How do I match plastic products factory tonnage to my part?

Answer: Projected area times cavity pressure: 2,604 square centimetres at 300 kg needs 781 tonnes, so specify a 1,000 tonne press.

Can a plant without IATF 16949 supply automotive parts?

Answer: As tier two, yes; not as tier one, which needs the certificate plus PPAP, and a waiver adds weeks.

What should be ready for a two day audit?

Answer: First-off sheets, patrol logs, retained samples, incoming reports, machine and mould registers; half the 42 items test dates.

Is a sampling charge normal?

Answer: Yes. CNY 800 for three parts, usually credited above 5,000 units; free samples queue behind paid work.

Can tooling cost be folded into the unit price?

Answer: It can. CNY 80,000 across 20,000 units adds CNY 4; below 8,000 units the spread adds over twenty percent.

Plastic Products Factory: 5 Checks Before You Order

Quick answer: Judge a plastic products factory on five points: clamp tonnage against projected area, mould list and changeover time, certificate scope, four record sets at audit, then sampling and a cost breakdown. A 620 x 420 mm case needs 781 tonnes of clamp force, so a plant capped at 550 tonnes cannot mould it.

Five Checks a Plastic Products Factory Must Pass
Check One: Tonnage Against Projected Area
Check Two: Mould List and Changeover
Check Three and Four: Certificates and the Audit Walk
Check Five: Sampling, Quoting and Lead Time
FAQ

1. Five Checks a Plastic Products Factory Must Pass

Showroom samples prove little; part fifty thousand is the real test.

Each check answers one question: tonnage sets the largest part, moulds set scheduling, certificates set which industries you reach, the audit sets whether paperwork is real.

Check	Evidence	Vague answer
Tonnage	machine register	we can make anything
Moulds	mould list, changeover log	plenty of moulds
Certificates	number and scope	we have them all
Records	first-off sheet, patrol log	management is solid

A plastic products factory running twelve presses from 90 to 1,000 tonnes covers bodies from 200 to 780 mm; one capped at 250 tonnes cannot hold a 620 mm tool.

2. Check One: Tonnage Against Projected Area

Bigger is not better; tonnage must match projected area. Too little clamp force flashes the part, too much wastes hours: area times cavity pressure, plus twenty percent.

Plastic products factory: black case open upright, blue lining in the lid, black foam holding a screened meter, two modules and a metal rod

A 620 x 420 mm case projects 2,604 square centimetres; at 300 kg per square centimetre it needs 781 tonnes, so a 1,000 tonne press keeps 22 percent in reserve while a 550 tonne one flashes.

A plastic products factory quoting capacity is really quoting effective hours. Two-up on a 550 tonne press at a 68 second cycle gives 2,320 parts a day over 22 hours, about 60,000 a month.

3. Check Two: Mould List and Changeover

The mould list says more about a plastic products factory than the machine list. A 620 mm tool costs CNY 80,000, and steel grade sets life: 718 for 300,000 shots, 2738 for 500,000.

Press	Usable projected area	Typical body
250 t	0.08 sq m	320 x 250 mm
550 t	0.18 sq m	480 x 360 mm
1,000 t	0.33 sq m	620 x 420 mm

Changeover decides whether small orders are welcome. Quick-release swaps a mould in 40 minutes; bolted clamps take three hours, so three swaps a day costs seven hours of output.

4. Check Three and Four: Certificates and the Audit Walk

Read the scope, not the logo. ISO 9001 covers a quality system, not product performance; RoHS and REACH target substances and reports expire yearly; IATF 16949 matters only for automotive work.

Plastic products factory: corner close-up in white, pale grey foam cut with a round counterbore and a groove, bead texture visible along the rim

An audit runs two days over 42 items and rarely starts in the filing cabinet: signed first-off sheets, patrol inspection every two hours, samples from three months back, resin bag numbers matching issue slips.

Check the test bench: a plastic products factory cycling parts from minus 20 to 60 C over 48 hours can take winter transport work.

5. Check Five: Sampling, Quoting and Lead Time

Sampling filters suppliers faster than meetings: a free sample drifts three weeks, a paid one at CNY 800 lands in seven days because the schedule has a slot.

Stage	Time	Cost	Delivered
Sampling	7 days	CNY 800	three parts
Tooling	25 days	CNY 80,000	first-off
Production	20 days	per unit	inspection record

Split the quote into resin, machine time, tooling and finishing. At 3.0 mm wall a 620 mm body weighs 2.6 kg, so resin costs CNY 23 at CNY 9 a kilo; a 550 tonne press at CNY 180 an hour adds CNY 4.8 a part. A lump sum hides which line carries the margin.

Lead time follows: 20 days standard colour, five more custom, 25 more for tooling. A plastic products factory that writes all three into the contract holds its schedule.

Conclusion

Run the five checks and the shortlist becomes evidence: 781 tonnes of clamp force, 718 or 2738 steel, a certificate number that resolves, four record sets whose dates agree. Choosing a plastic products factory is a matter of records, not showroom size.

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.