Buying rubber stoppers can be a more complex process than you might think. You should think about how the stoppers work on your products or applications to make sure you choose the right products.
So, before you order stoppers, ask yourself the following questions. The answers will help you find the right products for your needs.
What Size of Stoppers Do You Need?
Off-the-shelf rubber stoppers come in a range of sizes. They have standard widths and depths.
Think about the size of the hole a stopper has to fill. You don't want an exact width match here. You usually use a stopper that is slightly larger than the width of its vessel. This extra size allows you to compress the stopper to put it in place. Once it is in position, the rubber expands to create a tight seal.
If your stoppers are too small, then they won't give you that seal. The liquid or materials they are supposed to hold in place will leak out. If they are too big, then they simply won't fit.
If you can't find a regular size to fit your product or application, then you can ask manufacturers to make custom stoppers. You might also need to order custom sizes if you need stoppers to fit unusual vessel shapes or depths.
Do You Have Non-Standard Environmental or Contact Needs?
Rubber works well as a stopping material. It is resilient and long-lasting. However, regular stoppers might not work well in every application if you have unusual circumstances.
For example, if you want stoppers for medical vials, then you need a medical-grade rubber. You need to know that the rubber won't contaminate the contents of the vial. You might also want to buy stoppers with needle holes in them.
The materials in your containers also affect your purchasing decision. If you store substances that could degrade a regular rubber stopper, such as some chemicals or hazardous substances, then you might need to buy specialized products.
Ambient temperature plays a part here too. If your stoppers will be exposed to extreme heat or cold, then they might lose some of their useful properties. For example, too much heat can make rubber contract and too much cold can make it expand. Either of these events affects the fit of a stopper.
So, if your stoppers will be exposed to temperature extremes, then you need to find products that won't be affected by heat or cold. This ensures that your stoppers keep their original size.
Once you have answers to these questions, contact rubber parts manufacturing companies and ask about their rubber stopper ranges.