Composites
AFC has been in the field of composites since last 25 years
Here is a brief overview of composites:
Composites are an innovative replacement for conventional materials such as steel, aluminum and plastics for a wide range of applications
Advantages:
* Consistent in material quality
* Uniform & consistent thickness
* Pre-finished holes & features – NO rework line
* Consistent painting quality
* No waviness on outer surface
* In-built ribs for strengthening
* Moulded inserts and studs for assembly
* Part integration & consolidation
* Non corrosive
* Excellent thermal, electrical insulation properties
* High Mechanical Strength (Density 1.8)(MS 7.8)
Manufacturing Methods
(A) HAND LAY-UP
Handlayup refers to the manufacturing process for fibre reinforced plastic (FRP) products in which an operator deposits the thermoset resins and reinforcements in or on a mould by hand or using hand tools. It is a non mechanised or open mould manufacturing method.
Even after 70 years since GRP was introduced, handlayup is the major process for the manufacture of GRP products and the most cost-effective
Advantages
It is a fast process – time saving
It is the most economical process
Repair of the part is possible
Best for low volume production
Limitations
Low dimensional stability
Intricate details & undercuts are difficult to achieve
Both side finish is not possible
Thickness of the component cannot be maintained
Small and intricate components are not suitable
Dimensional stability of inserts are difficult to achieve
(B) RESIN TRANSFER MOULDING (RTM)
It is a one step higher process as compared to Hand Lay-up. In Hand Lay-up there is only one side mould. For RTM process a male – female mould is required. Gel coat is applied on the cavity, the developed length glass matt is placed. The mould is closed by the male part of the mould. Resin is injected at pressure through a suitable point. Curing takes place at room temperature. Vacuum assisted process is also employed in relevant cases.
Advantages
Both side finish
Better Dimensional stability than Hand lay-up
Disadvantages
Only suitable for RTM friendly shapes
Part may be weak because of non impregnation of resin in some areas
Best suited for larger surface area components
Tooling cost is more compared to Hand Lay-up
(C) COMPRESSION MOULDING WITH SMC
Compression moulding is one of the fastest GRP processing methods. The product is made within the cavity of the mould and hence it is a closed mould processing method.
Advantages
Both side finish
Faster production
Uniform Product Quality
Less Labour Required
Very little finishing operations required.
Disadvantages
Not suitable for low volume of production because of high cost of metallic moulds and press
Change in drawing of the part may render the mould useless for further production
The process is also not suitable for very large sized products