1. A Presentation of the OSHA-SPI Alliance
Machine Safety for Injection Molding Machines
A Presentation of the OSHA-SPI Alliance
The Society of the Plastics Industry and OSHA formed an Alliance last fall in order to help employers in the plastics industry provide safer working environments in their plants.
This is a national Alliance, signed with federal OSHA.
As you may know, there’s Federal OSHA and there are State Plan States that run their own occupational safety and health programs. This course is based on Federal OSHA standards.
This course on Machine Guarding and lockout/tagout (LOTO) was created by a dedicated team, of which we were both a part.
This is a train-the-trainer course—That is, the package you receive today not only consolidates all the critical information you need on machine guarding and LOTO, but prepares you to go back to your worksites and train employees. You’ll have PowerPoint presentations, handouts, outside references, and even certificates you can print to hand out to employees you have trained.
And we hope that it doesn’t end there. We want to hear back from you—not only about how well these tools work for you and how many people you train, but also about ideas you may have for other areas that we can work together on to make a safer workplace in our industry.
Occupational
Safety and Health
Administration
The Society
of the Plastics
Industry, Inc.

2. Course Objectives
Identify the types of injuries that can occur while operating injection molding machines
Describe the possible causes of these injuries
Identify ways to safely operate injection molding machines
Recognize the importance of a total safety and health approach
Please note: This course is on safety issues relating to injection molding machines. It does not cover everything you need to know about plant safety.
You’re going to hear a common thread running through this course today, which is that machine safety and lockout tagout programs are only part of the effective safety and health management system at your plant. You can use the Safety and Health Management eTool ( to use what you’ve learned today to develop, refine, or improve your company’s goals for addressing safety and health in your workplace.

3. Reasons to Focus on Injuries in the Injection Molding Process
High injury/illness rates
OSHA citations
National Emphasis Program
Site-Specific Targeting
Plastics is the fourth largest manufacturing industry in the US. We have over 1.5 million workers. And plastics processors are the most frequently cited industry for machine guarding.
#Cited #Insp $Penalty Industry Classification
$200, Plastics Products, Not Elsewhere Classified
The reason the Alliance has chosen to focus initially on this topic is because of:
Our mutual concern for high injury and illness rates in plastics processing.
Those high rates have resulted in the plastics industry being included in OSHA’s annual Site-Specific Targeting program.
The top two OSHA citations in the plastics processing industry are machine guarding and lockout/tagout.
OSHA’s National Emphasis Program on Amputations also targets plastics processors.
Your handouts include more information about these important concerns.

4. Types of Injuries Fatalities Amputations Avulsions Fractures
Cuts and bruises
Sprains and strains
Burns
Electric shock
These are some of the common injuries that occur in the plastic processing industry.
We are focusing today on the more severe injuries—those in the left column.
Fatalities, obviously, are the most severe of all.
Amputations can disable and disfigure.
Avulsions should be considered a near-miss to amputations.

5. Some Causes of Injuries
Reaching around, under, over or through guards into hazardous areas
Removing or bypassing guards
Reaching into equipment to remove stuck parts
Not using LOTO procedures
Machine/equipment malfunctions
Never attempt to reach around, under, over, or through a guard. If a person standing on the floor can reach over the machine into the mold area, install a top guard that is fixed or interlocked.
Never remove, alter, or attempt to otherwise bypass a safety interlock.
To prevent these types of injuries the operator’s gate must be installed to block operator access to moving parts while the machine is operating. Utilize interlocks (mechanical, electrical, hydraulic) that prevent the mold from closing when actuated.
Access the mold cavity via the operator’s gate only. Do not remove or open a fixed gate for normal operating tasks.
Provide training on the safety hazards and features of the injection molding machine for all employees who will potentially use it.
We will discuss LOTO requirements in the second halve of the program.

6. 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

7. Injection Molding Machinery
Horizontal injection molding machine (HIMM)
Vertical injection molding machine (VIMM)

8. Vertical Injection Molding Machines - VIMMs
We are covering both horizontal and vertical injection molding machines today. We are going to begin by highlighting the unique hazards and issues associated with VIMMs in the next two slides.
In spite of these unique hazards and issues associated with VIMMs, the safe operating practices and procedures apply to both types of machines.

9. VIMMs
Combinations of vertical and horizontal clamp and injection configurations of machines
Regardless of the configuration of the machine, basic machine guarding and good safe work practices must be applied
Point of operation
Other moving machine parts

10. Unique Hazards and Issues
VIMMs:
Unique Hazards and Issues
Gravity
Plastic splatter/missing insert
Flying inserts
Unexpected bystander interventions
Gravity present a unique hazard associated with vertical injection molding machines. Examples include hydraulic line or linkage failure that could cause the movable platen to fall.
Plastic splatter can occur when an insert is missing or misplaced. Example would be failure to place a spoon insert into the mold cavity when the handle is being molded around the spoon insert to make a finished spoon. The missing insert creates an opening that allows plastic to shoot out from the mold and splatter.
Improperly placed inserts can be caught between the mold halves and ejected under great force.
The guarding protects the operator but not necessarily other people who might unexpectedly reach into hazardous areas.

11. Horizontal Injection Molding Machines - HIMMs
Now we will discuss safety issues related to horizontal injection molding machines.

12. HIMMs: Mechanical Hazards
Point of operation
Pinch points
Nip points
Rotating parts
The point of operation is considered the area between the movable and stationary platens.
Pinch points can occur where two or more surfaces come in close proximity and a crushing hazard is created.
Nip points in the injection molding machine include chains and sprockets, belts and pulleys, and gears. Although not part of the injection molding machine, nip points can occur due to mechanisms and motions of mold components (such as core pulls, unscrewing devices, sliding cams, sliding cores, sprue pickers) and auxiliary equipment.
Rotating parts that might pose a hazard include pump shafts and couplings, die height adjustments, and rotating screws.

13. Potential Injuries from Mechanical Hazards
Fatalities
Amputations
Avulsions
Crushing injuries
Fractures
Avulsion is a ripping away of the flesh that does not include bone loss.
An example might be where your finger gets caught in a nip point, you pull it out, and flesh is torn off, but the bone is still there.
It’s impossible to see the scale in this picture, to be able to tell how big a body part can fit in this space, but you should know that IMMs come in many sizes, from small enough to fit on a tabletop to large enough to produce a whole car body. Depending on the particular machine, these potential injuries might be to a finger, arm, head, or entire body.

14. Safety Guards and Devices
Types of guards and devices
Movable guards with interlocks
Fixed barrier guards
Presence-sensing devices
Mechanical safety bars
Locations of guards
Over moving equipment
Around electrical hazards
Around thermal hazards
Newer US-made machines usually come in compliance with all ANSI safety standards, but please note that many older machines have not been retrofitted with additional safeties.
In addition, foreign-made machines may not meet all the safety requirements in the US. It is your responsibility, when purchasing any injection molding machines, to ensure that they are in compliance with all appropriate safety standards.

15. Operator’s Gate Equipped with redundant interlocks
Electrical
Hydraulic
Mechanical safety bar
Allows the machine to operate only when the gate is closed
The operator's gate allows the operator access to the mold and should be equipped with interlocks (such as electrical, hydraulic, and mechanical) that allow the machine to operate only when the gate is closed.
Do not attempt to override any of the interlocks or to reach over, under, around, or through the operator's gate (or other guards) while the machine is operating.

16. Electrical Interlock
Allows the electrical system to operate and close the clamp
Actuated when the operator’s gate is opened or closed
Prevents clamp from closing when the operator’s gate is open
The electrical interlock prevents the mold from closing when the gate is open.

18. Hydraulic Interlock Actuated by opening or closing the operator’s gate
Each hydraulic IMM requires at least one
Prevents clamp from closing when the operator’s gate is open
The hydraulic safety interlock valve prevents the clamp from closing when the operator's gate is open.

20. Mechanical Safety Device
Prevents clamp from closing when the operator’s gate is open
Must have at least one mechanical device on all IMM’s
The mechanical safety device physically prevents the mold and clamp from closing when the operator's gate is open.

22. Other Guarding Rear guard Top guard Parts discharge guard
Feed opening guard
Electrical system guards
Purge guard
Injection barrel cover

23. Rear Guard
Prevents clamp from closing when interlocked rear guard is opened
Should have at least two interlocks
Prevents access to mold areas
The movable rear guard should be equipped with at least two interlocks that stop clamp motion when the guard is open.
This guard should only be opened for setup and maintenance activities.
Use the front operator's gate for operator access to the mold space.

24. Top Guard
Required if operator can reach over the top of the machine and into hazardous areas
Should be interlocked if movable
On low profile machines, a top fixed guard should also be installed. This prevents a person from reaching in from the top of the clamp unit and getting injured via this route. The majority of molding machines do not require this guard, as they are approximately 9 feet tall. Like the other fixed guards on the rearward half of the clamp, this guard, if installed, should have an electric interlock to prevent its being removed (NSC Data Sheet I-454, 1988).
Guards that are removed only for maintenance, and that require tools to be removed do not need to be interlocked.

25. Top Guards (cont’d)

26. Parts Discharge Guard
Keeps employees from reaching under operator’s gate and into the danger zone
A guard should be placed at the opening for parts discharge to prevent an employee from reaching under the operator's gate and into the mold area.
A chute, conveyor, or other object can take the place of a guard attached to the machine if it prevents access to this area.

27. Purge Protection Covers the nozzle and purging area
Purge guard
Covers the nozzle and purging area
In combination with PPE, minimizes exposure to molten plastic during purging
Window allows observation through purge guard, if equipped
Should be equipped with an interlock
The injection unit can also be controlled via guards. All three of the standards (ANSI 1990; SPI 1992; SPI 1996) again call for guards to protect the front, rear and top of the purging area. An electrical interlock insures that the guard is in place during the automatic running of the machine or during the purging cycle. Should viewing of the purge area be necessary, a window should be provided that will with stand the splashing of the plastic material without failure.
The purge shield covers the nozzle of the injection molding machine and helps to prevent burns from molten plastic material inside the injection system. The operator may monitor the purging area through the window in the purge shield. Injection unit operation proceeds while the purge shield door is closed, but is interrupted when the door is out of position.
Heater Band Shield
This metal guard cover the barrel and heater bands. It must be in position when power is on and/or the machine is in operation.
Heater band terminal ceramic covers insulator caps should be maintained in good condition. If contact is made with any bare terminal while the power is on, electrical shock may result.
Severe burns may also result if contact is made with hot metal surfaces or heater bands.
Never stand on this shield, as it is not designed to bear weight.
Safety
window
Barrel cover

28. Injection Barrel Cover
Protects from exposure to high voltage and high temperatures
The barrel cover acts as a barrier to block access to the injection unit to prevent contact with high voltage and high temperatures.

29. How to Protect Yourself
Recognize the hazards in the job you are doing
Understand the requirements for guarding machines
Implement guarding solutions

30.                                                                
       
Virtual Safety Tour
Now you’re going to see the location of the guarding devices we’ve been discussing.
(Click on the photo to start the video)

31. Emergency Stop Know: Where it is located What it controls
When to use it
The control panel on the front of the injection molding machine features a Red Emergency Stop Button that stops all machine function when pressed.

32. Signs are posted on a machine to inform us of danger points
Signs are posted on a machine to inform us of danger points. We are so used to looking at them that we often do not see them as we are running the molding machine.
Periodically it is good to review the different safety and warning signs on the injection molding machine with employees to maintain consciousness of the safety that they provide.
Periodically it is good to review the different safety
and warning signs on the injection molding machine with employees to maintain consciousness of the safety that they provide.
Signs and Warnings

33. Colors used with Safety Signs have meaning!
DANGER
White Lettering/Red Background
WARNING
Black Lettering/Orange Background
Indicates an imminently hazardous situation which, if not avoided, will result in death or serious injury.
Indicates a potentially hazardous situation which, if not avoided, could result in death or serious injury.
Indicates a potentially hazardous situation which, if not avoided, may result in minor or moderate injury.
CAUTION
Black Lettering/Yellow Background

34. High Voltage
Placed on each electrical cabinet and/or box containing dangerous high voltage.

35. Rotating Screw

36. High Temperature

37. High Pressure
Place on the purge guard.

38. Robots Used to automate repetitive or hazardous tasks
Must be guarded to prevent workers from entering or reaching into hazardous areas
A robot can be attached or placed adjacent to an injection molding machine to automate repetitive or potentially hazardous tasks.
The robot in the image to the left is placed on top of the injection molding machine for vertical entry.
The robot must be guarded to prevent workers from entering or reaching into its space during operation.

39. The Robot
Three simple fixes are available to elude injuries due to robots trapping a person.
Place a fixed guard around the area where the robot operates. This type of guard could be an inconvenience when the robot and/or machine need to be worked on, but it is the most sure way to avoid trapping.
A second method involves using safety mats around the area of operation. A safety mat is a device that disables the operation of the robot when sufficient weight (< 10 pounds) is applied to the mat. . Thus, when a person walks up to the operational area of the robot, they step on the mat and the robot shuts down.
The final method is to create a light curtain around the operational area of the robot. A light curtain operates in the same manner as the safety mats, except that it beams light around the operational area. Then, when one of the light beams are broken, the robot shuts down.
All of these methods keep the person away from the robot during its motions.

40. Our sincere thanks to: United Southern Industries, Inc. OSHA Region V
The OSHA Training Institute
OSHA’s Salt Lake Technical Center
Paulson Training Programs, Inc.
The Society of the Plastics Industry, Inc.
United Southern Industries, Inc., for Wayne Wilson’s time and expertise
OSHA Region V, for John Hermanson’s strong support of the Alliance goals and Jim Washam’s time and expertise.
OSHA Training Institute, for Cathy Cronin’s vision and leadership.
OSHA’s Salt Lake Technical Center for developing the Virtual Safety Tour and animations for this course.
Paulson Training Programs, Inc. for allowing us to use of some of their animated graphics and video sequences.

41. Questions?