Sunflower seeds are the fruit of the sunflower (Helianthus annuus) and serve as a crucial oil-bearing material. The kernel has an exceptionally high oil content, ranking among the highest of major vegetable oil sources.

• Key Specifications: Sunflower seeds typically contain over 50% fat, approximately 23% protein, and about 10% carbohydrates. Oil-type sunflower seeds have a high kernel rate of 65%-75%, with a kernel oil content generally between 45% and 60%, making them the ideal raw material for oil extraction.s.

A complete sunflower oil production line primarily consists of three stages: Pre-pressing, Refining, and the specialized Dewaxing section. The table below details the steps and equipment functions for each stage.

Section	Process Step	Key Equipment	Equipment Function
Pretreatment & Pressing	Cleaning & Impurity Removal	Cleaning Sieve, Destoner	Removes impurities like sand, stones, broken shells, and stalks using vibration and specific gravity differences. Protects downstream equipment and improves oil yield & quality.
	Shelling & Kernel-Shell Separation	Sheller, Huller	Cracks and separates the hard outer shell from the edible kernel. Some processes may include decoritication to remove the seed coat.
	Flaking & Cooking	Flaking Rolls, Cooker	Flaking ruptures the oil cells, while cooking conditions the meal by adjusting temperature and moisture, preparing it for efficient oil extraction.
	Pressing	Screw Press	Mechanically squeezes the oil out of the prepared sunflower meal under high pressure to produce crude oil.
Refining	Crude Oil Filtration	Filter Press, Leaf Filter	Removes solid impurities from the crude oil.
	Degumming, Deacidification, Bleaching, Deodorization	Refining Vessels, Bleacher, Deodorizer	A multi-stage process to purify the oil: • Degumming: Removes gums & phospholipids. • Deacidification: Neutralizes free fatty acids. • Bleaching: Adsorbs color pigments. • Deodorization: Strips off volatile compounds and odors, producing a neutral, stable oil.
Dewaxing (Specialized)	Crystallization & Filtration	Winterizing Tank, Crystallizer, Filter Press	Cools the oil under controlled conditions to crystallize waxes, which are then removed by filtration. This prevents cloudiness in the final oil at low temperatures and enhances clarity.

Technology Process Specification

Section 1: Pre-treatment & Pressing — From Raw Material to “Crude Oil”

The objective of this section is to extract the maximum amount of oil from the raw sunflower seeds, producing “Crude Oil.”

1. Cleaning & Impurity Removal

• Purpose: To remove various impurities mixed with the raw material, such as sand, dust, metal fragments, stalks, and immature or moldy seeds.
• Detailed Process: The seeds first pass through a Vibrating Screen to remove large and small impurities based on particle size. They then go through a Destoner, which uses airflow and vibration to separate heavier materials like stones and metals based on density differences. A Magnetic Separator removes ferrous metals. This step is fundamental for protecting downstream equipment, improving oil yield, and ensuring oil quality.

2. Shelling & Kernel-Shell Separation

• Purpose: To remove the hard outer shell of the sunflower seed.
• Detailed Process: The cleaned seeds enter a Sheller (typically centrifugal or impact type), where high-speed rotating discs or impact forces crack and separate the hulls. The resulting mixture of kernels and shells is fed into a Kernel-Shell Separation System. This system uses an Air Aspirator (which exploits differences in density and suspension velocity) and Vibrating Screens to separate the lighter shell fragments from the heavier kernels. Shelling is critical because the shell has negligible oil content but absorbs oil, reducing overall yield. Furthermore, excessive shells impair the quality of both the oil and the meal cake.

3. Flaking

• Purpose: To alter the physical structure of the sunflower kernels.
• Detailed Process: The separated kernels pass through Flaking Rolls, where they are pressed into thin, uniform flakes. This process ruptures the oil cells within the seed structure, significantly increasing the surface area and reducing resistance for oil extraction during the subsequent cooking and pressing stages.

4. Cooking / Conditioning

• Purpose: To condition the flaked material for optimal oil extraction.
• Detailed Process: The flakes are conveyed into a Cooker where they are heated and stirred under controlled temperature and moisture conditions. This is a crucial biochemical preparation step:
  • Ruptures Cell Walls: Completes the destruction of oil cells, causing the oil to coalesce.
  • Denatures Proteins: Coagulates proteins, reducing their ability to bind with oil and thereby increasing yield.
  • Adjusts Plasticity: Adjusts the hardness and plasticity of the material to the ideal consistency for pressing.

5. Pressing

• Purpose: To mechanically squeeze the oil out of the conditioned meal.
• Detailed Process: The cooked meal is fed into a Screw Press. Inside the press cage, the meal is conveyed forward by a rotating screw shaft. The volume gradually decreases, creating extremely high pressure. Under this combination of heat and pressure, the oil is forcibly expelled and flows out through the slots in the press cage, resulting in “Crude Oil.” The solid residue is compressed into a hard “Press Cake,” which is discharged from the outlet. The crude oil is then preliminarily filtered to remove large meal particles.

You can also add the extraction section for more oil from the pressed cake.

Section 2: Refining — From “Crude Oil” to “Edible Oil”

Crude oil obtained from pressing contains numerous impurities and cannot be consumed directly. Refining is a continuous physico-chemical purification process.

1. Degumming

• Purpose: To remove gum-like impurities, primarily phospholipids.
• Detailed Process: A small amount of hot water or food-grade phosphoric acid is added to the crude oil. Under agitation, the phospholipids hydrate, swell, and coagulate. A High-Speed Centrifuge then separates the coagulated gums from the clean oil. Degumming prevents the oil from smoking at high temperatures, foaming, and improves its stability.

2. Deacidification (Neutralization)

• Purpose: To remove Free Fatty Acids (FFA).
• Detailed Process: This is a core step in refining. The most common method is Chemical Refining (Alkali Neutralization). A precisely measured amount of alkali (typically sodium hydroxide) is added to the oil. It neutralizes the FFAs, forming “soapstock.” The soapstock also absorbs other impurities like pigments and residual gums. The mixture is then separated again using a High-Speed Centrifuge. This step directly determines the oil’s acidity (FFA content) and is crucial for taste and shelf life.

3. Bleaching

• Purpose: To remove color pigments (e.g., chlorophyll, carotenoids) and improve oil clarity.
• Detailed Process: The oil is heated and transferred into a Bleaching Vessel under a vacuum. Bleaching Earth or Activated Carbon is added, which has a strong adsorptive capacity. These agents effectively adsorb pigments, residual soaps, and phospholipids. After thorough mixing, the spent adsorbent is separated from the oil using a Filter Press, resulting in clear, transparent oil.

4. Deodorization

• Purpose: To remove volatile compounds that cause off-flavors and odors.
• Detailed Process: The oil is heated to a high temperature (typically >220°C / 430°F) and enters a Deodorizer Tower under a high vacuum (very low absolute pressure). Steam is sparged through the oil. The volatile odoriferous molecules (e.g., aldehydes, ketones, oxidation products) are stripped away by the steam due to the high temperature and vacuum. Deodorization is the definitive step for the final flavor and quality of the oil, eliminating all undesirable odors from the raw material and processing, resulting in a pure, neutral-tasting oil.

Section 3: Dewaxing — Enhancing Oil Appearance (Specialized Process)

Sunflower oil, particularly from certain varieties, contains small amounts of wax. These waxes crystallize at low temperatures, causing the oil to appear cloudy, which is undesirable for consumers.

• Purpose: To remove waxes, ensuring the oil remains clear and bright even when stored at low temperatures.
• Detailed Process: The deodorized oil is slowly cooled to a specific low temperature (e.g., 5-10°C) and held there for a period known as crystallization or “winterization.” This allows the tiny wax crystals to grow and agglomerate. Subsequently, the crystallized waxes are completely removed using Precision Filtration Equipment (e.g., Plate & Frame Filter, Winterizing Filter), producing a Fully Refined, Winterized Sunflower Oil.

After all these steps, the final product is a sunflower oil that is clear, bright, has a neutral flavor, and is highly stable, meeting the standards of premium edible oil.