Contract Manufacturing of Plastic Products

Contract manufacturing of plastic products becomes more and more popular, as every industry needs plastic products for out case or interior parts, you can look around of automotive, airplane, medical, toy, electronic products, etc. It seems none of them could be launched on the market without plastic products.


But how can we get a plastic product contract manufactured with good quality, consistent supplement, and reasonable price? Here below we would like to share some useful tips:


  1. Design and verify your plastic products reasonably

The first important thing is to design your plastic products reasonably. Because of different function and using, the product design could vary a lot. However we should design a right products for function, assembly, and manufacturing. That is also being said, when we design a plastic part, we should consider for structure, material, assembly, mold tool making, plastic injection molding process, packaging, etc.

Once we finished our design, we should always make prototypes to verify if our design is feasible, reasonable, and most refined, instead of directly moving the design to manufacturing process. Otherwise we might spend lots of time and money on future’s design change.


  1. Prepare all of manufacturing document for potential manufacturer to quote

If your design is finalized, you should prepare some of your project information for potential contract manufacturer to quote. Basically the plastic products contract manufacturer need your 3D stp file(2D drawing is preferred if you have), BOM(including part name, material quantity, color, surface finish, etc), and your manufacturing quantity for first order and annual order. If needed, you should also need to provide a prototype for reference, as it’s more visible and the contract manufacturer would understand your products better.


But prior to sending any of your information to the potential contract manufacturer, a NDA or NNN is essential measure to protect your intellectual property. Otherwise you might get your products being copied or disclosed immediately.


  1. Finalize a right plastic injection molding contract manufacturer

There are numerous of plastic products contract manufacturers in the world or around you, but it’s not easy to find a suitable plastic injection molding contract manufacturer. As there are many factors that could affect our decision of choosing a contract manufacturer, which including manufacturing location, manufacturer size, capabilities, experience, price, quality level, lead-time, flexibility, ect. Relatively to say, the higher level and larger size of contract manufacturers will definitely provide better manufacturing service, higher quality, and quicker lead-time. But their manufacturing price would be certainly more expensive than a small or medium size contract manufacturer.

Since the labor cost in US or Europe is quite expensive, so many Western companies find contract manufacturing partner in Asian countries(like China, India, Vietnam, Malaysia, etc)

Just define where you want to manufacture the products, then get some contact information from potential manufacturers that you probably like to cooperate with. A factory visit is necessary to evaluate everything you might consider. And finalize one or two manufacturers you want to work with.


  1. Sign a golden sample and critical dimension for contract manufacturer

As soon as the contract manufacturer had finished the mold tool making, they will ship client some samples for review. And we can get them tested if the products is correctly made. If not, we will definitely let the contract manufacturer to improve any imperfections that we found. If everything is OK, we can get the products qualified by part qualification process, which means the part dimension, aesthetics, and function would be comprehensively evaluated.


Once the part qualification process past, we can release contract manufacturer a golden sample as well as a 2D drawing showing some critical control dimensions, which could be used for their reference sample and quality inspection criteria. In this way, we could avoid any big manufacturing mistakes or deviation.


  1. Pilot run to verify everything

Pilot run is known as small volume of production trial, which is used to test if manufacturing system can run smoothly as we expected. Meanwhile, it’s also a good measure to diagnose our product quality, market acceptance, and contract manufacturer service. Whatever how perfect our design might be, we should always perform pilot run process for any project.


  1. Quality control for mass production

Quality control for mass production is the most critical process to get our products manufactured. But most of time, the process is took by contract manufacturer, because the plastic parts manufacturing takes longer time from day to night. However we can request the manufacturer to perform strict quality measure for whole process. A cpk report is an useful measure to evaluate the manufacturing stability. Normally CPK rate of 1.33 shows a stable manufacturing system. Meanwhile, on side QC should check out part appearance every 30 minutes, finally we can send the third party of QC agency to do on-site inspection before shipping. It can save lots of shipping cost if any defective products found before shipment.