A very common question we receive is; What type of blade do I need to cut X-Type of foam?

While every application is unique, we've found that this guide is a very good starting point for blade to material selection. 

Knife Type

Material Removal Method: Slices Material
Dust: None/Low
Commonly Processed Materials: Flexible Foams, Low-Density Foams, Polyurethane, Fibrous Materials (Convex)
Edge Types: Band Knife, Concave, Scallop [1/2, 3/8], Wavy [3/4]

For low-density flexible polyurethanes, knife-type band saw blades are commonly used for their favorable finish and minimal removal of material. The cutting method of knife-type blades imparts a slicing action, which is essentially parting the foam without any material actually being removed. Creating a low-dust if not dust-free process. 

For fibrous materials, we recommend a band knife with a concave or scallop edge. Our tests have shown that fibrous materials respond well to knife-type blades, but scallop out-performs in most instances.

Band Knife Edge Example

Convex Edge Example

Tooth Type

Material Removal Method: Cuts Material
Dust: Low, Medium-low
Commonly Processed Materials: Med-density foams, Polyethylene
Edge Types: V-Tooth [10T, 10T GG, 14T, 18T, 24T], F-Tooth [11T, 14T]
Applicable Machinery: AV, AVX, Models C E G H, F-3W, F-24, LVR, A-2 Tilt, HT, HTX, 51-88, HPX, VPX

For medium-density polyurethane foams such as; Polyethylene. Tooth-type band saw blades are preferred over knife-type blades, as the material demands a more aggressive tooth-type to accurately process material. The cutting method of tooth-type blades utilizes a cutting action, which removes a minimal amount of material from the foam. Creating a low-dust process. 

For firmer foams that still require a smooth finish 18T-24T V-Tooth blades are a good starting point. If the material still requires a more aggressive blade, try using an 11T-14T Flat-Tooth blade. Generally speaking the lower the tooth count the more aggressive the blade will be in separating material and will impart a rougher finish. Our Flat-Tooth blades help rectify this issue by being more aggressive but also providing a smooth finish because of the honed edge, increasing overall sharpness of the blade. Selecting the correct tooth-type for you material is not a one-size-fits-all approach. Part of your process development should be testing which TPI and tooth-type accurately achieves your process parameters. 

10T V-Tooth Example

14T V-Tooth Example

Saw Type

Material Removal Method: Saws Material
Dust: Medium-High
Commonly Processed Materials: High-density Rigid Foams, HR Foams, Balsa
Edge Types: Raker, Raker Hardback, Raker 14T, Kerf, Kerf 10T, 
Machinery: WHDS-54, SHR 60-20, SHR 60-30

For high-density, rigid polyurethane foams and balsa wood, a saw-type band saw blade is preferred over knife-type and most tooth-type blades. The material requires a kerf (width and amount of material removed from cut) to effectively process material. The cutting method of saw-type (kerf) blades utilizes a sawing action, in which the kerf-type removes a set amount of material from the foam. This process creates a large amount of dust as the maximum amount of material is being removed in comparison to other blade types.

Selecting the correct saw-type for you material is again not a one-size-fits-all approach. Part of your process development should be testing which TPI and kerf-type effectively processes your material.

Example of a saw-type kerf blade