Thermoplastic polyimide TPI

Thermoplastic polyimide (TPI) is developed on the basis of traditional thermosetting PI. Compared with thermosetting PI, TPI has many potential advantages.

1. TPI has excellent processing performance, toughness and damage resistance, short production cycle, simple operation and low manufacturing cost.

2. TPI can be melted and reprocessed, so damaged structures can be repaired by heating and pressurizing.

3. TPI has advantages in environmental friendliness. It is a fully imidized polymer and does not contain reactive chemicals, so the toxicity is very low.

TPI Processing Production Technology

For the processing of thermoplastic polymers, there are three common processes, namely injection molding, compression molding, and extrusion.

1) Injection Molding

Injection molding refers to the method of injecting heated and melted materials into a mold, and obtaining a molded product after cooling and solidification. It is also called injection molding, which is suitable for mass production and complex-shaped products.

Advantages of injection molding process:

A. Less waste loss.

B. No need to continue to improve the parts after molding.

C. Short molding cycle.

Disadvantages of injection molding process:

A. Parts must be designed according to specific molding requirements.

B. Injection molded parts may have fusion seams.

C. Products with thicker walls cannot be injection molded, and shrinkage holes are prone to occur.

D. Suitable for products with large batches, and products with small batches have greater waste.

The injection molding process of thermoplastic polyimide (TPI) is relatively mature, but there are still major limitations. For example, it is not suitable for injection molding of large parts, and shrinkage holes after injection molding will significantly affect the use of the product.

2) Compression molding process

In compression molding, a certain amount of plastic (which can be powder, granular or sheet, etc.) that is usually preheated is placed in the heated mold cavity, and then the mold is closed and pressure is applied to the plastic to melt it into a viscous flow state and fill the mold cavity to form a product; after the product solidifies, the mold is opened and the product is taken out.

Advantages of compression molding:

A. The internal stress of the product is very low, and the warping deformation is also very small, and the mechanical properties are relatively stable.

B. The wear of the mold cavity is very small, and the maintenance cost of the mold is low.

C. Large flat products can be formed. The size of the product that can be formed by compression molding is only determined by the clamping force of the existing compression molding machine and the size of the template.

Disadvantages of compression molding:

A. The molding cycle in the entire production process is long, the efficiency is low, and it consumes a lot of physical energy for the staff.

B. Compression molding is not suitable for complex products with depressions, side slopes or small holes.

C. For products with high dimensional accuracy requirements (especially for multi-cavity molds), this process is somewhat limited.

Thermoplastic polyimide (TPI) compression molding process is relatively mature and more suitable for making some thick-walled plates, which are then machined into the required parts. In the on-site market, this process is basically used to produce TPI plates. However, its molding cycle is long, and the low-efficiency processing method leads to slow batch production and high processing costs. In addition, the compression molding method cannot guarantee the yield of bars and pipes, which relatively increases the cost of use for the client.

3) Extrusion molding process

Extrusion molding is also called extrusion, extrusion, and extrusion molding. It is to use the extrusion effect of the screw and the plunger to force the plasticized plastic to pass through the die to become a continuous product with a constant cross-section.

Advantages of extrusion molding:

A. The equipment is easy to manufacture and the cost is low.

B. Continuous production is possible, with high production efficiency.

C. The equipment has a high degree of automation and low labor intensity.

D. Simple production operation and easy process control.

E. The extruded products are uniform, dense and of high quality.

Disadvantages of extrusion molding:

A. Three-dimensional products cannot be produced.

B. The cost of raw materials required for startup is relatively high, and it often takes dozens or even hundreds of kilograms to start the machine once.

The extrusion molding process of thermoplastic polyimide (TPI) is relatively immature. Due to the poor thermal stability of thermoplastic PI, easy degradation and hydrolysis, and severe die swelling effect, the continuous extrusion of thermoplastic polyimide (TPI) is directly affected. The production of continuous extrusion of thermoplastic polyimide (TPI) has resulted in almost no domestic manufacturers being able to achieve continuous extrusion molding of polyimide (PI) profiles. TPI requires relatively stringent processing conditions during extrusion, and the processing window of extrusion temperature, molding pressure, etc. is relatively narrow. The extrusion molding process can significantly shorten the molding cycle, and continuous production can ensure product consistency and good stability.

Through a long period of exploration, Jiangsu Junhua Special Engineering Plastics Products Co., Ltd. has been able to maturely and stably extrude thermoplastic polyimide (TPI) profiles continuously.

Industrial Application of TPI

Mechanical Industry: TPI has excellent mechanical properties and friction resistance, and can replace titanium alloys to manufacture various parts, such as engine inner covers, dense parts, clutch gear rings, etc.

Aerospace: TPI has good flame retardant properties and is used to produce aircraft parts to reduce damage caused by fire.

Electronic Communications: TPI can maintain good electrical insulation in harsh working environments such as high temperature, high pressure and high humidity, and is usually used to manufacture wafer carriers, electronic insulation diaphragms and various connected equipment.

Medical:Artificial bones made of TPI resin have the advantages of light weight, non-toxicity and strong corrosion resistance.

Electricity:TPI has good thermal stability and dielectric properties and can be used to produce various power equipment such as wires and cables.

Coating:The fine powder coating of TPI on the metal surface can obtain TPI powder metal coating products with excellent insulation, strong corrosion resistance, heat resistance and water resistance, which are widely used in chemical corrosion protection, household appliances, electronic products, machinery and other fields.

Shandong Junhao

The company has been committed to the research and development, production and sales of high-performance special engineering plastics such as PEEK and PI for many years. It has rich experience in collaborative research and development, sample testing, batch production, technical support and after-sales service guarantee. We look forward to using our knowledge and capabilities to provide you with long-term application solutions in various application fields such as PEEK and PI.