Overmolding Insert Molding

Founded in 1978, Zhongde is a professional cnc machining company focusing on OEM ODM customized services. Based on 40 years technology deposition, we have developed a one-stop solution from mold designing and rapid prototyping to mass production. Our manufacturing capabilities include plastic injection molding service, compression molding service, CNC machining service, metal stamping service, 3D printing service, custom molding service, overmoulding services, etc.



Zhongde can provide over-molding and insert overmolding to produce unique multi-material parts. Our production materials range from thermoplastic to elastomer-rubber, as well as metal. We've broken down the differences and similarities between the two processes. Let us help you decide which process is right for your project.



Both over-molding and insert molding processes involve putting two types of materials together to make one part,also named molding over molding. Overmolding is a two steps process that one to create the substrate and one for the oversold that goes on top of it. Insert molding is a slightly faster process as it takes only one step that the two materials are molded at the same time.



Guideline of Overmolding Insert Molding



Insert molding injection is a process where a single part is created using two or more different materials in combination. Traditonally, overmolding starts with injection molding a hard plastic resin that has a higher melting point. Once that part is cooled, another material is injection molded over the first part, resulting in a single, finished product.We also offer injection molding threaded inserts.



Insert molding combines metal and plastics into one single part. It allows plastic to bond to insert pieces, mostly brass or stainless steel metal component, which go inside a mold cavity. There are many options for insert that can be placed into the mold. A few of examples are warming labels, threaded bushings, wires, batteries, etc.



Size of Overmolding Insert Molding



Below table shows the size of Overmolding Insert Molding parts we usually make. If you need a larger size, we can also help you achieve it.



Size Metric Inch

Length 2500 98.4

Width 2000 78.7

Height 1500 59

Available Material of Overmolding And In sert Molding In addition to the general materials listed below, Zhongde can also modify the materials according to the special needs of customers. Our professional engineers will adjust the raw material formula to meet the unique conditions of use.



Overmolding Insert Molding Plastic



ABS | Acrylonitrile Butadiene Styrene



PA 6 | Polyamide 6, Nylon 6



PA 6/6 | Polyamide 6/6, Nylon 6/6



POM | Acetal Polyoxymethylene, Delrin



PP | Polypropylene



PE | Polyethylene



LDPE | Low-Density Polyethylene



HDPE | High-Density Polyethylene



UHMWPE |Ultrahigh Molecular Weight Polyethylene



PTFE | Polytetrafluoroethylene



PEEK | Polyether Ether Ketone



PC | Polycarbonate



PMMA | Polymethyl Methacrylate, Acrylic



PS | Polystyrene



PVC | Polyvinyl Chloride Shore D



PU | Polyurethane



Overmolding Insert molding Rubber

NR | Natural Rubber



NBR | Nitrile Rubber



SBR | Styrene-butadiene Rubber



HNBR | Hydrogenated Nitrile



CR | Neoprene Rubber



VMQ | Silicone



LSR | Liquid Silicone Rubber



FVMQ | Fluorosilicone



FKM | Fluorocarbon



FFKM | Perfluorocarbon Rubber



EPDM | Ethylene-Propylene Diene Monomer Rubber



IR | Polyisoprene Rubber



IIR | Butyl Rubber



Additives of Overmolding Insert Molding

Name Description

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.



Surface Finishing of Overmolding Insert Molding



Name Description

Glossy The mold is smoothed and then polished with a diamond buff, resulting in parts with a mirror-like finish.

Semi-gloss The mold is smoothed with fine grit sandpaper, resulting in parts with a fine surface finish.

Matte The mold is smoothed using fine stone powder, removing all machining marks.

Textured finish 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.