prEN ISO 8351-1

prEN ISO 8351-1 is a CEN/ISO draft standard for packaging that gives a method for specifying paper sacks when ordering. It is a checklist for the sack description that customers and manufacturers agree on, and it does not set quantitative performance requirements. It is primarily intended for the types of paper sacks covered by ISO 6590-2.

What does prEN ISO 8351-1 specify?

prEN ISO 8351-1 specifies which characteristics of paper sacks should be included in an ordering specification. The standard helps the buyer and the sack maker describe the product in the same way, so the order is clear before production starts.

The document is organized into four main clauses:

• Clause 1 gives the scope.
• Clause 2 lists the normative references.
• Clause 3 gives the terms and definitions to use.
• Clause 4 sets out the method of specification, with detailed items for describing the sack.

Clause 4 is the core of the document. It covers sack type, dimensions, plies, perforations, valve or sleeve details, seams, closures, filling aperture, adhesives, printing, packaging, and accompanying documentation.

What are the key requirements of prEN ISO 8351-1?

prEN ISO 8351-1 is not a performance standard. Its key requirement is that the customer and manufacturer review each relevant item in the checklist and agree the order specification, including the format used for that specification. In practice, that means the document is used to prevent ambiguity in procurement and production.

Sack description and type

prEN ISO 8351-1 requires the sack type to be identified first. Clause 4.2 separates open-mouth sacks, valved (closed-mouth) sacks, and tube type sacks, with subtypes such as sewn, pasted, flush-cut, stepped-end, and notched-end. This matters because the type determines how the sack is filled, closed, and measured.

Dimensions and plies

prEN ISO 8351-1 requires dimensions to be specified in millimetres in accordance with prEN ISO 6591-1. Clause 4.2.4 also requires the number of plies and the description of each ply by material type, colour, grammage, thickness, or surface treatment. For thermoplastic film plies, the order should also state details such as film type, state, thickness, melt flow index, and whether the ply is loose or integral.

Perforations, valves, seams, and closures

prEN ISO 8351-1 requires the order to describe any air permeability perforations, including sack perforation, tube perforation, tube micro-perforation, and tube extra fine-perforation. It also asks for valve or sleeve type and position, longitudinal seam type and overlap width, pasted closure type, bottom patches or caps, bottom orientation, and sewn closure details. In practice, this is where the buyer defines how the sack will vent air, seal, and hold together in filling and transport.

Filling aperture, adhesives, printing, packaging, and paperwork

prEN ISO 8351-1 requires open-mouth sacks to state the filling aperture features, such as knife-cut pattern, transverse pasting, and thumb cut. It also covers adhesives for different pasting operations, print coverage and placement, packaging of sacks into bundles, bales, reels or palletized units, and the accompanying documentation. This helps align machine handling, visual appearance, shipping configuration, and order records.

What terms does prEN ISO 8351-1 define?

prEN ISO 8351-1 uses the terms and definitions from EN ISO 6590-1:2025. The following terms are central to the document:

• Open-mouth sacks - sacks with an open top that are filled before the top is closed.
• Valved (closed-mouth) sacks - sacks filled through a valve or sleeve that closes after filling.
• Tube type - a sack made from a tube form, with ends finished in different ways such as flush-cut or stepped-end.
• Plies - the layers that make up the sack wall, each of which can be described separately.
• Valve/sleeve - the filling and closing feature used on valved sacks, including the sleeve material and position.
• Air permeability perforations - perforations used to let air escape during filling, including sack and tube perforation variants.

Who uses prEN ISO 8351-1?

prEN ISO 8351-1 is used by packaging buyers, sack manufacturers, and quality managers who need a shared description for paper sacks. It is relevant to procurement, product specification, production setup, and order verification in packaging supply chains. It is also useful where sacks are ordered with specific closures, printing, palletizing, or documentation requirements.

What changed in prEN ISO 8351-1 from the previous edition?

prEN ISO 8351-1 cancels and replaces ISO 8351-1:1994 and is technically revised. The stated changes are:

• Clause 3 now refers to EN ISO 6590-1:2025 for terms and definitions.
• Clause 4.2.5 on perforations has been expanded to cover air-permeability perforations, including sack perforation, tube perforation, tube micro-perforation, and tube extra fine-perforation.

Which standards are used with prEN ISO 8351-1?

prEN ISO 8351-1 refers to two companion standards:

• EN ISO 6590-1:2025 - provides the vocabulary for paper sacks used in Clause 3.
• prEN ISO 6591-1 - provides the dimensions and method of measurement for empty paper sacks used in Clause 4.2.3.

What does the prEN ISO 8351-1 document contain?

prEN ISO 8351-1 contains a structured specification checklist rather than test methods or performance limits. Clause 4.2 gives item-by-item fields for describing the sack, including type, dimensions, plies, perforations, seam and closure construction, printing, packaging, and documentation.

The document also includes detailed sub-items for specific sack constructions such as valve/sleeve arrangements, bottom inner patches, bottom caps, sewing details, and filling apertures. For ordering, that means the buyer can specify the features that affect filling, closure, handling, and identification.

It also covers packaging formats such as bundles, bales, palletized units, shingled reels, pallet type, wrapping, strapping, and labelling. This is useful when sacks are supplied ready for transport or automatic packing lines.