Processes - Meena Fiberglas Industries

SPRAY-UP

Spray-up is an open-moulding composites fabrication process where resin and reinforcements are sprayed onto a reusable mould. The resin and glass may be applied separately or simultaneously "chopped" in a combined stream from a chopper gun. Workers roll out the spray-up to compact the laminate. The spray-up process offers the following advantages: It is suitable for small to medium-volume parts. It is a very economical process for making small to large parts. It utilizes low-cost tooling as well as low-cost material systems.

VACUUM INFUSION

The Vacuum Infusion Process (VIP) is a technique that uses vacuum pressure to drive resin into a laminate. Dry materials are laid into the mould and the vacuum is applied before resin is introduced. Once a complete vacuum is achieved, resin is literally sucked into the laminate via carefully placed tubing. Higher fibre-to-resin ratio (up to 70% fibres by weight). It has higher strength and stiffness. No resin entrapped air/ very low voids. It is very consistent laminate with great process control (less human errors). It has minimal part shrinkage with good surface profile and accuracy. It has faster cycle time.

PULTRUSION

Pultrusion is a continuous process for manufacture of fibre-reinforced plastics with constant cross-section. The term is a portmanteau word, combining "pull" and "extrusion". As opposed to extrusion, which pushes the material, pultrusion pulls the material. The Pultrusion process is a highly automated continuous fibre laminating process producing high fibre volume profiles with a constant cross section. Having a high fibre volume fraction makes pultrusion an ideal process for structural component production giving a high strength to weight ratio.

FILAMENT WINDING

Filament winding is a fabrication technique mainly used for manufacturing open (cylinders) or closed end structures (pressure vessels or tanks). This process involves winding filaments under tension over a rotating mandrel. The most common filaments are glass or carbon and are impregnated with resin by passing through a bath as they are wound onto the mandrel. Once the mandrel is completely covered to the desired thickness, the resin is cured. Depending on the resin system and its cure characteristics, often the mandrel is autoclaved or heated in an oven or rotated under radiant heaters until the part is cured. Once the resin has cured, the mandrel is removed or extracted, leaving the hollow final product. For some products such as gas bottles, the 'mandrel' is a permanent part of the finished product forming a liner to prevent gas leakage or as a barrier to protect the composite from the fluid to be stored.

LRTM

Light Resin Transfer Moulding, or Light RTM, is a process by which composite products are manufactured using a closed mould system. Transfer moulding is similar to compression moulding except that instead of the moulding material being pressurized in the cavity, it is pressurized in a separate chamber and then forced through an opening and into a closed mould. The advantages of closed moulding for either true RTM or RTM Light, offers working environments for the moulding operators that are far more comfortable and healthier. They then are willing to apply their skills of quality and productivity at a consistently higher level each day. Even though it is true that RTM Light will not yet meet the production rates that are enjoyed in traditional RTM, RTM Light will provide a 300 to 400% increase in per square foot productivity over open mould, with significant improvement of bill of material compliance and lower operator employment turnover.

COMPRESSION MOULDING

Compression moulding is considered as the main method for making many structural car body parts, fiberglass bumpers, fiberglass manhole cover and plate-spring. The entire process of pressure forming is accomplished by converting the sheet plastic into the FRP finish in the mould. It can generate complex geometric shapes in a short time. Mould forming can eliminate some secondary finishing operations such as drilling, forming and welding. And the whole process can be automated. There are few advantages of compression moulding. Good finish on both sides. Faster fibre glass production. Uniform fiberglass reinforced plastic products quality. Less labour content. Very little finishing operations are required. There are also two glass reinforced plastic disadvantages of pressure forming. On the one hand, due to the high cost of moulds and printing presses, this process is not suitable for low yield. On the other hand, this process also does not apply to very large FRP grp composite products.

DMC/BMC

Bulk moulding compound (BMC), bulk moulding composite, or dough moulding compound (DMC), is a ready-to-mould, glass-fibre reinforced thermoset polymer material primarily used in compression moulding. DMC has the unique property of di-electric strength, arc resistance, insulation, flame retardancy and temperature resistance. Due to this DMC is suitable for electrical products, which have to meet stringent requirements. BMC/DMC provides solution for Dimensional Stability, Low Moisture Absorption, Heat Resistant, Good Creep Resistance, Low Linear Expansion, Good Mechanical Strength and Electrical Property.

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