How long does injection moulding take from design to delivery?

Mould design and build takes 4–8 weeks including a physical sample for sign-off. Once the mould is approved, a production run of 10,000 units typically completes in 5–10 working days.

What Is Injection Moulding? Process, Machines & Materials Explained

What is injection moulding?

Definition: Injection moulding is a manufacturing process in which molten plastic is injected under high pressure into a precision steel mould, cooled until solid, and ejected as a finished part. It is the world's most widely used method for producing plastic components at scale — from bottle caps and sealant cartridges to automotive housings.

The economics are what make it remarkable: the mould (the "tool") is a one-time investment, and every part made from it afterwards costs only material, machine time and energy. That's why a part that would cost hundreds of rupees to machine individually can be injection moulded for a few rupees — and why the process rewards volume.

The quality lives in two places: the tool and the process control. A well-cut, well-maintained mould produces identical parts for millions of cycles. Disciplined process control — melt temperature, injection pressure, cooling time — keeps part number 1 and part number 1,000,000 indistinguishable.

How injection moulding works — step by step

Material preparation

Resin pellets (PP, HDPE, ABS, PET, PVC, Nylon or PC) are dried to remove moisture — wet resin causes surface defects — then blended with colour masterbatch to a recorded formula, so colour is repeatable batch after batch.

Melting & injection

Inside the machine barrel, a rotating screw shears and melts the pellets at 180–300 °C depending on the polymer. The screw then rams forward, injecting the melt into the closed mould at pressures up to 1,500 bar in under a second.

Packing & holding

Plastic shrinks as it cools. Holding pressure keeps feeding material into the cavity to compensate, so the finished part is fully formed with no sink marks or voids.

Cooling

Water channels machined through the mould pull heat out of the part until it is rigid. Cooling is usually the longest phase of the cycle — and clever channel design is a big part of why some moulders are faster than others.

Ejection

The mould opens and ejector pins push the part out onto a conveyor. The mould closes and the cycle repeats — fully automatic, 15–60 seconds per cycle, around the clock.

Quality control & finishing

Parts are checked against the signed master sample — dimensions, colour, finish, weight. Approved parts move on to decoration (dry offset, screen print or IML), assembly or packing.

Machines, materials & specifications

Parameter	Ripu Plastox Capability
Machine range	15+ machines, 80-tonne to 450-tonne clamping force
Materials	PP, HDPE, ABS, PET, PVC, PC, Nylon (PA6/PA66) — incl. food-grade & pharma-grade with batch traceability
Tolerance	±0.05 mm, held across all cavities
Tooling	In-house CAD/CAM mould design, multi-cavity tools, free long-term mould storage
Part sizes	From sub-gram closures to large panels and 20 L bucket bodies
Volumes	MOQ 500 units · scales to 5 million+ per run
Lead time	Tooling 4–8 weeks (incl. sample sign-off) · production 5–10 days per 10,000 units

What it's used for

Sealant cartridgesCaps & closuresCosmetic jars & sticksAutomotive housingsTractor body partsElectrical enclosuresPaint bucket bodiesCustom OEM parts

See the full range on our products page, or how moulding pairs with decoration on the technology page.

Frequently asked questions

How much does an injection mould (tool) cost in India?

A single-cavity mould for a simple part can start around ₹50,000–₹1.5 lakh; multi-cavity production tools for complex parts run into several lakhs. It's a one-time investment — we design tooling in-house and store your mould free for repeat orders, so every future run needs no new tooling spend.

What is the minimum order quantity?

Custom moulded parts start at 500 units and scale to 5 million+ on the same lines. Standard catalogue items such as sealant cartridges ship from stock.

How long from design to delivery?

Mould design and build takes 4–8 weeks, including a physical sample you sign off before bulk. Once approved, a 10,000-unit run typically completes in 5–10 working days.

Which plastics can be injection moulded?

Most thermoplastics: PP, HDPE, ABS, PET, PVC, polycarbonate and nylon — including food-grade and pharma-grade resins with full batch traceability and documentation.

What tolerance can the process hold?

±0.05 mm — about half the width of a human hair — repeatably, across every cavity and every shot. That's the difference between a cap that seats first time and a batch of returns.

Injection Moulding,
Explained.