What to ask a supplier before comparing prices
A useful first conversation is about your process, not about the supplier's catalogue. A supplier who cannot say what they need from you in order to recommend a product is likely to recommend whatever is easiest to sell. Before requesting quotations, prepare a short brief and ask the supplier to respond against it.
- Substrates: the exact board, film, foil or label stock, including coatings, inks and varnishes on the bonding surface.
- Process: manual or automatic application, machine type, line speed, open and closing times, and how soon the pack is handled after bonding.
- Storage and use conditions: cold chain, heat in transit, humidity, stacking load and the expected life of the pack.
- End of life: whether the packaging has to be recycled in the paper stream or another route.
- Regulatory status for packaging: whether the adhesive may touch the packed product or only sits between layers of packaging.
- Current problem: what fails today, where on the line, and how often.
Then ask how the supplier would verify that their recommendation works on your materials. A credible answer involves testing on your substrates and your equipment, not just a reference to a datasheet. If you are still deciding which chemistry fits, a general overview of industrial adhesives helps you frame the right questions.
Selection criteria that matter in practice
Price comparisons only make sense between products that perform the same job. Score each candidate against the same criteria and weigh them according to your own risks.
| Criterion | What to check |
|---|---|
| Technical fit | Bond performance on your actual substrates, at your line speed and under your storage conditions. |
| Application behaviour | Compatibility with your dispensing equipment, cleaning routine and downtime behaviour. |
| Regulatory support | Ask whether the supplier can state the regulatory status for your use and back it with documents. |
| Technical service | Access to someone who can visit the line, interpret failures and respond quickly. |
| Consistency | How the supplier controls batch-to-batch variation and informs you of formulation changes. |
| Supply resilience | Sources of raw materials, stock policy and alternatives if a grade becomes unavailable. |
| Total cost | Consumption per pack, rejects, cleaning time and line stoppages, not only the price per kilo. |
If your line uses thermoplastic adhesives for case or carton sealing, compare hot melt adhesives on application behaviour as well as on bond strength, because the same grade can perform very differently on different equipment.
Documents to request
Ask for documents before the trial, not after. The set below lets your quality, technical and regulatory colleagues assess the product in parallel with production.
- Technical data sheet for each grade, with the test conditions stated for every property.
- Safety data sheet in a language your staff can read, for handling, storage and waste decisions.
- Ask for a written statement on suitability for your intended use, if packaging touches or may touch the packed product.
- Information on migration testing or extraction testing where the use case calls for it.
- Recyclability information, if the pack is destined for paper recycling.
- A change notification policy that explains how you will be told about changes in formulation or raw materials.
Read the technical data sheet critically. Viscosity is a typical example: a single figure is useful for comparing grades on equipment that runs at low shear, but the test method itself warns that the result may not correlate well with end uses involving high shear. [1]
Food contact: ask the right question
For plastic materials and articles that contact food, the EU has specific rules in Regulation (EU) No 10/2011, adopted under the framework regulation on food contact materials. Ask the supplier how their statement for your product relates to those rules when plastic layers are involved. [2]
Where testing is relevant, migration tests use food simulants that imitate how food behaves, while extraction tests look at the amount of substances that could migrate. Ask which type was carried out, on which sample, and who performed it. [3]
Recyclability of paper-based packs
If your packaging goes into the paper recycling stream, the adhesive influences how well the pack recycles. The harmonised European laboratory method for paper and board looks at process parameters, including coarse reject, flake content, dissolved or colloidal solids and small adhesive particles, and at quality parameters such as sheet formation, interfering materials like stickies and visual appearance. [4]
For heavier products, the method expects the test sample to contain the same share of non-base elements as the whole pack, including labels, seals, hot-melt application and inks. Ask your supplier whether any recyclability data they provide was produced on a sample like your finished pack, or only on a generic one. [5]
Logistics and supply continuity
A good adhesive that arrives late stops the line just as effectively as a poor one. Treat logistics as a technical criterion and put the answers in writing.
- Where is the product made, and is there a second production or filling site?
- Which raw materials are single-sourced, and what is the contingency if one is disrupted?
- What stock does the supplier hold of your grades, and can a consignment stock be arranged?
- What are the order cycle, minimum order quantity and packaging formats, and do they suit your storage space and handling equipment?
- How is shelf life shown on the label, and what storage conditions do you need to provide?
- How are batches identified for traceability if a problem appears in production?
- What happens when a grade is discontinued or reformulated, and how much notice will you get?
If you operate across several sites or countries, check that documents and labelling are available in the languages your teams need and that technical support covers your time zone.
How to run a supplier trial
A trial is only informative if it is designed in advance. Agree the plan with the supplier and your production team before the first drum arrives.
- Define success first: bond quality, rejects, cleaning effort and stoppages, with the way each will be measured.
- Use your real substrates from normal production lots, including the difficult ones, rather than selected samples.
- Run on the production equipment, with the operators who normally run it, and record settings.
- Keep a control: compare against the current adhesive under the same conditions where possible.
- Test over time and under storage conditions that reflect real distribution, not just at the moment of bonding.
- Record every deviation, including environmental changes and operator interventions.
- Hold a review with the supplier and agree what was learned, what needs adjusting and whether a second round is justified.
Ask the supplier to attend the first run or support it remotely. How they react when something does not work is as valuable as the result itself.
Warning signs
- The supplier recommends a product without asking about your substrates or equipment.
- Statements about suitability are vague, verbal only, or unrelated to your intended use.
- Datasheet values are presented without test conditions, or are used as promises of line performance.
- Documents arrive late, are incomplete or are only available after you place an order.
- No clear process exists for notifying you of formulation changes.
- Answers on supply, stock and second sources are evasive.
- Technical support is difficult to contact before the sale, which suggests it will be harder after it.
- Pressure to commit to volume before any trial has been completed.
None of these signs proves a supplier is unsuitable, but each one is a reason to ask for clarification in writing before you proceed.