Injection Molding FAQ

 Injection Molding is the standard manufacturing process for mass-producing plastic parts with high consistency and tight tolerances. At Boona, we specialize in Rapid Tooling (Bridge Production) and Low-Volume Production. We use aluminum or steel molds to inject molten plastic into a cavity, creating parts identical to final mass-produced products but with a much faster turnaround time than traditional mold makers.

• Rapid Tooling (Soft Tooling): Uses Aluminum (7075) or soft Steel (P20). It is cheaper and faster to build (10-15 days) but has a shorter life (10k-50k shots). Ideal for market testing.

• Production Tooling (Hard Tooling): Uses hardened Steel (NAK80, H13). It costs more and takes longer (4-6 weeks) but lasts for millions of cycles. Boona helps you choose the right strategy based on your volume.

No. Unlike traditional factories that demand 10,000+ units, Boona supports Low-Volume Manufacturing. We can mold as few as 50 to 1,000 parts for your pilot run. If you only need 1-10 parts, we recommend 3D Printing or Vacuum Casting.

 For simple molds, we can ship T1 samples (first shots) in as little as 10-15 days. Complex molds with side actions or sliders usually take 20-30 days.

You do. Once you pay for the tooling, the mold is 100% your property. We store it in our facility for free for your future production runs, or we can ship it to you (shipping costs apply).

Tooling cost is driven by:

1. Part Size & Complexity: Larger parts require larger mold bases. Undercuts require expensive sliders/lifters.

2. Cavity Count: More cavities = higher tooling cost but lower unit price.

3. Mold Material: Steel is more expensive than Aluminum. Tip: To get an accurate price, upload your STEP file to our Online Quote Form.

•  Remove Undercuts: Simplify the design to open/shut without side actions.
• Use MUD Inserts: We use shared standard mold bases (Master Unit Die) and only machine the core/cavity inserts for your part. This saves 30-50% cost.
• Relax Tolerances: Tighter tolerances require EDM machining, which increases cost.

 A Family Mold creates multiple different parts (e.g., Top Case + Bottom Case) in the same mold base during one shot.

• Pro: Saves tooling cost (1 mold instead of 2).
• Con: Hard to balance flow if parts have different sizes. Boona engineers will advise if your parts are suitable for a family mold.

While the initial tooling cost is high, the material cost (plastic pellets) is very low, and the cycle time is fast (seconds). Once you produce over 100-300 units, Injection Molding becomes cheaper per unit than 3D Printing or CNC Machining.

Yes, absolutely. A draft angle (usually 1° to 3°) allows the part to eject smoothly from the mold without dragging or scratching.

• Smooth surfaces: 1° is minimal.
• Textured surfaces: Require 3° or more. Our DFM engineers will help you analyze draft angles before cutting steel.

 Uniform wall thickness is key. Variations cause cooling issues.

• Recommended: 1.5mm to 3.0mm.
• Issue: Thick sections cool slowly, causing Sink Marks. Thin sections may cause Short Shots (incomplete filling).
• Solution: If you need a thick section, core it out and use ribs for strength.

Yes. We use Sliders (Side Actions) or Lifters to mold undercuts. Note that these mechanisms increase the tooling cost. For low-volume parts, we can also use “Hand-Loaded Inserts” to save money.

Edge Gate: Most common, located on the parting line. Easy to trim.

• Sub Gate (Tunnel): Automatically trimmed upon ejection.
• Sprue Gate: Direct flow for large parts, but leaves a large mark.
• Hot Runner: For mass production, zero waste, but expensive setup.

Yes.

• Overmolding: We can mold soft rubber (TPE/TPU) over a hard plastic substrate (e.g., Tool handles).
• Insert Molding: We can place metal inserts (threaded brass nuts) into the mold before injection. This is stronger than heat-staking post-process.

We process hundreds of thermoplastic resins. Common choices include:

• Commodity: PP (Polypropylene), PE (Polyethylene).
• Engineering: ABS (Standard), PC (Polycarbonate – High impact), Nylon (PA6/PA66 – Wear resistance).
• High Performance: PEEK, ULTEM (Aerospace grade). Check our full Material List.

Yes. Adding glass fiber (e.g., PA66+30%GF) significantly increases strength and stiffness. However, it increases mold wear and may affect the surface finish (fiber exposure).

Yes. We use Pantone or RAL color codes. We mix masterbatch pigments with the base resin to achieve the exact color you need.

Standard production uses 100% virgin material for best properties. If you require cost savings or sustainability, we can discuss using specific regrind percentages.

 Sink marks are depressions on the surface caused by uneven cooling in thick areas.

• Prevention: Ensure ribs are no more than 60% of the main wall thickness.

Flash is excess plastic leaking from the parting line. It usually means the clamp pressure is too low or the mold is worn. Boona maintains strict mold maintenance to prevent flash.

Our standard tolerance is ±0.1mm (DIN 16742 / ISO 20457). High-precision molds can achieve ±0.05mm. Note that some materials (like PP) shrink more than others (like ABS), affecting tolerance.

If the parts do not meet your drawing specifications due to our error, we will modify the mold (mold tuning) at our cost and re-sample until approved.

We follow the SPI (Society of the Plastics Industry) standards:

• SPI A-1 to A-3: High Gloss (Diamond Polish). Requires hardened steel.
• SPI B-1 to B-3: Semi-Gloss (Paper Polish). Good for hiding marks. •
• SPI C-1 to C-3: Matte (Stone Polish).
• SPI D-1 to D-3: Textured (Sandblast). Best for consumer electronics. Learn more at our Surface Finishing Options.

Yes. We can apply EDM textures (VDI) or chemical etching (Mold-Tech) to the mold cavity to give your part a specific grain (e.g., leather look, matte finish).

Yes. We offer post-molding services including:

• Spray Painting: Soft touch paint, UV coating.
• Electroplating: Chrome plating on ABS.
• Laser Etching: For backlit buttons.

• Choose Vacuum Casting: For 10-50 parts. Low tooling cost (Silicone mold), but high unit price. Good for marketing models.
• Choose Injection Molding: For 100+ parts. Higher tooling cost, but very low unit price. Real production material.

Yes. “Rapid Injection Molding” is increasingly popular for prototyping because it provides the exact material properties (which 3D printing often mimics but doesn’t replicate 100%).

Yes. We provide a One-Stop Service Solution. We can mold the parts, install inserts, paint, print logos, and assemble the final product with packaging.

Absolutely. We work with many international clients and strictly adhere to NDAs. Your mold designs and part files are kept confidential on our secure servers.

• Export your design as a STEP/STP file.

• Visit our Get a Quote page.

• Specify material, quantity, and finish. We will provide a DFM report and quotation within 24 hours.

Yes. For complex parts, we perform Mold Flow Analysis before cutting steel. This simulation predicts filling patterns, air traps, weld lines, and potential warpage, allowing us to optimize the gate location and design in advance.

Ejector pins are necessary to push the part out of the mold. They leave small circular marks. 

• Solution: We will discuss the pin locations with you during the DFM phase, ensuring they are placed on the non-cosmetic side (B-side) or hidden under features.

Warpage is caused by uneven shrinkage.

• Design: We recommend uniform wall thickness.
• Process: We adjust cooling time and packing pressure.
• Fixturing: If necessary, we use “Cooling Fixtures” to hold the part in shape immediately after ejection until it fully solidifies.

We have injection machines ranging from 50 Tons to 800 Tons. This means we can mold tiny gears (0.5g) up to large automotive covers (approx 1000mm length).

We perform Mold Maintenance (cleaning, greasing, and rust prevention) after every run. We store your mold in our climate-controlled warehouse for free for up to 2 years of inactivity, ensuring it is ready for your next order anytime.