The quality of fiberglass products depends not only on the overall technical quality of the factory workers, but also on the quality and service life of the molds. The domestically produced fiberglass molds are structurally good and can be compared with other industrialized countries. However, the surface quality of fiberglass molds is generally poor. Apart from the defects in the mold resin and tool equipment used for mold preparation in China, most domestic manufacturers do not attach as much importance to the production of master molds and the treatment of mold surface smoothness as foreign factories.
The smoothness of fiberglass products depends on the smoothness of fiberglass molds. Therefore, high-end fiberglass products at home and abroad require precise surface treatment of fiberglass molds. Fiberglass molds are the mother of products, and putting more effort into fiberglass molds can achieve better results in fiberglass products in the future.
The surface treatment technology for fiberglass molds is introduced as follows:
1、 Renovation of new and old models
1. Water mill
When renovating a new or old mold, the first step is to use water sandpaper for water grinding. The starting point of the water sandpaper should be high, usually starting from size 600. Some users, in order to improve work efficiency, start with water sandpaper that is even coarser than size 400 or below, in order to achieve quick results. Little do they know that fine sandpaper cannot remove the coarse sand marks caused by coarse sandpaper no matter how hard they are sanded; After the 600th, we need to gradually progress from the 800th, 1000th, 1200th, 1500th (or even 2000th), without any savings, and we must be meticulous and willing to put in a lot of effort and effort, without any speculation or opportunism.
2. Polishing
First, apply an appropriate amount of rough polishing agent to the surface of the mold, and use an electric polishing machine to polish it. When polishing, place the wool disc flat on the surface of the mold, and start the polishing machine to rotate in a circular spiral shape, throwing pieces by pieces without missing them. The main workload is rough polishing, so generally rough polishing should be done at least twice until the mold is smooth. After rough polishing, replace the wool disc with a new one and use a fine polishing agent to polish it. Repeat the above operation. The coarse and fine polishing agents cannot be used on the same wool disc, it is best to use one polishing machine each.
3. Jiemo
The cleaning process of the mold is to remove the residual polishing agent or oil on the surface of the mold, so that the subsequently added sealing agent and release agent (wax) can firmly adhere to the mold. The cleaning water is usually wiped twice. First, wipe the cleaning water on the surface of the mold with gauze and then dry it. Then apply a layer of cleaning water, let it evaporate completely (about half an hour), and then wipe it with a clean dry cloth until it is shiny.
4. Sealing mold
For fiberglass products that require moderate smoothness, polishing with No. 3 polishing agent is generally sufficient. However, even after polishing, there are still many micro holes on the surface of the mold that are not visible to the naked eye. Therefore, for glass fiber reinforced plastic products that require high precision, these micro holes must be sealed off. This way, the precision of glass fiber reinforced plastic products has been upgraded to another level. The specific method is to evenly apply the sealing agent on the mold surface with gauze, let it dry completely (about 30-60 minutes), and then wipe it with a clean dry cloth until it is shiny. If it is a new mold, the holes need to be sealed four times. If it is an old mold renovation, the holes can be sealed twice.
5. Demoulding
Select different release agents based on the thickness of the produced fiberglass products. For cast fiberglass sanitary ware or other fiberglass products with a thickness of about 5MM, high-temperature demolding wax should be used due to the high heat generated by the solidification of fiberglass. It is best to wrap an appropriate amount of demoulding wax with gauze and apply it evenly to the surface of the mold by squeezing it through the gauze. This is both uniform and economical, and will not cause a large amount of demoulding wax to scatter. Wait for it to dry completely (30-60 minutes), then use a hand wrapped clean gauze or a polishing machine to polish it until it is shiny. The new mold needs to be waxed 4 to 5 times before it can be used. After the first product is demolded, apply demolding wax every time it is demolded thereafter.
In order to improve the smoothness of the product and increase work efficiency, a release agent is applied once during demolding. This ensures a high smoothness of the product and avoids the pain of cleaning wax stains after multiple uses of demolding wax.
2、 After a period of production, the surface of the mold was refurbished
After multiple uses of demoulding wax or long-term storage, the demoulding wax of the mold has oxidized, and when producing fiberglass products, the surface becomes rough due to wax accumulation, affecting the smoothness of the product. At this time, it is necessary to renovate and refurbish the product. The mold can be cleaned twice with a cleaning agent to remove all accumulated wax, sealed twice with a sealing agent, and then coated with demoulding wax three times. The mold will be refreshed again and can be used normally again.
Post time: Aug-12-2024
