Hot Runner Injection Molding Service

Zero waste. Faster cycles. Better parts. As a China-based hot runner injection molding manufacturer and supplier, YiguProto delivers factory-direct production solutions for high-volume plastic parts — with free DFM, tight tolerances, and quotes back in 24 hours.

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Hot runner injection molding system diagram showing heated manifold and nozzles
Hot runner system keeps plastic molten from machine nozzle to cavity gate — no runner scrap, faster cycles, cleaner parts.

The Problem We Solve

Tired of runner waste eating into your margins?

You need high-volume plastic parts that look clean, ship on time, and do not cost a fortune in scrap. Cold runner molds waste 15–30% of every shot on solid runners that must be trimmed, reground, or thrown away. Cycle times drag. Gate marks ruin cosmetic surfaces. And the wrong supplier adds weeks of delay.

With YiguProto as your China hot runner injection molding manufacturer and supplier, you get one accountable factory partner from first quote to final delivery — no middlemen, no surprises.

  • Zero runner waste — heated runners stay molten; material savings up to 30%
  • 20–30% faster cycles — no runner cooling time, parts eject ready to ship
  • Factory-direct pricing — we own the tool shop and molding floor, no markup chain
  • Free DFM review — engineers catch design issues before you spend on tooling
  • Clean gate marks — valve gate options for cosmetic A-surface parts
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What It Is

What Is Hot Runner Injection Molding?

A plain-English guide — no engineering degree required.

Think of a hot runner system like a heated pipe inside your mold. Instead of letting plastic cool and harden in the runner channels (the roads that carry melted plastic to each part cavity), we keep those channels hot with electric heaters and precision thermocouples.

The result? The plastic in the runners stays molten from one shot to the next. When the mold opens, only the actual parts are ejected — fully solid, clean, and ready to use. No cold plastic "trees" attached. No trimming. No wasted material.

A hot runner mold has two main heated parts:

  • The manifold — a heated block that distributes molten plastic from the machine nozzle to each nozzle drop, balancing flow so every cavity fills evenly.
  • The nozzles (hot drops) — heated tips that sit right at the gate of each cavity, delivering plastic precisely where it needs to go.

Each heating zone is controlled independently (typically within ±1°C), so we can tune temperatures for your specific resin and part geometry. That level of control is why hot runner systems deliver more consistent parts shot after shot, cavity after cavity.

Compare

Hot Runner vs. Cold Runner: Which Do You Need?

Not every project needs a hot runner. Here is a quick side-by-side to help you decide.

Factor Cold Runner Hot Runner
Material waste15–30% of every shot becomes runner scrapNear zero — >97% material utilization
Cycle timeLonger (runner must cool before ejection)20–30% shorter (no runner to cool)
Degating / trimmingRequired — manual or automated laborNone — parts drop ready to use
Part consistencyCan vary across cavities in unbalanced layoutsHighly consistent — balanced melt flow, precise temp control
Gate qualityVisible vestige; limited gate controlValve gate gives near-invisible marks for cosmetic parts
Upfront tooling costLowerHigher (heated components, controllers)
Best forLow volume (<50K/yr), prototyping, frequent color changesHigh volume (100K+ parts/yr), multi-cavity production, cosmetic parts
Typical ROIN/A (lower initial spend)Most projects break even within 6 months
Rule of thumb: If you are making more than 100,000 parts per year, using expensive engineering resins (PC, PA, PEEK, PPS), or need clean cosmetic surfaces, a hot runner mold almost always pays for itself quickly. Ask our engineers for a free cost analysis.

Why YiguProto

Your Trusted China Hot Runner Injection Molding Factory

We are not a trading company. We are the factory — with in-house mold making, injection molding, and quality inspection under one roof in Dongguan, Guangdong.

Factory-Direct Solutions

Work directly with the company that builds your mold and molds your parts. No broker markup, no miscommunication, faster problem-solving.

Fast Lead Times

T1 samples in 15–25 business days. Production ramp-up immediately after approval. Global shipping with tracking to your door.

Quality You Can Trust

ISO 9001 quality management, CMM inspection, FAI reports, and material certificates. Every batch is inspected before shipment.

Free DFM Engineering

Every quote includes a design-for-manufacturing review. We flag wall thickness issues, gate location problems, and cost-saving opportunities before you commit.

Full Service, One Partner

From mold design and prototyping to mass production, surface finishing, and assembly — one supplier manages the whole project. Less admin, fewer delays.

IP Protection & NDA

Your designs, files, and product ideas are kept strictly confidential. We sign NDAs and maintain secure file handling throughout every project.

System Options

Two Hot Runner Gate Types — Which Fits Your Part?

We design and build both main hot runner styles. The right choice depends on your part's appearance needs, material, and budget.

Open Gate (Thermal Gate)

Cost-effective • High-volume • Simple design

An open gate (also called a thermal or hot-tip gate) has no moving parts. Plastic flows through a heated nozzle tip. When injection stops, a small plug of plastic freezes at the gate and is blown out on the next shot.

Best for:

  • High-volume, non-cosmetic parts (internal components, industrial parts)
  • Projects where upfront tooling budget matters
  • Standard resins like PP, PE, ABS, PS
  • Multi-cavity molds where simplicity reduces maintenance

Valve Gate

Premium finish • Precise control • Cosmetic parts

A valve gate uses a mechanical pin (actuated by pneumatic, hydraulic, or servo power) that opens and closes the gate at precise times. The pin physically shuts off plastic flow when the cavity is full.

Best for:

  • Cosmetic / visible A-surface parts (near-invisible gate mark)
  • Medical, automotive, and consumer electronics housings
  • Engineering resins (PC, PA, PBT, POM, glass-filled materials)
  • Sequential gating for large parts or family molds
  • Tight tolerance parts where shear stress must be controlled

Not sure which gate type your project needs?

Ask an Engineer — Free Consultation

Benefits

Why Hot Runner Molding Saves You Money

The headline numbers that matter to your bottom line.

97%+

Material Utilization

Almost no runner scrap. Big savings on expensive resins like PC, PA, PEEK, PBT.

20-30%

Faster Cycles

No runner cooling time = more parts per hour, lower per-piece cost.

±0.02mm

Tight Tolerance

Precise temperature and pressure control means consistent, dimensionally accurate parts.

~6 mo

Typical ROI

Most high-volume projects recover the tooling premium within six months through waste and time savings.

Beyond the numbers, hot runner molding removes several headaches from your production line:

  • No degating labor — parts eject without runners attached, so there is nothing to trim or separate by hand.
  • Better automation compatibility — because every shot produces clean parts, robots can pick and pack directly from the mold.
  • Less regrind variation — mixing regrind back into virgin material causes color and property shifts. With no runners, every shot is consistent virgin resin.
  • More cavities per mold — hot runner manifolds can feed many cavities evenly, letting you scale up output without adding machines.

Applications

Industries & Parts We Serve

Our hot runner injection molding solutions support customers across a wide range of sectors.

Automotive

Interior trims, connectors, housings, brackets, dashboard components, lighting parts — glass-filled PA, PP, ABS, PC/ABS.

Medical & Healthcare

Syringe components, diagnostic housings, pipette tips, surgical device parts — cleanroom-compatible valve gate systems for COC/COP, PP, PC.

Consumer Electronics

Phone cases, charger housings, connector shells, enclosures, keyboard parts — cosmetic valve gate finishes in PC, ABS, PC/ABS, PA.

Packaging & Caps

Bottle caps, closures, thin-wall containers, lids — high-cavity hot runner molds for PP, PE, PS running at ultra-fast cycles.

Home & Household

Appliance parts, kitchenware, storage containers, garden tools, furniture components — cost-effective open gate for high-volume PP, PE, ABS parts.

Industrial & New Energy

Connectors, sensor housings, battery components, gear housings — engineering resins PA, PBT, PPS, PEEK with glass fiber reinforcement.

Materials

Materials We Process in Hot Runner Molds

We work with a full range of thermoplastics. Our engineers match nozzle type, temperature profile, and gate design to your material.

ABS
PC (Polycarbonate)
PP (Polypropylene)
PA / Nylon (6, 66)
POM (Acetal)
PMMA (Acrylic)
PBT
PEEK
PE / HDPE / LDPE
PS / HIPS
TPE / TPU
Glass-Filled Resins

Need a material not listed? Ask us — we work with many specialty and engineering-grade compounds.

Capabilities

Hot Runner Injection Molding Capabilities at a Glance

Real factory specs so you can plan your project with confidence.

SpecificationCapability
Runner system typeHot runner (open thermal gate & valve gate available)
Gate optionsOpen gate (hot tip), valve gate (pneumatic / hydraulic), edge gate, sub gate
Cavity count1 to 96 cavities (custom manifold design)
Part weight range0.1 g to 3,000 g
Tolerance±0.02 mm (on critical dimensions, material-dependent)
Maximum part sizeUp to 800 mm × 600 mm
Mold base materialS50C, P20, 718H, NAK80, S136, H13 (per project requirements)
Mold life300K–1,000K+ shots (steel grade dependent)
Surface finishesSPI-A1 to SPI-D2, texture (VDI/MT), polishing, painting, plating, silk screen
Mold lead time (T1)15–25 business days
Production lead time7–15 business days after sample approval (quantity dependent)
Machine tonnage50T–650T injection molding presses
Color optionsCustom color matching (Pantone / RAL); masterbatch or pre-colored resin

How It Works

From CAD File to Shipped Parts — Our Simple Process

Getting started with YiguProto is straightforward. Here is what happens step by step.

1

Send Your Design

Upload your 3D CAD files (STEP, STP, IGES, X_T) or 2D drawings. Tell us your material, quantity, finish, and timeline.

2

Get Quote + Free DFM

We review your design for manufacturability and send an itemized quote within 24 hours — including mold cost, piece price, lead time, and DFM feedback.

3

Approve & We Build the Mold

Once you approve the quote and pay the tooling deposit, our tool room starts building your hot runner mold. You get T1 sample shots for approval in 15–25 days.

4

Production Runs & QC

After sample approval, production begins. Every batch goes through in-process QC and final inspection — dimensional checks, visual inspection, material certification.

5

Pack & Ship Worldwide

Parts are packed securely (PE bags, cartons, or custom trays per your request) and shipped via DHL, FedEx, sea freight, or your forwarder. Tracking provided.

Start Your Project — Get a Quote

Quality Assurance

Quality That Does Not Get Left to Chance

As a professional hot runner injection molding supplier, we know that bad parts cost you time, money, and customer trust. That is why quality checks happen at every stage — not just at the end.

  • Incoming material inspection — every resin batch is checked with melt flow index (MFI) testing and material certificates.
  • Mold trial (T1) reporting — detailed sample report with dimensions, photos, and any suggested adjustments.
  • In-process QC — operators check parts at set intervals during production for dimensions, appearance, and weight.
  • CMM dimensional inspection — coordinate measuring machine for critical dimensions on request.
  • FAI (First Article Inspection) reports — available for PPAP or customer-specific requirements.
  • Final outgoing inspection — AQL standard sampling before packing and shipment.

We provide material certificates (COC/COA), inspection reports, and test data with every shipment on request.

Quality assurance process - inspection checklist
Every batch goes through documented quality checks before it leaves our factory floor.

FAQ

Frequently Asked Questions

Hot runner injection molding uses heated manifolds and nozzles inside the mold to keep plastic molten between shots. Unlike cold runner molds (where plastic in the channels solidifies and must be removed as scrap), hot runner molds produce only the parts themselves — no attached runners, no trimming, less waste.
Hot runner molds typically cost 30–50% more upfront than equivalent cold runner tools because of the heated components (manifold, nozzles, temperature controllers). However, most projects recover this premium within 6 months through material savings, faster cycles, and eliminated degating labor. We can run a free cost comparison for your specific part during DFM review.
Send your 3D files (STEP, STP, IGES) or drawings via our Get Quote page. Most quotes come back within a few hours on business days, and never more than 24 hours. Every quote includes a free DFM review with actionable feedback.
We can hold tolerances up to ±0.02 mm on critical dimensions, depending on the material, wall thickness, and part geometry. We confirm achievable tolerances during the DFM review and document them in our quote.
For hot runner injection molding, we typically support runs starting from 500–1,000 pieces for prototype tooling, up to millions of parts per year for full production. Because hot runner tooling represents an investment, it is best suited for runs of 100,000+ parts annually — but we review every project and will tell you honestly if cold runner is a better fit for low volumes.
Yes. We recommend and build both. Open (thermal) gates are a cost-effective choice for high-volume non-cosmetic parts. Valve gates (pneumatic or hydraulic actuation) give near-invisible gate marks, better flow control, and are ideal for cosmetic surfaces, medical parts, and large or sequential-fill parts. Our engineers will recommend the right option during DFM.
T1 (first sample shots) typically takes 15–25 business days, depending on part complexity, number of cavities, and gate type. After you approve samples, production runs usually ship within 7–15 business days depending on order quantity. We always confirm exact lead times in your quote.
Absolutely. Every quote includes a free DFM review from our engineering team. We look at wall thickness, draft angles, gate location, sink marks, weld lines, ejector pin placement, and other factors that affect moldability — and suggest changes that can cut cost, improve quality, or speed up delivery, before you spend money on tooling.
Yes. All customer files, drawings, and product ideas are treated as strictly confidential. We are happy to sign a mutual NDA (Non-Disclosure Agreement) before you share sensitive designs. Our factory follows secure file handling protocols to protect your intellectual property.
We produce T1 samples as part of the mold building process, and these are included in your tooling cost. If you need pre-production samples beyond T1, the cost depends on material and quantity, but sample costs are credited back against your first production order.

Ready to Cut Waste and Speed Up Production?

Send your CAD files today and get a free DFM review + factory-direct quote within 24 hours. Let our China hot runner injection molding team help you make better parts at lower cost.

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