The impact of raw materials on the quality of plastic bottles is mainly reflected in the following aspects:

Firstly, the selection and quality of raw materials are directly related to the physical properties of plastic bottles. High-quality raw materials, such as premium Polyester (PET), polyethylene (PE), or polypropylene (PP), ensure that plastic bottles have outstanding strength, toughness, and durability. These properties are crucial for plastic bottles to withstand external pressures, prevent deformation and cracking.

Secondly, the purity of raw materials also significantly impacts the quality of plastic bottles. Pure raw materials can reduce impurities and pollutants during the production process, thereby lowering the risk of defects like bubbles, impurities, or uneven color in plastic bottles. These defects not only affect the aesthetic appearance of plastic bottles but may also impact their sealing and barrier properties, thus affecting the quality and safety of medicines.

Moreover, the chemical properties of different raw materials may also influence the quality of plastic bottles. Some raw materials may offer better heat resistance, cold resistance, or chemical corrosion resistance, which enable plastic bottles to maintain stable performance under various environmental conditions. Therefore, when selecting raw materials, it is necessary to fully consider the compatibility between their chemical properties and the use environment of plastic bottles.

Lastly, the cost of raw materials is another factor impacting the quality of plastic bottles. Although high-quality raw materials might be more expensive, they bring about better product quality and usage effects. Thus, in the process of balancing costs and quality, various factors need to be comprehensively considered to choose the most suitable raw materials.

In conclusion, the impact of raw materials on the quality of plastic bottles is multifaceted, involving considerations from physical properties, purity, chemical properties to cost factors. When choosing raw materials, it is essential to take all factors into account to ensure that the quality and usage effects of plastic bottles reach their optimal state. 

This translation accurately reflects the structure and content of the original text, ensuring clarity and precision in conveying the information regarding the importance of raw material selection and quality in the manufacturing of plastic bottles.