Polytetrafluoroethylene Resin

Polytetrafluoroethylene resin, abbreviated as PTFE, is resistant to almost any concentration of strong alkali, strong acid, strong oxidants and solvents, and is known as ‘King of Plastics’. In recent years, along with the promotion of China's new infrastructure, as well as new energy, semiconductor, BIPV and other industries, the rapid development of the market demand for high-performance fluoropolymers continued to release, bringing strong momentum to the development of the PTFE market.


The application of PTFE resin in many fields such as electronic communications, photovoltaic power generation, industrial coatings, agricultural films, aerospace, medical devices, etc. has been expanding and deepening, which has further promoted the expansion of the market scale. The state attaches great importance to the development of new high-performance chemical materials and policy support, PTFE, as a high-performance gas-containing polymers, is expected to benefit from the relevant industrial policies, accelerate the realisation of domestic substitution, and further expand the market share.

Suspension method polytetrafluoroethylene (PTFE or F40) is a white powdery material, which is made from tetrafluoroethylene polymer by pounding, grinding, washing and drying. After washing PTFE water content of about 35%, particle size of about 150um, the final moisture must be dried to 0.04% or less to meet the production requirements, and PTFE powder has a strong adhesion, high temperature is easy to agglomerate and sticky wall, easy to form a group after extrusion; product whiteness and cleanliness requirements are high, its drying process has special requirements.

Jiangsu Bohong polytetraethylene PTFE suspension resin drying process improvement and equipment development, so that the production operation is more convenient, simple, minimise the manual operation of the link, so that the drying of PTFE is more efficient, energy-saving, reduce production costs, improve product quality and production efficiency, reduce the drying unit of the pollution of PTFE powder, and to promote its application in more fields.

Polytetrafluoroethylene PTFE Suspension Resin Airflow Dryer Working Principle

Polytetrafluoroethylene PTFE Suspension Resin Airflow Dryer is characterised by good operating environment, automatic and continuous feeding and discharging, high product cleanliness and low temperature of finished products.

The outside air enters into the venturi feeder after heating and purifying, which generates negative pressure suction and sucks the wet materials into the air duct. The hot air carries the material into the airflow dryer for drying. The dried material enters the cyclone separator with the airflow for recovery. After purified, cooled and de-misted, the outer fruit air enters the cooling section of the venturi feeder, and the recovered material from the cyclone separator is sucked into the air duct for cooling, and the cooled material is then collected by the cyclone separator to get the finished product.

Due to the special nature of PTFE suspension resin, the dryer can not accumulate materials, the inner wall of the equipment are polished (roughness of 0.2um), equipment and pipeline connections without sharp corners, the duct turns with a large curvature radius pipe.


PTFE suspension resin air dryer Performance characteristics

(1) High drying efficiency

Fast drying.

Adopting the way of direct contact between the hot airflow and the material, the material is dried instantly in the suspension state, and the drying time is short, generally only 2-3 seconds, which greatly improves the production efficiency.

Efficient heat and mass transfer.

As the material is suspended, and the hot airflow full contact, gas-solid two-phase contact area is large, strengthen the heat and mass transfer process, can quickly evaporate the moisture in the material out, to achieve high efficiency drying.


(2)Good product quality

Uniform drying.

The hot airflow can uniformly surround the material particles, so that it is heated evenly, avoiding the same part of the overheating or inadequate drying, thus ensuring the stability of the quality of PTFE resin after drying and the consistency of the product performance.

Low water content.

Through precise control of drying temperature, wind speed and residence time and other parameters, the water content of PTFE Perlite resin can be reduced to less than 0.02%, to meet the strict requirements of the ga0-end application fields on the low water content of the product.

High purity.

Equipped with efficient filtration system, the hot and cold air entering the dryer is strictly filtered, which can reach 100,000 or 100 class or even aseptic purification requirements, effectively preventing impurities from mixing into the material and ensuring the high purity of the product, so that it can be better used in the field of high purity requirements, such as electronics, pharmaceuticals and so on.


(3)Precise temperature control

Wide temperature range.

The heating system can make the temperature of the hot airflow reach a high level, and the high temperature is usually up to 280°C, which meets the temperature conditions of PTFE suspension resin drying, meanwhile, in the cooling stage, it can effectively reduce the temperature of the material to below 30°C, which is convenient for the subsequent packaging and storage.

Precise temperature control.

Adopting advanced temperature control system, such as PLC or DCS remote control, it can realise precise control and automatic adjustment of drying temperature and cooling temperature, with high precision of temperature control to ensure that the drying and cooling process is carried out stably within the set temperature range, so as to ensure the stability and reliability of product quality.


(4)High degree of automation

Automatic control.

Equipped with perfect automatic control system, it can realise automatic monitoring and precise control of parameters such as feeding volume, air intake, wind speed, temperature, pressure, etc., and can automatically adjust the running status of the equipment according to the preset parameter values, which reduces manual intervention and improves the stability of the production process and the consistency of product quality.

Fault warning and protection.

With the functions of motor overload protection, over-temperature automatic alarm, etc., it can monitor the running condition of the equipment in real time, and once an abnormal situation occurs, the system will immediately issue an alarm and take corresponding protective measures to avoid equipment damage and safety accidents, which guarantees the safe and stable operation of the equipment.


(5) High reliability of equipment

Materials and Components.

Components in contact with materials and hot air are usually made of corrosion-resistant and high temperature-resistant materials, such as 316L clean tube, 310S material or Hastelloy, etc., which ensure stable operation of the equipment under long-term high temperature and corrosive environment and prolong the service life of the equipment.

Good mechanical design.

The structure of the equipment is reasonably designed, with mechanically polished sanitary clean pipes and flange connection, which is easy to install, dismantle, clean and disinfect and sterilise; at the same time, taking into account the characteristics of PTFE, metal expansion joints are used for mechanical compensation, preventing the equipment from deformation due to thermal expansion, and wooden brackets are used for fixing to reduce the heat loss, which improves the reliability and stability of the equipment.

Polytetrafluoroethylene PTFE suspension resin air dryer Technical improvement

(1) Purification of drying and cooling media

The production plant of PTFE is a clean workshop, which should comply with the GMP standard, and the drying medium is required to reach a certain clean level, so the hot air and cold air are purified by multi-stage.


(2) Feeding system

Feeding system is the key equipment of the whole set of PTFE air drying system, domestic air drying common feeding methods are venturi feeding and rotating equipment feeding two kinds of PTFE in drying to venturi feeding is common. Due to the common venturi feeder structure is too simple, no adjustment function, pressure loss, feed too much or agglomeration will affect the operation, serious cases will form in the venturi throat diameter of the material, resulting in pipeline clogging, so it is difficult to achieve automation of a single Venturi feeder feeding, and at the same time, due to the nozzle position of the Venturi nozzle is fixed, the improper design is easy to cause the feeding port or plugging of the material spraying.

Aiming at the shortcomings of the venturi feeder, Loncin Drying has developed an adjustable feeding system, the nozzle position can be achieved by increasing the gasket between the tapering section and the venturi feeder shell. Usually the nozzle position adjustment is only used in the trial stage, and it is basically unchanged after adjustment. Daily operation, when the output, pressure, material erection and so on changes through the adjustment of the bypass valve to adjust can achieve the purpose of regulation.


(3) Airflow drying main machine

Air drying host try not to use right-angle elbow, it is appropriate to use the angle is greater than 120 °, large radius elbow, in order to reduce the resistance, to prevent the accumulation of material. Material pipeline and equipment wall finish to 0.2um is good, so that the inner wall is not easy to stick material.


(4) Discharge system

Discharge using rotary discharge valve, will lead to lubricant contaminated material, and the rotor and the inner wall friction will produce a lot of lumps and pieces of waste, affecting the performance of the product. Loncin drying has developed a new type of automatic flap valve, which can achieve sealing and continuous automatic discharging, and there is no waste material.


(5) Control system

Polytetraethylene PTFE suspension resin air dryer using PLG for control, while adding two chain protection: ① electric heater and fan chain to protect the electric heater from overheating; ② condenser regulator valve and fan chain to prevent the condenser from freezing, cold air, hot air induced draught fan are used in frequency conversion speed control, increasing the adjustability of the system.


Vibrating fluidised bed dryer manufactured by Jiangsu Bohong Drying Company can effectively solve the problem of heat loss in the traditional drying method, and greatly reduce the drying time, while maintaining the original quality of the material. Whether large-scale production or experimental production, we can provide you with professional technical support and solutions to help improve production efficiency and product quality. When you choose Jiangsu Bohong, you will get a reliable and industry standard vibrating fluidised bed dryer.