Screw Cap Closures

Key Features of the Screw Cap Closure Range

Neck Sizes from 18/415 to 130/400

The range covers one of the broadest neck size spectrums of any closure category on the BlueSky site — from the 18/415 narrow-neck finish used on small personal care and healthcare bottles, through standard 20/410, 24/410 and 28/410 personal care and home care sizes, up to the 100/400 and 130/400 large-format sizes used on wide-mouth straight-sided jars. This breadth means a single supplier can cover closure requirements across a full product range.

Comprehensive Liner Range

Liner selection is critical for product integrity, seal quality and regulatory compliance. The range includes EPE-lined, IHS-lined, PS-lined, monoseal and unlined caps, as well as boreseal options for liquid sealing. See the liner type guidance section below for a full breakdown.

Child-Resistant and Tamper-Evident Options

Child-resistant (CRC) screw caps are available within the range — including the 24/400 White Clic Lock CRC with EPE liner. These are relevant for pharmaceutical, chemical and household cleaning products where child-resistant closures are required under UK/EU regulations. Tamper-evident options are also available.

Internal Hole Plug Caps

Selected SKUs include an integral internal hole plug — a fitment that sits inside the bottle neck to restrict product flow and prevent drips. These are suited to liquid products in bottles with an open neck where controlled pour or drip prevention is required. Available in 20/410 and 24/410 neck sizes.

Smooth, Ribbed and Radtop Styles

Cap surface styles include smooth (clean, contemporary finish for personal care and cosmetic applications), ribbed (textured sides for grip, suited to frequent-use and larger-format caps), and Radtop (a specific domed/rounded style available on 18/415). The choice affects both aesthetics and ease of opening.

Complete Jar-and-Cap Combinations

The range includes complete combinations of straight-sided PP jars with matching ribbed screw caps in 1L, 1.25L and 1.75L formats — suited to bulk personal care, food, home care and industrial applications where a complete jar-and-lid pack component is required.

UK Stock on Core SKUs — Scheduled Supply Available

Core stocked SKUs are held in UK stock for fast dispatch. A number of SKUs — particularly larger neck sizes and speciality liner variants — are available subject to minimum order quantities. A scheduled order service is available for production buyers who need consistent forward supply.

Choosing the Right Liner

The liner is the material fitted inside the cap that creates the seal between the cap and the bottle or jar neck. Liner selection directly affects seal quality, product compatibility, shelf life and regulatory compliance. Specifying the wrong liner for a product can result in leakage, contamination or failed seals.

EPE Liner (Expanded Polyethylene)

EPE liners are a foam-based liner that compresses against the bottle neck to create a basic but reliable seal. They provide good cushioning, are compatible with a wide range of product types, and are the most commonly used general-purpose liner across personal care, home care and non-aggressive chemical applications. EPE liners are not heat-activated and do not create a hermetic seal — they provide physical compression sealing only.

Suited to: personal care liquids, home care products, dry goods, powders, non-aggressive formulations.

IHS Liner (Induction Heat Seal)

IHS liners create a hermetic, tamper-evident seal using an induction sealing process at the capping stage — heat from an induction coil fuses the liner to the bottle mouth, creating an airtight, leak-proof seal that must be peeled or punctured to open. This is the seal type of choice for liquid products requiring a hermetic seal, products with extended shelf life requirements, pharmaceutical and nutraceutical applications, and where tamper evidence is required without a separate tamper band.

Several IHS-lined SKUs are noted as PET Compatible — meaning the liner foil specification is calibrated for PET bottle mouth properties. Confirm bottle material when specifying IHS-lined caps.

Suited to: liquid pharmaceuticals, nutraceuticals, supplements, food products, products with hermetic shelf life requirements, tamper-evident liquid products.

PS Liner (Pressure Sensitive)

A pressure sensitive liner adheres to the bottle or jar mouth on application through contact pressure alone — no heat, induction or separate sealing process required. The liner bonds to the container neck when the cap is tightened, creating a clean, reliable seal that peels away cleanly when the cap is first opened. PS liners are suited to dry goods, powders, tablets, capsules and non-aggressive liquid products where a simple, process-free seal is required at capping.

Suited to: dry goods, powders, nutritional supplements, tablets and capsules, non-aggressive liquids where induction sealing equipment is not available or required.

Monoseal

A Monoseal is a specific liner format that combines the liner and wad in a single-piece construction — the seal surface bonds to the bottle mouth on application without a separate induction step. Monoseal caps provide a clean, reliable seal for PET-compatible applications and are used where a simplified sealing process is required. Available in 100/400 IHS Monoseal format in the range.

Boreseal

A boreseal cap includes an internal plug or seal that fits inside the bottle neck bore (the interior of the neck opening) rather than sealing against the top face of the neck. This creates a tight, leak-resistant seal particularly suited to liquid products — the plug fits snugly into the neck to prevent leakage without relying solely on cap-face compression. Suited to liquid products in bottles where a secure bore seal is needed.

Unlined / Internal Hole Plug

Unlined caps and caps with integral internal hole plugs are suited to dry goods, granules, powders and products where a liner is not required. The internal hole plug restricts flow from the bottle neck for controlled pour applications.

What is a Screw Cap Closure?

A screw cap is a closure that threads onto the neck of a bottle or jar by rotating, creating a secure, removable seal. The cap is opened by unscrewing and removed entirely from the container — unlike flip tops and disc tops which stay attached. The threading provides a mechanically secure closure that can be resealed repeatedly, making screw caps suitable across a wide range of product types from pharmaceuticals to food to personal care.

What is a PP screw cap?

PP (polypropylene) is the standard material for plastic screw caps. It provides good chemical compatibility across personal care, food, pharmaceutical and home care formulations, resists fatigue from repeated opening and closing, and is compatible with standard recycling streams. PP screw caps are used across the majority of plastic bottle and jar formats.

What is the difference between a screw cap and a flip top?

A screw cap is removed entirely by twisting and replaced after use. A flip top stays attached to the bottle and is opened and closed with a single push or snap action — no twisting required. Flip tops are preferred for frequent-use products in wet environments where one-handed operation matters. Screw caps provide a more secure, airtight seal and are used where product preservation, hermetic sealing or child resistance is required.

What is the difference between a screw cap and an ROPP cap?

ROPP (Roll-On Pilfer Proof) caps are applied using specialist capping machinery that rolls the cap material onto the bottle threads, creating a tamper-evident closure that cannot be reapplied once removed. They are standard for alcoholic beverages and some pharmaceutical products. Standard PP screw caps are pre-threaded and applied by hand or standard capping machinery — they can be reapplied and are used across a broader range of products. See BlueSky’s ROPP article for more detail.

Where Screw Cap Closures Are Used

Personal Care and Beauty

Screw caps are used across shampoo, conditioner, body wash, cream and lotion bottles where a secure, removable closure is required. Ribbed caps in 24/410 and 28/410 are the standard for many personal care formats; smooth caps suit premium or contemporary pack aesthetics.

Pharmaceuticals and Nutraceuticals

IHS-lined and child-resistant screw caps are standard for pharmaceutical oral liquid, tablet and capsule products, supplements and vitamins where hermetic sealing, tamper evidence and child resistance are regulatory requirements. The boreseal format is relevant for liquid pharmaceutical products requiring secure bore sealing.

Food and Beverage

Screw caps are used for sauces, condiments, supplements, powders and food products in bottles and jars. IHS-lined caps suit liquid food products requiring hermetic sealing; EPE-lined caps suit dry goods and powders.

Home Care and Cleaning

Household cleaning products, surface cleaners and similar home care formulations use screw caps across a range of neck sizes. EPE-lined caps suit general home care liquids; child-resistant options are required for household products classified as hazardous.

Industrial and Chemical

Larger neck sizes (100/400 and above) suit industrial containers and chemical product packaging. Boreseal and EPE-lined options provide appropriate sealing for non-aggressive chemical and industrial liquid applications.

Large-Format Jars — Personal Care, Food and Industrial

The 1L, 1.25L and 1.75L straight-sided jar-and-cap combinations suit large-format applications across personal care (bulk creams, body butters), food (bulk condiments, dry goods), nutritional supplements (protein powders, bulk vitamins) and industrial (lubricants, chemicals).

Contract Filling

For contract fillers, the breadth of neck sizes and liner options across the BlueSky screw cap range covers the majority of specification requirements encountered across personal care, pharmaceutical, nutraceutical and food product briefs. UK-held stock and scheduled ordering support production planning across multiple client programmes.