Case Study: Custom Glass Water Bottles for a Swedish Small Company

Client Background

A Canadian craft beverage company specializing in small-batch cider and fruit-flavored sodas planned to expand production for national retail sales. They needed a bulk order of 330ml clear glass bottles with a vintage-style round body and a twist-off metal cap for freshness preservation. They chose Minghang because of our proven track record in bulk glass bottle production—prioritizing product consistency, food safety, and on-time delivery to meet retail launch deadlines.

Our Challenge

Initial samples of the bulk order contained significant defects: some bottles had uneven wall thickness (leading to breakage during filling), the metal caps had a poor seal (causing carbonation loss in the soda), and the logo printing color varied from light to dark across batches. These issues threatened the brand's reputation, as inconsistent bulk glass bottle quality disappointed retailers and consumers.

Root Cause Analysis

Our team identified the issues as: misaligned molds on the production line, resulting in uneven glass thickness (causing a 0.5-1 mm variance); mismatched thread sizes causing loose caps (neck: 28 mm, cap: 27.5 mm); and a lack of calibration in the ink mixer, leading to inconsistent logo color (resulting in an incorrect pigment ratio across the glass bottle batch production).

Our Solution

To address the issues with the glass bottle batch order, we recalibrated the molds to ensure a uniform wall thickness of 2 mm (consistency tested on 200 pcs random samples). We adjusted the cap thread size to 28 mm and added food-grade silicone gaskets to improve the seal—carbonate retention testing was conducted on 50 filled bottles. For the logo, we calibrated the ink mixer to achieve the precise pigment ratio and added a quality inspection step after each batch of glass bottles was printed.

Custom 400ml Double Wall Glass Water Bottle	Custom 550ml 750ml 1000ml Glass Water Bottles

Results

The final glass bottle batch order met all criteria: uniform thickness (no breakage), a tight cap seal (100% carbonate retention), and uniform logo printing. We delivered 50,000 pcs bottles on time, two weeks ahead of the customer's retail deadline. Sales of cider and soda exceeded expectations by 35% in the first month, with retailers praising the bottles as “reliable and eye-catching.” The customer noted, “The high quality of Minghang’s mass-produced glass bottles has made our expansion smooth – we plan to double our next order.”