From Recycled PET Bottles To Fibers

The Recycling Journey of PET bottles

As common plastic products in daily life, PET bottles have significant environmental protection significance and economic value in terms of recycling and reuse.

Recycling and Collection:

Residents put used PET bottles into recyclable trash bins, or they are collected through means such as waste collectors' door-to-door collection, recycling points set up in communities, and smart recycling machines.

Sorting and Screening:

The recycled PET bottles will be sent to sorting centers, where the staff will separate them from other recyclable materials and further subdivide them. For example, PET bottles are classified into categories like "PET bottles" and "HDPE bottles". PET bottles are further divided into sub-categories such as "PET general goods", "PET bottles of mixed colors", and "PET transparent bottles".

The Pre-treatment Stage

Removing Caps and Labels:

The sorted PET bottles need to undergo pre-treatment. First, the caps are unscrewed. The caps are usually made of PP and can be recycled separately. Most of the labels are made of PVC or PP and are peeled off from the bottle body by mechanical or manual means so as to facilitate the subsequent processing of the bottle body.

Compression and Packaging:

The bottle bodies after the removal of caps and labels will be compressed and packaged. This not only facilitates transportation but also improves transportation efficiency and reduces transportation costs.

Crushing and Cleaning

Crushing:

The compressed PET bottles are sent into crushers and broken into smaller pieces. This step increases the surface area of the plastic, which is beneficial to the subsequent cleaning and processing, enabling it to have more sufficient contact with the cleaning liquid and remove the dirt and impurities on the surface.

Cleaning:

The crushed plastic pieces will enter the cleaning equipment and go through multiple cleaning processes to remove impurities such as stains on the surface and residual label glue. Professional detergents and clean water are usually used in the cleaning process to ensure the cleanliness of the pieces and lay a solid foundation for the subsequent production of high-quality plastic pellets and fibers.

Pelletizing Process

Drying:

The plastic pieces after cleaning contain a certain amount of moisture and need to be dried. Only after the moisture is removed can the pieces enter the next process. The drying equipment will heat the pieces to a certain temperature to make the moisture evaporate and obtain dry plastic pieces.

Melting and Extruding:

The dried plastic pieces are sent into extruders. Under high temperature, they are melted and then extruded through specific molds to form long and thin plastic strips.

Cooling and Pelletizing:

The extruded plastic strips are quickly cooled and solidified after passing through cooling water tanks or air cooling devices, and then are cut into uniform plastic pellets by pelletizers. These pellets are recycled plastic pellets, which have good fluidity and processing performance and can be used as raw materials for the production of plastic products and fibers.

Fiber Production

Spinning:

The recycled plastic pellets are sent into spinning equipment. After being heated and melted, they are extruded through spinnerets to form fine filaments. During the spinning process, parameters such as temperature, pressure and extrusion speed need to be precisely controlled to ensure the quality and performance of the fibers.

Drawing:

The fibers just spun out have relatively low strength and need to be drawn to make their molecular chains arrange in a more regular orientation, thereby improving the strength and toughness of the fibers.

Post-treatment:

The fibers after drawing may also undergo some post-treatment processes, such as crimping, setting, oiling, etc., to improve the hand feel, luster and processability of the fibers, making them more suitable for different application fields, such as textile and filling.