Case Study: 8-Cavity 500 ml Square Container Mold

One machine producing about 115,000 pieces per day, with unit cost reduced to around $0.0145

By Zhang, Senior Sales Engineer at H T Mould

Product type: 8-cavity thin-wall PP 500 ml square container mold
Applications: takeaway meals, delivery containers, and food packaging (500 ml food container)
Customer region: large disposable food-container manufacturer in North China

1. Customer Challenge: Explosive Delivery Growth Turned Capacity into a Survival Issue

Last year, a customer in North China called us. They had been producing disposable meal boxes for eight years, mainly for major food-delivery platforms. Their first words were:

"Zhang, this is no longer about whether we buy a new mold. If we don't switch to a high-speed mold now, our competitors will take the orders."

Existing mold: 4 cavities, 11-second cycle, about 31,000 pieces per day
Order demand: 80,000-100,000 pieces per day on average, peaking at 120,000
Temporary workaround: three machines running together, even though the factory only had five presses in total, severely squeezing other products

Worse still, 11 seconds was already the limit of the old mold. Trying to go faster led to short shots, flash, and sticking.

The customer was very clear: one machine, more than 100,000 pieces per day, and a cycle time below 7 seconds.

I directly recommended one of H T Mould's flagship products: the 8-cavity 500 ml square container mold, running at a 6-second cycle on a 420T press.

2. Solution Core: How the 6-Second Cycle Is Achieved

The 500 ml square container is a high-volume takeaway product with intense market competition. Whoever can run the shortest stable cycle while Maintenanceing quality gains the biggest market advantage.

This 8-cavity mold is not simply a higher-cavity version of the old tool. The runner system, cooling, venting, and ejection were all redesigned as an integrated high-speed thin-wall injection system.

1. Process data (actual production)

Item	Value	Item	Value
Cavities	8 CAV	Cycle	6 s
Mold size	610×975×465 mm	Press	420 T
PP melt	310 °C	Cooling water	18–22 °C
Water pressure	0.5–0.6 MPa	Production yield	99.2%

2. What a 6-second cycle really means

Cooling: conformal channels plus high-pressure turbulent cooling, reducing cooling time to about 3 seconds
Runner system: symmetrical H-shaped layout with large hot-runner nozzles, cutting filling time to about 0.8 seconds
Ejection: rapid demolding with air assist, completed in under 0.5 seconds without sticking or whitening marks

3. Field data: ~115k pcs/day—one press replaces three

Daily output: ~115,000 pcs/24 h; steady 112,000–114,000

Yield: 99.2%; defect rate under 0.8% in steady run

Metric	Old (4 cavities)	H T Mould (8 cavities)
Daily output	~31,400	~115,000
Output vs baseline	1×	3.66×
Yield	96.8%	99.2%

4. Cost: piece cost at a surprisingly low level

Power: $0.0017/pc saved—$5,990.15/month
Labor: six fewer people—$5,208.83/month
Equipment: two presses avoided—$173,627.6 capex
Maintenance: $3,617.24 saved per million shots
Material: 6.5 g/pc saved—$25,957.33/month

5. Profit: one press can add a car’s worth per month

Item	Old	H T Mould
Daily output (pcs)	~31,400	~115,000
Total cost/pc (USD)	0.264	0.1803
Profit/pc (USD)	0.116	0.1997
Daily profit	$526.96	$3,322.8

+$2,795.84/day; ~$83,876.6/month
Mold investment $54,982.07—full payback in under 20 days

6. 3M shots guaranteed; 5–6M is normal with care

We warrant 3 million shots; with routine maintenance 5–6 million is typical.

This customer is at 2.8M shots with excellent condition. At 5.5M shots amortized, mold cost per part is only $0.0012.

7. Customer voices (edited from interviews)

“I didn’t believe 6 s at first. At first trial I timed it—really 6 s, eight parts dropped clean—I signed that day.”
“What shocked me was resin savings. We used to have mountains of scrap; now almost none—~$26,044.14/month on material alone.”
“Eight months, 2.8M shots, not a single screw replaced. H T Mould quality—I respect it.”
— General manager, customer plant

8. How big is the 500 ml square box market?

Nationwide takeaway uses over 200 million boxes daily; 500 ml squares are ~35%—~70 million/day. At 115k pcs/day per machine, scale matters.

9. Who is this mold best for?

500 ml square demand ≥80k/day
Current cycle >8 s or fewer than six cavities
High resin share or scrap over 5%
Limited presses—need maximum output per machine
Expanding share in takeaway packaging

Closing

6 s × 8 cavities × 24 h = 115k pcs/day

Cost ~$0.026, sell ~$0.055—~$3,327.86/day profit per press

H T Mould—helping you outrun the competition in takeaway containers.