If a recycled content case claims 30%, what measured value passes?

Answer: 28% to 32% on a ±2% band. Below 28% usually means the supplier quoted virgin pricing.

Can a 30% ratio case still pass a 1.2 m drop?

Answer: At room temperature yes, with 34 kJ/m² and corner marks only. At -20 °C impact falls to 12 kJ/m², so the drop height drops to 0.9 m or the wall goes to 3.4 mm.

Why does a recycled content case show colour variation?

Answer: The regrind base yellows, its index 6 units above virgin. Black hides ΔE 4.0, off-white shows ΔE 2.0, so one colour needs one washing line.

Can the odour be removed completely?

Answer: It presses to grade 1.5, not to zero. Devolatilising takes volatiles from 1.5% to 0.3%; grade 1 needs virgin resin.

How is RoHS retested when the lot is regrind?

Answer: One XRF screen per furnace lot, ICP for suspect lots, judged at 0.1% for the five restricted substances and 0.01% for cadmium.

How much cheaper is a recycled content case?

Answer: 8% to 15% on the resin bill, banded by ratio. A 30% ratio nets 6% and a 50% ratio nets 11% after the extra wall and cooling.

Recycled Content Protective Case: Ratio and Strength

Quick answer: A recycled content protective case stays usable to about 30% post-consumer resin, where notched impact falls 18% and tensile 8%. At 50% the impact value drops 35% and melt index swings 25%, so the ratio is fixed per part and locked by batch traceability.

PCR Ratios for a Recycled Content Case
Impact and Tensile Loss Across Three Ratios
Melt Index Shift, Wall Variation and Colour Drift
Odour, VOC and RoHS Retesting
Acceptance Clauses, Cost Gap and Grade by Part
FAQ

1. PCR Ratios for a Recycled Content Case

The question is never whether recycled content works, but at which ratio it still works. At 10% post-consumer resin in copolymer PP, a 3.0 mm lid keeps 39 kJ/m² against 42 kJ/m² virgin, with no drop or leak difference. At 30% it reads 34 kJ/m² with sink marks behind the latch bosses; at 50% it reads 27 kJ/m² and the 1.2 m drop crack moves to the handle root.

Source sets the starting point. Closed-loop sprue from the same moulder breaks the chain once, so molecular weight falls 5% to 8%. Municipal bales carry 3% to 5% PS and PET, pushing melt index from 8 to above 10 g/10min.

Ratio	Notched impact retained	Tensile retained	MVI swing	Colour ΔE	Resin price
10%	94%	97%	±8%	1.5–2.0	-3% to -5%
30%	82%	92%	±14%	3.0–5.0	-8% to -10%
50%	65%	86%	±25%	4.0–6.0	-12% to -15%

Retention compares against virgin control parts from the same tool: impact to GB/T 1843 on a 1eA bar, tensile to GB/T 1040.2 on a 1A dumbbell. The ratio column is mass fraction, and regrind scatter is already inside the retained figure.

2. Impact and Tensile Loss Across Three Ratios

The 30% band takes 8% to 10% off the resin bill while the loss stays explainable. At 23 °C, 34 kJ/m² survives a 1.2 m six-face drop; cooled to -20 °C the same batch reads 12 kJ/m² against 18 kJ/m² virgin, so the loss widens from 18% to 33%.

Recycled content protective case in off-white seen from above, gloss lid, two body-colour latches at the front lip, grey seamless backdrop

Tensile curves tell the same story: yield drops from 26 to 24 MPa, elongation at break from 320% to 210%, and the fracture turns brittle. A 3.0 mm wall under 500 N reads 4.2 mm deflection at 30% against 3.6 mm virgin. In the drop test a 30% recycled content case cracks at the corner on the third face, a 50% recycled content case splits 15 mm on the second.

Weld lines are the second weak point. With 3% foreign matter, weld strength falls to 45% of bulk against 62% virgin, and latch bosses on that line account for 7 of 10 drop failures at 30%. Moving the gate 40 mm away cuts it to 3 of 10. Five bars from a bale spread 3.5 kJ/m², so acceptance belongs on the lowest bar.

3. Melt Index Shift, Wall Variation and Colour Drift

A ±14% melt index swing changes fill-front speed, so one packing curve no longer holds one wall. On a 30% lid the corners measure 3.18 mm to 3.42 mm against 3.2 mm nominal, and ±0.3 mm eats the tolerance. At 50% sink marks run 0.15 mm to 0.25 mm deep.

Three compensations are standard: add 0.2 mm to the main wall, add 8 s to cooling so the slower crystallising fraction sets, and drop screw speed 15% to cut shear heat by 8 °C.

Compensation	Virgin	30% ratio	50% ratio
Main wall	3.0 mm	3.2 mm	3.4 mm
Cooling time	22 s	26 s	30 s
Screw speed	60 r/min	55 r/min	51 r/min
Packing pressure	55 MPa	60 MPa	66 MPa

Colour is hardest to hide. On the ISO 105-A02 grey scale, batch variation at 30% sits at grade 3 to 4, ΔE 3.0 to 5.0. Black with 1.5% carbon black passes at ΔE 4.0, off-white separates at ΔE 2.0. Clear regrind yellows to index 8, and 0.3% brightener pulls it back.

4. Odour, VOC and RoHS Retesting

Odour comes from incomplete washing. Ink and label adhesive survive 2 h at 60 °C, and the smell peaks within 24 h of moulding. Drying at 100 °C for 2 h plus 4 h of devolatilising at 80 °C drops volatiles from 1.5% to 0.3% and odour grade from 3 to 1.5.

Recycled content protective case in blue viewed from above, smooth lid, colour-matched latches, two hinge ears at the rear edge, white surface

RoHS risk sits in the source, not the formula. Shredded electronics housings bring lead and cadmium, judged per homogeneous material at 0.1% for lead, mercury, hexavalent chromium, PBB and PBDE, and 0.01% for cadmium. XRF only screens; a suspect lot goes to ICP, one report per lot.

Food-contact surfaces cannot take regrind, with no exception. A recycled content case sold as a catering tote needs virgin resin on the contact face and its own food-contact report; a shell that never touches food is free to carry regrind.

5. Acceptance Clauses, Cost Gap and Grade by Part

Four clauses cover acceptance: the PCR mass fraction and its source class, with ±2% deviation allowed on a 30% claim; a furnace lot tied to the moulded code; third-party reports, RoHS quarterly and impact plus tensile per batch; a first-article plaque at ΔE 3.0 or better.

The cost gap runs 8% to 15%, wider as the ratio rises. A 30% ratio takes 8% off unit cost, minus 2% for the thicker wall, leaving 6% net. A 50% ratio claims 15% and nets 11% once the tool and process are re-set for regrind.

Part	Ratio ceiling	Criterion
Non-structural shell and lid	30%	Notched impact ≥25 kJ/m² at 23 °C
Structural parts, hinge bosses	≤10%	20,000 open-close cycles, no crack
Latch bosses and inserts	0%	500 N pull-out without failure
Sealing face and groove	0%	-30 kPa held 5 min, drop ≤1 kPa

Conclusion

The ratio is the only number that can be negotiated and the only one that disqualifies a part. At 10% the case behaves like virgin, losing under 6%. At 30% it needs compensation: 0.2 mm more wall, 8 s more cooling, weld lines moved 40 mm. At 50% it belongs on non-structural shells, with latch bosses and sealing faces at 0% recycled content.

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.