P-04 / Presses
Equipment and capacity
Injection molding presses and press tonnage estimator
Chang-Hao has 10 injection molding presses: one 80-ton, two 100-ton, one 140-ton, one 180-ton, one 260-ton, one 280-ton, one 500-ton and two 850-ton machines.
With the estimator below you can choose a resin, enter the part size and number of cavities, and see the press tonnage range recommended by resin makers, with the presses that have enough force marked.
By 昌昊興業 (Chang-Hao) · Updated
01 / Presses
Press specifications
By tonnage, 10 presses in total: five from 80 to 180 tons, three from 260 to 500 tons and two at 850 tons. The table lists shot weight, tie-bar spacing, mold height and other specifications for each press.
| Press tonnage | Presses | Brand | Shot weightg / oz | Injection pressurekg/cm² | Screw diametermm | Tie-bar spacingmm | Platen sizemm | Mold heightmm | Opening strokemm |
|---|---|---|---|---|---|---|---|---|---|
| 80 t | 1 | 精機 | 30 / 1.2 | 2,404 | 22 | 410 × 360 | 580 × 530 | 150 to 380 | 320 |
| 100 t | 2 | 精機 | 56 / 2.0 | 2,490 | 28 | 410 × 410 | 580 × 580 | 150 to 430 | 360 |
| 140 t | 1 | 精機 | 138 / 4.9 | 1,968 | 36 | 460 × 460 | 600 × 660 | 150 to 450 | 400 |
| 180 t | 1 | 精機 | 242 / 8.5 | 1,487 | 46 | 510 × 510 | 720 × 720 | 200 to 500 | 470 |
| 260 t | 1 | 精機 | 312 / 11 | 2,250 | 46 | 615 × 615 | 890 × 865 | 250 to 700 | 580 |
| 280 t | 1 | 精機 | 601 / 21.2 | 2,065 | 55 | 605 × 605 | 820 × 820 | 250 to 650 | 580 |
| 500 t | 1 | 琮偉 | 1,601 / 56.04 | 2,369 | 75 | 820 × 820 | 1,190 × 1,190 | 300 to 900 | 800 |
| 850 t | 2 | 琮偉 | 4,031 / 142 | 1,613 | 110 | 1,100 × 1,000 | 1,570 × 1,470 | 500 to 1,200 | 1,025.5 |
| Total | 10 | ||||||||
Presses at the plant
Injection molding machine JW-850CF Injection molding machine 500SD LCH-180 with take-out robot LCH-140 with take-out robot
02 / Tonnage
Press tonnage estimator: which press does your part need?
The press tonnage needed is roughly the projected area times the value recommended for the resin. Projected area is the whole area under injection pressure: all cavities plus the runners, projected onto the platen plane.
Choose a resin, set the part length and width and the number of cavities; the estimator shows the recommended tonnage range and marks the Chang-Hao presses with enough force.
- Projected area
- 616 cm²
- Recommended press tonnage
- 174 to 260 t
- Enough
- Within the recommended range; depends on wall thickness and flow length
- Not enough
Presses with enough force: 260 t, 280 t, 500 t, 850 tMore than Chang-Hao’s largest press (850 t)
03 / Resin makers
Press tonnage recommended by resin makers
The estimator uses the tonnage per square inch of projected area recommended in resin makers’ processing guides. The guides state “tons”; the converted column treats them as US short tons (1 ton = 907 kg) and shows metric tons.
| Resin | Resin maker (per in²) | Converted (per cm²) | Source |
|---|---|---|---|
| PP (polypropylene) | 2 | 0.28 | INEOS, Polypropylene Processing Guide |
| ABS | 2 to 3 | 0.28 to 0.42 | SABIC, CYCOLAC ABS Processing Guide |
| PC/ABS | 3 to 5 | 0.42 to 0.70 | SABIC, CYCOLOY PC/ABS Processing Guide |
| PC (polycarbonate) | 3 to 5 | 0.42 to 0.70 | Bayer (now Covestro), Makrolon 2405, 2407 and 2456 product information |
SABIC’s PC/ABS processing guide states that wall thickness, flow length and molding conditions determine the tonnage actually required; INEOS also notes that PP parts with integral hinges need at least 4 to 6 tons per square inch.
04 / Tool room
Tool room equipment
Mold components are machined in Chang-Hao’s tool room, which has EDM, milling, turning and surface grinding machines.
Mold makingFAQ
Equipment and press tonnage questions
- What is press tonnage?
- The force a press uses to hold the two mold halves shut. If the tonnage is too low, the plastic forces the mold open and flash forms; INEOS’s guide lists insufficient clamp pressure as one cause of flash.
- How much press tonnage does an ABS part need?
- SABIC’s CYCOLAC ABS processing guide recommends 2 to 3 tons per square inch of projected area, about 0.28 to 0.42 metric tons per cm².
- How is projected area calculated?
- It is the whole area under injection pressure: all cavities plus the runners, projected onto the platen plane. For a multi-cavity mold, multiply by the number of cavities.
- How accurate is the estimator?
- It is an estimate. SABIC’s PC/ABS processing guide states that wall thickness, flow length and molding conditions determine the tonnage actually required; Chang-Hao confirms the press after seeing your drawing or sample.
- How large a mold fits the biggest press?
- The 850-ton presses have a tie-bar spacing of 1,100 × 1,000 mm, a platen size of 1,570 × 1,470 mm, a mold height of 500 to 1,200 mm and a shot weight of 4,031 g (142 oz).
Send a sample or drawing for a quote
Please send a sample or drawing of your part. We confirm the details and then send a quote.