Large Part Injection Molding — Molds Built In-House, Pressed Up to 3300T
You need a large part molded right on the first trial. KTM builds the mold in our own shop and runs it on presses from 90T in-house up to 3300T through a long-term partner network — all under our own project and dimensional control. Full DFM, Moldflow, and inspection reports reach you before you commit a dollar to steel. The factory is run day to day by a mold-design engineer with 20+ years on large-part.
- ✓Presses 90–3300T — molds built and project-managed by KTM
- ✓2-color, 3-color, and gas-assist tooling for large parts
- ✓Custom cooling and checking fixtures to control large-part warpage
- ✓DFM, Moldflow & CMM reports on every large mold
- ✓ISO 9001 · founder-led · 20+ years in mold engineering
Our Large Part & High-Tonnage Capabilities
Engineers check one thing first: can the press clamp the part? Here is the honest model. KTM builds every mold in-house, then matches it to the right press — ours or a vetted partner's — under our own scheduling and inspection. You deal with one team, not a chain of subcontractors.
In-House Presses (90–400T)
40 injection machines from 90T to 400T, each fitted with a robot for unattended 24-hour runs. This covers mid-size large parts and keeps full production control in one.
High-Tonnage Network (450–3300T)
Press tonnage
450 / 600 / 800 / 1000 / 1300 / 1600 / 2100 / 3300T
3300T projected area
4.5 – 6.5 m²
Max single-side dimension
2.0 – 2.5 m
Shot weight
10,000 – 30,000 g
This range covers structural panels, large enclosures, and oversized industrial parts beyond standard.
Multi-Shot & Gas-Assist Equipment
- 2-color machines — two materials or colors in one cycle
- 3-color machines — multi-material large parts without secondary assembly
- Nitrogen gas-assist — hollow sections in thick large parts
The mold is ours and the press is matched to your part. That clarity matters most once you see the engineering problems large parts.
When You Need Large Part / High-Tonnage Molding
You already know what injection molding is. The real question is where your part crosses into large-part territory, and which failure modes appear.
What Counts as a Large Part
A part moves into the large or high-tonnage category when one of these is true:
- Projected area pushes required clamp force past 400 tons
- Flow-length-to-wall ratio runs long enough to risk short shots
- A single dimension exceeds roughly 1 meter
Past those thresholds, three problems decide whether the program launches on.
Warping on Large Flat Parts
On large flat parts, warpage starts with geometry — uneven wall thickness, long unsupported spans, rib layout — then uneven cooling. We predict it in Moldflow, design balanced cooling circuits, and build checking fixtures that hold the part flat while it stabilizes after.
Sink Marks, Weld Lines & Flash
| Problem | Root cause | KTM control |
|---|---|---|
| Sink marks | Thick ribs and bosses | Wall-thickness DFM, gas-assist |
| Weld lines | Multi-gate fill on long flow paths | Gate and runner optimization |
| Flash | Low clamp force, poor mold fit | Clamp-force calc + precision fitting |
We size clamp force and fit the mold before the first shot. The next section shows how that risk gets removed before T1.
How We De-Risk Your Large Part Project
Large molds are costly to correct after the steel is cut. So the risk moves to the front, where a change costs hours instead of weeks. Every large part plastic injection molding program runs the same.
Preliminary DFM at quote
We review your 3D file and return early feedback on wall thickness, draft, gate options, and tonnage fit. No charge.
Detailed DFM after PO
A full report covering parting line, ejection, shrinkage, and shutoff for your exact geometry.
Moldflow on complex parts
For large flat panels and multi-gate parts we predict fill, weld-line position, and warpage. Simple parts skip it, so you don't pay for analysis you don't need.
Custom checking fixtures
Large housings warp to some degree; we build fixtures to hold and verify them, so flatness is controlled, not hoped for.
T1 trial report
First-shot sampling comes documented: shot conditions, dimensions, and any corrective action.
Inspection matched to the feature
CMM for what fits it; pin and plug gauges, thickness and go/no-go gauges, calipers, micrometers, height gauges, and optical comparators for the.
Not sure your part fits a 1000–3300T press? Send the 3D file — we'll return an honest feasibility check and preliminary DFM.
Request a Free Review →Large 2-Shot & Gas-Assist for Big Parts
Two processes separate a capable large-part molder from a basic one. We run.
Large 2-Shot / Two-Color Molding
- Combines two colors or materials in a single part
- Removes a secondary bond or assembly step
- Trialed on a 2100T press for large two-color automotive parts
- Eliminates a tolerance stack on Class-A surfaces
Gas-Assist for Large Parts
- Cuts sink marks on thick ribs, handles, and bosses
- Reduces part weight and resin cost
- Lowers required clamp force on large projected areas
- Improves flatness on long structural sections
Materials for Large Molded Parts
Material choice decides whether a large part stays flat, carries load, and survives service. These are the resins we run most for large part plastic injection molding, with applications we've actually.
| Material | Where it fits on large parts |
|---|---|
| PC | Covers and enclosures needing impact strength |
| PC/ABS | Electronics housings balancing toughness and finish |
| ABS | Cosmetic enclosures and large housings |
| PP | Automotive parts and chemical-resistant components |
| HDPE | Rugged handling and containment parts |
| POM | Wear surfaces and dimensionally stable mechanical parts |
| PA6/PA66+GF | Glass-filled stiffness and warp control on flat parts |
| PEEK | High-temperature, high-load components |
Glass-filled and engineering resins do the heavy lifting on large structural parts, where unreinforced plastic would bow or creep. If your drawing calls a grade not listed, send it — material matching is part of the DFM review.
How these resins perform shows up clearest across the industries we serve.
Industries That Rely on Large Molds
Large tooling concentrates where part size, structural load, or volume rule out smaller presses. If your part lives in one of these, you're in familiar territory for.
Automotive
Bumpers, grilles, spoilers, instrument panels, door panels, front-end modules, headlamp housings
Aerospace
Cabin ceiling and overhead-bin panels, ventilation ducts and distributors, structural seat brackets, navigation light lenses
Consumer Electronics & Home Appliances
Refrigerator doors and drawers, washing-machine inner/outer tubs, AC air-guide louvers, large TV bezels, range-hood covers
Energy Storage & Solar
C&I storage enclosure panels, battery protection housings, inverter cabinets, combiner-box shells
Logistics & Warehousing
Plastic pallets, foldable crates, automotive parts bins, IBC bases, heavy-duty storage totes
Medical & Environmental
MRI/CT equipment covers, hospital bed head/foot boards, sharps and clinical-waste containers, exhaust-scrubber panels
See your part type above? Send the 3D file and we'll return a free preliminary DFM with an honest tonnage call — before you spend on.
Request a Free DFM →Why Engineers Trust KTM on Large Tooling
A small mold forgives mistakes. A large mold does not — a misjudged gate or cooling layout means scrapped steel, not scrapped shots. Two things carry a large program: inspection built for the part's size, and a technical decision-maker who owns the.
Inspection Sized for Large Parts
Measuring a 50mm bracket and a 1.8m panel are not the same job. On large parts the risk shifts to flatness drift, long-axis dimensional creep, and weld lines that surface only after the cavity fully.
- Large-envelope Inspection — full-coordinate measurement across long, wide parts, not just sampled corners
- Feeler gauges on large flat panels — we measure the actual deformation, then adjust the custom holding fixture to pull the part back to spec
- T1 trial report sized to the part — first-shot dimensions, short-shot and weld-line checks logged against the mold number
Every reading traces to a part number and mold number under our ISO 9001 system, so a program you reopen in two years still has its full history — and re-orders without re-qualifying the.
One Engineer Owns the Call
At KTM the hard decisions sit with our founder, who holds a degree in mold design and manufacturing and has spent 20+ years on the floor. When you raise a warpage or fill question, the answer comes from someone who has cut the.
- Engineer-to-engineer contact — your project engineer works in clear English and stays until 20:00 local time to overlap North American and European hours
- A price that holds — the quoted mold price is what you pay; if you revise the drawing, any cost change is quoted and approved by you first
- Long retention — several large-part customers have run with us for 6, 10, and 15+ years
A few questions come up on nearly every first large-part call, so here they are answered directly.
Large Part Injection Molding FAQ
Can you produce a part as large as mine? ▼
How do you control warpage on large flat parts? ▼
Can you do large two-color or 2-shot parts? ▼
Do you provide DFM and Moldflow reports? ▼
What is the typical T1 lead time for a large mold? ▼
Will the price change mid-project? ▼
How do you handle the time-zone and language gap? ▼
Once these are settled, the fastest next step is a feasibility check on your actual part.
Get a Free Large-Part DFM Review
Send your large-part 3D file. You'll receive a free preliminary DFM and an honest tonnage recommendation — the press class your part needs, plus any warpage or fill risk we see before tooling.