Solvent-based high-performance colorant filtration, washing and drying machine

In recent years, the development of pigments and dyes in our country has been rapid, but the variety structure is unreasonable and the proportion of low-end products is too large. Traditional varieties fail to meet the requirements in terms of tinting strength, temperature resistance, lightfastness, durability, solvent resistance and weather resistance, and have poor application performance. For instance, in the field of high-end automotive paint coloring, domestic dye and pigment varieties cannot meet the requirements in terms of dispersion and weather resistance, and have always relied on imports.

Environmental protection has become a key factor in promoting the technological revolution of dyes and pigments. Using traditional dyes for dyeing not only requires a large amount of specialized auxiliaries but also inevitably generates a large amount of colored wastewater during the dyeing process, seriously polluting the environment. Most traditional organic pigments are azo pigments containing benzidine structures. During processing and use, they will decompose, generating harmful substances that can cause cancer in the human body. This has drawn great attention from many developed countries around the world. Relevant labor safety and health management departments in China are also very concerned about this issue. Therefore, it is an inevitable trend for the industry to develop new varieties of green and environmentally friendly dyes and pigments to replace harmful ones.

Solvent-based high-performance colorants feature excellent lightfastness and weather fastness, solvent resistance, and processing application performance. They are mainly used in water-based coatings, high lightfastness printing inks, and plastics (mainly hard and impact-resistant polyethylene). The new high-performance colorant features environmental friendliness, non-toxicity and other characteristics. It is widely used in high-end decorative fabrics, plastics, high-grade printing inks, automotive paints, nylon spinning, military camouflage clothing, etc This belongs to the 8th item of the "Chemical Industry" under Article 11 of the "Encouraged Category" in the "Catalogue for the Guidance of Industrial Structure Adjustment (Revised Edition 2013)" (Order No. 21 of the National Development and Reform Commission of the People's Republic of China), which states that it is used for dyeing with high fixation rate, high color fastness, high lifting property, high leveling property, high reproducibility, low staining property, as well as for dyeing with low salt, low temperature and small bath ratio, and for wet short steam retaining dyeing The development and production of organic dyes, disperse dyes for high fine denier polyester fiber dyeing, high washing fastness, high dyeing rate, high light fastness and low staining (nylon, spandex), small bath ratio dyeing, metal-free weakly acidic dyes for polyamide fiber, wool and leather dyeing, and organic pigments with high light fastness and high weather fastness.

Conventional post-treatment process for solvent-based high-performance colorants

Add the measured water and hydrochloric acid into the pulping kettle. Under stirring, the dried materials were heated to 60℃ and maintained for 2 hours, resulting in a yield of 94.9%. After the heat preservation time is up, the materials are placed in the suction filter tank, washed with hot water until neutral (the washing wastewater is sent to sewage treatment), then drained, sent to the oven for drying, crushed, packaged and stored in the warehouse. The water vapor generated during the drying process is directly discharged into the atmosphere. The dust produced after crushing is treated by a bag filter and then discharged into the atmosphere. The recovered dust is mixed into the finished product, with a total recovery rate of 66.8%.

In the post-treatment process of conventional production, each unit operation in the production equipment has corresponding unit equipment. Most of these devices have single functions, high labor intensity, and significant material loss during operation. What is more worthy of attention is that these devices are generally operated in an open manner, which can easily cause pollution to the environment and endanger the health of the operators. There are also some problems with the use of drying equipment. The most prominent ones are that solvents cannot be fully recovered and there is a lack of dust collection devices. Some production enterprises even use open-air drying for drying, which is not only uneconomical and not environmentally friendly, but also affects product quality. It is urgent to improve.

Fully sealed post-treatment process for solvent-based high-performance colorants

The fully enclosed production process of solvent-based high-performance organic pigments includes: (1) Preparation of diazo salt solutions; (2) The diazonium salt solution is added to the suspension for coupling reaction; (3) Add rosin soap and emulsifier fatty alcohol polyoxyethylene ether to the products of the coupling reaction, and carry out filtration, water washing and drying using a fully sealed three-in-one method to obtain crude pigment dry powder. (4) Add polar solvents to the integrated filtration, washing and drying machine containing crude dry powder. Under the condition of 0 to 50℃, carry out pigment treatment, filter, wash and dry to obtain the finished pigment product. The pigments produced by this method have significantly enhanced tinting strength, and their comprehensive application performance has been improved. They are suitable for applications in systems with high requirements for tinting strength and also provide an effective way to increase the tinting strength of pigments.

The fully enclosed post-treatment process for solvent-based high-performance organic pigments has the following advantages:

(1) Pigmentation is carried out under low-temperature conditions, eliminating the need for reflux devices. The solvent odor during the production process is minimal, and the evaporation loss of the solvent is relatively small.

(2) The solvent concentration in the pigment mother liquor is high, which is conducive to solvent recovery, saves the cost of solvent distillation and recovery, and results in less solvent loss.

(3) The obtained pigments have high tinting strength. On water-based coatings, the tinting strength is more than 10% higher than the external standard, which can meet the demands of applications with high tinting strength requirements. Additionally, under the same tinting strength conditions, the surface treatment amount of the pigments is correspondingly increased, reducing the raw material cost.

(4) The fully enclosed post-treatment process, while meeting all the application performance requirements of the pigments, further enhances the tinting strength, reduces production costs and increases economic benefits.

Technical advantages of solvent-based high-performance colorant filtration, washing and drying machine

In accordance with the process requirements for advanced liquid-solid separation and drying systems in clean production and intrinsic safety of dyes and dye intermediates, Shuangrui Machinery has developed a fully enclosed reaction crystallization filtration and drying multi-functional equipment that integrates filtration, washing, solvent recovery, drying and dust collection. It features high filtration and drying efficiency and is easy to operate. The performance of the multi-functional filtration and drying equipment is significantly superior to that of other traditional filtration and drying equipment, and it has the following advantages:

(1) Safe and environmentally friendly

The fully enclosed reaction crystallization filtration and drying multi-functional equipment can be designed as a fully enclosed operation system, which can completely avoid the pollution of the operating environment air by solvents during the production process, and at the same time reduce the occurrence of poisoning accidents of operators caused by contact with toxic substances. Today, with the growing calls for environmental protection and labor protection, this advantage becomes even more crucial.

(2) Complete recycling

The materials and solvents are nearly completely recycled, avoiding waste and pollution caused by material omission and solvent evaporation, which brings significant economic benefits, especially when processing materials and solvents of high value.

(3) Save manpower

A non-technical person who has received simple training can complete the operation. Opening, closing, automatic feeding and automatic discharging do not require technical personnel to monitor.

(4) Thorough cleaning

The multi-functional filtration and drying equipment has the function of re-suspension, and the filter cake can be cleaned very thoroughly.

(5) Vacuum drying

Filtration, washing and drying can be completed in the same system.

(6) Continuous operation

Filtration and drying can be carried out in a continuous system. Wet filter cakes that do not require treatment can be discharged directly. If further drying is required, the wet filter cake is directly discharged from the filter into the dryer. After drying, it can be mechanically conveyed to the weighing, packaging and other sections.

The research and development of the fully enclosed filtration, washing and drying integrated machine meets the environmental protection production requirements of solvent-based high-performance organic pigments. It is also an inevitable trend to eliminate technological barriers in the process and promote the optimization and upgrading of the industrial structure in the high-performance colorant industry. Wuxi Shuangrui's multi-functional filtration, washing and drying equipment is bound to promote the development of the domestic dyeing and pigment industry, meeting the needs of industrial development for improving the grade and performance of dyeing and pigment products, environmental protection and scale expansion.