Reinforced Plastics

MFG 355

Composites

Metals are isometric materials

Composites can cut weight by not being isometric and still maintain the strength in the desired directions• Composites are, by definition, solid

materials composed of more than one substance in more than one phase

• Metals are isometric materials• Composites can cut weight by not being

isometric and still maintain the strength in the desired directions

• Composites are, by definition, solid materials composed of more than one substance in more than one phase

• Metals are isometric materials• Composites can cut weight by not being

isometric and still maintain the strength in the desired directions

• Composites are, by definition, solid materials composed of more than one substance in more than one phase

Composites

Processes

Thermoplastic processes –Very short fibers

Matched die/compression molding

RTM

Spray-up

Hand lay-up for wet and prepreg materials

Filament winding and fiber placement

Pultrusion•• Thermoplastic processes –Very short fibers• Matched die/compression molding• RTM• Spray-up• Hand lay-up for wet and prepreg materials• Filament winding and fiber placement• Pultrusion•• Thermoplastic processes –Very short fibers• Matched die/compression molding• RTM• Spray-up• Hand lay-up for wet and prepreg materials• Filament winding and fiber placement• Pultrusion•• Thermoplastic processes –Very short fibers• Matched die/compression molding• RTM• Spray-up• Hand lay-up for wet and prepreg materials• Filament winding and fiber placement• Pultrusion•• Thermoplastic processes –Very short fibers• Matched die/compression molding• RTM• Spray-up• Hand lay-up for wet and prepreg materials• Filament winding and fiber placement• Pultrusion•• Thermoplastic processes –Very short fibers• Matched die/compression molding• RTM• Spray-up• Hand lay-up for wet and prepreg materials• Filament winding and fiber placement• Pultrusion•• Thermoplastic processes –Very short fibers• Matched die/compression molding• RTM• Spray-up• Hand lay-up for wet and prepreg materials• Filament winding and fiber placement• Pultrusion•

Advanced Composites• Long (continuous) fibers• Very high performance reinforcements

– Carbon and aramid• Resins are also very high performance• Typically aerospace applications

Engineering Composites

Shorter fibers/fiberglass

Lower mechanical properties (stiffness)• Lower performance resins• Shorter fibers/fiberglass• Lower mechanical properties (stiffness)• Lower performance resins• Shorter fibers/fiberglass• Lower mechanical properties (stiffness)• Lower performance resins

Matrix Materials

• Resins– Both thermosets and thermoplastics can be

used– Short fibers are generally used in

thermoplastics– Long fibers are generally used with

thermosets

Matrix Materials

• Short fiber composites– Less than 0.2 inches (whiskers)– Processed through standard thermoplastic

processes• Must pass through gates, runners, and gap

between processing screw and barrel walls

– Thermoplastics generally benefit greatly from even the short reinforcement materials

Matrix Materials – FRP

• Intermediate length fiber reinforcement– The longer the fibers, the more difficult it is to

coat the fibers enough to reap strength benefits

– Low viscosity thermosets “wet-out” the materials better than high viscosity thermoplastics

– Generally use unsaturated polyester and vinylester resins for FRP

Matrix Materials – Advanced

• Very long fibers or continuous fibers– Typically used with thermosets, also for “wet-

out” reasons– Used generally in advanced composite parts

and have greater material property requirements

– Generally use epoxy resins

Reinforcements

• Three main types of fibers– Fiberglass– Carbon fiber or Graphite– Organic fibers, aramids (kevlar)

Fiberglass

• Spin molten glass• Different types of glass can be made

– E-glass (improved electrical resistance)– S-glass (high strength)– C-glass (high chemical resistance)

Carbon or Graphite Fiber

• Originally some distinction was made—now the two refer to the same material

• Made from PAN fibers, pitch or rayon fibers

• Through heating, raw material looses most non-carbon atoms in the chain

• Processing also aligns carbon chains• Carbon fibers have very high modulus

(stiffness)

Organic Reinforcement Fibers

• Aramid fibers have greatest strength and modulus properties of organic fibers

• Kevlar is the most commonly used aramid fiber

• Aramids are strong and stiff but their greatest value is in impact applications– Front of airplane wings– Armor applications

Reinforcement Forms

• Fiber manufacturers package the fibers on spools called tows

• Fibers are generally converted to other forms after manufacturing– Chopped fibers (including whiskers)– Mat (random)– Woven fibers– Tapes– Prepregs

Manufacturing Methods

• Thermoplastic processes using short fibers– Injection molding– Extrusion– Minor changes are made to accommodate the

fiber reinforcements• All gaps in flow path should be increased• A resin viscosity decrease may be necessary

Manufacturing Methods

• Matched die or Compression molding– Reduced flow path over injection or extrusion– SMC compression molding allows for

continuous fibers, mats or weaves– These processes offer parts that are finished

on both sides where most other composite processes do not

Manufacturing Methods

• Resin transfer molding– Fiber preform is placed in the mold cavity– Preform doesn’t move—resin is pulled/pushed

in

Manufacturing Methods

• Spray-up– Fibers are chopped, coated with resin and

sprayed onto the mold

Manufacturing Methods

• Hand Lay-up (wet and prepreg)

PrepregWet

Fiber Orientations

Isometric materials have equal strength in all directions

Composites can be lighter weight by not having strength in the directions that it is not needed• Lay-up still has to have some balance and

symmetry• Isometric materials have equal strength in

all directions• Composites can be lighter weight by not

having strength in the directions that it is not needed

• Lay-up still has to have some balance and symmetry

• Isometric materials have equal strength in all directions

• Composites can be lighter weight by not having strength in the directions that it is not needed

• Lay-up still has to have some balance and symmetry

Vacuum Bagging

Provides for increased part consolidation• Reduces matched die mold costs• Provides for increased part consolidation• Reduces matched die mold costs

Manufacturing Methods

• Filament winding and fiber placement– Fiber placement has greater accuracy– Fiber placement can wind on less symmetrical

and even partially concave mandrels • Tubes, tanks, wind turbine blades and

rockets

Manufacturing Methods

• Roll wrapping– Faster than filament winding– Limited to symmetrical mandrels

Manufacturing Methods

• Pultrusion– High volume production– Comparable to extrusion but the main

processing force is tension– Profile is pulled from the machine

Plant Concepts

Many of the processes require considerable space

Curing equipment for large parts can be very large (and expensive)

Controlling volatiles (solvents and resins) must be taken care of

Molds can be both expensive and fragile•• Many of the processes require

considerable space• Curing equipment for large parts can be

very large (and expensive)• Controlling volatiles (solvents and resins)

must be taken care of• Molds can be both expensive and fragile•• Many of the processes require

considerable space• Curing equipment for large parts can be

very large (and expensive)• Controlling volatiles (solvents and resins)

must be taken care of• Molds can be both expensive and fragile•• Many of the processes require

considerable space• Curing equipment for large parts can be

very large (and expensive)• Controlling volatiles (solvents and resins)

must be taken care of• Molds can be both expensive and fragile•

Thank You

FIBER REIN FORCED PLASTCS (FRP) Introduction-:

For many application it is possible to increase the modulus and strength of plastics by means of reinforcenent.reinforced plastics are genrally similar to laminates in a number of applications.basically they differ in use of pressure as prescribed for laminates.fibre reinforced plastics are genrally consists of polymer resin matrix and reinforcement alo g with other additives such as catlyst,initiator,filler lubricant etc.

WHY USE FRP?

1.Hight strength/weight ratio

2.Rigidity

3.Low capital out lay

4.chemical resistance

5.weathering resistance

6.Transparent

7.good eletrical and thermal properties

USE OF MATERIALS-:

1.Resin system

2.Epoxy resin

3.Vinyal ester resin

4.Silicon resin

5.Glass fibers

6.Carbon fibers

7.Aramid fibets

8.Other materials

GLASS FIBRES-:

Industrially the most important fibers used with polyester and epoxy resins in glass fiber.which is relatively in expensive.the fiber is available in variety of forms like chopped stand,continuous fiber woven roving,cloth tape,surface tissue,staple fiber,staple yarn,chopped strand mat etc.

CARBON FIBERS-:

Recently,high strength and rigid carbon fibers reinforced resin system,coupled with their low density is an ideal materials for applications typical application include aero spce and reciprocating machine parts where the metal parts where the metal parts permit either faster machine operation with less wear and light weight ancillary equipments.

ARAMAID FIBERS-:

Use of aramid fibers provides up to 30%weight saving overglass and up to 50% over aluminum alloys .another fiber used in frp is asbestos which provied composite with greater stiffness than glass reinforcement alone.other fibers used in frp are cotton,sisal and cellulose.

OTHER MATERIALS-:

All though fiber reinforced materials primary comprise a resin system plus a fiberous reinforcement .other comonents are frequently added to produce decorative effects,aid handling,improve moulding charateristics and cured properties .these materils include fillers,pigments,flow promoters lubricnts,light stabilizer,fire retardant etc.

1.CATLYST OR INITIATORS-:

Catlyst some times called as initiator or hardener,which may be supplied as powder,paste or liquid,all of which must be throughly dispersed in the resin to ensure uniform cure.organic petoxide is most widely used as catalyst in polyestet.

2.ACCELERATOR-:Accelerator or promaters are used in conjuction with a catalyst to increase the

rate of reaction. 3.INIHIBITOR-:Inihibitor are added to the resin to ensure adequaye self-life either butyl catechal or di-t butyl can be used with polyester.

4.CURING AGENT-:

They are variously know as curing agents,hardeners and activators produce a cross linked thermosetting polymer from an initially linked or branched polymer.cure of unsaturated polyester resin takes place by freetedical polymerization through unsaturated group (double bond) in the polyester chain and the styrene or other monomer.

5.FILLERS-:

These are those additive which are added in polymer to reduces its cost and to improve physical properties.

6.PIGMENTS AND DYES-:These are in solubel colourant pigment which are pered or suspent in or resin burin processing these are opeqa nature.

7.LUBRICANTS-:

These are those subcenes which are added to polymer to reduce internal and external of molden polymer and facilitate its processing by improving flow properties.

8.COUPLING AGENT-:Coupling agent are also know as adhesion pramotr.these materials improve the addition property of the bond between two disprsion of minral.

MECHANICAL PROPERTIES-:

*Strength/weight ratio

*Specific gravity

*Importance of strength

THERMAL PROPERTIES-:*Heat distortion temp.

*operating temp.

*Humidity condition

CHEMICAL REGISTANCE-:

•Registance to liqid,gases or solvent solution

•Weather exposed to continuous/intetmittent operating temperature

ELETRICAL PROPERTIES-:*Dieletric strength and dieletric constant

*Tracking resistance

*Dissipation factor

CLARITY AND COLOUR-:

•Transparent

•Colour

•Surface finishers

CONTANT MOULDING-:1.Hand lay -up process

2.Spray-up process

3.Pressure bag moulding

4.Resin injection resin transfer moulding(RTM)

INJECTION MOULDING-:

A moulding procedure where by a heating soften plastic materials is fotced from a cylinder in to a relatively cool couity giving the articale tesired shope injection moulding is a manufacturing technique for making parts from plastic material molten plastic is inject high presure in to a closed mould injection.

Moulding very widly wed for manufacture a variety at part from the smalles component to entire

body parts at cors is the most common method of production with some common

terms including

bottels cop&out doar furniture.

TRANSFER MOULDING-:Transfer moulding is use for the manufacture of small components and is particularly are suitable with multi-cavity tools and where small inserts are to moulded in tooling costs are higher than or compression mouldin high frequency preheater mould temp.range from155to170°c both polyester.

CENTERIFUGAL COSTING-:

Centrifugal moulding or costing method used for making cylinderical hollow objects with uniform wall thickness.it is mainly used for the prodct of large pipes up to5mm diameter from either polyester or vinyal ester system,all though epoxy resin system may also be used other products can be made by this technique are tank,polester for street lighting,telephones cables and fluge.

CONTINOUS LAMINATING OR SHEET MANUFACTURING-:

The process can used to make either a falt sheet or by passing the material over fromes prior to curing a corrugated roof sheet or profiles,transparent and decorative sheeting.

Resin and glass reinforcement are sandwiched between two sheets of release film such as melinex mylar or cellophone which act as carriers transporting the laminate on a convery and passesd through rollers to consliedate the laminates before curing in an over.

APPLICATION-:1.TRANSPORTATION-

Interior components such as safety seat,engineering parts are leaf for trunks,bmper fascia,and front grill acoustic sheilds.under bonnet components are oil rocker cover,air channel.

Boats and boat hull,marine application include power boats,sail boats cones marine.

celling panel,tailand other hornet for helicopteres,seal plates,elevators,spoilers and radoms etc.

2.ELECTRICAL AND ELECTRONICS-

Roofing lights,electrical insulators,encapsulating housing bushing,circuit breakers bobbins,wire connector,compressor bases,power tool housing stand off rods,electrical junction boxes,cherry picker buckets,electrical trucking conduit etc.

3.BUILDING AND CONSTRUCTION-

Uses include building panels pipes for building,high ways,bridges and docks,cladding pannel sheet for roofing and building insulation pipe for machine ,pumps,single and turbine pump.other application of frp are swimming pools,cooling towers,showers,sky lights.

processing wall panel,roof fitting,strural frame doors and windows interior decorations,wash basin sinks.

4.LAMINATE AND FURNITURE-

Unsaturated polyester laminate is widely used in making building panels,beams,out door structural panel,roofing,corrugated panels and office furniture,chairs,tables and other moderm furniture design,silicones are used in electrical application such as electric moters ,terminal boards,printed circuit board and transformer.