Machine Guarding

for Plastic Sheet and Roll Stock Extrusion

OSHA 10-Hour Outreach Training Program for the

Plastics Processing Industry

A Presentation of the SPI-OSHA Alliance

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Course Objectives

• Identify the types of injuries that can occur while operating plastics sheet and roll stock extrusion equipment

• Describe the possible causes of these injuries

• Identify ways to safely operate plastic extrusion equipment

• Recognize the importance of a total safety and health approach

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Reasons to Focus on Injuries in the Extrusion Process

• High injury/illness rates

• OSHA citations

• National Emphasis Program on Amputations

• Site-Specific Targeting

• High workers compensation costs

Types of Injuries

• Fatalities

• Amputations

• Avulsions

• Fractures

• Burns

• Cuts and bruises

• Sprains and strains

• Electric shock

Some Causes of Injuries

• Reaching around, under, over or through guards into hazardous areas

• Removing or bypassing guards

• Inadequate temperature monitoring during cleanup

• Not using LOTO procedures

• Machine/equipment malfunctions

Causes of Injuries (cont’d)

• Lack of recognition of hazards of the job

• Lack of familiarity with the equipment

• Inadequate training, comprehension, or both

• Operating machines with missing or inoperable guards and improper or inadequate machine maintenance

• Lack of proper PPE

• Loose clothing around winding equipment

Schematic of Extruder

Schematic of Extrusion Process

Risk Areas

• Feed Tubes

• Roll Stack

• Trim Knives

• Pull/Nip Rolls

• Shear

• Winder

• Grinder

Feed Tubes

Accident #1Third-Degree Skin Burns

• Two employees were cleaning the feed pipe for a line extruder

• Resin in the feed pipe hardened during shutdown

• Employee heated the feed pipe to soften the plastic for 30 minutes

• The employee pulled plastic plug at bottom of feed pipe

• Hot plastic sprayed out causing 2nd & 3rd degree burns

Roll Stack

Accident # 2Fatality

• Machine operator was threading plastic film through rolls of film extruder line when he got caught between top and bottom rolls

• Skull fracture and head trauma resulted in his death

Trim Knives

trim knife pivoting blade guard

Trim Knives

Trim Knives

Trim Knife Guarding

Trim Knife Blade Disposal

Pull-Roll Nips

Emergency stop pull cord

Sturdy metal mesh in guard

Shear

Shear

Winder

Accident #3Fatality

Employee was splicing plastic on new extruder winder rolls to get it started

– drawstring on hooded sweatshirt got caught in roll

– employee died by asphyxia

Grinder Guarding

Guarding by:

•Enclosure over moving components

•Anti-kickback flaps in feed throat

•Proximity guarding – distance from feed chute to rotating knives

Proximity

Guarding

Abrasive Wheel MachineryWork rests on offhand grinding machines must be kept adjusted closely to the wheel with a maximum opening of 1/8-inch to prevent the work piece or tool from being jammed between the wheel and the rest, which may result in wheel breakage or wheel explosion.

Abrasive Wheel Machinery

The distance between the wheel periphery and the adjustable tongue must never exceed 1/4-inch.

Power-Transmission Apparatus

Power-transmission apparatus (shafting, flywheels, pulleys, belts, chain drives, etc.) less than 7 feet from the floor or working platform must be guarded.

Unguarded beltand pulley

Safety Guards and Devices

• Types of guards and devices– Movable guards with interlocks– Fixed barrier or proximity guards– Presence-sensing device

• Locations of guards– Over/around moving equipment– Around electrical hazards– Around thermal hazards– Around cut hazards

Movable Guards with Interlocks

• Allows the electrical system to operate

• Actuated when the interlocked guard is closed or opened

• Prevents machine from operating when the guard is open Electrical Interlock Switch

Interlocked Guard

Electrical interlock switch

Emergency stop pull cable

Electrical Interlock Operation

Fixed Barrier Guards

• Prevent contact with the hazard

Yellow fixed guard

Fixed Barrier Guards

Guard over moving machine components

Wing guards

Fixed Barrier Guards

Presence Sensing Devices

• Safety mat

• Light curtain

Presence Sensing Devices

Safety Mat

Safety Guards and Devices

Light Curtain

How to Protect Yourself

• Recognize the hazards in the job you are doing

• Understand the requirements for guarding machines

• Implement guarding solutions

Emergency Stop Button

Know:

• Where they are located

• What they control

• When to use them

Emergency Stop Cable

• Know:

– Where they are located

– What they control

– When to use them

Signs and Warnings

Colors used with Safety Signs have meaning!

DANGER

White Lettering/Red Background

WARNING

Black Lettering/Orange Background

CAUTIONBlack Lettering/Yellow

Background

High Voltage

Rotating Screw

High Temperature

High Pressure

Crushing Fingers

Amputated Fingers

References for Extrusion Safety

•ANSI B11.TR3-2000 Risk Assessment and Risk Reduction - A Guide to Estimate, Evaluate and Reduce Risks Associated with Machine Tools

•ANSI B11.19-2003 Performance Criteria for Safeguarding

•ANSI/SPI B151.7-1996 Plastics Machinery - Plastics Extrusion Machines - Requirements for the Manufacture, Care and Use

•ANSI/SPI B151.5-2000 Plastic Film and Sheet Winding Machinery - Manufacture, Care, and Use

•ANSI/SPI B151.20-1999 Plastic Sheet Production Machinery - Manufacture, Care and Use

•ANSI Standards are available at the following web site: www.ansi.org

•SPI Guide to Extruded Plastic Sheet Products, www.plasticsheet.org/Guide/index.htm

OSHA's Site-Specific Targeting (SST) Program

OSHA's Site-Specific Targeting (SST) program selects for inspection individual worksites with the nation's highest Days Away from Work Injury and Illness (DAFWII) Case Rate and Days Away, Restricted, or Transferred (DART) Rates. It is based on data reported by more than 80,000 employers surveyed by the agency.

See the OSHA Web site for the most current directive and the rates used to target inspections.

In order to verify the reliability of claims by establishments thatthey have achieved low DART rates, OSHA inspects a certain percentage of employers with low rates.

OSHA National Emphasis Program on Amputations

On October 27, 2006, the Occupational Safety and Health Administration (OSHA) revised its national emphasis program aimed at reducing amputations in general industry workplaces. The National Emphasis Program on Amputations targets all types of machinery and equipment that are considered a high risk for causing amputations. The plastics processing industry is among the industries under scrutiny for workplace amputations.

The twenty-four states and two territories which operate their own OSHA programs are encouraged, but not required, to adopt a similar emphasis program. State Plan State information is available on OSHA’s Web site. The OSHA directive on this emphasis program is available on OSHA's Web site under Regulations and Compliance, subcategory Compliance Directives, No. CPL 03-00-003.

Under this initiative, regional and area OSHA offices will continue to conduct outreach; targeting and selection; and inspections. Area offices will obtain and use additional data to identify and add establishments where serious injuries or fatalities related to these machines have occurred.

The Job Safety Analysis Process

The Job Safety Analysis (JSA) process is a very effective means of helping reduce incidents, accidents, and injuries in the workplace. It is a multi-step process.

•Basic Job Steps

•Potential Hazards

•Recommended Safe Job Procedures

Summary

• Injuries can occur while operating plastics sheet and roll stock extrusion equipment

• Risk areas can be protected by safety guards and devices

• Protect yourself and operate plastic extrusion equipment safely

• Recognize the importance of a total safety and health approach

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