The search for an ideal plastic cap for your container depends entirely on the type of bottle you have chosen and the type of product you are trying to market. Each container size has certain types of thread or crown, which refers to the size of the plastic cap that fits.

In the descriptions of the bottles when we see an R together with a number followed by the acronym mm, it refers to the fact that the neck of the bottle has that size according to the millimeters of the diameter.

A plastic cap for PET containers

Small plastic bottles, that is, less than 250 milliliters, usually have caps of the same caliber, although it is not a necessity. For example, the 2 oz. PET Cosmo Round Bottle 60 ml. Max 60-20 is compatible with those caps that have a size of 20 millimeters such as the 20mm Plain Cap Induction Liner for PET Containers or the 20mm Flip-Top Cap Linerless The first features a perfect seal that prevents spills, while the second is ideal for evenly spreading liquid or viscous content.

There is a particular case that we would like to highlight, it is the 28-millimeter caps since it is very common to find this plastic cap size for different containers, in capacities ranging from 250 milliliters to one liter as an example, 8.5 oz. PET Oval Round Bottle Surf 250 ml, 16 oz. PET Square Bottle 480 ml, Bell 17 oz. PET Clear Round Bottle 500 ml, 17 oz. PET Boston Round Bottle 500 ml, 34 oz. PET Clear Round Bottle Multi-Max 1 lt, or 34 oz. PET Boston Round Bottle 1 lt. All these bottles are compatible with R-28 caps in their different variants such as 28mm Plain Cap Short neck Tamper Evident for a secure closure, 20mm Flip-Top Cap Linerless, or 28mm Dispensing Disc-Top Cap so that the product can be taken from the bottle, or by, on the contrary, 28mm Dispensing Pump Cap, where the main focus is the cap since it is the one that has all the mechanism to dispense.

A plastic cap for HDPE containers

The caps of these containers are usually larger because they are regularly used in markets such as chemicals, agrochemicals, or for packaging products in large quantities. For this reason, we can find covers for Missile and Missile Light of one-liter size R-50 mm with different characteristics: without liner, with induction liner for HDPE, and with induction liner for HDPE and ventilation valve. In the case of one gallon, 5, 10, and 20-liter jerrycans, we have the R-53 mm caps in their different versions: with foamed liner, with induction liner for HDPE, with foamed liner and ventilation valve, and with washer.