Composite sleeper

The composite sleeper, or synthetic sleeper is composed of continuous glass fiber reinforced polyurethane foam material. It has the characteristics of glass fiber reinforced plastic composite material and foam material. composite railroad tie has the advantages of natural wood and plastic. For example, it has higher strength, higher specific modulus and can be used as structural material. It is light in weight, heat-insulating, chemical-resistant, insulating, and resistant to aging, similar wood properties, such as nailing and riveting. In general, composite sleeper is mainly used in high-speed railways and subways (such as ballasts, Bridge tops, platforms, etc.) ,especially where the use of concrete sleepers is limited.

Composite sleeper features

• The installation on site is simple, and the maintenance and repair works are greatly reduced.。
• It can keep the distance between the rail and the guard rail, the sleeper and the guard and the geometry of the line well, and the line condition is excellent and basically unchanged.
• The sleeper surface is not easily peeled off. 
• Sizes available: sleeper height not less than 140mm, width not less than 200mm, and length upon customer need.
• Product quality standard: CJ/T399-2012

Composite sleeper material strength

Item		JIS E1203:2007 Strength	(CJ/T399-2012) AGICO Sleeper Strength
Material Strength	Bending Strength	min. 70 N/mm2	min. 80 N/mm2
	Young 's modulus in flexure	min. 6000 N/mm2	min. 7000 N/mm2
	Withstand bending load	min. 170 kN	min. 170 kN
	Longitudinal  compressive strength	min. 40 N/mm2	min. 50 N/mm2
	Shearing  strength	min. 7 N/mm2	min. 7 N/mm2
	Adhesion shearing strength	min. 7 N/mm2 (base-material  breakage)	min. 7 N/mm2 (base-material  breakage)
Electrical Properties	Alternating-current breakdown voltage	min. 20 kV	min. 20 kV
	Direct-current insulation resistance	min. 1 X 1010 Ω	min. 1 X 1010 Ω
Pulling Strength	Track spike pulling strength	min. 15 kN	min. 20 kN
	Screw spike pulling strength	min. 30 kN	min. 40 kN
Unit volume mass		0.74土 0.1 g/cm3	0.74土 0.1 g/cm3
Amount of water absorption		max. 10 mg/cm2	max. 10 mg/cm2

Composite sleeper production process

Main raw and auxiliary materials: continuous glass fiber, polyether polyol,  isocyanate and related components

1) Yarn system (creel, collection plate, traction head)

2) Polyurethane foam feeding system (batch tank, foaming machine, sweeping frame, swing frame and chiller)

3) Material unwinding system (unwinding frame, heating platform and structure)

4) Rolling mold system

5) Rear conveying system (conveying platform and cutting machine)

6) Impregnation Facility

7) Adhesive equipment

8) Surface coating equipment

9) Inspection equipment

The composite sleeper is made of long glass fiber as the reinforcing material, with polyurethane resin as base material to be foamed, solidified and synthesized. At the beginning, two kinds of liquid polyurethane raw materials of A and B are sent to mix by the metering pump in certain ratio at the head facility, then uniformly poured onto the glass fiber surface, and after being evenly kneaded, it is then foamed, solidified and formed into a rolling mold, and finally the synthetic product is automatically tracked and cut at the production line. The semi-finished product is cut into a certain length as needed, and then grinded, compounded, coated or sprayed to become a finished product. 

Woking shop of composite railroad tie