Fibers and Fillers

Mold Making Fibers and Fillers

Fillers are used to alter form and function of resins as well as latex. Some may decrease shrinkage, increase or decrease weights, assist in rotational-casting, add thermos-conductive properties for vacuum forming, or alter appearance. Many types of fillers are versatile and offer one or more benefits. Recommended levels of additional filler are based on the total resin weight—(Part A Base + Part B Catalyst. Fillers are always premixed to the A-side of mixture before to blending both components (Part A and Part B).

Fibers and fillers are often considered a secondary commodity in the field of mold making and casting. However, they are an important ingredient in the mold making and casting process. Fillers make the cured resins stronger, save cost because less resin is used, and impart a desired look or heft to the cured plastic. Thus fillers are used to:

1. Act to extend more expensive mold making and casting materials, or
2. To alter the weight of a casting, or
3. Use to bind dissimilar materials such as cotton fiber used to bind alginates to plaster of Paris bandages.

The one single common denominator of all fillers is their effect on the curing of resins and other materials as they all slow the set time down. The addition of these items inhibits the exothermic reaction time. The benefit is that in the case of most resins this will reduce shrinkage.

We stock a wide range of fillers from basic padding fillers like Marble Powder or Calcium Carbonate through to specialty fillers like Metal Powders, Cab-o-Sil and Glass Bubbles. Each has its own properties and uses

Types of Mold Making Fibers and Fillers

Certain fillers such a pecan shell flour are multi-use as it can be used to make a realistic cold cast wood look, or as a resin or latex filler. In addition used as a latex filler one can control the hardness of a latex mold by simply adding a bit more filler.

• Marble powder – use to add weight and extend your resin to make it go further
• Calcium Carbonate - Will improve brittleness, surface durability and extend your resin without impacting on viscosity
• Glass Bubbles - Will lighten your cast to the maximum but will also improve water resistance and surface durability
• French Chalk (Talc) - Will thicken resin rapidly making an simple filler for composites
• Ruberfil - Will allow thicken and extend latex rubbers for mold making
• Cab O Sil (Fumed Silica) - Will thicken resin to make it cling to verticals such as gelcoats
• Cotton fiber
• Fiberglass fiber adds strength to plaster
• Nylon fiber adds strength to mold rubbers