Where Does Breakage Come From?
Glass bottles rarely break in transit from a single drop. The real culprits are vibration and point pressure. A bottle vibrates for hours on a conveyor belt, gets wedged against other parcels, and cracks at its weakest point. Think of shipment as an engineering problem: the goal is to absorb impact and eliminate movement.
Three forces act simultaneously. Packaging without understanding them is nothing more than wrapping bubble wrap blindly.
| Force | Source | Solution |
|---|---|---|
| Impact | Parcel dropped or thrown | Corner and base padding, double-wall box |
| Vibration | Continuous jolting on vehicles/conveyors | Secure the bottle completely; leave no gaps |
| Compression | Stacking load from above | Rigid inner dividers, vertical load-bearing surfaces |
The Right Material in the Right Place
No single padding material does every job. Foam absorbs vibration, corrugated board carries load, air pillows fill voids. Use one in place of another and protection fails.
| Material | Strengths | Weaknesses |
|---|---|---|
| Double-wall corrugated board | Stacking load, external impact | Does not absorb vibration on its own |
| Moulded foam insert (EPE/EVA) | Grips bottle precisely, eliminates vibration | Higher cost, requires tooling |
| Air pillows / inflatable cushions | Void fill, lightweight | Bursts under point impact, shifts around |
| Kraft paper fill | Economical void fill | Flattens under compression, reducing protection |
| Corner protectors (edge guards) | Reinforces box corners | Insufficient on their own |
The ideal combination: moulded foam insert + double-wall box. The foam secures the bottle; the corrugated board carries the outer shell. For low-volume production, tightly wrapped bubble wrap and a rigid inner divider can substitute for foam — provided the bottle has absolutely no movement inside.
From Bottle to Box: Step by Step
Sequence matters. Stop leaks first, then secure the bottle, then seal the box. Every skipped step comes back as a return.
- Lock the cap
Check the spray/valve cap is firmly seated. Where possible, apply a Shrink Sleeve (heat-shrink protective film) or a tamper-evident seal — it prevents leaks and builds first-open confidence for the customer.
- Perform a leak test
Before shipment, invert the bottle, apply light pressure, and check for any transfer onto a tissue. Alcohol-based fragrance liquid will seep through the smallest opening and stain the interior of the box.
- Wrap each bottle individually
Wrap every bottle separately in a foam sheet or bubble wrap. Bottles must not touch one another; glass-to-glass contact is the most common point of breakage.
- Place in the inner insert
Seat the bottle in a moulded foam insert or a rigid-compartment inner tray. The bottle should stand upright, with the neck (the most fragile point) fully protected.
- Fill all voids
Close every gap between the insert and the box walls with fill material. When you press the bottle with a finger, it should not move at all.
- Seal with double tape
Reinforce the top and bottom seams of the box with H-taping. Attach "FRAGILE" and "THIS SIDE UP" labels to the outside.
Weight, Volume and Shipping Regulations
Packaging is not only about protection — it is also about accurate declaration. Two technical points frequently catch new producers off guard: ml-to-gram conversion and regulations for shipping alcohol-based products.
A bottle label states volume (ml), while courier dimensional weight is calculated from weight and dimensions. The density of fragrance liquid varies by formulation: high-alcohol, light formulas fall in the ~0.84–0.89 g/ml range, while dense formulas with heavy resin/synthetic content can exceed 1.00 g/ml. In other words, 100 ml does not always equal 100 g. If you fill by volume, factor in this difference; otherwise you will end up with overflow or underfill.
Because fragrance liquid contains a high proportion of alcohol, it is classified as a flammable liquid. For domestic and especially international shipments, UN/ADR (dangerous goods road transport) regulations may apply, potentially requiring a UN number, packing group designation and appropriate labelling. Confirm your carrier's acceptance conditions for alcohol-based products and check current regulations in advance.
Common Mistakes and Frequently Asked Questions
High breakage rates almost always stem from the same handful of mistakes. Fix them and the returns graph drops. The rest is down to your discipline.
The most common errors: using a weak single-wall box, placing bottles side by side with gaps between them, skipping cap and seal checks, and choosing an oversized box then "getting away with" minimal fill. A large void is more dangerous than the most expensive padding material.
Is bubble wrap enough on its own?
Is a leak test before dispatch really necessary?
What extra requirements apply for international shipments?
Related Articles
Leak Testing: Pre-Shipment Bottle Test
Methods for detecting leaks in filled bottles before dispatch.
Read →Shrink Sleeve and Tamper-Evident Seal
Applying shrink sleeves and seals for product security and presentation.
Read →Shipping Alcohol-Based Products: UN/ADR Transport Regulations
Dangerous goods classification for alcohol-based fragrances and carrier rules (verify against current sources).
Read →