Glassworks: from 130 to 90 µm and no more broken bottles in weekend transport

A glassworks supplying bottles and jars to markets including Germany was losing part of its goods to breakage after pallets stood on trailers over the weekend. We rebuilt the formulation of the NEX-SHRINK shrink sleeve for work at elevated temperatures and went down from 130 to 90 µm, and to 70 µm in some deliveries.

01 Customer

A container glass works producing bottles and jars, with deliveries to markets including Germany. Pallets are secured with a shrink sleeve applied at the cold end and shrunk with hot air. We have worked together for years: the formulation for this glassworks was developed in stages, as routes and the requirements of the glassworks’ customers changed.

02 Challenge

Pallets of bottles and jars waited on trailers over the weekend, in full sun in summer. The film heated up to approx. 70 °C and lost stiffness. The load became loose, and bottles rubbed and broke against the pallet edges, most often in deliveries to the German market.

The glassworks paid for this with complaints and repacking, not for the film itself. A thicker sleeve did not solve the problem: it bought a margin, but the film was still working outside its temperature window.

Cold end of a glassworks: a shrink sleeve applied to a pallet of bottles and shrunk with hot air.

03 How we did it

• Formulation for temperature: a higher stabilisation temperature, so the film holds the load even after a weekend in a hot trailer.
• Mechanical properties: an additive package that strengthens the film at elevated temperatures, not only under laboratory conditions.
• Downgauging: only on a stable formulation did we go down from 130 to 90 µm with full logistic performance.
• 70 µm where it is enough: in some deliveries the glassworks runs an even thinner sleeve.

04 Results

Before and after

Sleeve thickness	130 µm → 90 µm, 70 µm in some deliveries
Film weight per pallet	−31% at 90 µm with the same format*
Complaints about breakage in transport	a clear decrease in international transport
Performance in a hot trailer	approx. 70 °C without loss of stiffness

Pallet after shrinking: an even film surface without folds, film anchored under the pallet.

05 What it looks like in numbers

The customer’s commercial data stays with the customer. To show the scale, we used the Kablonex calculator for an example glassworks with a similar profile.

Calculated example, not customer data: 60,000 pallets per year, pallet 1200 × 1000 × 2400 mm

130 µm (starting point)	1.71 kg of film per pallet · 102.6 t per year
90 µm	1.18 kg per pallet · 71.0 t per year · 31.6 t less film every year
70 µm (selected applications)	0.92 kg per pallet · 47.4 t less film every year
Over 5 years at 90 µm	approx. 158 t less film

06 What this means for you

If your pallets stand on a trailer over the weekend or in the yard in summer, standard shrink film works outside its window. This is not a thickness problem but a formulation problem. Thicker film buys a margin, not a solution.

Downgauging is always preceded by a trial on your line and a transport test. We do not commit to a thickness before the trial.

*Weight reduction when changing thickness from 130 to 90 µm with an unchanged sleeve format. The calculated example in section 05 was produced with the Kablonex calculator (hood made from gusseted tubing, working density 0.930 g/cm³); it is not customer data. The implementation is described anonymously.