Customer: North American independent fragrance brand (anonymized)
Project: 50 ml square glass perfume bottle with a concealed magnetic wooden cap
Market: Premium natural fragrances and gift sets
Scope: Structural engineering optimization, magnet corrosion protection, drop and vibration testing, and bulk production
Production Status: Two sea-freight orders delivered, totaling 35,000 sets
The Challenge: Keeping the Magnetic Cap Secure During Ocean Freight
The customer selected a minimalist square wooden cap featuring concealed magnets that connected the cap to a metal ring around the bottle neck. The design combined natural materials with a premium magnetic closure, but initial simulated shipping tests revealed two potential reliability issues.
1. Magnet Corrosion and Adhesive Failure
After 14 days of simulated shipping exposure, some samples showed signs of oxidation on the internal magnets. The adhesive securing the magnets inside the wooden caps also weakened, allowing the magnets to loosen within their recesses.
The project team identified moisture exposure, temperature variation, magnet protection, and adhesive compatibility as areas requiring further investigation.
2. Insufficient Cap Retention During Vibration and Impact
The weight of the wooden cap, combined with movement during simulated transport, raised concerns about the magnetic holding force.
Some samples lost cap retention during drop testing, leaving the glass bottle more exposed to direct impact.
For a premium fragrance product, a detached cap can compromise the unboxing experience and increase the risk of packaging damage, returns, and customer dissatisfaction.
The challenge was to improve transport reliability without making the magnetic closure difficult for consumers to open.
Our Approach: Magnet Protection, Retention Optimization, and Shock Absorption
1. Improving Magnet Corrosion Protection and Bonding
The original magnet and adhesive assembly was reviewed to improve resistance to moisture exposure and temperature variation.
The project specification was upgraded to use nickel-plated neodymium magnets with an additional epoxy protective coating. The adhesive was changed from conventional hot-melt adhesive to an industrial two-part epoxy adhesive selected for the intended temperature range and bonding requirements.
The magnet recess was also redesigned with a recessed pocket that allowed the adhesive to surround more of the magnet's sides and base, improving mechanical retention.
These changes were intended to reduce corrosion risk and prevent the magnets from loosening inside the wooden cap. The actual protective performance depends on coating integrity, adhesive compatibility, surface preparation, and the validated assembly process.
2. Matching Magnetic Holding Force to the Cap Design
The original N35 magnets were replaced with N42 neodymium magnets as part of the revised design.
The magnet alignment and pocket tolerances were also reviewed to improve the consistency of the magnetic connection.
However, stronger magnets do not automatically produce a better user experience. Excessive holding force can make a cap difficult to remove, while insufficient force can allow it to detach during handling or transport.
The team therefore evaluated both retention and opening feel. According to the project records, the revised assembly underwent 5,000 insertion-and-removal cycles to assess durability and consistency.
The closure was also evaluated after three hours of simulated vibration. The goal was to maintain secure cap retention during transport while preserving a smooth, controlled opening experience.
3. Adding a Protective Cushion at the Bottle Shoulder
The team introduced an EVA foam cushioning ring inside the wooden cap at the contact area with the glass bottle shoulder.
The cushioning layer was designed to reduce direct contact between the cap and glass, helping absorb localized impact and reducing the risk of damage if the components moved relative to each other.
The master-carton insert was also reinforced. Individual bottle positions were redesigned to limit movement within their compartments during handling and shipment.
This combined approach addressed both the closure itself and the surrounding packaging system, rather than relying on magnetic force alone to prevent transport damage.
Project Results
Following the design and process adjustments, the project progressed to repeat bulk production.
Reported project results included:
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Corrosion resistance: No visible magnet corrosion or adhesive failure reported after the specified 14-day simulated shipping test involving humidity and temperature variation.
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Cap retention: No cap detachment reported during the specified 1-meter drop-test sequence covering the six faces and eight corners.
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Transport performance: No packaging damage reported after two sea-freight orders totaling 35,000 sets arrived at the customer's North American warehouse.
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Closure experience: The customer reported a secure, smooth opening feel.
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Repeat business: A third order was reported to be in production, with an additional travel-size design included in the new order.
These results describe the reported outcome of this particular project. Test conditions, acceptance criteria, packaging configuration, and shipment records should be retained to support the claims.
Customer Feedback
“Our biggest concern was damage during ocean freight. The Ejosson team did more than manufacture the bottles; they considered how transportation conditions could affect the packaging. Their test data and improvement plan gave us confidence when launching the product in North America.”
— Operations Director, North American fragrance brand (anonymized; quote used subject to customer approval)
What This Project Demonstrates
A magnetic perfume cap is not simply a magnet inserted into a decorative component. Its reliability depends on several interacting factors, including magnet protection, adhesive selection, pocket geometry, holding force, opening feel, cushioning, and the stability of the outer packaging.
For fragrance brands using magnetic closures, wooden caps, or other multi-component packaging designs, evaluating these factors during sampling can help identify transport-related risks before bulk production.
Ejosson Packaging supports custom fragrance packaging projects involving bottle-and-cap coordination, structural design review, decorative components, and packaging optimization for international shipments.
Explore our Custom Perfume Packaging Solutions, browse our Perfume Bottle Collection, or Request a Product Catalog to discuss your next packaging project.
