Plastics granulator

A plastics granulator shears and smashes scrap plastic to make granules for moulding. Heavy knives are bolted to a rotor turn at high speed, close to a fixed anvil. Plastic offcuts from pressed products are loaded into a small granulator beside the press. Larger quantities are brought to a large granulator.

While this guidance has not been updated to reflect current work health and safety legislation (the Health and Safety at Work Act 2015 and regulations), it may still contain relevant information and practices to keep workers and others healthy and safe.

Please read this guidance in conjunction with all relevant industry standards that apply to you as a PCBU. This guidance will be progressively reviewed and either updated, replaced with other guidance, or revoked.

Granules pass through a screen which limits their maximum size. Granules that fall through the screen are collected for moulding.

Figure 1: Plastic granulator

[Image] Diagram showing granules passing through granulator with labels and red arrows pointing to all components

Figure 2: Side elevation of plastics granulator

[Image] Cross-section with labels and red arrows pointing all elements of delay mechanism

Hazards

  • Contact with knives
  • Entanglement
  • Contact or impact from ejecting plastic
  • Dust
  • Fire & explosion
  • Noise
  • Slips, trips and falls
  • Entanglement from unexpected rotor movement (during maintenance, cleaning & repairs)
  • Collision between moving and fixed knives

Personal Protective Equipment (PPE)

  • Ear protection
  • Eye protection
  • Face protection
  • Hand protection
  • Dust protection

Tasks

Task – Load & unload

Hazard

Contact with knives while handling rotors

Harm

  • Deep cuts or amputation

Controls

  • POWER the cutters from interlocked circuits to ensure they do not move until guards are closed.
  • ENSURE that the size and shape of the chutes prevents reach to the knives.
  • USE a paddle to push items into the chute.
  • CUT material (like plastic sheet) to a MAXIMUM length of 1.5 metres, to prevent entanglement.
  • NEVER stand on raised supports that increase the chance of reaching the cutters.
  • KEEP guard interlocks safely maintained.

Rotors are somewhat sluggish, revolving for several seconds after power is turned off. Operators can slip and make contact with sharp knife edges while handling rotors.

Task – Breaking down plastics

Hazard

Entanglement when feeding long lengths of material into chute

Harm

  • Hands and arms pulled into chute

Controls

  • REDUCE length of material for granulation to a maximum of 1.5 metres.

Hazard

Contact or impact from ejecting plastic

Harm

  • Cuts
  • Bruising

Controls

  • USE flexible curtains in the throat of the chute to minimise the chance of thrown items. Curtains MUST allow entry of items for granulation.
  • WEAR a face guard as protection from ejected items.

Items that contact the knives and are thrown back from the chute can be hazardous.

Other (non-mechanical) hazards

Hazard

Dust

Harm

  • Eye irritation or damage
  • Breathing problems, lung damage or cancer
  • Worsening of existing health problems

Controls

  • CONTAIN plastics dust as much as possible during granulation.
  • CLEAN plastic dust from surfaces where it lands. Blowing dust with compressed air is NOT acceptable.
  • Handling and storage processes MUST MINIMISE spills and dust.
  • PROVIDE adequate ventilation/extraction.
  • ALWAYS USE respiratory protection.
  • ALWAYS USE eye protection.

Hazard

Fire and explosion

Harm

  • Burns
  • Property damage

Controls

  • KEEP fire extinguishers readily available, and ENSURE staff know how to use them.

Plastics dust not contained during and after granulation could cause fire and explosion.

Hazard

Noise

Harm

  • Hearing damage or loss

Controls

  • INSTALL granulators in rooms separate from the main factory.
  • Hire specialists to engineer NOISE REDUCTION.
  • ALWAYS WEAR hearing protection.

A safe level of noise over an eight hour day is 85dB(A). A plastics granulator may exceed this noise intensity.

Hazard

Slips, trips and falls

Harm

  • Potential for hands to be trapped
  • Cuts
  • Bruising from impact or contact

Controls

  • KEEP up-to-date housekeeping procedures.
  • KEEP the area around granulators clear of slip and trip hazards.

Task – Maintenance, cleaning & repairs

Hazard

Entanglement from unexpected rotor movement

Harm

  • Deep cuts or amputation

Controls

  • LOCK-OUT all power supplies before maintenance, cleaning and repairs.
  • ENSURE that guards cannot be opened until knives stop moving.
  • APPLY daily safety checks, and arrange regular inspections by a competent person.
  • REMOVE or LOCK-OUT granulators that do not meet safety check requirements, and DO NOT USE until and repaired or replaced.
  • KEEP guard interlocks safely maintained.
  • WEAR gloves and USE appropriate tools when handling knives.

If additional safeguards are required they MUST be fitted by a competent person working to recognised safety standards. Instructions MUST BE provided in a language that operators understand.

Hazard

Collision between moving and fixed knives

Harm

  • Sparking
  • Damage to granulator
  • Consequent damage to property and people

Controls

  • ENSURE knives are secured according to manufacturer’s instructions.

Download fact sheet

Plastics granulator (PDF 389 KB)