Repair of Unscrewing Plastic Mold



Plastic Injection Molding / Repair of Plastic Mold


Export (to US company)

Project Description:

The part manufactured by this mold is a fixture used in sealing gas tanks. It has high precision external thread and internal thread thus requires slides and unscrewing device in the mold.

Type of Material Used:

Nylon material


Our customer had a mold manufactured in the northern mainland China, at a very cheap cost. The mold has undergone production trials for more than one (1) year already but the customer still could not confirm any sample plastic parts. The customer then contacted us and passed on the mold to us so that Richfields can help them repair the mold.


We underwent a series of mold testing steps: we reviewed the 3D of the plastic part and the tool layout. We also put the mold on test production to get measurements of the samples from the mold. Aside from measuring the sampled plastic parts, we measured the tool and obtained the insert dimensions of the tool. We found out that the problem was due to improperly machined mold inserts. The mold inserts had incorrect dimensions.

We redesigned the mold inserts, keeping in mind that this needs to be a high precision mold to prevent gas leak. After replacing the old mold inserts, the mold is now working well and produces parts with correct dimensions. This mold which the previous manufacturer could not repair for more than 1 year was repaired by Richfields in less than 10 days.

Many reasons contribute to why we think the first factory could not finish the mold in more than a year. Since this is an unscrewing mold, technical skills and experience become very important factors. For Richfields, we have professionals who bring with them decades of experience in plastic injection. Another important thing for this project is the equipment used. At Richfields we make sure the equipment we used for measuring and making molds are well-maintained and updated.