Advantages of Powder Chopped Strand Mat than Emulsion ones.

People use powder chopped stand mat and emulsion chopped strand mat because of different crafts and daily usage habits. But next time you use fiberglass chopped strand mat for an application, think powder ones firstly. Below are some reasons.

Firstly, the corrosion and water resistance of composites made with powder CHOPPED STRAND MAT are far better (compared to emulsion CHOPPED STRAND MAT) in view of the inherent superior chemical resistance of bisphenol fumarate polyester powder compared to plasticized PVAC. Composites are less prone to osmotic blistering when powder CHOPPED STRAND MAT is used. Hence more widespread use of powder CHOPPED STRAND MAT in manufacture of boats, tanks etc. that use the contact molding technique.

Secondly, composite strength has a direct correlation with % by weight of the fibrous reinforcement – higher reinforcement content (weight %) results in superior mechanical properties such as tensile, flexural strength and related moduli. As the degree of wetting is more thorough and speed of wetting is faster, consolidation of layers with powder CHOPPED STRAND MAT is easier and better. This is more evident in vertical sections due to less resin drip (better resin retention), aided primarily by superior consolidation capability. Drain resistance is very good as faster wet-out with polyester powder binder provides lower surface tension. Logically, use of powder CHOPPED STRAND MAT must result in lower resin consumption in view of the above. Operators tend to dab more resin on each layer of emulsion CHOPPED STRAND MAT in the layup sequence to ensure wetting is thorough (to avoid resin-starved areas) and avoid possible springback (in case of contoured sections). The end result is more resin consumption and a relatively lower glass-resin ratio compared to powder CHOPPED STRAND MAT. The key lies in shopfloor operators adapting to handling powder CHOPPED STRAND MAT differently - since wetting is more through and faster and consolidation of individual layers requires lower roller pressure (or reduced frequency of brush stipling as the case may be) and relatively lesser resin usage.

When large areas are involved with multiple layers (ie. thicker laminates), the resin saving can be more pronounced with powder CHOPPED STRAND MAT without sacrificing aesthetics – differential wetting is more common with emulsion CHOPPED STRAND MAT due to slower speed of dissolution in the styrene. The higher glass content (% glass fiber by weight) in the molded composite would be evident with powder CHOPPED STRAND MAT when quality control personnel conduct tests for mechanical properties (tensile, flexural strength and modulus) on cut-out sections.