Polypropylene (PP) is currently the second-largest general-purpose plastic. With the development of construction, automotive, home appliances, and packaging industries, waste PP has become one of the waste polymer materials with a large output in recent years. At present, the main ways to deal with waste PP include: incineration for energy supply, catalytic cracking to prepare fuel, direct utilization and recycling. Considering the technical feasibility, cost, energy consumption and environmental protection in the process of disposing of used PP, recycling is currently the most commonly used, effective and advocated way to dispose of used PP.

Due to the effects of light, heat, oxygen, and external forces during use, the molecular structure of PP will change, and the product will turn yellow, brittle, and even crack, resulting in obviously deteriorating of Polypropylene (PP) toughness, dimensional stability, thermal oxygen stability, and processability. It is difficult to meet the requirements of processing by using waste PP products directly.

Therefore, the recycling technology of waste Polypropylene (PP) has been continuously developed. The use of alloying with other polymers or compounding with fillers can significantly improve the processing performance, thermal properties, physical and mechanical properties of waste PP, and achieve high performance of waste PP.

Compounding

Compounding is the process of mixing waste Polypropylene (PP) with non-polymer materials to prepare composite materials. It is the main way to achieve high performance and functionalization of waste Polypropylene (PP). Compounding waste PP can improve its rigidity, strength, thermal, electrical and other physical and mechanical properties, and reduce costs.

According to the filler composition, it can be divided into inorganic filler and organic filler.

Inorganic Filler Compounding

Inorganic fillers commonly used in Polypropylene (PP) compounding can be used to compound waste PP, such as calcium carbonate, talc, montmorillonite, metal oxides, fly ash and glass fiber. The research found that although these inorganic fillers can significantly improve the rigidity and reduce the cost of waste PP, they have large differences in polarity from waste PP, high surface energy and poor compatibility lead to a reduction in elongation at break and impact toughness of the composite.

Organic Filler Compounding

Common organic fillers include wood flour and wood fiber, starch, wheat straw, hemp fiber, and discarded newspapers. A study on wood fiber filled waste PP microcellular foaming technology has been conducted. The results show that the microcellular structure is uniformly distributed at a melting temperature of 180 ° C and a holding pressure of 12.5 MPa. Because the microporous structure can extend the propagation path of cracks, absorb external impact energy, thereby improving impact strength.

Natural fiber is a new waste Polypropylene (PP) filling material. In view of its high water absorption and incompatibility with waste PP, carrying out surface treatment for the natural fiber is the main method to achieve high performance of natural fiber filled waste PP composite materials. In addition, waste polyester can also be used to modify waste PP. Some scholars have studied the crystallization behavior of β-nucleating waste PP / waste polyester fabric composites. The results show that waste polyester and β-nucleating agent have different phases to the waste PP nucleation, which increases the crystallization temperature of waste PP and induces the formation of β crystals.

Hybrid Compounding

Hybrid compounding is a process of preparing composite materials by filling polymers with two or more fillers. Due to the limitations of a single filler, hybrid composites can better improve the overall performance of polymers through the complementary and synergistic effects of different fillers. Therefore, research on the preparation and related properties of mixed filler filled waste Polypropylene (PP) composite materials has attracted attention. The fillers involved mainly include different inorganic filler mixtures and inorganic / organic filler mixtures.

Alloy Compounding

In order to fully get the advantages of alloying and compounding, some researchers have begun to combine alloying and compounding to further improve and enhance the physical and mechanical properties of waste PP, and to achieve high-performance and industrialization of waste PP, such as organic fillers and elastomers, inorganic Filler and elastomer are combined to modify waste Polypropylene (PP).

The research in this field shows that: the waste PP and talc powder-filled waste PP composites are brittle at low temperature, and the addition of EOC (ethylene-octene copolymer) can significantly improve the impact resistance of the composite. The dynamic mechanical behavior of ductile talc powder filled waste PP composites does not change with the increase of the number of recycling. 

For SGOP, Our Goal is to offer our customers green office products at affordable price but great value. We keep investing on new ideas and innovation on products development. Some of our products are patent protected which will bring you unique products based on exclusive contract. All of our experienced and enthusiastic sales team are willing to offer our great 7/24 service. 

The company's main products include:

* oxo-biodegradable PP folder

* FSC certified Paper folder.

* Colabag: Recycled PET  (RPET) bottle fabric office bags.

* Naturual Ingredients Glue Stick and liquid Glue.

* Latex Free Natural Rubber band. 

* Natural Wood Pencil without any lacquer. 

* MC Paper: Recycled Paper notebook from milk cartons. 

* PVC Free Ring binders and file folder. 

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