Pet bottle washing line, pet bottle washing process

The development history of pet bottle washing line

As early as the 1980s, the PET bottle washing process began to appear, but recycled bottle fragments were mainly used as raw materials for ordinary fibres in the last century. The requirements for the quality of raw materials were not so high, so it could not be highlighted. The advantages of the whole bottle washing process, as the PET raw materials develop more profound and broader downstream products, more and more high-value-added PET products are more eager for high-quality recycled PET bottle flakes. Therefore, the whole bottle washing process is gradually regarded as a new type of technology, which has attracted the industry's attention.

The bottle washing and film washing processes of the Pet bottle washing line have different effects on clearing magazines.

What is the difference between bottle washing and tablet washing effects? Will the bottle wash be cleaner? There is empirical data for reference. From the 1980s to the 1990s, most of the PET recycling process in Taiwan was a bottle washing process, and there was no other film processing process. Generally, the average quality standard of the bottle washing factory can reach the so-called "A" level; that is to say, the total impurity content is within 200ppm. According to the empirical estimation of plastic bottles recycled in the market, the total amount of impurities is about 8-10%, with an average of 9%. Therefore, the impurity removal rate can be estimated to be 99.77% from the two figures.

The data alone cannot express why this conclusion is reached? The bottle washing process has a core concept: "When solids are separated, the greater the difference between each other, the smaller the total work consumed for separation. The differences include weight, volume, surface area, and specific gravity." This concept supports this concept—process development of the entire line. Empirically, the difference between the entire bottle body and other foreign matter (including the label) is large, but if it is crushed into bottle flakes first, the difference is shortened. So the comparison between bottle washing and tablet washing is not whether it can be washed clean, but that it is easier to wash clean.

Two whole bottle washing processes of the pet bottle washing line

1. Batch washing type; the other is continuous feeding and discharging type; there is a big difference in design concept and structure between the two.
Batch washing type: The main structure is a double-layer cylinder with a closed upper opening and bottom, the outer cylinder is fixed, the inner cylinder can be rotated forwards and backwards, and the inner cylinder wall has spiral blades, which becomes the main source of kinetic energy for bottle stirring and can be corrected—reverse control to feed in and out. The double-layer cylinder is installed at an oblique angle (the appearance is similar to the cement mixing drum, and the structure is similar to the drum washing machine). The washing method is similar to the automatic washing machine. After quantitative feeding, according to "rinsing (pre-washing)"-"washing"-" "Rinse" is carried out in three stages.
After completion, the washing machine reverses and discharges the bottle material. It is also equipped with a set of washing water supply, circulation and filtration systems.

2. Continuous feeding and discharging type: the main structure is a tunnel-shaped horizontal round drum, the front end is the inlet, and the rear end is the outlet. The lower part of the circular drum is immersed in the lotion tank, and the inner section of the drum is provided with interspersed propulsion. Open spiral blade with function and damping function.

The bottle body is put into the drum by the force of the blades; while rolling and stirring, it slowly advances to the outlet and discharges. Part of the impurities separated in the process is discharged into the lotion tank from the opening of the drum wall, and some of the larger impurities are discharged from the outlet along with the bottle.

Analyzing the two from the perspective of washing function, the batch washing method can be considered as a complete washing process, and the continuous washing method can only achieve the pre-washing stage. The degree of decontamination of the bottle body of the two methods is naturally different. This conclusion leads to an increase in the load of the subsequent film processing system of the continuous process, and the matching conditions of the film processing are almost the same as the pure film processing process.