Scientific name: Polypropylene

Commonly known as Baifolded glue

English name polypropylene

Natural polypropylene is a crystalline plastic, which is a white woody material that is more transparent than PE. Depending on its crystallinity, it forms products that are transparent to semi transparent. Lightweight, with a specific gravity lower than water, and a harder surface than polyethylene. Thin walled products are resistant to folding, commonly known as 100 fold adhesive. Monomer propylene - a gas produced in petroleum refining

Combustion characteristics: Polypropylene is relatively easy to burn and continues to burn after leaving the flame. The upper end of the flame is yellow and the lower end is blue, with a small amount of black smoke produced. During combustion, it melts and drips, emitting a petroleum smell.

Advantages: The mechanical properties of polypropylene are better than PE ABS PS at room temperature, especially when the temperature exceeds 80 ℃, its mechanical properties will not decrease much; At low temperatures, the mechanical properties deteriorate and become brittle. High temperature, softening, insufficient rigidity; Low temperature, ductile fracture, brittle.

The surface hardness of polypropylene is not as good as PS ABS, but it is higher than PE and has excellent surface gloss; Therefore, it can be used to make home appliance casings and other products.

The biggest feature of polypropylene is its good resistance to bending fatigue; The flexible hinges produced from polypropylene can withstand hundreds of thousands of folds and bends without damage. Therefore, it is called Baifolded glue.

The excellence of polypropylene lies in its ability to withstand boiling water without damage, making it suitable for use as medical equipment and tableware.

The tensile strength of polypropylene varies greatly in the longitudinal and transverse directions, therefore, it has good fiber forming properties and is suitable for making fibers and ropes

Polypropylene is acid and alkali resistant, resistant to many organic solvents, and has excellent electrical insulation properties.

The biggest disadvantage of polypropylene is that it lacks rigidity at high temperatures and becomes brittle at low temperatures; Poor environmental resistance, prone to yellowing, discoloration, and brittleness when used outdoors. The anisotropy of tensile strength is large, the product is prone to deformation, the continuous use temperature is low, the creep performance is high, and it is not resistant to long-term loads; Poor printing performance.

Suitable for producing woven bags, fibers, ropes, and fish nets

Production of conveying pipelines, packaging, shrink wrap films

Production of medical devices, heat-resistant tableware, food packaging, acid and alkali resistant containers

Production of household appliance casings, wires, cables, etc

Injection molding characteristics: Polypropylene is a crystalline high polymer with a clear melting point. It can generally melt when heated to 173 ℃ and decompose slightly at 300 ℃; A large amount of decomposition occurs at 360 ℃; Therefore, during injection molding, the temperature adjustable range is relatively large. During injection molding, the general operating temperature is between 190 ℃ and 240 ℃; Polypropylene can also be used as a cleaning agent for other easily decomposable raw materials during material changes.

Polypropylene does not absorb water and generally does not require drying. Sometimes, for product quality reasons, it can be dried at a

temperature of 60 ℃ for 30 minutes to 1 hour to remove any floating water from the raw materials.

Polypropylene is a highly crystalline plastic, and its liquid and solid volumes differ greatly near its melting point. In addition, its anisotropy during shrinkage can easily cause uneven shrinkage, known as shrinkage; Therefore, when designing products, try to avoid uneven wall thickness as much as possible; Polypropylene has low melt viscosity, good flowability, high flow length ratio, and may be able to fill thin-walled products; However, at the same time, the precision of its mold production must be high, otherwise it will result in peak production; Due to its anisotropy, the product is highly deformed. The shrinkage rate is 18 ‰; The overflow value is 0.03m.