Vacuum Cream Making Machine: Analysis of the Core Equipment for Paste-like Material Preparation

In numerous industries such as chemical, pharmaceutical, food, and cosmetics, the quality of paste-like material preparation directly determines the quality and competitiveness of the final product. As the core equipment for achieving refined and standardized production of these materials, the vacuum cream making machine has become an indispensable key asset in modern industrial production. This is due to its unique advantages of operating in a vacuum environment and its highly efficient mixing and emulsifying capabilities. With over two decades of experience in the design, R&D, and manufacturing of cream making machines, Jinzong Group will now provide a comprehensive and detailed analysis of this equipment, covering its definition, working principle, core structure, performance advantages, application fields, and usage maintenance.

I. What is a Vacuum Mixing & Homogenizing Kettle?

A vacuum mixing and homogenizing kettle is an integrated paste preparation system that combines multiple functions including stirring, emulsification, homogenization, deaeration, heating, and cooling. By creating a vacuum environment within a sealed vessel and utilizing specialized stirring and emulsification mechanisms, it enables rapid mixing of materials, refinement of particles, removal of air bubbles, and ultimately produces paste, semi-solid, or emulsion products that are uniform, smooth, bubble-free, and highly stable. Compared to conventional paste-making equipment, its most distinctive feature is the use of a vacuum environment to solve issues such as residual air bubbles and oxidative deterioration during the mixing process, significantly enhancing product quality and shelf life.

II. Core Working Principle: The Logic of Efficient Preparation under Vacuum

The operation of a vacuum mixing kettle revolves around two core concepts: "Vacuum Deaeration" and "Efficient Emulsification & Mixing". Its overall working principle can be divided into the following key stages:

1. Establishment of the Vacuum Environment
   After startup, the vacuum system (comprising a vacuum pump, valves, etc.) rapidly evacuates air from the mixing vessel, creating a negative pressure environment (typically achieving a vacuum level between -0.095 MPa and -0.098 MPa). This environment not only effectively prevents contact between the materials and air—thereby avoiding oxidation, discoloration, or microbial growth during stirring—but also lays the foundation for subsequent deaeration.

2. Material Feeding and Pre-treatment
   Solid materials (e.g., powders, granules) and liquid materials (e.g., oil phase, water phase) can be fed into the vessel through separate charging ports on the top. Some equipment is equipped with pre-treatment devices for solids (e.g., powder dispersers), which prevent dust generation during feeding while enabling preliminary dispersion of the solids into the liquid, reducing agglomeration. For materials requiring heating or cooling, the vessel's jacket system can circulate steam, hot water, or chilled water to achieve precise temperature control, meeting the process requirements for material reaction or dissolution.

3. Emulsification, Mixing, and Homogenization
   The stirring and emulsification mechanisms inside the vessel are the core components responsible for mixing and refining the materials. The stirring mechanism typically employs a combination of a frame-type impeller and wall-scraping blades. The frame-type impeller drives the overall circulation of the material within the vessel, ensuring uniform mixing from top to bottom and inside out. The wall-scraping blades rotate in close contact with the vessel wall, continuously removing material that adheres to it, preventing localized overheating or deterioration due to prolonged contact.

   The emulsification mechanism (e.g., high-speed homogenizer, colloid mill) generates intense shear forces, impact forces, and cavitation effects through high-speed rotation. This breaks down larger particles or oil droplets in the material into micron-sized particles and disperses them uniformly within the continuous phase, forming a stable emulsion or suspension. Under vacuum, this refinement process proceeds more efficiently because the absence of air reduces resistance, improving material flowability and allowing shear forces to act more directly on the particles.

4. Vacuum Deaeration and Product Discharge
   Microscopic air bubbles that may form during mixing and emulsification rapidly expand in the vacuum environment, rise to the surface of the material, and are ultimately evacuated by the vacuum pump. This ensures the final paste product is bubble-free and smooth in texture. Once the material meets the preset process specifications, the vacuum system and stirring/emulsification mechanisms are stopped. The finished paste is then discharged through a bottom outlet valve. Some models are equipped with pressure discharge systems to enable rapid, low-residue discharge.

III. Key Structural Components: The Synergy of Systems

The structural design of a vacuum mixing kettle is closely aligned with process requirements. It primarily consists of the mixing vessel, stirring/emulsification system, vacuum system, heating/cooling system, control system, and frame. These systems work in synergy to ensure stable and efficient operation.

1. Mixing Vessel
   As the core container for material reaction and processing, the mixing vessel is typically constructed from stainless steel 304 or 316L, offering excellent corrosion resistance and hygiene properties that comply with sanitary standards for the food and pharmaceutical industries. The inner wall is precision-polished to an extremely low surface roughness, facilitating easy cleaning and preventing material residue. Vessel capacity can be customized from tens of liters to several thousand liters to suit different scales from lab/pilot trials to full-scale industrial production.

2. Stirring and Emulsification System
   This system is the "heart" of the equipment, directly determining the efficiency and quality of paste production. The stirring part includes a stirring motor, reduction gearbox, stirring shaft, and impellers. Impeller types (e.g., frame, anchor, helical ribbon) can be selected based on material characteristics. The emulsification part consists of a homogenizer motor, shaft, and homogenizing head. The high-speed homogenizing head typically rotates at 1,000–3,000 rpm, generating powerful shear forces. Some advanced models feature a liftable homogenizing mechanism that adjusts the head's position according to the material level, ensuring consistent emulsification.

3. Vacuum System
   This system mainly comprises a vacuum pump, vacuum buffer tank, vacuum gauge, and piping. The vacuum pump is the core component; commonly used types include rotary vane pumps and liquid ring pumps. Rotary vane vacuum pumps are widely used in these kettles due to their high ultimate vacuum and stable pumping speed. The buffer tank helps reduce pressure fluctuations during pump operation, protecting the pump and enhancing system stability.

4. Heating and Cooling System
   This usually employs a jacketed design, where a layer (jacket) is created between the outer and inner walls of the mixing vessel. By circulating a heating medium (e.g., steam, hot water) or cooling medium (e.g., chilled water, glycol) through the jacket, precise temperature control of the vessel contents is achieved. The jacket design provides a large heat transfer area and high efficiency, enabling rapid adjustment to the required process temperature range with control accuracy typically within ±1°C.

5. Control System
   Modern vacuum mixing kettles commonly utilize a PLC-based control system with a touch-screen HMI (Human-Machine Interface) for precise control and real-time monitoring of all operational parameters. Operators can set parameters such as stirring speed, emulsification time, vacuum level, and material temperature via the touch screen. The system automatically runs according to the preset program and triggers alarms for abnormal conditions (e.g., insufficient vacuum, temperature exceedance), ensuring safe and stable production. Some advanced models support integration with factory MES systems for automated production data collection and management.

6. Frame and Auxiliary Structures
   The frame, welded from carbon steel or stainless steel, provides stable support for all components, ensuring rigidity and stability during operation. Auxiliary structures include charging ports, sight glasses, cleaning balls (CIP spray balls), and manholes. Charging ports facilitate material feeding, sight glasses allow visual monitoring of the process, and cleaning balls enable automatic cleaning of the vessel interior, reducing manual labor and meeting sanitary production requirements.

IV. Outstanding Performance Advantages: Why It Is the Preferred Choice in the Paste Manufacturing Industry?

Compared to traditional open-type paste-making equipment, the vacuum mixing and homogenizing kettle offers significant performance advantages, which is the core reason for its widespread adoption. These advantages are mainly reflected in the following aspects:

1. Superior Product Quality
The vacuum environment effectively prevents contact between materials and air, reducing risks of oxidative degradation, color change, and microbial contamination, thereby extending product shelf life. Simultaneously, the vacuum deaeration function thoroughly removes air bubbles from the material, resulting in a paste product with uniform and smooth texture, good gloss, and no granular feel or residual bubbles. This significantly enhances the product's appearance and user experience.

2. Higher Production Efficiency
The combination of efficient stirring and emulsification mechanisms enables thorough mixing and refinement of materials in a short time. Compared to traditional equipment, the production cycle can be shortened by 30% to 50%. Furthermore, the high degree of automation allows the entire paste-making process to be completed automatically once the operator sets the process parameters, reducing manual intervention and improving production efficiency.

3. Strong Process Adaptability
The vacuum mixing kettle can meet the preparation requirements for various paste-like materials by adjusting parameters such as stirring speed, emulsification time, temperature, and vacuum level according to the characteristics of different materials (e.g., viscosity, particle size, heat sensitivity). Whether it's high-viscosity ointments and cosmetic creams or low-viscosity emulsions and sauces, high-quality production can be achieved with this equipment, making it suitable for diverse process requirements across multiple industries.

4. Safe and Convenient Operation
The enclosed vacuum environment reduces dust dispersion and leakage of harmful gases, improving the working conditions in the production area and safeguarding the health of operators. The PLC control system with a touch-screen interface is intuitive and user-friendly. Operators can become proficient after brief training. The equipment is also equipped with comprehensive safety protection devices (e.g., overload protection, overpressure protection, temperature protection), ensuring a safe and reliable production process.

5. Easy Cleaning and Maintenance
The inner wall of the mixing vessel is precision-polished and equipped with automatic cleaning devices (e.g., CIP spray balls), facilitating thorough and convenient cleaning and preventing cross-contamination between different production batches. Key components (e.g., impellers, homogenizing head) feature a modular design for easy disassembly, cleaning, and maintenance, reducing equipment maintenance costs and downtime.

V. Wide Range of Applications: A Core Production Machine Covering Multiple Industries

Thanks to its excellent performance, the vacuum mixing and homogenizing kettle is widely used in industries such as chemicals, pharmaceuticals, food, cosmetics, and daily chemicals. It has become the core equipment for producing various paste, semi-solid, and emulsion products. Specific application scenarios are as follows:

1. Cosmetics Industry
It is an indispensable piece of equipment in cosmetics manufacturing, used for producing creams, lotions, serums, mask pastes, lipstick bases, etc. Its vacuum deaeration and efficient emulsification functions ensure the cosmetic paste is smooth, fine, and bubble-free, enhancing the product's texture and stability to meet consumers' high demands for cosmetic appearance and user experience.

2. Pharmaceutical Industry
It is used for preparing ointments, pastes, gels, and other medicinal semi-solid preparations. The equipment is constructed with stainless steel that complies with pharmaceutical hygiene standards. The smooth inner surface is easy to clean, preventing material contamination. The vacuum environment also reduces oxidation of active ingredients, ensuring drug efficacy and safety, and complies with Good Manufacturing Practice (GMP) requirements.

3. Food Industry
It is suitable for producing food paste materials such as jams, sauces (e.g., ketchup, chili sauce), chocolate spreads, creams, and ice cream mixes. The vacuum environment prevents microbial contamination and oxidative spoilage of food materials during production, preserving flavor and quality. The efficient mixing function ensures uniform distribution of ingredients in the food product.

4. Chemical Industry
It is used for preparing chemical paste products such as coatings, paints, inks, adhesives, sealants, and lubricating greases. Its powerful emulsification and mixing capabilities ensure uniform composition and refined particles in chemical materials, enhancing product performance, such as the adhesion of coatings or the bonding strength of adhesives.

5. Daily Chemicals Industry
It is used for manufacturing daily chemical products like toothpaste, soap paste, shower gel base, shampoo concentrate, and laundry paste. The paste products made by the vacuum mixing kettle have a fine texture, are free of bubbles, produce rich foam during use, and are easy to rinse, improving the product's performance and market competitiveness.