Forming Fabric General

Question 1

What are the raw materials used in forming fabric?

Answer 1

Polyester and polyamide.
Need Polyamide for durability!!
Polyester is stiffer

Question 2

Why is polyamide used in forming fabrics?

Answer 2

For durability

Question 3

What is the roll of forming fabric

Answer 3

Dewatering, Retention and Transportation

No marks, high dry content and good formation. Stable, clean, predictable `

Question 4

What direction is the warp yarn

Answer 4

Machine Direction

Question 5

What direction is the weft yarn

Answer 5

Cross direction

Question 6

What yarn is cross direction

Answer 6

Weft

Question 7

What yarn is machine direction

Answer 7

Warp

Question 8

What does SSB stand for? (Forming Fabric)

Answer 8

Sheet support binder fabric

Question 9

Why was SSB forming fabric developed?

Answer 9

Designed so we can have two distinct sides. A fine paper side and a coarse wear side without impacting either side.

Fine top for good retention and contact points
Bottom for wear resistance

Question 10

What is SSB forming fabric

Answer 10

Binding yarn in CD goes into paper side then into warp so it acts as sheet support as well as binding to the wear side

Question 11

What is yarn count

Answer 11

2 values
nMD = number of MD yarns in cm
nCD = number of CD yarns in cm

Question 12

What is T count

Answer 12

Its nMD + nCD

nMD = number of MD yarns in cm
nCD = number of CD yarns in cm

Question 13

What is SP count

Answer 13

Support count
It is number of yarn knuckles that support the paper web in 1/cm2

Question 14

What do FSI and DI stand for

Answer 14

Fibre support index and drainage index

Question 15

What are the benefits of SSB fabric?

Answer 15

Sheet support binder
More stable and even profile
Higher wear potential
Higher fibre support - better retention and smoothness

Question 16

What does a lower FSI mean in forming fabrics?

Answer 16

Means a coarser fabric which means water can exit faster

Question 17

What are the different caliper values examined on forming fabrics?

Answer 17

Total caliper
Critical caliper - when MD yarns start to wear
Wear margin caliper between CD yarn to MD yarn

Question 18

What is void volume in forming fabrics?

Answer 18

Free space inside the fabric

Question 19

Do we want a high or low void volume in forming fabrics?

Answer 19

Ideally want low, because the more water we carry inside the more chance of misting… But we need to balance this with durability - compromise

Question 20

What is a shaft count

Answer 20

Number of MD yarns until a weave pattern repeats itself.
Number of yarns known as shed

Question 21

What is polishing?

Answer 21

Fine grinding to smooth topography and give better guiding - but this is very rare.