How is the 15ml centrifuge tube with conical bottom manufactured?

The 15ml centrifuge tube with conical bottom is a fundamental laboratory consumable widely used in life science research, clinical diagnostics, and biotech applications. Its design ensures efficient sample separation, pellet collection, and secure storage. Understanding its manufacturing process provides insight into quality control, material selection, and functional optimization.

1. Material selection for 15ml centrifuge tube with conical bottom

The manufacturing process begins with selecting the appropriate polymer. Most 15ml conical tubes are made from polypropylene (PP) due to its chemical resistance, durability, and ability to withstand high-speed centrifugation. Some variants may use polystyrene (PS) or polycarbonate (PC), depending on specific applications.

Key material properties include:

• Autoclavability (withstand temperatures up to 121°C)
• Clarity (for easy sample visualization)
• Mechanical strength (to prevent deformation during centrifugation)
• Biological inertness (to avoid sample contamination)

For sterile centrifuge tubes 15ml, additional gamma irradiation or ethylene oxide (EtO) sterilization is applied post-production.

2. Injection molding of the tube body

The 15ml lab tube screw cap and conical body are typically produced via injection molding, a high-precision manufacturing method.

Steps in injection molding:

1. Pellet melting – Polypropylene pellets are heated until molten.
2. Injection into mold – The liquid polymer is injected into a pre-designed mold cavity shaped like a 15ml conical tube.
3. Cooling & solidification – The mold is cooled, allowing the plastic to harden.
4. Ejection – The newly formed tube is ejected for further processing.

The conical bottom is carefully designed to facilitate pellet formation during centrifugation, ensuring minimal sample loss.

3. Cap production and assembly

The cap of a 15ml falcon tube equivalent is usually made from the same material as the tube body. Common cap types include:

• Screw caps (for secure sealing)
• Snap caps (for quick access)
• Plug seals (for enhanced leak resistance)

Caps are molded separately and later assembled onto the tubes. Some 15ml disposable conical tubes feature vented caps for cell culture applications.

4. Graduation marking and labeling

Many centrifuge tubes 15ml with graduation include volume markings for accurate measurement. These markings are applied via:

• Laser etching (permanent, chemical-resistant)
• Ink printing (cost-effective but less durable)

Labels may also include:

• Batch numbers
• Sterility indicators
• Manufacturer certifications

5. Quality control and sterilization

Before distribution, 15ml centrifuge tubes with conical bottom undergo rigorous quality checks:

For sterile 15ml conical tubes, final sterilization methods include:

• Gamma irradiation (for pre-assembled tubes)
• Ethylene oxide (EtO) gas (for heat-sensitive components)
• Autoclaving (for reusable autoclavable 15ml centrifuge tubes)

6. Packaging and distribution

The final 15ml plastic centrifuge tubes are packaged in:

• Bulk bags (for non-sterile tubes)
• Individually wrapped sterile pouches (for clinical use)
• Racks or boxes (for lab organization)

Proper packaging ensures protection from contamination and physical damage during transit.

The manufacturing of a 15ml centrifuge tube with conical bottom involves precise material selection, injection molding, cap assembly, quality testing, and sterilization. These steps ensure that the final product meets the demands of life science research supplies, clinical lab plasticware, and biotech lab supplies. By understanding this process, researchers and procurement specialists can make informed decisions when selecting laboratory consumables for centrifugation, sample storage, and cell culture applications.