BEFORE YOU BEGIN
Three things to take away.
- Match the complete neck finish and closure specification.
- Select seals for the container material and actual contents.
- Confirm application settings through trials with the assembled package.
Specify the interface before choosing the cap
Begin with the container drawing and its neck-finish designation. Confirm the matching closure specification, including the intended liner or gasket. A similar appearance or approximate diameter is not a sufficient purchasing description. TricorBraun’s compatibility guidance pairs the closure with a matching neck finish and recommends testing the actual bottle and product before a large order.
Ask the supplier to identify the complete assembly on the quotation. This makes it easier to compare offers, organise samples and prevent a cap or insert from being substituted without review.
References: [1]
Give the seal a defined job
State whether the brief calls for a primary seal, visible evidence of opening, a particular removal method or another function. For induction sealing, Selig explains that the heat-seal layer must suit the container material. The contents also matter: some formulations require a barrier that protects the foil against degradation.
Describe the expected opening experience as precisely as the sealing requirement. Include any pouring insert, dosing accessory or repeated opening and reclosing in the sample review. Do not assume that a seal selected for one product will suit another formulation.
References: [2]
Treat venting as an application decision
Where pressure equalisation is part of the requirement, discuss the formulation, temperature changes and transport orientation with the component supplier. Gore’s guidance explains that liquid contact can change vent airflow, and that a result obtained with water does not establish performance with a chemical formulation.
Request evaluation with the actual contents and intended package. For Gore’s membrane vents, liquid covering the active membrane can prevent gas exchange. This illustrates why a vent specification needs to address package orientation and use, rather than relying only on a dry airflow value.
References: [3]
Set and verify the production conditions
Obtain application settings for the selected assembly; avoid adopting a torque figure from a different cap. Selig identifies both inadequate torque and excessive torque among causes of sealing problems. Its troubleshooting guidance also highlights sealing-surface contamination and induction-equipment settings.
During trials, document the equipment settings, inspection method and acceptance criteria. Agree which checks will be repeated during production and after relevant material or formulation changes. Keep an approved sample and component references so procurement, production and quality teams work from the same definition.
References: [4]
PUT IT INTO PRACTICE
Your next-step checklist.
Bring these points to your packaging discussion.
- Are the container drawing, neck finish and closure references matched?
- What sealing, opening and reclosing functions are required?
- Have the actual contents been included in the compatibility review?
- If venting is needed, which conditions and orientations will be evaluated?
- Who will approve the application settings and production checks?
Sources & further reading
References support the specific points noted above. Confirm the requirements that apply to your product, market and intended use.
- TricorBraun — bottle, lid and liner compatibility (opens in a new tab)
Explains matching neck finishes and recommends testing with the specific bottle and product.
- Selig Group — container sealing (opens in a new tab)
Covers liner selection, container materials, product characteristics and seal-removal functions.
- Gore — packaging vent application guidance (opens in a new tab)
Explains formulation testing, liquid contact, airflow and orientation for Gore packaging vents; no supplier relationship with Polytainer is implied.
- Selig Group — sealing troubleshooting (opens in a new tab)
Identifies torque, contamination and process settings among potential causes of seal failure.
EXPLORE THE POLYTAINER RANGE
