Pre-threaded Aluminium Screw Caps

Pre-threaded aluminium screw caps (typically of the ROPP - Roll-On Pilfer-Proof type) are metal closures with pre-formed internal threads. Pre-threaded aluminium screw caps are designed to be screwed onto bottles or jars with matching neck sizes (e.g., 18 mm, 22 mm, 28 mm, 31.5 mm). Some are also equipped with security rings or tamper-evident bands that break upon first opening.

Pre-threaded aluminium screw caps are ready-to-use closures whose internal threads match standard bottle necks. They combine an aluminium shell with a liner (usually EPE foam or a plastic pourer) to create an airtight seal. Unlike roll-on caps, these pre-threaded caps can be applied manually or with tools, without the need for specialized machinery.

Materials and Structure of Pre-threaded Aluminium Screw Caps

Metal Alloy: Typically aluminium alloys such as 8011 H14/H16/H18—lightweight, corrosion-resistant, and easy to decorate.
Liner Types: Usually include polyethylene foam (EPE), foil, or Saralon liners to ensure sealing integrity and prevent contamination.
Cap Sizes: Standard diameters are 18×12 mm, 22×15 mm, 28×18 mm, and 31.5×24 mm; height varies (for example, 31.5 mm caps often have a height of 24.1 mm).

Liners for Pre-threaded Aluminium Screw Caps

EPE Foam: Adheres tightly to the bottle opening for leak-proof sealing.
Plastic Pourer: Integrated flow controller, suitable for liquids like oil or syrup.
Tamper-Evident: Many products feature tamper-evident bands or breakable seals.

Common Sizes and Configurations of Pre-threaded Aluminium Screw Caps

Neck Finish (mm)	Height (mm)	Common Uses	Example Colors
PP18	10.5–12	Small bottles, pharmaceuticals	Silver, black, gold, white
PP24	15	Olive oil, spirits, syrups	Gold, silver, black
PP28/PP31	15–44	Large bottles, pourer caps	Green, blue, gold, silver

Decoration and Customization of Pre-threaded Aluminium Screw Caps

Logos or patterns can be printed or embossed using techniques such as offset printing, screen printing, UV printing, hot stamping, embossing, or knurling. Colors and finishes are also customizable.

HC Provides Pre-threaded Aluminium Screw Caps

Product Name	Color	Size (mm)	Features
BVS Aluminum pre-threaded screw cap with security ring	Black	30×60	Pre-threaded, security ring
BVS Aluminum pre-threaded screw cap with security ring	Black	30×60	Pre-threaded, security ring
PP18 Aluminum pre-threaded screw cap with security ring	Black	18×12	Pre-threaded, security ring
PP18 Aluminum pre-threaded screw cap with security ring	Gold	18×12	Pre-threaded, security ring
PP18 Aluminum pre-threaded screw cap with security ring	Silver	18×12	Pre-threaded, security ring
PP22 Aluminum pre-threaded screw cap with security ring	Black	22×15	Pre-threaded, security ring
PP22 Aluminum pre-threaded screw cap with security ring	Gold	22×15	Pre-threaded, security ring
PP22 Aluminum pre-threaded screw cap with security ring	Silver	22×15	Pre-threaded, security ring
PP28 Aluminum pre-threaded screw cap with security ring	Black	28×18	Pre-threaded, security ring
PP28 Aluminum pre-threaded screw cap with security ring	Gold	28×18	Pre-threaded, security ring
PP28 Aluminum screw cap	Light Wood	32×22	Pre-threaded
PP28 Aluminum pre-threaded screw cap with security ring	Silver	28×18	Pre-threaded, security ring
PP31.5 Aluminum pre-threaded screw cap with pourer and security ring	Black	31.5×24	With pourer, security ring
PP31.5 Aluminum pre-threaded screw cap with pourer and security ring	Gold	31.5×24	With pourer, security ring
PP31.5 Aluminum screw cap	Light Wood	36×22	Pre-threaded
PP31.5 Handschraubverschluss Silber mit Gewinde, Ausgiesser und Sicherungsring	Silver	31.5×24	Threaded, pourer, security ring (German)
PP31.5 Deep Aluminum pre-threaded screw cap with security ring	Black	31.5×24	Deep type, security ring
PP31.5 Deep Aluminum pre-threaded screw cap with security ring	Gold	31.5×24	Deep type, security ring
PP31.5 Deep Aluminum pre-threaded screw cap with security ring	Silver	31.5×24	Deep type, security ring
PP31.5 S Aluminum pre-threaded screw cap with security ring	Black	31.5×18	Short version (S), security ring
PP31.5 S Aluminum pre-threaded screw cap with security ring	Gold	31.5×18	Short version (S), security ring
PP31.5 S Aluminum pre-threaded screw cap with security ring	Silver	31.5×18	Short version (S), security ring
Screw cap PP black RD 25 with PE foam insert	Black	RD 25	PE foam liner insert

Functions of Pre-threaded Aluminium Screw Caps

Threads: Pre-formed internal threads allow for secure screw-in connections—ideal for both manual and machine application.
Tamper-Evidence: Many caps include breakable rings that indicate the first opening—commonly used for spirits, oils, cosmetics, or pharmaceutical bottles.
ROPP Application: Certain models require roll-on capping machines to ensure tamper-evident sealing—commonly used in bottling operations.

Applications of Pre-threaded Aluminium Screw Caps

Food & Beverage: Olive oil, vinegar, spirits (for sealing glass/plastic bottles; pourer caps allow precise dispensing), oil, syrup, sauces. Pharmaceuticals: Securing medicine bottles with sterile EPE liners. Cosmetics: Enhancing premium aesthetics; suitable for PET/glass bottles.

Advantages of Pre-threaded Aluminium Screw Caps

Sealing Integrity: Liners conform to bottle imperfections, ensuring airtight/vacuum sealing.
Lightweight and corrosion-resistant, with tamper-evident sealing to ensure product safety.
Sustainability: 100% recyclable; often made with recycled content.
Customization: Available in a variety of colors (silver, black, gold, etc.), with options for embossing, UV printing, or logo stamping.
User-Friendly: Can be manually tightened (tamper-evident seal recommended with tools).

Choosing the Right Cap

Choose the appropriate bottle neck and thread type: e.g., 28×18 mm ROPP bottle body.
Select the liner based on product compatibility.
If tamper-evidence is needed, confirm the presence of a security ring.
Decoration and quantities can be customized to match branding needs.

Pre-threaded aluminium screw caps are versatile, secure, and suitable for a wide range of bottled products. Their durability, tamper-resistance, and customizability make them a top choice in the packaging industry.

The following bottle caps may interest you