How to Look for in PET preform Mold Supplier
When engineering comes to purchasing with a requirement for PET preform molds , many times the purchasing person isn’t knowledgeable enough about purchasing PET preform molds to know where to go for the requirement. In some companies, project or product engineers are in charge of finding a mold manufacturer, but even then there are questions about what to look for in a mold supplier.
Many purchasing people will go online as a first step, and there they will find a plethora of mold manufacturers. So how to pick the right one for the job? Most mold shops have similar machine tool capabilities and CAD/CAM software systems. Where the differences come into play are the mold types in which different shops specialize. Some of the types of molds include:
• Insert Molds: molds which accommodate inserts (either robotically or manually inserted) which the plastic is molded around to eliminate secondary or post-molding operations.
• Overmolding molds: molds which accommodate placement of a substrate part over which another material is molded, i.e. an ABS substrate with a thermoplastic elastomer (TPE)
• Two-shot molds: mold which are built to accommodate multi-material molding or multicolor molding, such as an automotive tail light, which might require both red and orange polycarbonate material to be molded for a complete tail light.
• Rotary Stack Molds: molds that produce multiple parts that require multiple processes. The mold is built in a “cube” and after each process the mold rotates 90 degrees for the next process. This is for highly complex components requiring both multi-material or multiple steps to complete, but the result is a final, completed and assembled unit. Eliminates secondary operations, multiple steps after molding or multiple molds to make a complete unit.
• Unscrewing molds: molds that accommodate threaded parts such as screws, caps and closures, and generally have either id or od threads.
Some molds manufacturers specialize in very large-sized molds such as those that would be used for bumpers on cars or trucks. Some specialize in very small molds for micro-molding. Most fall somewhere in between, and can generally handle molds that fit up to a 500-ton injection molding press. Mold manufacturers also have market niches with which they have become well-acquainted with such as extremely high-cavity molds (128 cavities for example) for the packaging industry; or smaller cavitation molds for the medical industry; or very aesthetic molds for the cosmetics packaging industry.
Mold manufacturers develop certain areas of expertise over their years in business, and generally are more successful when they stick to those areas of expertise. While it’s not impossible that a moldmaker that has only built smaller, 2, 4, 8 or 16-cavity molds could successfully build a 96-cavity medical mold, it’s best to find a mold manufacturing company that has a track record in building the type of mold that the OEM requires to help ensure everyone’s success.
For example, a mold manufacturer might be good at large multi-cavity molds, but has never built an unscrewing mold for a cap application. There are mold manufacturers that specialize in building unscrewing molds and have built hundreds over the years. The opportunity for a successful build for a large, multi cavity unscrewing mold from a shop experienced in this type of mold is much greater than one which has never built an unscrewing mold.
If the price sounds too good to be true…
You’ve heard it before – it probably is. Mold manufacturers do not have “standardized” pricing, so if you go out for bid from several different mold companies, you’ll probably get several different prices which can range all over the map. Much of this price variable has to do with the expertise of the mold manufacturer in designing and building the type of mold you require. It also has to do with their shop rates, which can vary depending on the size of the shop or where the shop is located, and other variables. But beware of a mold price that sounds just too good to be true
If you get quotes that are very wide in price, go talk to each preform molds maker that submitted the bids and ask for a detailed explanation of the quote and how he/she arrived at that price. Make sure your RFQ contained all the detailed information about the mold’s requirements and that the moldmaker didn’t miss something that might have added cost to the mold. Moldmakers are human too, and none of them are mind-readers.