Why engineers use 3D Hubs for injection molding
Our injection molding capabilities
Our network of Manufacturing Partners gives you easy access to diverse capabilities to serve all your manufacturing needs.
|Single cavity molds||Molds containing only one cavity, producing one unit per run.|
|Molds with side-action cores||Cores slide out of the part from the side before it is ejected from the mold. This allows for undercuts to be molded.|
|Multi-cavity molds||Multiple identical cavities are machined into the mold tool. This allows for more parts to be produced per shot, minimizing the unit costs.|
|Family Molds||Several parts are designed into the same mold tool. This allows for the minimization of tooling costs.|
|Insert molding||Inserts are placed into the mold and molding occurs around them. This allows for inserts such as helicoils to be molded in your design.|
|Overmolding||Premade parts are placed into the mold to mold over them. This allows for multi-material injection molding.|
Our injection molding service
Our injection molding service allows you to seeminglessly move from prototyping to end-part production.
|Minimum order quantity||500 runs|
|Mold material||Tool Steel P20, Carbon Steel S50C|
|Mold storage||Minimum 2 years|
|Mold lead time||Typically 4-5 weeks|
|Quality assurance||Inspection reports included, full dimensional report and material certifications available upon request.|
|Design verification program||Similar to First Article Inspection, you will receive 2 sets of parts upon the machining of the mold to test fit before continuing with full production.|
|Mold remachining||We can remachine the molds should any changes be required, changes to be reviewed on a case by case basis.|
|Reorders||Unit price is based on the quantity required for the reorder with an additional set up fee of $150/€100.|
|Additional technical support||Dedicated 3D Hubs Mechanical Engineer for technical support.|
Available materials for plastic injection molding
All thermoplastics can be injection molded. Some thermosets and liquid silicones are also compatible with the injection molding process.
Common thermoplastic with high impact resistance, low-cost & low density. Vulnerable to solvents.
Nylon (PA 6)
Engineering thermoplastic with excellent mechanical properties and high chemical & abrasion resistance. Susceptible to moisture.
Blend of two thermoplastics resulting in high impact strength, excellent thermal stability, and high stiffness. Vulnerable to solvents.
Thermoplastic with high impact strength and good mechanical properties & hardness. Suitable for molding parts with thick walls.
UV resistant plastic with good abrasion resistance, stiffness and hardness.
The most common Injection molding plastic. Excellent chemical resistance. Food-safe grades available. Not suitable for mechanical applications.
Lightweight thermoplastic with good impact strength & weather resistance. Suitable for outdoor applications.
High density polyethylene (HDPE)
Excellent strength-to-weight ratio, impact and weather resistant.
The Injection molding plastic with the lowest cost. Food-safe grades available. Not suitable for mechanical applications.
The plastic with the highest impact strength. High thermal resistance, weather resistance & toughness. Can be colored or transparent.
Polyvinyl chloride (PVC)
Light weight plastic with good mechanical strength and abrasion resistance. Generally used in building and construction applications.
High-performance engineering thermoplastic with excellent strength and thermal & chemical resistance. Used to replace metal parts.
Engineering thermoplastic with high strength, stiffness & moisture resistance and self-lubricating properties. Relatively prone to warping.
Additives and fibers
3D Hubs offers additives and reinforcements as options for your plastics parts.
|UV absorbers||Absorb UV radiation, slowing down the degradation of the material when used outdoors.|
|Flame retardants||Prevent ignition and inhibits spread of fire.|
|Plasticizers||Increase flexibility and promotes plasticity, reducing brittleness of the material.|
|Colorants||Used to color plastics.|
|Carbon fibers||Increase strength, toughness, and rigidity of the material at the expense of making the material more brittle.|
|Glass fibers||Increase strength, toughness, and rigidity of the material at the expense of making the material more brittle. It is more flexible than carbon fibers.|
Available surface finishes for injection molding
Injection molded parts are not usually post-processed, but the mold itself can be finished to affect the surface finish of the molded part.
This way aesthetic needs or technical requirements can be achieved.
|Glossy||A-1, A-2, A-3||The mold is smoothed and then polished with a diamond buff, resulting in parts with a mirror-like finish.|
|Semi-gloss||B-1, B-2, B-3||The mold is smoothed with fine grit sandpaper, resulting in parts with a fine surface finish.|
|Matte||C-1, C-2, C-3||The mold is smoothed using fine stone powder, removing all machining marks.|
|Textured finish||D-1, D-2, D-3||The mold is first smoothed with fine stone powder and then sandblasted, resulting in a textured surface.|
|As-machined finish||The mold is finished to the machinist's discretion. Tool marks may be visible.|
For a detailed description of the SPI standards and their compatibility with each material take a look here.
Injection molding design guidelines
The table below summarizes the recommended and technically feasible values for the most common features encountered in injection molding.
Learn more in our Engineering Guide to Injection molding.
|Wall thickness||Thickness: 1 mm and 3 mm||To avoid warping and sinking, parts should be designed with the smallest possible and constant wall thickness.|
|Smooth transitions||3 × wall thickness difference||If wall thickness cannot be avoided, use a chamfer or fillet to make the transition as smooth as possible.|
|Rounded edges||Internal edges: > 0.5 × wall thickness External edges: internal fillet + wall thickness||Add a fillet with a radius that is as large as possible to all internal and external edges.|
|Draft angle||For parts taller than 50 mm: increase the draft by 1° for every 25 mm For parts with a textured finish: increase the draft by an extra 1°-2°||Add a draft to all vertical walls to make the ejection of the part easier and avoid drag marks.|
Design verification program for injection molding
3D Hubs offers the Design Verification Program (DVP) for all injection molding orders.
Similar to First Article Inspection, our Design Verification Program allows you to receive two sets of parts for inspection and test fit before continuing with the full production run.