أخبار

For machining companies in Thailand, Vietnam, Malaysia and Indonesia, aluminum chip briquetting is not simply a matter of compressing loose material into cylindrical blocks. The amount and condition of residual cutting fluid can determine briquette stability, workplace cleanliness and the real recycling value achieved during melting.

Automotive component plants, motorcycle-parts factories, aluminum profile processors, mold manufacturers and precision-machining companies continuously generate aluminum chips from turning, milling and drilling operations.

Cutting oil or water-based coolant is used to control tool temperature, improve surface quality and extend tool life. These fluids remain on the surface of the aluminum chips or become trapped inside curled and tangled material.

When wet chips enter a briquetting press, a large amount of liquid may be discharged from the die and drainage ports. However, the finished briquettes can still remain wet, expand after discharge or develop cracks during storage.

This creates an important question for customers:

Should aluminum chips be fed directly into a briquetting press, or should the line include gravity draining, crushing or centrifugal deoiling first?

Not every project requires a complete deoiling system. At the same time, higher pressing force alone cannot solve every fluid-content problem. The correct process depends on chip form, fluid condition, daily volume, cutting-fluid value and the final use of the briquettes.

Why Do High-Fluid Aluminum Chips Require Special Treatment?

Loose aluminum chips have a low bulk density, a large exposed surface area and a tendency to tangle. Residual cutting oil or coolant increases the difficulty of handling and processing them.

Customers commonly face four major problems.

Excessive Liquid Discharge Creates Housekeeping Problems

When wet chips are compressed directly, free liquid is rapidly squeezed out. Without sufficient drainage channels, collection trays and filtration equipment, cutting fluid may spread around the machine and foundation.

In the warm and humid conditions common in Southeast Asian factories, oily floors are difficult to maintain and may increase slip and contamination risks.

Briquettes Can Expand or Break After Pressure Release

Briquette stability depends not only on pressing force but also on particle interlocking, chip form and residual liquid.

Oil acts as a lubricant between the particles and reduces internal friction. A briquette may appear stable inside the die but expand, crack or lose material after discharge.

Recoverable Cutting Fluid May Be Sold as Waste

Some cutting oils have a relatively high purchase and maintenance cost. When oily chips are sold without separation, part of this potentially reusable fluid leaves the factory with the scrap.

The recycler may still apply weight deductions or reduce the purchase price because of excessive oil or water content.

Residual Fluid Can Generate Smoke During Melting

Oil vaporizes or burns when wet chips enter a hot furnace, creating smoke, odor and visible flames. Water-based coolant contains additional moisture and may affect furnace-charging safety if large quantities of wet material are introduced.

Briquetting improves density, but it does not automatically mean that the material has been properly deoiled or dried.

When Is Direct Briquetting Suitable?

Direct briquetting offers a shorter process and lower initial investment. For relatively dry and uniform aluminum chips, the drainage function of the press may be sufficient.

Direct briquetting can be considered when:

• The chips are slightly damp but do not drip continuously;
• There is no significant liquid accumulation at the bottom of the container;
• The material mainly consists of short chips or uniform particles;
• Daily processing volume is limited;
• The equipment operates intermittently;
• The cutting fluid has low recovery value;
• The main objective is volume reduction and lower transport cost;
• The downstream buyer accepts a small amount of residual fluid;
• The press includes a reliable drainage and collection system.

Direct briquetting does not mean that fluid management can be ignored. Drip trays, storage tanks and basic filtration are still required, and the company must decide how the discharged liquid will be stored or treated.

When the briquettes are returned to an in-house furnace, the customer should also confirm that the residual fluid condition is acceptable for the furnace and charging practice.

When Is Gravity Draining More Economical?

Gravity draining is one of the lowest-cost pretreatment methods.

Perforated containers, inclined hoppers or double-layer chip bins allow free liquid to drain before the material reaches the press.

This method is suitable when the fluid mainly exists as free-flowing liquid. For example, chips may drip heavily when first discharged from the machine tool but become significantly drier after several hours of storage.

Gravity draining is generally suitable when:

• Daily chip volume is low or moderate;
• Chips are not generated continuously in large quantities;
• The factory has enough temporary storage space;
• Production allows a waiting period before briquetting;
• The fluid drains relatively easily;
• The customer wants to improve briquette quality with limited investment.

The system is simple, consumes little energy and is easy to maintain. However, it is less effective for fluid trapped inside long turnings, coolant attached to fine particles or high-volume continuous production.

The draining area must also be protected from rain, dust and material mixing. Long outdoor storage can introduce water and contamination, reducing scrap quality.

Which Companies Benefit from Centrifugal Deoiling?

A centrifugal separator uses high rotational force to remove liquid from the chip surface and internal spaces.

Compared with natural draining, it processes the material more quickly and is better suited to continuous operation.

Centrifugal deoiling should be evaluated when:

• Chips continue dripping after leaving the machine tool;
• Significant liquid collects at the bottom of the chip container;
• The press discharges more liquid than the existing collection system can handle;
• The factory generates several tons of chips per day;
• Expensive cutting oil may be filtered and reused;
• The recycler applies deductions because of high fluid content;
• The customer wants to reduce floor contamination;
• Briquettes will be returned to a melting furnace;
• Multi-shift or extended continuous operation is required.

The value of a centrifuge should not be measured only by the amount of liquid removed. It may also reduce cleaning labor, transport leakage, briquette cracking and waste-fluid handling.

Recovered liquid should not be returned directly to the machine tools without inspection. It may still contain fine aluminum particles, water, contamination or degraded coolant and may require filtration and testing.

Why Should Long Aluminum Turnings Be Crushed Before Deoiling?

Some lathes produce continuous, curled or tangled aluminum turnings. These materials create problems during conveying, centrifugal separation and briquetting.

Long chips can bridge inside a hopper, leaving material above the outlet while the feeding system remains empty. They may also wrap around screw feeders, centrifuge rotors or other rotating parts.

Curled chips can trap cutting fluid inside the bundle. Even when surface liquid has drained, a significant amount may remain internally.

A more suitable process for this material is often:

Chip Collection → Crushing or Cutting → Centrifugal Deoiling → Buffer Feeding → Hydraulic Briquetting

The crusher reduces long turnings into shorter, more consistent pieces, improving feeding and liquid separation.

However, the material should not be crushed excessively. Producing too many fines increases exposed surface area, oxidation risk, dust and equipment wear. The objective is to create a chip size suitable for conveying, deoiling and briquetting—not to pulverize the aluminum.

How Should Customers Select Among the Four Processing Methods?

A company should not select a process based on one fluid-content percentage alone.

Two chip samples may contain the same percentage of liquid, but short granular chips and long tangled turnings can behave very differently inside the equipment.

Application Case: Why Did Briquettes Crack Even Though the Press Had Sufficient Force?

A Southeast Asian precision-component manufacturer generated a large quantity of aluminum chips containing water-based coolant.

The company initially purchased a hydraulic aluminum chip briquetting press, expecting it to provide both volume reduction and fluid removal.

During early operation, the press produced cylindrical briquettes successfully. After extended production, however, several problems became clear:

• Fluid content varied significantly between batches;
• Large amounts of coolant were suddenly discharged during pressing;
• Finished briquettes continued leaking;
• Some briquettes cracked during storage;
• Workers frequently cleaned liquid around the machine;
• The melting department still reported visible smoke during charging.

Management initially believed that the press force was too low and considered purchasing a larger machine.

A review of the material flow showed that the main problem was upstream.

Short chips and long turnings from different machines were mixed in the same containers. No fixed draining period was used. Fresh wet chips were mixed with material that had already drained for several hours, causing large variations in each batch.

The company improved the process in stages rather than immediately replacing the press.

Short and long chips were collected separately. Short chips were placed in perforated bins for basic draining. Long turnings were crushed and processed through a centrifugal separator. The drainage channels and collection tank around the press were also redesigned.

The factory began recording input weight, recovered liquid and briquette condition for each shift.

After these changes, feed condition became more consistent, briquette cracking and leakage decreased, and the cleaning burden around the equipment was reduced.

The case demonstrates that when fluid content varies significantly, increasing pressing force alone may not solve the problem. Stabilizing the incoming material is often more important than purchasing a higher-tonnage press.

Does Deoiling Reduce Briquetting-Line Capacity?

Adding a deoiling stage introduces another machine into the process, but it does not necessarily reduce total production.

Untreated wet chips may cause unstable feeding, cracked briquettes, drainage overflow and repeated cleaning stops. The press may have a fast cycle, but the accepted output per shift can remain low.

A properly selected centrifugal separator and buffer system can create more uniform feed and reduce:

• Press waiting time;
• Blockage clearing;
• Reprocessing of broken briquettes;
• Drainage-system overflow;
• Manual handling of wet chips.

Production efficiency should therefore be measured by the weight of acceptable material processed by the complete line per shift, not only by the hydraulic cycle time of the press.

How Can a Customer Evaluate Whether a Deoiling System Is Worth the Investment?

The value of deoiling equipment should be calculated across the entire recycling process rather than compared only with the machine purchase price.

Useful operating data include:

• Daily aluminum chip volume;
• Approximate cutting-fluid quantity carried by each ton of chips;
• Weight deductions or lower prices applied by the recycler;
• Daily labor required for cleaning floors and containers;
• Leakage during chip transportation;
• Potential value of recovered cutting fluid;
• Briquette breakage and rejection rate;
• Smoke and melting-loss problems;
• Expected production growth over the next two or three years.

A factory producing only a small amount of chips may not justify a complete crushing and centrifugal-deoiling line.

For a plant generating large quantities of wet chips continuously, the benefits may come from several areas at once: fluid recovery, stable briquettes, environmental control and lower transport costs.

What Additional Factors Matter in Hot and Humid Regions?

Thailand and nearby markets have high ambient temperatures and humidity, creating additional challenges for chip and coolant management.

Cutting fluid may degrade or develop odor more quickly in warm conditions. Wet aluminum chips should not remain in storage for unnecessarily long periods, and rainwater must be prevented from entering the material.

Automated lines should also consider:

• Corrosion protection for hoppers and conveyors;
• Moisture protection and ventilation for electrical components;
• Regular cleaning of drainage pipes;
• Closed storage and settling filtration for recovered fluid;
• Hydraulic oil temperature control;
• Leak-resistant flooring and collection areas.

The line must match not only the required output but also the actual site environment.

What Information Should Customers Provide Before Equipment Selection?

To determine whether gravity draining, crushing or centrifugal deoiling is required, the supplier should receive:

• Clear close-up photographs and continuous-discharge videos;
• Chip form: granular, short curled, long curled, flaky or tangled;
• Whether the cutting fluid is oil-based or water-based;
• Whether the material drips continuously;
• Approximate daily liquid accumulation in the container;
• Hourly, daily and shift-based chip volume;
• Whether cutting fluid recovery is required;
• Whether briquettes will be sold or returned to an in-house furnace;
• Target briquette weight, shape and throughput;
• Available power supply, floor space and drainage conditions;
• Whether continuous feeding and automatic operation are required.

Where possible, representative material should be tested under normal production conditions.

A dry sample that has been stored for a long time may not represent the condition of the chips entering the equipment during actual operation.

Conclusion: Identify the Fluid Condition Before Selecting the Briquetting Process

When aluminum chips contain cutting fluid, the customer should not treat the choice as a simple decision between direct briquetting and mandatory deoiling.

Small quantities of short, slightly damp chips may only require gravity draining and the press’s own liquid-discharge system. Continuously dripping chips generated in larger volumes are more suitable for centrifugal separation. Long, tangled turnings often require crushing before deoiling and briquetting.

A practical aluminum chip recycling solution should connect collection, draining, crushing, deoiling, feeding and briquetting as one matched process.

When the incoming material is stable, the briquetting press can produce more consistent briquettes, while the customer can reduce workplace contamination, control transport costs and improve the overall value recovered from aluminum waste.