Sieving Machine For PET Recycling Plant

The sieving machine for PET recycling plant is a key equipment for separating and classifying different particle sizes or partitions. In the plastic recycling process, it mainly processes polyethylene terephthalate raw materials, and common sources include discarded beverage bottles, food packaging, etc. that have been processed by equipment such as pulverizers. After the raw materials are crushed and cleaned, they need to be screened by selecting a suitable sieving machine to remove impurities, classify particle sizes, and improve the efficiency and quality of subsequent granulation or reuse.

Classification of sieving machines for PET recycling plant

The screening equipment commonly used in PET recycling plants mainly includes three types: drum screen, linear vibrating screen and rotary vibrating screen. The drum screen is suitable for the preliminary sorting of large particles and those containing more impurities. It has the characteristics of large processing capacity and is not easy to be blocked; the linear vibrating screen is suitable for the detailed classification of the crushed PET fragments and has high screening accuracy; the rotary vibrating screen has a compact structure and is mostly used for the screening of fine powders or tiny particles. It is suitable for the further processing of PET fine materials. Different screening machines are suitable for different links of the PET recycling process.

1. Drum screen

The screen of the drum screen is multi-layered and slightly tilted. The screen drum automatically slides and rotates around the axis, and the horizontal material is graded through the screen during rolling. The material enters from the feed port, and the rotation drives the material to roll and slide. Under the action of gravity, the material of different particle sizes is screened, and it also has a certain dehydration function. In PET recycling, screening is used for pre-screening before material crushing. Its screening form is rolling screening, with large feed volume, high screening output, and strong processing capacity (single machine capacity can reach 50-300 tons/hour), which is particularly suitable for large-scale PET recycling production lines.

2. Linear vibrating screen

The linear vibrating screen is usually driven by dual motors and can be equipped with multi-layer screens to achieve multi-level particle size separation. The material jumps forward along the screen surface under the action of vibration and is graded layer by layer according to the particle size. It is mainly used for particle size classification of fragments after PET bottles are crushed, and can effectively screen out fine powder or oversized particles generated during the crushing process. Linear vibrating screens have a high screening capacity and are usually used for dry screening. They are also suitable for light wet materials. The screening capacity varies depending on the material characteristics and the size of the screen surface, usually ranging from 0.5 to 20 tons per hour.

3. Rotary Vibrating Screen

The rotary vibrating screen generates three-dimensional composite vibrations through the upper and lower eccentric blocks of the motor, so that the material moves in a composite horizontal, vertical and inclined direction on the screen surface. 1 to 5 layers of screens can be installed to achieve multi-stage screening, which is suitable for high-precision screening of fine fragments and powders in the PET recycling process. The screening form is mainly dry screening, and it is also suitable for fine processing of small amounts of wet materials; high-frequency vibration promotes rapid stratification of materials, and materials of different particle sizes are discharged from the corresponding screen layers. Depending on the number of screen meshes, material properties and equipment diameter, the screening capacity is generally between 0.1 and 5 tons per hour.

The role of sieving machine for PET recycling plant

The application of sieving machine for PET recycling plant runs through the core links of the entire recycling process. Its value is reflected in improving recycling efficiency, ensuring the quality of recycled materials and promoting environmentally friendly production. It is mainly used for grading, removing impurities, color separation and homogenization of crushed PET fragments to ensure that the quality of recycled materials meets the requirements of subsequent processing.

Impurity separation: Through the difference in screen aperture, large impurities (such as bottle caps, labels, metal fragments) and small particle pollutants (such as sand and glass) in PET waste are removed to improve the purity and quality of PET.

Particle size standardization: Classify the crushed PET fragments by particle size (such as 3-8mm, 8-12mm) to adapt to different recycling process requirements:

Small particle size (<5mm): used to produce fibers and films.

Medium particle size (5-12mm): suitable for granulation and wire drawing.

Large particle size (>12mm): may need to be returned to the crusher for further processing.

Reducing energy consumption: Standardized particle size can optimize the melt extrusion process and reduce energy consumption by 10-15%

Working principle of sieving machine for PET recycling plant

The screening machine in the PET recycling plant is mainly used to separate and screen the recycled PET plastics for subsequent processing and reuse. Its working principle generally includes the following steps:

Feeding: Discarded PET bottles or other plastic materials are fed into the screening machine through a conveyor belt.

Screening: There are usually screens or screen plates of different sizes inside the screening machine, which are separated according to the size and shape of the plastic particles. Larger debris will be screened out, while PET plastics of the right size will continue to move forward.

Vibration: The sieving machine for PET recycling plant can use the vibration mechanism to make the material more evenly distributed on the screen, thereby improving the screening efficiency.

What are the advantages of the sieving machine for PET recycling plant?

 

High-precision sorting to improve the purity of raw materials: Through screens of different mesh sizes (such as 20-200 mesh), impurities such as labels, sand, unbroken bottle caps, fibers, etc. in PET fragments are removed step by step. The screening machine can ensure that the size of the crushed PET particles is uniform, avoiding the impact of too large or too small particles on the subsequent cleaning, granulation or melting process.

Improve recycling efficiency and reduce labor costs: The screening machine can run continuously for 24 hours, with a large processing capacity (such as the vibration screen can process up to 1-5 tons per hour), which greatly reduces the need for manual sorting. The sieving machine for PET recycling plant completes multi-level sorting at one time through the combined operation of coarse screening (20 mesh) + fine screening (80 mesh).

Reduce the waste of raw materials and improve economic benefits: through reasonable mesh screening (such as 60-80 mesh filtering and washing of fine impurities), reduce the mis-discharge of qualified PET fragments, and the recovery rate can reach more than 95%. The sieving machine for PET recycling plant can remove hard impurities in advance. Uniform particle size can improve granulation and melting efficiency.

Improve material purity: PET recycling plant screening machines can efficiently remove impurities in PET particles, such as paper scraps, metals, plastic fragments, etc., to ensure that the recycled PET materials are purer, which is conducive to subsequent processing and recycling.

Recommended mesh number of sieving machine for PET recycling plant

Purpose	Recommended mesh number of screen	Scope of application
Screening of coarse particles	10-20 mesh	Used to remove large particles, such as large plastic pieces, paper scraps and other impurities
Screening of medium and fine particles	30-50 mesh	Used to screen medium-sized particles and remove large plastics or impurities
Screening of fine particles	60-100 mesh	Used for screening fine particles, suitable for screening small plastic fragments, fibers, etc.
Screening of ultra-fine particles	120-200 mesh	Used for screening finer particles, suitable for plastic powder and fine impurities

The selection of a suitable screening machine should be determined based on the specific process flow of PET recycling, the processing volume requirements, the impurity content of the raw materials, and the quality standards of the final product. The sieving machine for PET recycling plant is an indispensable key equipment to ensure the efficient and stable operation of the recycling process and ultimately produce high-quality recycled PET products. It improves product quality and promotes the recycling of resources by removing various impurities. Usually, a PET recycling plant will use a combination of multiple types of screening machines to achieve the best separation effect.