PVA High Strength & Modulus Fiber

PVA High Strength & Modulus Fiber

PVA high - strength & high - modulus fiber taking polyvinyl alcohol as its major raw materials is produced by a special process. It is of high strength, high modulus, acidproof, alkaliproof, abrasion resistance and sunlight resistance which are possessed by PVA fiber, thus it is much better than the other products in general. With these excellent properties, it has a wide application in industry fabric, building reinforcing materials, package materials, ropes and meshes .

Applications:

• Concrete reinforcing materials used for buildings.

• Ideal replacement of asbestos and glass fiber.

• Reinforcing materials for upholstery.

• High strength fishing meshes, cables, safety nets.

• High strength fabric used in industry.

• Modern package reinforcing materials.

Specifications and properties:

Item Property	High strength & modulus Ⅰ.	High strength & modulus Ⅱ.	Super-short staple fiber Ⅰ. for building materials	Super-short staple fiber Ⅱ. for building materials
Density (g/cm²)	1.26	1.26	1.26	1.26
Titre (dtex)	2.0 _0.3	2.0_0.3	1.7 - 3.0	1.7 - 3.0
Length (mm)	2 - 65	2 - 65	2 - 65	2 - 65
Tenacity (CN/dtex)	> 10.5	> 10.5	≥8	≥6
Modulus (CN/dtex)	> 240	> 240	>200	>150
Breaking elongation (%)	< 7_1.5	<7_1.5
Reduction in hot water	< 2	< 3
Acid proof	Good	good	good	good
Alkali resistance	Good	good	good	good
Ultraviolet resistance	Good	good	good	good
Electric conductivity	Low	low	low	low
Thermal conductivity	Low	low	low	low

C. Fiber breaking elongation comparisons

Fiber	Vinylon (high strength)	Vinylon (usual)	Nylon	PP fiber	Polyester (usual)	Polyester (high strength)
Breaking elongation %	7	15	20 - 40	15 - 35	14 - 25	10 - 14

D. Alkali resistance comparisons:

Test condition				Fiber strength loss ratio (%)
Density %	Temperature℃	Duration time (hr)	Vinylon-high strength		Viscose fiber yarn	Nylon 6	Polyester
1	20	10	0		12	0	1
1	100	100	7		29	25	71
40	20	10	0		100	18	4

Sunshine resistance comparisons:

Exposed in the sunshine(hour)	Fiber strength loss ratio ( % )
Exposed in the sunshine(hour)	High strength vinylon	Nylon 6	Viscose fiber	Cotton
100	3.05	19.6	4.26	3.67
300	7.93	41.2	7.45	30.73
500	10.98	65.09	25.00	38.53
700	11.16	74.51	63.30	49.54

F. Applications in asbestos cement products of PVA high strength & modulus fiber:

Shortcomings of the main reinforcing materials:

ASBESTOS – harmful to the health and environment

• As a reinforcing material, asbestos has a small tenacity and is easy to break.

• It has the property of acid resistant but not alkali proof.

GLASS FIBER - costly and hard to be popularized.

AN IDEAL REPLACEMENT OF ASBESTOS AND GLASS FIBER:

Advantages:

• Good physical and chemical properties.

• Excellent mechanics properties to improve board’ toughness and anti-

shock ability and to reduce break rate.

• With adequate supply , good quality and good dispersing properties.

• Being suitable for all types of cement with good alkali & acid resistant properties.

• Raising the board’s anti-crook temperature and reducing the product volume.

• Improving the circumstances.

• No need to change original equipment.

Suggested formula:

Small corrugated tile: :

Unit	Cement	Asbestos	Vinylon	Paper pulp	Sepiolite		Additive agent		Ratio of the replacement by asbestos		Quantity of the replacement by asbestos
KG	250	26	4.7	6	proper amount	proper amount		1: 4.5		-
%	87.2	9.1	1.64	2.1	-		-	-		40

2) Cement plate

Unit	Cement	Asbestos	Vinylon	Sepiolite	Paper pulp	Quantity of replace asbestos
KG	250	15	4.7	30	6	-
%	81.78	4.91	1.54	9.81	1.96	70

H. Applications in building concrete of PVA high strength & high modulus fiber:

Structural tortoise-cracking in concrete:

In the concrete industry, the only reason for tortoise-cracking is that the inner stress to the concrete surpasses the strength it can bear. People have tried to reinforce the structural strength of the concrete products to offset the stress from outside, but they can’t control it effectively, for quite a long time, due to the inner stress caused by shrinkage. During the period of molding, the tortoise-cracking forms within 24 hours after it is molded because of the shrinkage caused by the dryness inside the concrete.

Effective method:

Mixing PVA high strength & high modulus fiber into the primary or secondary reinforcing materials can improve the building material's anti-draw ability and toughness, increase the concrete’s ability of tension resistance, reduce the water loss rate, improve the concrete material’s ability of anti-breaking and reduce effectively tortoise-cracking. Thus it is an ideal reinforcing material in the building industry.

Purposes of using the fiber:

• Prevent the tortoise-cracking.

• Increasing the tenacity, anti-breaking ability and abrasion resistance.

• Raising the weary resistance of anti-elasticity.

• Reducing the water osmosis.

• Extending the life cycle of the concrete.

Advantages:

• With good dispersing ability, it can be dispersed uniformly in every part of the product.

• It is suitable for concrete which can’t have metal in it.

• It does not corrode and does not have chemical reactions.

• With excellent ability of anti-alkali, it is suitable for any type of the cement.

• It doesn’t affect the surface property of the concrete.