Preform mould maker in China: how to tell a real factory from a trader
Many websites selling PET preform moulds from China look the same. Some belong to the factories that machine and assemble the moulds; others belong to trading companies that pass your order to a workshop you never see. A trader is not always a bad choice, but you should know which one you are dealing with, because it decides who answers when something goes wrong. These are the checks we suggest, and how OSLON answers each one.
1. A real address you can visit
Ask for the full factory address and compare it with satellite images and the company registration. A factory has a building with loading doors and workshop space, not an office floor in a business tower.
OSLON: No. 27 Maofeng Street, Xinqian Street, Huangyan District, Taizhou, Zhejiang. Founded in 2008, with a 2,000 m² factory. Huangyan is one of China's best-known mould-making districts.
2. Machining and assembly you can see
Ask for a live video call walking through the workshop: CNC machining, assembly benches and the inspection room. Photos can be borrowed; a live walk-through is much harder to fake.
3. Direct access to the engineer
Send a technical question about your preform, such as the gate design or the cooling around the neck, and see who answers and how fast. A factory engineer answers from the drawing in front of them. A trader has to forward the question and wait.
4. Progress photos of your own mould
Agree at the start that you will receive photos or video at fixed stages: steel received, rough machining, finished cores and cavities, assembly and trial. The mould number and your project name should be visible in the pictures.
5. Patents and exhibitions
Patents registered in the company's own name, and a booth under its own name at trade shows, show long-term investment in its own products. OSLON holds 6 utility model patents and exhibited at CHINAPLAS 2025 in Shenzhen and in New Delhi in February 2026.
6. Trial results before shipment
Ask to see the mould running and a complete shot of trial preforms before you pay the balance. A supplier who controls the mould can show this without delay.