Neck standards

In the production of containers for pharmaceutical and cosmetic products, the compatibility of the neck and cap of the bottle is considered one of the key factors. Standardisation of threads helps to use the same closure for different bottles.

Basic neck standards

Research institutes and international trade associations of packaging manufacturers have developed standards for bottle necks that guarantee the compatibility of containers with caps. There are quite a few of them for glass and plastic products, but the most well-known ones are designed to optimise costs and standardise production processes. They reflect the diameters of the necks on the outside of the thread or measurements on the inside surface of the cap.

DIN (18, 20, 24, 28 mm)

Deutsches Institut für Normung (DIN) is a German series of necks with diameters ranging from 18 to 28 mm, where the specified values correspond to the thread diameter rounded up to the nearest whole number. For example, the actual size of a 23.4 mm bottle neck will be represented by the value 24. The DIN standard is widely used in Europe.

PCO (1810, 1881)

Plastic Closures Only (PCO) 1810 is a common standard for plastic caps and bottles, known as a ‘Coca-Cola’ neck with a diameter of 28 mm. A neck of the same size is also designated by the code BPF, which differs in minor details.

PCO 1810 and PCO 1881 have the same diameter but differ in neck height – the PCO 1881 version is shortened due to the thread pitch and the tear-off ring. This neck is considered the standard in the beverage market and is also widely used for pharmaceutical vials, as matching caps are available for it.

BPF and BPF Light

British Plastics Federation (BPF) is a British standard with a diameter of 28 mm, popular in northern and eastern Europe, as well as in the countries of the former USSR. BPF and the modified BPF Light neck with a lightweight support ring perform an important function – gas retention. Excess carbon dioxide is removed when the bottle is opened through special grooves in the necks of this type of standard. Therefore, various carbonated drinks and mineral waters are stored in such bottles.

GPI

The American Glass Packaging Institute (GPI) screw neck standard ensures reliable sealing of glass bottles for various pharmaceutical products with a long shelf life. To ensure compatibility with common types of caps, standard thread types are used:

• 400 - single turn;
• 410 - one and a half turns;
• 415 - two turns with an extended neck;
• 425 - reduced thread with two turns;
• 430 - improved seal, thread with a support ring.

SPI

Society of the Plastics Industry (SPI) – international standard for plastic packaging containers:

• each type of plastic container has its own code;
• the code consists of numbers separated by a hyphen;
• the second number in the code (SPI code) indicates the height of the neck.

The height is measured from the top end of the neck to the beginning of its expansion (shoulders) or to the stop ring – this is parameter H. This is one of the key indicators when selecting the appropriate cap.

Bericap (38, 48 mm)

Bericap standards are named after the company that patented this design. Popular bottle neck standards with diameters of 38 mm or 48 mm are used for packaging milk, cream, juices, other non-alcoholic beverages, as well as automotive fluids and household chemicals. This type of neck is characterised by its low height, which allows the product to be poured without splashing or leaking.

VNF

A specialised type of neck with a high level of tightness for packaging strong alcoholic beverages containing up to 96% alcohol.

Oil

The standard with the telling name OIL (translated from English as ‘oil’) provides reliable sealing for edible vegetable oils - sunflower, olive, soybean, as well as industrial oils - motor and automotive. Plastic containers with OIL standard lids prevent leaks and protect the contents from oxidation, which is especially important for long-term oil storage.

Jar containers

A separate type of neck for jars with a short body and wide neck. The large neck diameter, for example, 58 mm or 82 mm, is designed to provide easy access to food products such as pâtés, preserves, jams and others.

Thread standards and sizes

Some types of bottle necks are interchangeable, but it is important to remember that the internal diameter of the neck is not standardised between plastic and glass. The thickness of the glass wall is always greater, so when the external diameter is the same, the internal diameter of the glass neck will be significantly smaller than that of the plastic neck.

In practice, the following can be observed:

• PCO 1810/BPF parameters are similar to those of the classic GL28 (syrup) glass neck;
• a standard 410 cap is compatible with a 415 neck if the cap does not have a control ring that prevents tight screwing;
• the 400 standard cap fits the 410 standard neck.

It is also necessary to take into account the individual tolerances of manufacturers. Even if the marking values match, absolute tightness is not guaranteed, so it is advisable to order products from one manufacturer to avoid incompatibilities.

Our company manufactures high-quality packaging for cosmetic and pharmaceutical products. We offer a wide range of bottles of various standards with guaranteed compatibility of necks and caps. We deliver finished products in St. Petersburg and the Leningrad Region within 1-3 working days. Deliveries within Russia are discussed with the manager.