Case 1


Article from:
http://www.mmh.com/article/CA6332907.html?stt=001&text=from+good+to+great

Company:
UPCO


Link to blog:
UPCO is a manufacturer of steel sucker rods used in the oil drilling industry. In order for UPCO to compete with other large companies, the company redesigned the material handling and the information technology processes to implement lean manufacturing. The company has changed the material handling equipment from life truck to conveyor. This helps to shorten the route for the material to reach the designated location and hence reduces the time. Therefore, better material flow will lead to inventory levels being reduced, and the plant will be performing at a more efficient manner.




Case 2

Article from:
http://www.ptonline.com/articles/200603bib2.html

Company:
Jackson Products Inc

Link to blog:
From the article, it is mention that with the purchasing of a $250,000 material-handling equipment, there is a quick savings from upsizing its material purchases from gaylord to silo quantities. Also, better resin usage through improved handling and drying boosted total savings to approximately 20¢/lb.

Semi-automated Handling

The semi-automated system supplements a mechanised system by automating specific handling requirements.

- Automated-Guided Vehicle (AGV)

The AGV is like a mechanised tow tractor with traileror rider pallet truck, without the need of any operator. It is automatically routed and positioned at the destination.


- Sortation



It is usually used together with conveyors to sort out differnet goods to spectific shipment docks.


- Robotics



It is a human-like robot that is programmed by using mircoprocessors to perform one or a series of activities.


- Live Racks



The goods, in the storage rack design, flows forward to the desired selection position. It is a commonly used device as it can reduce manual labour in the warehouse. the typical rack contains roller conveyors.



Automated Handling

An automated system can operate faster and more accurately and it uses less direct labour.

The requirement of high capital investment and the complex nature of development and applicantion forms its disadvantages.


- Order Selection Systems



The handling of the fast-moving products can be fully automated from the point of merchandise receipt to placement in over-the-road trailers. Such systems require the the use of an intergrated network of power and gravity conveyors linking power-motivated live storage.


- Automated Storage/Retrieval System (ASRS)



It is fully automated from recieving to shipping. The four main compoents constitue the basic systems: storage racks, storage and retrieval equipment, input/output systems, and control systems.

• How will the materials be received and shipped?
  Shipping materials from a loading dock allows for more space than materials that have to be received and shipped from a cold room. This will affect the size, lifting capacity and maneuverability of the lift truck required.

• What is the weight/size of materials that have to be lifted?
  Bigger is not always better in the materials handling business. One could easily reason that you just get a bigger truck for heavier loads. Bigger trucks require more space to move and may cost more, making it not the most suitable solution where heavy materials in small spaces have to be moved. Hence, we need to know which material to use so that it will reduce the cost and also be more efficient and effective in handling materials that are bulky. In addition, if the weight/size of the material is small, we probably should not use equipment that is big and expensive because it will show that the equipment is not fully utilized. Therefore, the weight and size of the material is one factor that we need to consider when choosing the type of equipment to use.

• At which height must the materials be stored?
  Lift height and load size determines the capacity of a lift truck. A bigger load size moves the lift truck´s center of gravity, reducing the lifting capacity, making the height at which the materials that have to be stored just as important as the load. This means that if we need to place a material(usually bulky ones) at a higher level of the rack, we will need to use equipment that can reach that height so that the material can be place there properly. However, if the material is to be stored on the floor or second/third level of the rack, we can just use simply equipment such as pallet trucks.

• Types of material?
  The type of equipment we use will also depends on the types of material. For example, if the material is expensive and need to be well taken care of, it should be handled properly and the equipment(not shaky,do not have sharp edges,etc) used must be right so that the material will not get damaged.
  It is same for how vulnerable the material is. If the materials are easily breakable, right equipment should also be used to handled them so that the material will not break and get thrown away. This will only incurred more cost which is not favorable to the company.
  One more example can be that if the material is hazardous, RIGHT equipment should be used to handled them. The equipment must prevent the material from spilling, falling off from it, and also prevent it from injuring the workers there.

• Quantity of the material?
  This means the amount of materials needed to be handled. If a large amount of materials is needed to be handled, a big equipment with large capacity is definitely needed to do the job. Therefore, we will need to know the quantity of the material when we are choosing the equipment that is needed to handle them.

These factors help the company to reduce cost by fully utilized the equipment, reduce labor cost if the equipment can handle the material more efficient then the labor, and get the right equipment for right type of material. As logistic aims to be a profit center instead of a cost center, we should not waste too much money on redundant equipment (equipment that are not used/needed in the warehouse).

Storage equipment are used for holding or buffering materials over a period of time.

The major types of storage equipment are:

• Block stacking
• Selective pallet rack
• Drive-through rack
• Drive-in rack
• Flow-through rack
• Push-back rack
• Sliding rack
• Cantilever rack
• Stacking frame
• Shelves/Bins/Drawers
• Storage carousel
• Automatic storage/retrieval system (ASRS)
• Split case order picking system
• Mezzanine

However, in the traditionally view of logistic, storage system is not closely related to material handling system (MHS). It only start to merge with MHS in the modern society.

Therefore, we will not explain much about individual equipment used for storing the material.

Unit Load Equipment is used to restrict materials so that they maintain their state and integrity when handled a single load during transport and for storage. If materials are single part or interlocking parts, then they can be formed into a unit load with no equipment



Advantages of unit loads:

• More items can be handled at the same time, thereby reducing the number of
  trips required and, potentially, reducing handling costs, loading and unloading times, and product damage.
• Enables the use of standardized material handling equipment.

Disadvantages of unit loads:

• Time spent forming and breaking down the unit load.
• Cost of containers/pallets and other load restraining materials used in the unit load
• Empty containers/pallets may need to be returned to their point of origin.

Types of Equipment:

Pallet

A pallet is a flat transport structure that supports goods in a stable fashion while being lifted by a forklift, pallet jack, or other jacking device. A pallet is the foundation of a unit load design, which can be as simple as placing the goods on the pallet, and securing them with straps or stretch-wrapped plastic film, or as exotic as a Unit Load Device minicontainer.

While the majority of pallets are made of wood, pallets that are manufactured from plastic, metal and paper can also be found. Each individual materials used has each own pros and cons.

Stringers is a frame of three parallel pieces of timer. Stringer pallets is a continuous, longitudinal, solid or notched beam – component of the pallet used to support the deck components, often identified by location a the outside or center stringer.

The stringer is the board located between the top deck boards and the bottom deck boards. The top deck boards are then affixed to the stringers to create the pallet structure. Stringer pallets is either notched making it a partial 4-way or solid with no notches, are also known as "two-way" pallets, since a pallet-jack may only lift it from two directions instead of four. Forklifts can lift a stringer pallet from all four directions, though lifting by the stringers is more secure.

SLIP SHEET

Used as a unit load support device in vehicle delivery and transportation of products. When slip sheets are supported by a pallet board, roller conveyor surface, flat load carrying surface, or a cart or lift truck, the structural strength of the slip sheet supports the product loads weight. With the slip sheet supported by one of these transportation devices the unit load can easily be transported both internally within a facility and externally between two facility locations.

It is shaped and dimensioned to the size of the product or unit load. The type of slip sheet varies depending on both the number of lip extensions and the material from which it is manufactured.

The variation used would depend on the loading patterns, unit load parameters, and desired maneuverability of the slip sheet/unit load. Normally, the thickness of the slip sheet is <1/2 in. For most warehouses, plant functional material handling equipment, and the travel-path clearances, this fraction of an inch height increase does not stage a problem. When designing an in-house transportation path for the slip sheet unit load, the slip sheet has a 4 to 6 in. lip (tab) that extends beyond one or more of the sides of the slip sheet. The lip extensions permit a push-pull device to lift the slip sheet unit load.

Slip Sheet Advantages:

· Using slip sheets instead of wooden pallets allows for 12-15% more products
in material handling containers
· Slip sheets do not require maintenance, but can easily be replaced
· Significant reduction in material handling costs
· Decreases loading/unloading time by up to 60%
· Weighs 20 times less than wooden pallets, saving shipping weight
· Can be customized to fit any size load
· Eliminates the need for pallet exchange
· Reusable and reliable
· Most are recyclable
· Is cost-effective

Slip Sheet Disadvantages:

· Pallets provide a greater clearance between the floor and the unit load
· Slip sheet usage requires special attachments on transportation devices such
as a lift truck (but are fairly cheap)
· When used alone, pallets provide more structural support than slip sheets
· Pallets are easily compatible with crane devices
· Lift truck attachment reduces load capacity
· Greater load damage
· Slower handling


Types of Slip Sheets

1.) Plastic Slip Sheets

Plastic Slip Sheets are custom designed, die cut flat sheets that are utilized in handling, storage and shipping of unitized goods, replacing traditional pallets and fiber slip sheets. Plastic slip sheets allow you to move packaged goods for less. You will be able to ship more products, in less space, and reduce overall freight cost associated with packaging.

Plastic slip sheets are cost effective and are an excellent alternative to expensive wood pallets and offer many advantages of fiber slip sheets.

2.) Bulk Load Containers

Reusable container used to unitize and protect bulk materials.

Includes drums, cylinders, etc.

Used for both distribution and in-process handling.

3.) Shrink-Wrap/Stretch-Wrap

Used for load stabilization

In shrink-wrapping, a film or bag is placed over the load and then heat is applied to shrink the film or bag; allows irregular loads to be stabilized; manual or automatic; most shrink-wrap applications are being replaced by stretch-wrapping.

In stretch-wrapping, a film is wound around the load while the film is stretched; allows irregular loads to be stabilized; manual or automatic; as compared to shrink-wrapping, stretch-wrapping has lower material, labor, and energy costs.

Stretch wrap is used as a pallet wrap to secure boxes on a pallet during shipment. The elasticity of the film holds the load tight.

Shrink Wrap is typically used when wrapping a single item or product such as CD’s, DVD’s, or gift baskets. A shrink wrap heat gun is used to heat the shrink film which causes it to shrink around and seal the product. Both stretch wrap and shrink wrap can be used to bundle products together for shipping purposes.


4.) Palletizers

Manual palletizing is labor intensive and represents the greatest source of workman compensation claims in the packaging operation.

We offer 2 methods: mechanical and robotic palletizers to help offset this risk and reduce labor cost.


i.) Mechanical Automatic Mechanical

Formed the layer pattern by turning the bags by means of a turning wheel or bar. The bags are then pushed onto a layer forming table from which the completed layer is deposited on the pallet.

These palletizers are programmed for each product and pallet configuration. Once the pallet is complete it is lowered by means of an elevator and exits the palletizer onto a downstream conveyor. Empty pallets are automatically dispersed to the system and slip sheets added when called for. Mechanical palletizers can run at rates of up to 35 bags per minute.




ii.) Robotic Palletizers

Programmed to handle up to 100 different pallet configurations. Rather than turning the bags the robot picks them up and rotates them before setting them down on the pallet.

Robotic palletizers have several advantages over traditional mechanical models, including smaller foot print, lower cost, and significantly less mechanical parts to maintain. Robotic palletizers will run rates up to 22 bags per minute.

Positioning equipment is used to handle material at a single location so that the material is in the correct position for subsequent handling, machining, transport, or storage. Unlike transport equipment, positioning equipment is usually used for handling at a single workplace. Material can also be positioned manually using no equipment.

However, as compared to manual handling, the advantage of using positioning equipments are [Modern Materials Handling, Sept. 1993]:

Transport equipment is used to move material from one location to another (e.g., between workplaces, between a loading dock and a storage area, etc.) within a facility or at a site.

Major subcategories of transport equipment:

This diagram gives a rough idea about the usage of the 3 type of equipment under the transport equipment.









1) Conveyors

Conveyors are used to move materials over a fixed path

It is used when material is to be moved frequently between specific points

Also, it is used when there is a sufficient flow volume to justify the fixed conveyor investment


2) Cranes

Cranes are used to move materials over variable(horizontal and vertical) paths within a restricted area

Used when there is insufficient flow volume such that the use of a conveyor cannot be justified

More flexible, in term of movement, than Conveyors

Loads handled are more varied with respect to their shape and weight than those handled by a conveyor

Hoist can be used together with cranes


3) Industrial Truck

Industrial trucks are used to move materials over variable(horizontal) paths, with no

Provide vertical movement if the truck has lifting capabilities

Used when there is insufficient flow volume such that the use of a conveyor cannot be justified

More flexible, in term of movement, than cranes

Not licensed to travel on public roads(commercial truck has licensed)


1) Subcategories of Conveyors:


Chute Conveyor

- Inexpensive

- Used to link two handling devices

- Used to provide accumulation in shipping areas

- Used to convey items between floors

- Difficult to control position of the items

Wheel Conveyor

- Uses a series of skatewheels mounted on a shaft (or axle), where spacing of the wheels is dependent on the load being transported

- Slope for gravity movement depends on load weight

- More economical than the roller conveyor

- For light-duty applications

Roller Conveyor

- May be powered (or live) or nonpowered (or gravity

- Materials must have a rigid riding surface

- Minimum of three rollers must support smallest loads at all times

- Tapered rollers on curves used to maintain load orientation


i) Gravity Roller Conveyor

- Alternative to wheel conveyor

- For heavy-duty applications

- Slope for gravity movement depends on load weight

- For accumulating loads

ii) Live (Powered) Roller Conveyor

- Belt or chain driven

- Force-sensitive transmission can be used to disengage rollers for accumulation

- For accumulating loads and merging/sorting operations

- Provides limited incline movement capabilities

Chain Conveyor

- Uses one or more endless chains on which loads are carried directly

- Parallel chain configuration used to transport pallets

- Vertical chain conveyor used for continuous high-frequency vertical transfers

Slat Conveyor

- Uses discretely spaced slats connected to a chain

- Unit being transported retains its position (like a belt conveyor)

- Orientation and placement of the load is controlled

- Used for heavy loads or loads that might damage a belt

- Bottling and canning plants use flat chain or slat conveyors because of wet conditions, temperature, and cleanliness requirements

There is also this tilt slat conveyor that is used for sortation

Flat Belt Conveyor

- For transporting light- and medium-weight loads between operations, departments, levels, and buildings

- When an incline or decline is required

- Provides considerable control over the orientation and placement of the load.

- No smooth accumulation, merging, and sorting on the belt

-The belt is roller or slider bed supported; the slider bed is used for small and irregularly shaped items

Magnetic Belt Conveyor

- A steel belt and either a magnetic slider bed or a magnetic pulley is used

- To transport ferrous materials vertically, upside down, and around corners

Bucket Conveyor

- Used to move bulk materials in a vertical or inclined path

- Buckets are attached to a cable, chain, or belt

- Buckets are automatically unloaded at the end of the conveyor run

Vibrating Conveyor

- Consists of a trough, bed, or tube

- Vibrates at a relatively high frequency and small amplitude in order to convey individual units of products or bulk material

- Can be used to convey almost all granular, free-flowing materials

Screw Conveyor

- Consists of a tube or U-shaped stationary trough through which a shaft-mounted helix revolves to push loose material forward in a horizontal or inclined direction

- One of the most widely used conveyors in the processing industry

- Many applications in agricultural and chemical processing

Tow Conveyor

- Uses towline to provide power to wheeled carriers such as trucks, dollies, or carts that move along the floor

- Used for fixed-path travel of carriers (each of which has variable path capabilities when disengaged from the towline)

- Towline can be located either overhead, flush with the floor, or in the floor

- Selector-pin or pusher-dog arrangements can be used to allow automatic switching (power or spur lines)

- Generally used when long distance and high frequency moves are required

Trolley/Overhead chain Conveyor

- Uses a series of trolleys supported from or within an overhead track

- Trolleys are equally spaced in a closed loop path and are suspended from a chain

- Carriers are used to carry multiple units of product

- Does not provide for accumulation

- Commonly used in processing, assembly, packaging, and storage operations

Power-and-Free Conveyor

- Similar to trolley conveyor due to use of discretely spaced carriers transported by an overhead chain; however, the power-and-free conveyor uses two tracks: one powered and the other nonpowered (or free)

- Carriers can be disengaged from the power chain and accumulated or switched onto spurs

2) Subcategories of Cranes:

Jib Crane

- Operates like an arm in a work area, where it can function as a manipulator for positioning tasks

- A hoist is attached to the arm for lifting

- Arm mounted on the wall or attached to a floor mounted support

- Arm can rotate 360°

- The hoist can move along the arm

Bridge Crane

- Bridge mounted on tracks that are located on opposite walls of the facility

- Enables three-dimensional handling

- Top riding (heavier loads) or underhung (more versatile) versions of the crane

- Underhung crane can transfer loads and interface with other Material Handling System

Gantry Crane

- Similar to a bridge crane except that it is floor supported at one or both ends instead of overhead (wall) supported

- Used to span a smaller portion of the work area as compared to a bridge crane

- The supports can be fixed in position or they can travel on runways

- Can be used outdoors when "floor" supported at both ends

Stacker Crane

- Similar to a bridge crane except that, instead of a hoist, it uses a mast with forks or a platform to handle unit loads

- Considered "fork trucks on a rail"

- Used for storing and retrieving unit loads in storage racks, especially in high-rise applications in which the racks are more than 50 feet high

- Can be controlled remotely or by an operator in a cab on the mast

- Can be rack supported

3) Subcategories of Industrial Truck:

Hand Truck

i) Two-Wheeled Hand Truck

- 2 wheels

- Load tilted during travel

ii) Dolly

- 3 or more wheeled hand truck with a flat platform

- Since it has no handles, the load is used for pushing

iii) Floor hand truck

- 4 wheels or more hand truck with handles for pushing or hitches for pulling

- Sometimes referred to as a "cart" or "(manual) platform truck"

Pallet Jack

Front wheels are mounted inside the end of the forks and extend to the floor as the pallet is only lifted enough to clear the floor for subsequent travel

Pallet restrictions: reversible pallets cannot be used, double-faced non reversible pallets cannot have deck boards where the front wheels extend to the floor, and enables only two-way entry into a four-way notched-stringer pallet because the forks cannot be inserted into the notches

i) Manual Pallet Jack

- Manual lifting and/or travel



















ii) Powered Pallet Jack

- Powered lifting and/or travel

Walkie Stacker

i) Manual walkie stacker


- Manual lifting and/or travel (and straddle load support)





















ii) Powered walkie stacker


- Powered lifting and/or travel (and either counterbalance or straddle load support

Platform Truck

i)Walkie Platform Truck

- Operator walks next to truck


















ii) Rider Platform Truck

- Operator can ride on truck

Counter-balanced forklift truck (CBFLT)

- Robust and fast machines with capacities ranging between 1,000kg and about 45,000kg (container handling)


- Lift and stack up to heights of about 5M

- 12-13 ft. minimum aisle width requirement

Narrow-Aisle (NA) Reach Truck

- 8-10 ft. minimum aisle width requirement

- Load rests on the outrigger arms during transport, but a pantograph (scissors) mechanism is used for reaching, thereby eliminating the need to straddle the load during stacking

- Reaching capability enables the use of shorter outrigger arms (arms > 1/2 load depth)

- Counterbalance of the truck used to support the load when it extends beyond the outrigger arms

Order Picker

- Typically has forks to allow the truck to be used for pallet stacking and to support a pallet during less-than-pallet-load picking

- "Belly switch" used for operator safety during picking

- Free path truck

Side loader

- Forks mounted perpendicular to direction of travel to allow for side loading and straddle load support

- 5-6 ft. minimum aisle width requirement

- Can be used to handle greater-than-pallet-size loads (e.g., bar stock)

Personnel and Burden Carrier

- Non-load-carrying vehicle used to transport personnel within a facility (e.g., golf cart, bicycle, etc.)

Automated Guided Vehicles (AGV)

- Powered driverless trolleys

- guided by following an under-floor wire which carries an electric signal or optically following a painted or plastic tap track laid on the floor

- Suitable for frequent movement on set routes