Generally, we not supply cork lids from stock, but rather we make them to order to pretty much any size and design that our clients request. There are a few design considerations as well as limitations on what kind of cork lids can be produced which we will outline here.
To manufacture cork lids we start with agglomerated cork boards (which are around 900x600mm in size) and of varying thickness. We do not make agglomerated cork ourselves, rather we buy in boards in large volumes of different thicknesses, then whatever thickness that you require for your lid, that will be the thickness of board that we use to make them.
These boards are then cut into squares sized a couple of millimeters more than the diameter of your lid, which will give us a square of cork that has the correct thickness, but needs rounding off. What we now have to do is grind away the corners of the square to give us a round lid of the right diameter and at the same time add a profile to the lid to give us the lip. The machine that we use for this grips the squares of corks and rotates them quickly and then offers up the edge of the cork squares to a grinding stone that has the inverse profile of the lip that we require. This grinding stone is circular and is also rotating and when it meets with the cork it very rapidly grinds the squares of cork into the rounded and lipped lid that we require.
We have a big range of differently profiled grinding stones in stock, but sometimes we have to adjust them to a specific profile that a lid may require. This is in fact an important part of our work – we always ask our clients to send us a sample of the jar that they will be using and then we measure it up and then try out some lids with different profiles until we get the exact right fit. Very small differences in the diameter of the cork lid will have a big impact on the fitting of the lid, so it has to be done very accurately.
We can adjust the design of the lids to have the top part with a beveled, rounded or flat edge and we can adjust the slope of the lower part of the lid to make it more or less conical, depending on the inner profile of the jar and the tightness of fit required.
With regard to the height of the lid, it is difficult to go under 12mm, because otherwise the penetration into the jar will be too short and it will not give a firm fit and there will be little to grip on to when you want to remove the lid from the jar. Generally, for larger lids (over 80mm) thicknesses of less than 15mm start to look disproportionate and the lids begins to lose strength as it bends to easily. Generally, more or less half of the thickness of the lid will be outside the jar and half inside and the outside part will have the same diameter or a fraction more than the jar external diameter.
If you are unsure about exactly what specification of lid you require, we can either make you up some samples (which has a cost) or we can show you some similar lids from previous orders and place them on your jar to give you an idea of the appearance.
Finally, we can also add a logo to your cork lid, which we can either make using a heat stamp, laser or print. The heat stamp will burn the cork and darken it, which gives an attractive ‘organic’ look, but it is not so good for fine lines as the burn can bleed a small amount. The laser also burns the cork but is more accurate to give clean lines (but also more expensive). Print can give a good quality reproduction of a logo and can be professional looking option. For the heat stamp and print there is a set up cost of around €180, but then the production cost is quite low. For the laser there is no set up cost, but the production cost is much higher.
If you need any further information about the options available for your cork lids, please get in touch!
