Quick answer: Four numbers decide the comparison: unit price, minimum order, cycle count and what survives a one metre drop. A paper box costs 1.2 CNY at 500 pieces, a PP case 3.8 CNY at 3,000, tinplate 5.6 CNY at 2,000, a fabric pouch 2.4 CNY at 300. Below 50 openings a year, do not buy the plastic.

Table of contents

  • Unit Cost Against a Paper Box
  • Where Fabric and Tinplate Win
  • Four Cases That Rule Out the Plastic Box
  • Four Numbers in One Table
  • FAQ

1. Unit Cost Against a Paper Box

Unit price is the easiest number to misread. For the same 130 by 90 by 35 mm volume, a three-wall corrugated box costs 1.2 CNY, a PP injection case 3.8 CNY, tinplate 5.6 CNY and a polyester pouch 2.4 CNY. The spread is 4.7 times.

The gap comes from tooling. A paper box runs on an existing die at 500 pieces with no mould cost. A Small Plastic Case needs a tool first: about 11 CNY per part across 3,000 pieces, down to 1.1 CNY at 30,000. Its price is a function of quantity; a carton's price is a function of paper.

A low unit price is not a low total.

MaterialUnit priceMinimumCyclesCost per cycle
Three-wall carton1.2 CNY50011.2 CNY
Polyester pouch2.4 CNY300600.04 CNY
PP case3.8 CNY3,0003000.013 CNY
Tinplate box5.6 CNY2,000250.22 CNY
ESD PP case9.5 CNY3,0005000.019 CNY

2. Where Fabric and Tinplate Win

Fabric and tin are not the budget version of a plastic box; each owns a stretch the others cannot enter.

Small Plastic Case: white body open on a steel bench, black lid gasket, four clear trays and kraft envelopes inside, grey egg-crate foam, ribbed walls
Small Plastic Case: white body open on a steel bench, black lid gasket, four clear trays and kraft envelopes inside, grey egg-crate foam, ribbed walls
  • Pouch: folds to 0.3 litres for a tool bag pocket, a 0.8 mm lining that will not scratch polished parts, 60 washes without fading. The cost is 3 percent moisture pick-up in 24 h, so a desiccant goes in.
  • Tinplate: 0.23 mm sheet, moisture transmission under 0.1 g per square metre per day, lithography printed straight onto the metal. The cost is 118 g of dead weight and a 3 mm dent that never comes back.
  • Carton: samples in 7 days, unlimited print, lowest cost. The cost is one trip, after which a wet corner goes soft.
  • Small Plastic Case: rebounds from a one metre drop, runs 300 cycles. The cost is the tool and a 3,000 piece minimum.

3. Four Cases That Rule Out the Plastic Box

Under 50 openings a year, price the carton before a Small Plastic Case. Below 1,000 pieces, a 1.2 CNY carton beats a case whose tool alone spreads to over 30 CNY per unit at that volume.

If contents must be read through a closed lid, a clear PS or PET folded box does it for 2.6 CNY.

Static-sensitive parts meet an insulator: plain PP sits near 10^16 ohm surface resistance. Conductive PP pulls that to 10^4 to 10^6 ohm, and the price steps from 3.8 to 9.5 CNY.

At a constant 130 C, PP creeps under load and a lid warps within six months. That slot belongs to tinplate or 0.8 mm stainless.

For gifting and display, the industrial look of a moulded case works against you.

One-hand opening plus IP67 is a contradiction: a four-latch box cannot be opened with one hand.

4. Four Numbers in One Table

The four numbers are unit price, minimum order, cycle count and post-drop condition. Skip one and the answer flips.

Small Plastic Case: white body half open on a galvanised rack, lid raised about thirty degrees, three front latches, two side handles, dark inserts inside
Small Plastic Case: white body half open on a galvanised rack, lid raised about thirty degrees, three front latches, two side handles, dark inserts inside
MaterialCyclesAfter a 1 m drop
Three-wall carton1Corner crushed, load shifts 8 mm
Polyester pouch60No cushion of its own
Tinplate box25Dented 3 mm, no recovery
PP case300Rebounds, load shifts 2 mm
ESD PP case500Same as the PP case

Run the arithmetic on an eight-person crew: 40 cases opened 260 times a year, 780 over three years. A PP case rated at 300 cycles is replaced three times, so material costs 456 CNY. A carton swapped weekly takes 156 units and 187 CNY. Paper looks half the price until repacking enters: 40 cases take 6 minutes, so 156 rounds consume 15.6 hours, adding 702 CNY at 45 CNY an hour and reversing the total. A 2.6 CNY price gap against a 700 CNY labour gap is why the numbers are read together. What put the Small Plastic Case on the shelf was never cheapness; it was the repacking it removes.

Flip it: a display sample opened 12 times a year is won by paper or fabric, never plastic.

Conclusion

The number most often misread is cycle count: it turns a 3.8 against 1.2 CNY price gap into 1.3 fen against 1.2 CNY per use. Cycle count only counts once labour joins it, because six minutes of repacking costs more than the box. A Small Plastic Case earns its place in one situation: frequent opening, occasional dropping, no appetite for repacking every week. Remove them and the job belongs to paper, fabric or tin.

This article discusses only the container (case body) side of specifications and design intent, and does not cover any handling, loading or use of the contents.

Related Reading

Related Products