Ladders are some tools to access to highlands and higher levels and will be assembled either one piece (simple) or slider (telecommunications) with Shelter or without Shelter according to the application in different environments and tailored to the client's request.
Advantages of FRP/GRP Composite Ladders in comparison with metallic ones
- Corrosion Resistant
- Non-Magnetic
- Safety and simpler installation
- Maintenance Free
- Impact Resistance
- Variety of colors
- Lighter weight
- More Fatigue Life
THE PULTRUSION PROCESS
Pultrusion is a manufacturing process for producing continuous lengths of reinforced polymer structural shapes with constant cross-sections. Raw materials are a liquid resin mixture (containing resin, fillers and specialized additives) and flexible textile reinforcing fibers. The process involves pulling these raw materials (rather than pushing, as is the case in extrusion) through a heated steel forming die using a continuous pulling device. The reinforcement materials are in continuous forms such as rolls of mat and doffs of roving. As the reinforcements are saturated with the resin mixture ("wet-out") in the resin bath and pulled through the die, the gelatin or hardening, of the resin is initiated by the heat from the die and a rigid, cured profile is formed that corresponds to the shape of the die. While pultrusion machine design varies with part geometry, the basic pultrusion process
concept is described in the following schematic.
The creels position the reinforcements for subsequent feeding into the guides. The reinforcement must be located properly within the composite and this is the function of the reinforcement guides.
The resin bath saturates (wets out) the reinforcement with a solution containing the resin, fillers, pigment, and catalyst plus any other additives required. The interior of the resin bath is carefully designed to optimize the wet-out of the reinforcement.
On exiting the resin bath, the composite is in a flat sheet form. The performer is an array of tooling which squeezes away excess resin as the product is moving forward and gently shapes the materials prior to entering the forming and curing die. In the forming and curing die, the thermosetting reaction is heat activated (energy is primarily supplied electrically) and the composite is cured (hardened). On exiting the die, it is necessary to cool the hot part before it is gripped by the pull blocks (made of durable urethane foam) to prevent cracking and/or deformation by the pull blocks. Strong well uses two distinct pulling systems, one that is a caterpillar counter-rotating type and the other a hand-over- hand reciprocating type to pull the cured profile to the saw for cutting to length.
