Silicone Soap Mold Liners

Question:

I am intrigued with the silicone liners. It seems to me to be a great solution to the problem of fitting liners for each batch. What do you think about silicone liners for the larger production shops where you have provided the soapmaking equipment?

Answer:

The silicone seems to work okay for hobbyists and small batch production. We have not found that to be the case ourselves, but we do see people using this liner method. Silicone tears, degrades over time and, of course, is expensive.

For a large block pour with a Manual Soap Cutter™ Mold, it is just too easy to line a soap mold, versus having to handle and wrangle around a 40 lb block of soap to remove the liner.

Soap Mold Release Liner
Soap Mold Release Liner

We have tried about everything out there. We were building professional soap cutters long before anyone else.

If silicone was a viable solution for Large Batch SoapMaking, guaranteed we would have been the first to have perfected it.

If you could take a poll of all the SoapMakers out there, you would find that 90% of the companies making large batches and pouring 500 lbs or more of soap per week are using paper liners.

Both of our Pro-Cutters are designed to load easily, either by sliding the block onto a Manual Soap Cutter™ Loaf Table or by setting onto the Air Soap Cutter™ Rolling Table, to cut right from the mold bottom itself. Silicone is too fragile to allow a 40 lb block of soap to be pushed around, while it is sitting on top of it (Manual Soap Cutter™). Having silicone rubber on the bottom of either types of Molds (Air Soap Cutter™ or Manual Soap Cutter™) would prevent the wires from passing through the block of soap into the grooves.

The reason things like lining, stirring, heating oils, mixing lye, etc. got put into the category of being a hassle by the Handcrafted SoapMaker, is probably because no one got fed up enough to step back and look at it another way and to find a more efficient way to do it. We just happen to be the first to do so.

Take for example, weighing and heating oils; before we started supplying Oil Heaters, people were doing this one batch at a time. It would take hours just heating oils to mix a few batches. Now, all the oils are mixed and heated for a number of batches all at once. Not only are they heated more efficiently, with less energy but in much less time. The SoapMaker also saves time in measuring both, in and out, of the Oil Heater.

Soap Mold Liner Paper Cutter
Soap Mold Liner Paper Cutter

With liners, you would do the same thing, pre-cut lots of liners. It only takes two sizes, one for the bottom the other for the perimeter. The height of the liner is already pre-cut. With a template for the soap mold bottom and a simple mark on the table for the length of the perimeter liner, you can make a hundred sets in a few hours. It takes 30 seconds to line a soap mold if you take the time to get the procedure down-pat. You get excellent release both from the soap and from the mold. It makes a very tight corner, adheres tightly to the soap mold, it is wrinkle free, does not outgas, does not need to be washed and does not matter if you get a little tear in it.

Here is a list of what we have seen over the years on liners and soap mold materials, and our opinion of them. This is based on using in professional soap molds, under constant use.

Types of Soap Mold Liners…

Mylar: Releases nicely but can stick a little. Do not wrinkle it or it will remain there and is very difficult to flatten. Hard to get to stick to the mold if too thick and soap sometimes gets behind the plastic, ruining part of the batch.. Wires will not press down into it to allow a clean cut on the bottom.

Silicone: Releases very well and seems to stick to the mold side well. Works well for small soap molds or soap molds that allow you to remove the soap by flipping it over. Will degrade over time and use, tears easily, expensive initially and with replacement. It can shrink over time if not made correctly. It can outgas depending on the type of silicone. Needs to be cleaned between uses to remove carry over fragrance. Wires will not press down into it to allow a clean cut on the bottom.

Thin Plastic sheets: Does not release any easier than the plastic soap mold that it is already poured in. Don’t see the point as once the mold is taken apart you still have to peal off the plastic and not bend it. Difficult to hold to the soap mold sides and soap sometimes gets behind the plastic, ruining part of the batch. Wires will not press down into it to allow a clean cut on the bottom.

Shower curtains: We understand they release well, are cheap and you can get nice floral patterns to look at while lining. We have not tested these. Most shower curtains are made in China, out of who knows what. Most are PVC, this outgases. Not sure if the wire will press into it to allow a good clean cut on the Loaf Table.

Teflon: Releases okay but is known to stick to some types of soap. Do not wrinkle it or it will remain there and is very difficult to flatten. Can tear easily if thin. Hard to get to stick to the mold if too thick and soap sometimes gets behind the plastic, ruining part of the batch.. Wires will not press down into it to allow a clean cut on the bottom.

Shortening or oil only: Some types of soap release well with just this. Sometimes just part of the soap mold can be coated, the rest lined. Inexpensive, fast and reliable but make sure you know it will release. You can in a pinch run a wide thin blade like a drywall knife between the plastic and soap and keep a good surface.

Freezer paper: Releases well, adheres to the soap mold well. The only real difficulty with it is that it is thick and does not make sharp corners without extra effort. It also wrinkles badly, so it may be best to have a thin waste cut.

Silicone paint or painted on release agents: These eventually break down and need to be recoated. Of course when they break down, where do they go? Into the soap.

Types of Soap Molds…

Acrylic plastic: You see people popping up every several years who make these and then they fade away. They really don’t release any easier than HDPE but they look pretty. Eventually, under lots of use, they break down and start cracking from the oils used in making soap, specifically the essential and fragrance oils. It is a real disservice to the unaware SoapMaker who has spent good money purchasing these. We used to make them for ourselves and when we found out what would happen under constant use, went to HDPE. The fragrance and essential oils, eventually start degrading the plastic, gradually working into it until it starts cracking.

Wood: Has to have some sort of liner. Breaks down over time, warps, does not stand up to professional, repeated use and will eventually have to be replaced.

Stainless Steel: Next to HDPE, this is the best but it is expensive both in labor and material. It also has to be insulated very well to maintain an even saponification.