 Re: Curable reducer, where to buy?
This thread started out with Controlled Images asking about "curable reducer" and then it got off onto "reducer/retarder" and then back and forth. These are two different things. Curable reducer is used for plastisol ink and reducer/retarder is used with water-based ink. Let me explain...
Curable Reducer
Curable reducer is also known as “Reducer-Detackifier” by some ink companies, such as Union Ink. It is used with plastisol inks.
Reducers and Extenders are very important to the textile screenprinting industry. Every shop that I have found to be efficient, uses these products in their ink departments and are using them to produce higher quality printing.
It is important to understand the roles that these products play in the printing process. The two are not interchangeable and actually have very different roles.
Reducers are used to lower viscosity and extenders are used make opaque inks right for printing on light substrates. As with all screenprinting products it is extremely important to learn to use the products in the correct manner. Just as anything worth knowing it will take time and effort to learn how to use them, but in the end the increased quality that can be achieved, the lower ink cost and ultimately the money saved is worth the effort.
When plastisol ink is heated in the curing process the PVC resin swells and absorbs the plasticiser. As the two combine and cross-link and then begin to cool to a flexible film of cured ink. That is the “bumper sticker” explanation of what happens when plastisol ink is cured.
It is extremely important to know that the main component in plastisol reducer is plasticiser, which is one of the main components in the aforementioned plastisol ink. Plasticiser is the liquid component of plastisol. In order to use the product correctly it must be blended in proper balance with the PVC Resin, the solid component of plastisol ink. If they are not in balance the plastic film will not be crosslinked and much of the ink will be washed away when the substrate is laundered.
There are many types of reducers on the market. Some are curable and some or not. The only ‘right’ type is the curable reducer. An easy way to tell the difference is that curable reducer will be a milky white or light cream color. If you have reducer that is clear it is nothing more than pure plasticiser. Do not use it with plastisol ink as it will create an unbalanced mix and will not crosslink. On the other hand, curable reducers are a mix of plasticiser and resins that will cure even if you print nothing else. You could add as much as you wanted to your ink and the only thing you’d be doing is reducing the pigment of the ink.
Reducing Water-based Inks
While water-based inks can be reduced with small amounts of water, some ink companies make reducers and retarders that can actually increase the control over the printability of the inks.
Generally speaking, almost all water-based inks are very creamy when first purchased and are considered ready to use right out of the container. If you must add a reducer, never add more than 5 to 10-percent of reducer by volume to the ink. This means that you should never use more than 1 part of reducer to 10 parts of water-based ink.
Retarding Water-based Inks
All water-based inks are air dry and will sometimes dry in the screens, especially in those shops that lack the proper humidity controls that air conditioning affords. If the ink is drying in the screen, you can add a small amount of the retarder to the ink, but never more than 5- to 10-percent by volume in order to retard the drying time. This is especially helpful to those who live in very hot, dry areas or at higher altitudes.
The retarder component in most reducer/retarder is actually nothing more than glycerin. If you are ever having a problem and need a quick fix, you can always add a small amount of glycerin to your water-based ink to retard the drying time. Never use more than 10-percent by volume. You can also use the propylene glycol type of anti-freeze if pushed. |