A bottle cap mould is used for producing a variety of caps ranging from the everyday small green bottle cap to the large elegant wine cap. These moulds can be formed from plastic (polystyrene) or metal (carbon steel). In fact any type of solid material that can hold liquid can be used, although some cavities are better moulded from metal than some others. If you're thinking about starting your own business by making bottles, then the best would to use is the metal type, as these are most stable and will not warp.
There are different types of bottle cap moulds. For example, the most common are the inverted cone bottle cap moulds, in which the cavity is inserted upside down into the lid so that the cap forms the base of the bottle cap. The caps can then be stacked, one on top of another, to form the bottle cap for shipping or storage. This is the most traditional way of manufacturing, however some companies now produce their bottles using the water bottle cap moulds, where the cavity is inserted upside down and into the lid of the bottle.
A third popular type of mould is the chute bottle cap mould, which is similar to the inverted cone mould. However, in this case the metal insert is inserted in a horizontal manner, onto the lid of the bottle, rather than being inserted upside down. One benefit of using the chute mould is that the insert does not need to be made into a hole, so there is no chance of it leaking. However, the downside to using this mould type is that it is relatively difficult to manufacture - although it is possible to get plastic caps manufactured from them.
Another option available to you when it comes to producing water cap moulds is the automatic unscrewing ejection cap solution. This technology means that when the cap has been removed, all that is required to do is to trigger the mechanism, and it will remove the cap by itself, automatically. The downside to this is that the process is a bit time consuming, as the person who is manually triggering the mechanism must stand by until the cap comes out. However, if you are a small business with little or no staff, then the cost of this option may be more affordable to you.
Finally, you may also want to consider the use of plastic cap moulds in a large scale production environment, where a large number of bottles are produced. If so, then you should consider either buying your own machine, or purchasing a combination of machines that can perform the automatic removal and insertion of the caps themselves. However, if you are a small business, then you may find that the cost of purchasing a small machine is more affordable to you, as you would not need to worry about paying for manual support and labour costs on a regular basis.
As well as the type of mould that you use, another thing to take into consideration is the design of the cavity. Most of these cavities will have a raised lip on one edge to help with the cap coming out easily, but some will not. This is generally seen on the "open end" of the cavity, where the cap can come out with ease. If you choose a cap without a lip on the edge, then this lip can prevent the cap from coming out at all, but it also means that the cap cannot be inserted and removed by a single person easily. You will find that the best performing moulds will have a lip around the entire perimeter to ensure that the caps come out together, which helps prevent people from inserting their own caps in the system.