In water and wastewater treatment projects, plastic films and flexible packaging is only acceptable when the paperwork is right. This article maps the standards, test methods and documents you should ask for.
This guide is written for engineers, purchasers and project managers who need a practical answer, not a resin data sheet.
This category covers a family of products rather than a single item. In practice a buyer defines plastic films and flexible packaging by three things: the base resin, the format or dimension, and the performance or certification level it has to meet. Typical options in this category include custom printed up to 8 colours; width up to 3000 mm; corona treated surface. Materials most often specified are High Density Polyethylene, Polypropylene, Low Density Polyethylene, Polylactic Acid, and the choice between them changes stiffness, temperature resistance, chemical behaviour and price.
In the water and wastewater treatment sector the decision is usually driven by drinking water approval and biofilm support, with corrosion free service as a secondary requirement. Typical end uses include MBBR bio media, pipework, lamella plates.
The table below summarises the values that usually decide the material choice.
| Material | Density | Tensile strength | Service temperature |
|---|---|---|---|
| Low Density Polyethylene | 0.91-0.93 g/cm³ | 8-20 MPa | -50°C to 70°C |
| Polylactic Acid | 1.24 g/cm³ | 50-60 MPa | up to 55°C (HDT) |
| High Density Polyethylene | 0.94-0.97 g/cm³ | 20-32 MPa | -50°C to 80°C |
Low Density Polyethylene is frequently the default selection here: LDPE is the workhorse of flexible packaging because of its softness and sealing behaviour.
Paperwork matters as much as the part itself in regulated markets.
Ask the supplier to state the standard number, the test method and the result on the certificate. A test report without a standard reference is difficult to defend during an audit.
Beyond the base resin, most suppliers offer UV stabilised, food contact, flame retardant, anti-static and recycled content versions of the same product. Ask which additive package is included, because it is often the difference between a part that lasts three years and one that lasts ten.
The route below is the one most factories use for this type of part.
Secondary operations such as printing, welding, machining and assembly are often cheaper to do in the same factory, and they reduce the risk of mismatch between components.
These are the criteria that actually predict whether the part will perform in service.
Send this list to your supplier with the drawing and you will receive comparable quotations from every factory you contact.
We can provide ISO 9001 quality system documentation, material certificates, RoHS and REACH statements, and where applicable food contact, flame retardancy or drinking water approvals. Tell us your target market and we will match the document set.
Standard packing is export cartons on fumigation-free pallets, with custom labelling, barcode and retail packing available. We also handle consolidated containers and door to door delivery.
Colour is controlled with a masterbatch reference approved by the customer, and every production lot is checked against the approved sample under standard lighting before shipment.
Yes. Standard samples are normally free of charge and shipped within three working days; custom samples are charged at cost and credited against the first production order.
Standard production tolerance follows the relevant ISO or DIN tolerance class for the process; tighter tolerances are possible after machining or grinding, but they add cost. Define the tolerance only on the functional dimensions.
If you are planning a new water and wastewater treatment project, send us your drawing, annual volume and target properties, and we will come back with a material proposal, a tooling plan and a budget quotation.
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