Everything You Need to Know About Bottle Caps & Closures

The mighty ‘bottle cap’ covers a vast range of criteria. Bottle Caps & Closures have been designed to keep the liquid contents inside the container, fresh and clean. The bottle cap also needs to be easy to use, while giving the consumer easy access to the liquid contents inside. If you’re looking for the perfect bottle cap solution? This guide should give you a better understanding of how a manufacturer and bottle cap supplier, operates on a day to day basis with clients all over the world.

Standard Bottle Cap & Closure Design

Bottle caps come in some really stylish choices. They are have been designed to work with creams, lotions and oils of all viscosities. Each cap and closures can be designed to work with a ‘dosage’ through a number of different ways. This can be emphasised through the dimension of the hole or using a silicone release valve. Sometimes it best to use a simple screw cap which enables the consumer to pour directly from the bottle.

Simple Screw Cap Design On a PET Bottle

Classic Bottle Caps & Closure Examples:

You may have seen some of the classic bottle tops & closures on the market today. Each design helps dispense liquid products such as soaps, shampoos, cleaning products, skincare creams, oils and so much more.

Disc Top Caps
Flip Top Bottle Cap
Classic Bottle Over Cap
Screw Bottle Cap
Nozzle Pull Top Bottle Cap

Bespoke Bottle Caps & Closure Examples:

Innovational bottle caps and closures are on the rise. Brands demand something that goes beyond expectation and assumption. They want something different, something that works or something distinctive. These factors help customer loyalty, marketing and profits. Here are some bespoke bottle cap examples.

Double Button Disc Top Cap.
Rose Foam Shaving Cap. A Perfect Treat Before Application.
A Double Twisting Locking Cap for Skincare, Beauty Products or Haircare Product Collections.
A dosing bottle cap that delivers a single dose every time

Caps & Closure Sizes

The cap or closure size has a very distinctive variable. An example of this would be 24/410. In manufacturing or distribution terms, this number has to match up with a bottle neck size of the same number. The 24 part of the code equates to ’24mm’, the width of the bottle cap, whereas the ‘410’ relates to the height of the cap. The height can be also be different, the ‘410’ can vary in height for each different cap. This will be looked up on a spread sheet if the data is required. In conclusion, a 24/410 cap size will work with a 24/410 bottle neck size.

Example of a single screw cap with matching bottle neck size.

20mm Bottle Screw Cap with Matching 20mm Bottle Neck Size

Some of the most popular cap & closure neck sizes include:

 

Neck Size Chart
20mm Bottle Closure
28mm Bottle Closure
20/410 Bottle Closure
20/415 Bottle Closure
24/410 Bottle Closure
28/410 Bottle Closure
Custom Bottle Closure
© Raepak Ltd

 

Cap & Neck Finishes

Here we can see how a transparent cap of 28mm, fits onto a 28mm bottle neck. Manufacturers use the following dimensions for heigh, width and diameter.

T – DIMENSION refers to the outer diameter of the thread on the bottle neck. This will make contact with the cap or closure.

E – DIMENSION is the edge of the bottle neck but excludes the edge of the thread. The difference between the “E” and “T” dimensions divided by two determines the thread depth.

I – DIMENSION this inner bottle neck determines the range of caps and closures compatible with the opening. This measermenet is also important for filling the bottle with the liquid contents, different closure types including plugs, seals and dispensing pumps.

S – DIMENSION measures the top edge of the bottle neck through to the first thread. This fact determines the connection type needed for the cap or closure to fit tight and secure.

H – DIMENSION is the height of the overall neck size. A measurement that starts at point “T” and finishes at the bottle neck shoulder.

Z – DIMENSION shows the thread connection point of a standard over cap. This is screwed down tight to fit the bottle neck perfectly.

Recyclability Factors

Bottle caps and closures that Raepak distribute are all 100% recyclable. This includes the disc top caps with metal disc inserts. The plastic is melted down in the ‘washing’ phase and a strong magnet pulls any metal out of the liquid plastic. The plastic used for bottle caps and closures are:

Polypropylene (PP – can be used for soft and a hard plastic finish). Polypropylene can be processed by virtually all thermoplastic-processing methods. Most typically PP Products are manufactured by: Extrusion Blow Moulding, Injection Moulding, and General Purpose Extrusion. Expanded Polypropylene (EPP) may be moulded in a specialist process. [Source]

Low Density Polyethylene (LDPE) can also be used in the manufacturing of bottle closures and caps. The finished effect can also be a hard or soft flexible finish.

Both these plastic types can carry the ‘widely recyclable’ and the ‘standard recyclable’ label.

Bottle Cap & Closure Torque Reference

Torque should be evenly distributed through the cap or closure. This allows the contents to be stored in an air tight condition. The torque should also allow consumer to easily open a bottle cap and apply the same pressure to close it.

Applying too much torque can lead to leakage, breakage or damage the bottle itself. Because torque is expressed in inches per pound. Manufacturers use a torquing system where by the amount of torque is about half of the diameter of the cap.

Here is a chart that shows torque to apply or remove closures of a specific size and material.

Phenolic / Urea Cap
on Plastic
PP / PE Cap
on Plastic
Cap Size(mm)Application Torque*Removal Torque*Application Torque*Removal Torque*
156384
187495
2084105
2295116
24105126
28126147
33157178
38177199
431892211
4820102412
5824122914
7028143517
8936184522
10040205025

We stock a wide range of bottle caps and closures that work with a range of bottle options. We also have a huge selection of non stock items. Need some help? Please get in touch today.

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Heidi Hodds

Heidi is a senior account manager with over 12 years experience in the packaging industry. Heidi understands all her customer's needs and proactively helps them into new product ranges, years ahead of anticipated release dates. Her great attention to detail gives rise to a wealth of product knowledge. Heidi enjoys family time, long country walks, the theatre and listening to music.

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