There will be scratches when the aluminum ring on the ice pack rubs against the card paper in the instruction manual. How can this be solved

I. Why are there scratches?
The aluminum ring is soft.
Aluminum alloy and thin aluminum rolls have low hardness. Even a slight friction will cause powder to fall off and create black lines/grey marks.
Card paper has a gritty feel.
Common hard card paper contains paper fibers and fillers, like fine sandpaper. Rubbing back and forth directly scratches the aluminum surface.
Packaging and transportation compression
After packing, shaking and stacking under pressure, the aluminum ring and card paper rub against each other closely. In large quantities, there are always scratches.
Aluminum surface without protection
Without coating or applying a protective layer, the bare aluminum directly contacts the paper, making it most prone to leaving marks.
II. Immediate solutions (from cost-effective to high-end)
1. Isolation and buffering (the most cost-effective, preferred by factories)
The aluminum ring is placed separately in a PE flat bag/matte bag, then separated by card paper, without direct contact.
An additional layer of copy paper, sulfur paper, or thin soft white paper is placed in the middle to separate the aluminum ring from the card paper, and the scratch marks disappear directly.
2. Replace card paper
Replace the ordinary hard card paper with matte soft card paper or coated card paper. The surface is smooth without a gritty feel, and it won't scratch the aluminum.
Do not use rough kraft card or recycled pulp card paper.
3. Protect the aluminum ring surface
Cover the aluminum ring surface with a protective film (static film/PE self-adhesive film). Tear it off during shipment or leave it for the customer to tear.
Perform a slight anodizing or apply a thin coating, increasing the surface hardness and making it less prone to leaving marks due to friction.
4. Structural separation
Make corrugated partitions and grids inside the carton, and place each aluminum ring in a separate compartment, avoiding close contact with the card paper.
5. Packaging process
Pad with pearl cotton and foam strips at the edges to reduce transportation shaking and friction; do not pack too tightly during packaging.
III. Quick conclusion
The root cause of scratches: soft aluminum + rough card paper + close friction
The simplest solution: Place the aluminum ring in a bag + add an intermediate layer of copy paper, with almost no increase in cost, and immediately solve the scratches.