Course:SPPH381B/TermProject/The Red Solo Cup/Hazards Of Thermoforming Machine
Introduction
There are many injuries that may occur from working with a thermoforming machine. As the processes of forming and trimming the object occur within the machine[1], the majority of injuries regarding the thermoforming machine occur while maintenance or changes are being made to the machine itself.
Feed end handling
Sheets that have been loaded onto the roll stand must be threaded through the end-feed rollers by a worker, this is called the thread up process, the machinery has many pinch points which may result in a range of injuries[1]. These injuries include crushing, pinching, amputations, and degloving injuries, involved with placing hands and limbs in feed mechanisms while the machine is running[1]. Loose clothing, hair, and jewellery may also be caught in the mechanism and pull the worker into the hazard area[1].
Form and trim stations
The form station includes a mold and a pressure box mounted inside the machinery, therefore the worker is not exposed to this hazardous area unless they reach into the guarded area[1]. Reaching into the machine may cause burns, electric shock, crushing, pinching, amputation, as well as exposure to gases and vapours emitted from the decomposing plastic[1]. The trimming process is also occurring within the thermoforming machine so workers will not be exposed to hazards unless they reach into the machine[1]. Injuries that may arise are crushing or amputations if limbs are placed beneath the blades, cuts and burns due to contact with the heated blade, electric shock, and getting caught in the machine due to contact with chains[1].
Below is a case study describing an incident of a machine operator who was injured while doing maintenance on a thermoforming machine[2].
Recognition
March 30th, 2006 a 38-year-old production machine operator was killed while making adjustments to a thermoforming machine. The worker was working inside the oven, changing plates to form a different product. He had been operating the machine for 7 years.
Evaluation
The safety manager of the plant had a written safety program, a safety committee, and monthly safety training sessions. There was a lockout/tagout procedure in place for the thermoforming machine but the operation and maintenance instructions were not all included in the lockout document. More information of lockout/tagout procedure can be found here Hazards of Working in the Plastic Manufacturing Industry - Lockou/Tagout Section. The machine operator and a co-worker performed maintenance tasks and made final adjustments in a machine in which the molds had been changed out during an earlier shift. The top and bottom plates could be activated by pneumatic toggle assembly and the oven rolled out manually. The machine operator rolled out the oven while the co-worker was on the opposite side of the oven adjusting the top plate. The co-worker yelled “clear” to indicate that he was going to activate the pneumatic switch. He then activated the switch, and left to retrieve a wrench to complete the adjustments to the machine, when he returned he found the machine operator lying on his back under the machine, bleeding from the face. The medical examiner and OR-OSHA investigators concluded that the operator was caught in the oven space when the top plate was lowered, resulting in a crushing head injury.
Controls
This incident may have been prevented by multiple means. First of all, when conducting maintenance inside machinery, appropriate lockout/tagout procedures must be conducted, in this case, the pneumatic source was still active during the maintenance to the machine, the appropriate lockout procedure was not followed because it was not included in the firm’s written document. An engineering control could involve the use of blocks between the plates to prevent them from closing when work was being done inside the machine. Additionally, verbal communication in a plant is not an appropriate way of communication, the running machinery in this plant made a noisy environment, and the machine operator probably did not hear when the co-worker yelled.
Pick End Process
The pick end process involves the processes that occur once the item is out of the thermoforming machine. This begins with a stacking tool that pushes the cups into a magazine, these are then counted and visually checked for defects[1]. The scraps from the machine are rewound manually by a worker and removed when it is full, the scraps are often cut into sheets by a guillotine cutter for easy collection and recycling, these scraps are then fed into a web grinder that further cuts them into pieces[1]. The hazards associated with these processes include crushing injuries, lacerations, amputations, dust exposure, slips and falls, and struck-by moving machine parts[1].