machine guarding for plastic sheet and roll stock extrusion

Machine Guarding

for Plastic Sheet and Roll Stock Extrusion

The Society of the Plastics Industry, Inc.

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 Knife Guarding


Trim Knife Blade Disposal


Pull-Roll Nips

Emergency stop pull cord

Sturdy metal mesh in guard


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


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



Guard over moving machine components

Wing 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 lost workday injury and illness rates based on data reported by more than 80,000 employers surveyed by the agency. In April of this year, OSHA announced that its site-specific targeting plan for 2006 would focus on approximately 14,000 worksites with higher than average injury and illness rates for unannounced comprehensive safety and health inspections over the coming year. The 14,000 identified sites are establishments located in stated covered by Federal OSHA.

This year's program was announced on April 21, 2006 and will initially cover worksites that reported 6 or more injuries or illnesses resulting in days away from work, restricted work activity, or job transfer for every 100 full-time workers (known as the DART rate). The average national DART rate in 2004 for private industry was 2.5.

Over the past eight years, OSHA has used a site-specific targeting inspection program based on injury and illness data. This year's program stems from the agency's Data Initiative for 2005, which surveyed approximately 80,000 employers to attain their injury and illness numbers for 2004.


OSHA National Emphasis Program on Amputations

On March 26, 2002, the Occupational Safety and Health Administration (OSHA) announced a special national emphasis program aimed at reducing amputations in general industry workplaces. The National Emphasis Program on Amputations targets all types of power presses, including press brakes, saws, shears and slicers. This program is targeted to industries that are considered a high risk for operating equipment that can be very dangerous, as injuries involving these machines are often fatal or result in permanent disability. The plastics processing industry is among the industries that is under scrutiny for workplace amputations.

In keeping with OSHA's mission to identify and reduce or eliminate the workplace incidence of hazards which are causing or are likely to cause amputations, OSHA initiated targeted inspections of workplaces under SIC 3089, Plastics Products, Not Elsewhere Classified. These amputation hazard inspections began in April 2002. This is a Federal Emphasis Program. The twenty-four states and two territories which operate their own OSHA programs are encouraged, but not required, to adopt a similar emphasis program. The OSHA directive on this emphasis program is available on OSHA's web site under Regulations and Compliance, subcategory Compliance Directives, No. CPL 2-1.35.

Under this new initiative, regional and area OSHA offices will conduct outreach programs to identify, reduce and eliminate workplace hazards associated with these machines. Their programs will be conducted in three parts: outreach; targeting and selection; and inspection. 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


Our sincere thanks to:

• United Southern Industries, Inc.

• SPI Sheet Producer’s Division

• Spartech Plastics, Inc.

• OSHA Region V & VIII

• The OSHA Office of Education and Training

• OSHA’s Salt Lake Technical Center

• Michigan OSHA

• The Society of the Plastics Industry, Inc.


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machine guarding for plastic sheet and roll stock extrusion

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