1 What is fiber impregnation Talk briefly about the differen

1. What is fiber impregnation? Talk briefly about the different methods for fiber impregnation.
2. Assume that you are manufacturing a product in which all of the gears are made of metal. A
salesperson visits you and asks you to consider replacing some of these metal gears with
plastic ones. Make a list of the questions that you would raise before making a decision.

Solution

1.

Fiber Impregnation is a reinforcing fabric which has been pre-impregnated with a resin system.

This resin system (typically epoxy) already includes the proper curing agent.

As a result, the prepreg is ready to lay into the mold without the addition of any more resin. In order for the laminate to cure, it is necessary to use a combination of pressure and heat

Different methods:
(a) Solvent Dip Process
involves dissolving the resin in a solvent bath and dipping the reinforcing fabric in the resin solution. Using a drying oven, the solvent is then evaporated off the prepreg.
(b)Hot Melt Process
There are two stages in this process. The first stage involves coating a thin film of the heated resin on a paper substrate. The reinforcement material and the resin are allowed to interact in the prepreg machine. On application of pressure and heat, the resin is impregnated into the fibre resulting in the final prepreg, which is ultimately wound on a core.

2. The following are the list of the questions:

(a) Will the plastic gear retain its required strength, stiffness, and tolerances if the temperature changes during its use?

(b) How acceptable is the wear resistance and fatigue life of the plastic gears?

(c) Is it compatible with meshing metal gears and other components in the gear train?

(d) Are there any backlash problems?

(e) What are its frictional characteristics?

(f) Is noise a problem?

(g)  Is the plastic gear affected adversely by lubricants present?

(h)Is the lighter weight of the plastic gear significant?

(i) Will the supplier be able to meet the quantity demanded?

(j) How much cost savings are involved?