Maidder Technology Co., Ltd is a custom plastic injection molding ODM/OEM manufacturer founded in 2016 and based in Hengli Town, Dongguan City, Guangdong, China. We provide one-stop product development, 3D printing, mold and fixture manufacturing, injection molding, and assembly. Our over molding service is built for brands that need a durable substrate, a soft-touch surface, or a sealed interface in one controlled process.
What Is Over Molding?
Over molding is an injection molding process in which a second material is molded directly over a previously molded substrate or insert. The substrate provides structure; the overmold material provides grip, sealing, cushioning, color contrast, or protection. When the two materials are compatible, the bond can be chemical. When they are not, the design can use mechanical interlocks such as holes, ribs, undercuts, or raised features to lock the layers together.
In practice, over molding is often run as a two-material or 2K process. A 2K mold can combine two materials in one machine cycle or in sequential shots, depending on part design and tooling strategy. It is also common to overmold onto metal inserts, cables, or preformed plastic components.
Typical Applications
Over molding is used where one material cannot deliver every requirement. Typical applications include:
- Soft-touch grips for power tools, handles, and consumer products
- Seals, gaskets, and sealing interfaces for enclosures
- Electronics housings and control panels needing grip, strain relief, or environmental protection
- Medical device and equipment components with cleanable or ergonomic surfaces
- Automotive and industrial parts with vibration damping or wear resistance
- Food-contact or children's products where FDA-compliant materials are required
Maidder has produced custom molds for hard cooler programs, including a 10QT hand-carry model measuring 380x255x270 mm and a 16QT shoulder-strap model measuring 380x356x270 mm. Both use a custom mold with capacity, color, and LOGO options, and both are company-reported: ice remains unmelted for 60 hours at 25°C without frequent opening. While these are not overmolded parts, they show the same disciplined approach we apply to two-material tooling: mold design, material selection, process validation, and batch traceability.
Our Overmolding Capability
As a custom injection molding ODM/OEM factory, Maidder supports over molding from concept through production. Our mold types include overmolds, 2K molds, multi-cavity molds, auto-unscrewing molds, collapsible-core molds, and gas-assist molds. We manufacture molds up to 15 tons and run injection molding machines from Yizumi and Tairui in the 130-500T range on 24-hour shifts.
Our engineering team has 15 years of experience and works from an independent design department. For complex high-precision products, we provide free Moldflow analysis and DFM reports before cutting steel. This helps catch material compatibility, filling, warpage, and bonding risks early. Supporting processes include CNC machining, EDM, and wire cutting, so tooling changes and insert work stay under one roof.
For buyers, this means:
- One supplier for mold, molding, and assembly
- No MOQ; volume is negotiable
- Orders under 3000 pcs incur a machine setup fee
- Molds belong to the customer, with free maintenance and 1-year free storage
- Batch quality issues answered within 1 day
- Cambodia production base and OEM Cambodia service as an alternative manufacturing origin (according to company information)
Design Considerations for Over Molding
Successful over molding starts before the mold is cut. The substrate and overmold material must be reviewed as a pair. Key questions include:
- Will the materials bond chemically, or does the part need mechanical interlocks?
- Does the substrate need surface preparation, cleaning, or texturing?
- Are melt temperatures and injection pressures compatible with the substrate?
- Will differential shrinkage cause warpage, stress marks, or dimensional drift?
- Where should the gate be placed to avoid displacing the insert or damaging the first shot?
- How will the part be ejected without separating the layers?
Material selection matters. Some combinations bond well; others need an adhesive layer, a primer, or a mechanical lock. For regulated products, we review environmental compliance early. Tell us your application and target market; we will confirm suitable materials and documentation for your program. Certificates available upon request.
Tooling strategy is equally important. A 2K mold may be the most efficient path for high-volume parts, while insert overmolding can be more practical for lower volumes or complex inserts. Multi-cavity layouts can reduce cycle time, but they also raise the bar for balance, cooling, and process control. Our team uses Moldflow analysis and DFM reporting to compare options before committing to a tool design.
Quality Control and Project Experience
Overmolded parts often fail at the bond line or at the interface between hard and soft materials. Maidder controls these risks with first-article inspection, in-process patrol inspection with traceability, process testing, per-product batch trace codes, and a PPAP approval process. Our inspection equipment includes CMM (coordinate measuring), vision measuring instruments, calipers, colorimeter, melt flow indexer, and Minitab statistical software. We are certified to ISO 9001 and ISO 14001:2015.
Our project experience includes the HP printer base ECN project in 2020 (part F0V63-90005), an engineering change with add/remove steel, welding and remake of CAV/COR inserts, revision from 4.9 to 12.1, a modification cost of USD 25,000, and a documented 3-week lead time, with customer approval "HP - Proceed this modf." Related capability areas include hard cooler ODM with secondary foam injection, large-format containers, medical device components, and automotive overmolding and 2K parts.
The founder's pre-2016 career includes mold design engineering from 2006 to 2016 at Junyi, Foxconn-group Fugang, and Fuyu. Maidder was founded in 2016. That background informs our review of over molding projects, but it is not presented as company case work.
Talk to Our Sales Team About Over Molding
If you need a two-material part, a soft-touch grip, a sealed housing, or an overmold tool that can hold tolerance in production, send your 3D files and requirements to our Sales Team. We will review material compatibility, propose a tooling approach, and provide a DFM report for complex high-precision products.
For related capabilities, review custom injection molding, DFM analysis, and 2K molding.
Contact us:
- Email: [email protected]
- Phone: +86 137 13040698
- Address: Hengli Town, Dongguan City, Guangdong, China
- Certificates available upon request.