Material Handling Complete

8/8/2019 Material Handling Complete

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Copy Right: Rai University

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UNIT II

MATERIAL HANDLING SYSTEM

LESSON 8

IMPORTANCE, PRINCIPLES OF

MATERIAL HANDLING SYSTEM , AS/RS

SYSTEMS.

Po i n t s t o b e d is cu s s e d i n t h i s le c t u r e :

1.Importance of material handling

2.Principles of material handling3.Material handling system

4.AS/ RS systems.

Introduction

Material handling is a very important area of concern for

industrial engineers. This is due to following reasons:

1. More than 90% of the time in material spends on shop-

floor is either in waiting or for being transported. This is a

non-value added activity. Nearly 20-30 % of this non-value

added time is consumed in material handling. Therefore,

efficient handling will save some of this non-value added

time.

2. Safe handling of material is important in the plant. This

reduces wastage, breakage, loss, scrapes, etc.

3. Efficient material handling is needed for less congestion,

timely delivery and reduced idle time of machine due to non-

availability of material.

4. Cost-efficient material handling is an important issue.

Material movement usually accounts for 10 to 90% of total

factory cost, whose average is, as per one estimate, about

25%. Therefore, a careful study of alternative modes of

material transportation are very important.

5. Better material handling is helpful in good housekeeping. .

Material handling is needed in the entire supply-chain of the

manufacturing system. From supplier to the in- coming store

of the plant, raw material or sub-assemblies are shipped.

Sometimes subcontractors supply semi-finished items. For this,

road transport or rail, transport is needed. At the plant Level,

raw material or semi. finished items are transported to the

various machines. Movement of material is not only along the

floor, but it may be vertical (i.e., against/ along gra50,51,52vity) also.

Mate rial Hand ling

It is the art and science involving movement, packaging and

storing of materials in any form by n1eansof gravity, manual

effort or power-activated machinery.

- Ame rican Ma te rials Hand ling Society

PRINCIPLES OF MATERIAL HANDLING

There are some guiding principles of material handling. These

are :

1. Reduce unnecessary movement: This calls for selecting

shortest path to reach the destination.

2. Reduce congestion and bottlenecks: This calls for

eliminating obstruction and congestions in the material

handling.

3. Scientific factory layout: This is to minimize the overall

material movement, reduced number of trips, and reduced

costs associated with transportation.

4. Use of standard material handling equipments: This

facilitates easy maintenance of material handling equipment,

as spares are readily available.

5. Plan minimum, number of loading/ unloading: This

reduces, the chances of breakage. It also reduces loading/

unloading time and cost.

6. Use gravity to transport material.

7. Use mechanized material handling equipment: This

reduces dependence on human labor.

8. Use specialized equipment, if needed.

9. Use flex ible equipments, if the part variety is more or unstable.

10.Use simple and safe equipments for material handling. Operatorsafety should be of prime importance. Blinkering light and

bell/ sound maybe attached to material handling equipments

to warn the persons, working nearby.

11.To minimize the. down-time of the equipments, use

preventive maintenance of all equipments.

12.If labor is cheap and parts are lighter, human laborfor

transporting material in trolley may be employed.

13.Loading on material handling equipment should not exceed

its designed capacity.

14. S tandard size of material should be transported to reduce

time and increase efficiency.

15. C oncept of unit siz e loadshould be employed. Aggregating

material into a longer Unit/ container or pallet of standard

size.

16. Efficient planning and control should be ensured, for

efficiency.

17. The material. handling equipment should preferably be

dispatched if it is full of its capacity. This reduces number of

trips.

18. The material handling equipmen1should not be very bulky.

The ratio of its load carrying capacity and its own dead

weight should be high:

19.Concept ofstraight line flow should be employed as zigzagflow causes more congestion and more time.

20.Load should preferably. be carried both ways. This means

while coming back some material may be picked-up for

delivery to an intermediate and originating point.

21.Part orientation principle should & be employed so that, while

unloading, the material position should be as per the need

of the destination point. During the transportation also,

parts should be oriented in such a way that maximum

material is accommodated with least chances of damage.


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22.S ystem principle should be employed so that material handling

system is integrated with facilities, such as inspection,

receiving, storage assembly, packaging, etc.

23.Backtracking of parts movement should be avoided.

Mate rial Handling Equipme nt

Material handling equipments are classified under various

headings. These may be:

1. Manual, or

2. PoweredAnother classification is based on the paths followed by

material. These may be:

1. Fixed path equipments, such as : elevator, conveyors, chutes,

wire-guided AGV, etc.

2. Variable path equipments, such as : trolley, trucks, free-

ranging AGV, etc.

Fixed path material handling equipments allow material to

follow along a line or fixed path. Variable path equipments

allow flexibility in the path of material flow.

Pallets

Pallet is the base over which the load of material is assembled.

Pallets are specially designed platforms, which may be lifted bymeans of fork- lift operation.

Conveyor

Conveyors are used to transport material from one fixed point

to another fixed point. These use gravity or powered device to

carry material. Some of the conveyor systems are portable which

may be moved from time to time, but generally these are fixed.

These are more useful for the following situations:

Moving homogeneous material

Fixed route of movement

Constant rate of material movement

Mass production unitsIndustrial Trucks

These are manual or external powered vehicles, which can move

on a variety of paths. These are particularly useful for the

following situations:

Uneven (intermittent) supply of material

Varying paths of movement

Job-shop production units

Crane s an d Hoists

These are overhead lifting devices used for the movement of

material in a fixed route and fixed area of operation. These are

particularly useful in the following situations:

Movement of intermittent load

Different loads are of varied size, shape and weight

Provision of ceiling support at roof of the building

columns

Relatively heavy loads

When horizontal movement of material is difficult due to

conjestion, obstacles or navigation problem of

vehicles.(Footnotes)

Example pallet-load ing pat terns

Unit Load Desig


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Material han dling equipment

Different Material Handling Equipments


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FACTORYAUTOMATION

Different Material Handling Equipments (contd)


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Different Material Handling Equipments (contd)


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Different Material Handling Equipments (Contd)


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Different Mate rial Handling Equipme nts (cont d..)

Different Material Handling Equipments (Contd)


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FACTORYAUTOMATION

Elevators and Lifts

These are used to raise or lower material in the vertical direction.

These are different from cranes and conveyors in the sense that

lifting is done by elevators/ lifts byplacing the material on the

elevators/ lifts just like human being-carried in lifts of a multi-

storied building.

Containers and Racks

For transporting bulk material, containers/ racks are used. Bulk

material is stored in them. The advantage is the utilization of

cubical space, ease in storage and ease in handling.

AS/RS

Automated storage and Retrieval system (A S / R S ) is storage

racks system in which each location and its inventory status is

maintained by a computer-controlled central unit. When certain

item is needed, computer, using its status file, locates the item

on the shelf. A driverless device, such as crane, automatically

picks up the item. This is the retrieval mechanism of theA S /

RS. In case a new item comes, the computer communicates the

lifting device about the proper place in the rack where it is to be

stored. Subsequently, the inventory status is updated.

Rectangular, automatic storage and retrieval system, which is

similar in design to most industrial automatic storage and

retrieval systems. ASRS2 has 72 cells arranged in two parallel

storage racks.

A dedicated Cartesian robot tends the two storage racks and

transfers parts between the

storage cells and the conveyor pallets stopped at the ASRS

station. A real-time, multi-tasking stand-alone controller

controls the robot.

The ASRS software provides graphic display and tracking of

ASRS contents. Different parts and templates are defined by

easy to understand symbols and can be updated online.

The software provides real-time control of inventory and part

storage and retrieval operations.

Notes:

Material Handling Complete

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