Plastic cosmetic tubes are typically sealed using heat sealing or ultrasonic welding after the product has been filled through the open end. These methods bond the tube material to create a secure closure that helps prevent leakage and protects the formula during storage and transportation. The appropriate sealing method depends on the tube material, layer construction, and filling equipment.
Proper sealing is an important part of cosmetic packaging production, particularly for creams, lotions, gels, and other skincare products. Understanding how different materials behave during sealing helps brands select cosmetic tube packaging that meets their manufacturing and product requirements.
Common methods for sealing plastic cosmetic tubes
Different sealing technologies are used depending on the tube structure and production process. The most common methods include heat sealing, ultrasonic welding, and impulse sealing.
Heat sealing
Heat sealing is widely used for polyethylene (PE) cosmetic squeeze tubes. The process applies controlled heat and pressure to the open end of the filled tube, allowing compatible plastic layers to bond together.
Once the seal has formed and cooled, excess material may be trimmed to create a clean, consistent appearance. Temperature, pressure, and sealing time must be adjusted according to the tube's material and wall thickness.
Ultrasonic sealing
Ultrasonic sealing uses high-frequency mechanical vibrations to generate localized heat within compatible plastic materials. This allows the tube end to be joined without relying entirely on externally heated sealing surfaces.
The method can be useful in cosmetic manufacturing where controlled sealing and consistent production are important. However, its suitability depends on the tube's material structure, equipment, and processing conditions.
Impulse sealing
Impulse sealing uses a heating element that applies heat for a controlled period before allowing the seal to cool under pressure. This method can be used for certain thermoplastic packaging structures.
Its suitability for cosmetic tubes depends on the tube's construction and the available equipment. Manufacturers should confirm that the process produces adequate seal strength without damaging the material.
How are cosmetic tubes sealed after filling?
Plastic squeeze tubes are commonly supplied with their shoulders and dispensing closures already formed. The opposite end remains open so the cosmetic formula can be filled into the container.
A typical production process includes:
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Tube preparation: Inspect and position the empty tubes in the filling equipment.
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Product filling: Dispense the required quantity of cream, lotion, or gel through the open end.
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Seal preparation: Keep the sealing area free from excess formula or contamination.
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Tube sealing: Apply the appropriate temperature, pressure, or ultrasonic settings.
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Cooling and trimming: Allow the seal to stabilize and remove excess material when required.
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Quality inspection: Check the finished tube for seal consistency, correct fill quantity, and leakage resistance.
The exact procedure depends on the tube material, formula viscosity, filling system, and sealing equipment.
Choosing the right tube material for sealing
Material selection plays an important role in sealing performance. Different plastics respond differently to heat and pressure, making it important to choose tubes that are compatible with the manufacturing process.
Common material structures include:
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Polyethylene (PE): A widely used flexible material suitable for many conventional heat-sealing processes.
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Low-density polyethylene (LDPE): Provides a softer structure that can be used in compatible squeeze tube designs.
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High-density polyethylene (HDPE): Offers greater rigidity and may require different processing conditions.
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Multilayer PE tubes: Combine layers to achieve specific packaging properties while using compatible sealing surfaces.
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Laminated tubes: Require sealing methods suited to their internal layers and material construction.
For skincare applications, PE five-layer cosmetic tubes with flip-top caps are available in 100ml and 200ml capacities. Their PE construction, five-layer structure, and customization options make them an option for brands developing skincare and beauty packaging.
Brands should verify sealing compatibility with the tube supplier and filling manufacturer before production.
Why proper tube sealing matters
A properly sealed cosmetic tube supports product protection and reliable handling throughout distribution. The sealed end helps contain the formula, while the dispensing closure provides access during everyday use.
Inadequate sealing can result in leakage, product loss, or damage during transportation. Excessive heat or pressure may also deform the tube or affect the appearance of printed packaging.
A suitable seal helps maintain package integrity, but it does not automatically guarantee product sterility or an extended shelf life. Formula preservation, material compatibility, and stability testing remain essential.
Quality control and sealing performance tests
Manufacturers should evaluate sealing quality before approving cosmetic tubes for commercial production. Testing helps identify weak seals, inconsistent processing conditions, and potential leakage.
Important checks include:
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Seal strength: Confirm that the sealed end withstands expected handling conditions.
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Leakage resistance: Evaluate the complete package under appropriate storage and transportation conditions.
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Seal appearance: Inspect for wrinkles, incomplete bonding, or damaged material.
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Fill accuracy: Verify that the correct quantity of product has been dispensed.
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Material compatibility: Confirm that the formula does not negatively affect the tube or closure.
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Transportation durability: Evaluate packaging performance under relevant shipping conditions.
These checks help manufacturers identify problems before finished products reach consumers.
Customization and sustainable tube options
Plastic cosmetic tubes can be customized with different shapes, capacities, closures, colors, and decorative finishes. Common options include Pantone color matching, silk-screen printing, hot stamping, and heat transfer labels.
Brands can also explore tubes containing post-consumer recycled (PCR) plastic or bio-based polyethylene. However, sealing conditions may differ depending on the material structure and recycled content.
Recyclability should be evaluated for the complete package, including its closure, barrier layers, and decoration. A successful sealing process does not automatically make a tube recyclable.
Explore our collapsible tube solutions for plastic, laminated, aluminum, and customizable cosmetic packaging options.
Choosing the right sealing solution
Sealing plastic cosmetic tubes requires a suitable combination of material, equipment, and processing conditions. Heat sealing is commonly used for PE tubes, while ultrasonic and impulse sealing offer alternatives for compatible packaging structures.
Before production, brands should confirm filling requirements, sealing parameters, tube dimensions, and quality testing procedures. Working with experienced packaging and filling partners helps ensure that the selected components perform as intended.
For assistance selecting cosmetic tubes or evaluating packaging requirements, contact us.