Charcoal buyer test guide
Charcoal Briquette Drop Test Guide
Define exactly what is dropped, how it falls, what it hits, how often it is repeated, and how damage is classified. Then report product breakage and packaging damage separately.
Define the unitControl the impactMeasure the result
The first decision
Name the object being tested before choosing the height.
A loose briquette test asks about direct impact resistance. A filled inner pack, retail box, or master-carton test asks how the complete product-and-pack system handles impact. Those are related questions, not interchangeable results.
Do not report that “the charcoal passed” when only one hand-picked briquette survived an undocumented fall. That is a stunt with gravity, not a procurement method.
Four test units
Choose the unit that matches the handling risk.
Keep results in separate lanes. Packaging may protect a weaker piece, while a strong piece may still arrive damaged inside a loose or poorly restrained pack.
Loose briquette
Question: Can one identified piece tolerate a defined direct impact?
Control: Record shape, dimensions, mass, condition, orientation, impact surface, height, and number of drops for each piece.
Limit: It does not measure protection from an inner pack, carton, stacking, vibration, or transit handling.
Filled inner pack
Question: Do the briquettes and immediate pack survive a handling event together?
Control: Use the intended count or net mass, fill pattern, headspace, liner, seal, and product orientation—not a loosely filled substitute.
Limit: It does not establish the performance of the retail box or master-carton system.
Retail box
Question: Does the sale unit restrain and protect its contents after defined drops?
Control: Test the production-intent box, closure, inner liner or pouch, dividers, net weight, and orientation markings.
Limit: A retail-box result cannot be stretched into a container-shipping guarantee.
Master carton
Question: Does the complete shipping unit protect all packed sale units under the agreed sequence?
Control: Use the actual carton grade, closure, packed weight, internal arrangement, number of units, void treatment, and conditioning history.
Limit: A drop test is one controlled impact screen; it does not reproduce every vibration, compression, humidity, transfer, or unloading event.
Drop-test worksheet
Record these seven fields for every test unit.
Write the method before the drop. If the rule is invented after seeing the debris, the test has already failed—regardless of what the charcoal did.
Sample ID, batch or lot, product and grade, geometry, dimensions, unit mass, pack version, test-unit number, and date.
Prevents a clean report from becoming detached from the material it supposedly describes.
Storage and conditioning time, temperature and humidity where relevant, pack integrity, visible cracks, existing chips, dust, and photographs.
A pre-cracked or moisture-affected sample can fail for reasons that began before the drop.
Loose piece, inner pack, retail box, or master carton; piece count, net mass, gross mass, fill arrangement, closure, and headspace.
Changing the tested object changes the question and the forces reaching each briquette.
Measured release height, reference point, free fall, release method, impact surface material and condition, and safety perimeter.
A hand-thrown pack and a guided free drop are not the same exposure, however similar the video looks.
Face, edge, corner, briquette end, briquette side, order of impacts, repetitions, and whether the same or fresh unit is used.
Damage accumulates; sequence and orientation can dominate the final breakage result.
Opening method, collection tray, material lost, whole pieces, chipped pieces, broken pieces, fragments, fines, pack damage, and photographs.
Rough opening or incomplete recovery can manufacture damage—or quietly make dust disappear.
Count or mass basis, denominator, category definitions, rounding, individual results, summary statistic, retest rule, and pass/fail boundary.
A percentage without a fixed denominator and category rule is decorative mathematics.
Orientation and sequence
Face, edge, corner, end, and side are different impacts.
Face drop
Method: The broad panel or flat briquette face strikes first.
Purpose: Screens panel compression, broad impact transfer, and product contact inside the pack.
Edge drop
Method: A specified long or short edge strikes first.
Purpose: Concentrates force and can expose weak seams, loose restraint, and edge chipping.
Corner drop
Method: One identified carton or box corner strikes first.
Purpose: Often stresses several panels and closures at once; corner identity must be recorded.
End or side drop
Method: A loose elongated briquette lands on its end or side.
Purpose: Separates geometry-dependent fracture behavior that a random toss would hide.
Repeated sequence
Method: The same unit receives an agreed series in a fixed order.
Purpose: Measures accumulated damage but cannot be compared with fresh-unit single drops.
Fresh-unit replicate
Method: A new equivalent unit is used for each orientation or repeat.
Purpose: Separates orientation effects from cumulative damage when enough samples are available.
Post-test classification
Define the bins before counting what survived.
Use measurable thresholds where the commercial channel needs them. Keep product damage, dust recovery, material loss, and packaging failure visible as separate outcomes.
Whole / intact
Meets the pre-agreed minimum length, mass, or visual condition and remains usable for the intended channel.
Chipped
Still substantially intact but has edge or end loss beyond the defined cosmetic allowance.
Broken
Separated into two or more pieces or falls below the agreed intact threshold.
Fragments
Pieces below the broken-piece threshold but above the fines screen or particle definition.
Fines / dust
Material passing the agreed sieve or meeting a written small-particle definition; recovery method must be stated.
Packaging damage
Tears, seal opening, panel crushing, puncture, closure failure, or loss of containment—reported separately from product breakage.
Calculation and evidence limit
Report the denominator—and do not turn one impact screen into a shipping guarantee.
On a mass basis, a category percentage is the recovered mass in that category divided by the stated pre-test or recovered mass basis, multiplied by 100. On a count basis, it is the number of pieces in the category divided by the stated initial or recovered piece count, multiplied by 100. State which denominator controls, how fines are recovered, and how lost material is handled.
Keep individual-unit results beside averages. A master carton with one catastrophic inner pack should not disappear inside a handsome mean. Define sampling, rounding, retest, concession, and rejection rules before testing.
A controlled drop test can compare designs and expose weak restraint or closures. It does not simulate the complete logistics route and does not prove that an untraced sample represents a commercial lot. Confirm the order-specific product, pack, protocol, acceptance rule, and controlling evidence with Unimax.
Drop-test FAQ
Control the impact before interpreting the breakage.
A repeatable method makes supplier, packaging, and arrival discussions far less theatrical.
01What is the correct drop height for charcoal briquettes?+
There is no honest universal height. Select it from the handling event being screened, the test unit, pack mass, relevant buyer or carrier requirement, and safety limits. Record the release reference point and surface so another party can reproduce the test.
02Should buyers drop individual briquettes or the complete package?+
Use the unit that matches the question. A loose-piece test screens direct briquette impact resistance; a filled pack or master-carton test screens the product-and-packaging system. Running both can be useful, but their results must remain separate.
03How should breakage be calculated after the test?+
Agree category definitions first, then use one basis—piece count or recovered mass—with a stated denominator. Report whole, chipped, broken, fragments, fines, material loss, and packaging damage separately rather than hiding everything in one number.
04Can a drop test predict arrival breakage after container shipping?+
Not by itself. It screens a defined impact sequence. Real logistics can add vibration, compression, humidity, temperature, transfers, load movement, unloading, and repeated handling. Use it with packaging review, loading controls, and representative arrival inspection.
05Should the same carton be used for every drop orientation?+
Only if cumulative handling is the intended method. If the goal is to compare orientations independently, use equivalent fresh units. Whichever design is chosen, state the sequence and do not compare cumulative and fresh-unit results as if they were identical.
06Does this guide state one Unimax drop-test guarantee?+
No. It is a buyer-side test framework. Confirm the exact product, pack configuration, conditioning, test sequence, damage definitions, sampling, acceptance rule, and controlling evidence for the proposed order.