Custom Protective Packaging Corner Solves Cast Iron Sink Damage Problem

A leading Midwest kitchen and bath fixture manufacturer was facing a costly and persistent shipping damage problem that had plagued their supply chain for over a year. Their flagship product — a 150-pound cast iron sink with a delicate porcelain coating — was sustaining damage during shipping and handling at an alarming rate. After thorough analysis, the company identified that passing a 12-inch edge drop test would eliminate approximately 50% of all product damage, saving significant money and reducing customer complaints.

The Packaging Challenge

Protecting a heavy cast iron sink with a fragile porcelain finish is no small feat. The challenge required a solution that could absorb and distribute the force of an edge drop without increasing the size of the existing carton, adding excessive cost, or creating operational headaches on the packaging line. The solution also needed to align with environmentally responsible material standards — a growing priority for manufacturers across the industry.

An Innovative Two-Material Corner Design

Within just three weeks, our engineering team developed a custom protective corner that combined two proven paper-based packaging materials: angle board and honeycomb. The angle board works by spreading the impact load across a wider surface area, while the honeycomb layer beneath it absorbs and dissipates energy through controlled crushing during a drop event. Together, these materials create a highly effective protective system that prevents the porcelain from shattering on impact.

During initial testing, the design successfully withstood edge drops from 19 inches — far exceeding the 12-inch requirement. This allowed us to refine and reduce the amount of material used, bringing the cost down while still comfortably meeting the target performance threshold.

Patented Results and Proven Scale

The solution didn’t just meet every project objective — it earned a patent for its innovative corner design. The customer went on to purchase 2.5 million units annually to protect their cast iron sink line.

Every project objective was achieved: passing the edge drop test, maintaining the existing carton footprint, delivering a cost-effective solution, using recyclable paper-based materials, and enabling smooth integration into their existing packaging line.