Composites Presented by :Rabha Fathy

Plywood

Advantages of Plywood

Plywood is constructed layers of wood are glued together at the right angles

that is what gives it its strength

where this layering make the plants resistant to warping, cracking and twisting

ideal for use in construction.

It is stronger than a similar thickness of natural wood because the fiber strands are oriented to form a cross pattern.

Disadvantages of plywood

plywood has lots of splinters on the edges after cutting

The layering effect in plywood makes it porous and susceptible to water damage if exposed over time.

Plywood becomes heavy when wet and should be covered if left outside to reduce the risk of water damage.

laminate plywood

Lamination plywood may be used for decorations

It also can add durability

water resistance to countertops.

Safety information

use full eye protection

use a well ventilated area to apply any type of glue or contact cement

disposable gloves

ear plugs

Method used

Hand lay up process

Hand lay-up

Used in application that is large is size but not in mass production

Used to make successive layers of resin and reinforcement is applied to open mold to build the laminated composite structure

Tools used

Glue

Formica

veneer

small roller

sandpaper on a block

contact cement

a brush to clean with

a screwdriver

Clippers

a table saw

steps

Before the veneer can be cut, the peeler blocks must be heated and soaked to soften the wood.

The blocks may be steamed or immersed in hot water.

This process takes 12-40 hours depending on the type of wood, the diameter of the block

Steps

Cut the laminate to stipes

Open the glue

wipe off any dust from laminate and the plywood.

make sure its clean

coat the bottom of the laminate and the top of the plywood with one coat of contact cement

Wait till the cement is dull and tacky, but not too wet or shiny, it is ready for contact.

a

Put the laminate on the plywood

Pressure roll

Pressure roll is used to make sure that the laminate is sticked to the plywood

. When all the sheets are loaded, the press squeezes them together under a pressure of about 110-200 psi (7.6-13.8 bar), while at the same time heating them to a temperature of about 230-315° F (109.9-157.2°C).

After a period of 2-7 minutes, the press is opened and the sheets are unloaded

Route the edges

make sure it keeps a constant distance with the edge to be flush

Plywood sheets range in thickness from. 06 in (1.6 mm) to 3.0 in (76 mm). The most common thicknesses are in the 0.25 in (6.4 mm) to 0.75 in (19.0 mm) range.