-low temperature ultrafine grinder:

After continuous experimentation and exploration by technical personnel, our company's model can crush modified materials. And it has high fineness（40MmThe above features include low temperature (no clumping of materials), low usage cost (normal temperature and pressure), no need for liquid nitrogen, adjustable particle size, and one-time crushing.

There are currently multiple use cases, as shown in the attached figure.

Users who encounter such crushing difficulties are welcome to communicate at any time.