Thermoforming machine in action

What is a Thermoforming Machine Operator?

Thermoforming is a manufacturing process where a plastic sheet is heated to a pliable forming temperature, formed to a specific shape in a mold, and trimmed to create a usable product. The sheet, or “film” when referring to thinner gauges and certain material types, is heated in an oven to a high-enough temperature that permits it to be stretched into or onto a mold and cooled to a finished shape. Its simplified version is vacuum forming.

In its simplest form, a small tabletop or lab size machine can be used to heat small cut sections of plastic sheet and stretch it over a mold using vacuum. This method is often used for sample and prototype parts. In complex and high-volume applications, very large production machines are utilized to heat and form the plastic sheet and trim the formed parts from the sheet in a continuous high-speed process and can produce many thousands of finished parts per hour depending on the machine and mold size and the size of the parts being formed.

Thermoforming differs from injection molding, blow molding, rotational molding and other forms of processing plastics. Thin-gauge thermoforming is primarily the manufacture of disposable cups, containers, lids, trays, blisters, clamshells, and other products for the food, medical, and general retail industries. Thick-gauge thermoforming includes parts as diverse as vehicle door and dash panels, refrigerator liners, utility vehicle beds and plastic pallets.

In the most common method of high-volume, continuous thermoforming of thin-gauge products, plastic sheet is fed from a roll or from an extruder into a set of indexing chains that incorporate pins, or spikes, that pierce the sheet and transport it through an oven for heating to forming temperature. The heated sheet then indexes into a form station where a mating mold and pressure-box close on the sheet, with vacuum then applied to remove trapped air and to pull the material into or onto the mold along with pressurized air to form the plastic to the detailed shape of the mold. (Plug-assists are typically used in addition to vacuum in the case of taller, deeper-draw formed parts in order to provide the needed material distribution and thicknesses in the finished parts.) After a short form cycle, a burst of reverse air pressure is actuated from the vacuum side of the mold as the form tooling opens, commonly referred to as air-eject, to break the vacuum and assist the formed parts off of, or out of, the mold. A stripper plate may also be utilized on the mold as it opens for ejection of more detailed parts or those with negative-draft, undercut areas. The sheet containing the formed parts then indexes into a trim station on the same machine, where a die cuts the parts from the remaining sheet web or indexes into a separate trim press where the formed parts are trimmed. The sheet web remaining after the formed parts are trimmed is typically wound onto a take-up reel or fed into an inline granulator for recycling.

Most thermoforming companies recycle their scrap and waste plastic, either by compressing in a baling machine or by feeding into a granulator (grinder) and producing ground flake, for sale to reprocessing companies or re-use in their own facility. Frequently, scrap and waste plastic from the thermoforming process is converted back into extruded sheet for forming again.

The Thermoforming Machine Operator Technician is the primary operator of the forming machines and is responsible for the set-up, maintenance, and production of customer orders and for meeting specifications for quality and efficiency. The Technician assures the thermoforming machine is operating properly and must follow company procedures for safety and provide accurate and timely reporting of production data to comply with the companies Good Manufacturing Practices. The Technician is responsible for performing maintenance and mechanical related duties within the production area.

Thermoforming Machine

                                                                         Thermoforming Machine Multiple Molds

Job Duties of a Thermoforming Machine Operator

Specific Duties:

  • Responsible for operating thermoform machinery while following safety requirements and assure safety procedures are followed in the work area:
  • Produce a variety of molded plastic parts by loading raw material, setting and adjusting cycle times, temperatures, pressures and cycle machine to ensure proper and safe operations.
  • Ensure machine is operating at or above established forming standards.
  • Ensure safe work environment and abide by 5S and Lean Manufacturing initiatives.
  • Provide leadership, training and direction to other thermoformers on the shift.
  • Perform in-process inspections of parts throughout production run and assure they meet visual standards of acceptance.
  • Responsible for producing customer parts to order in the proper quantity as identified by the production schedule.
  • Assures all manufacturing equipment is well maintained and calibrated.
  • Monitors production efficiency; addresses line stoppage and initiates immediate problem solving to correct the cause.
  • Report material utilization in the production report
  • Insure daily production report data is correct and up to date
  • Recognize defective materials for color, surface blemishes, finish and dimensions.
  • Segregate non-conforming materials and ensure non-conforming report (NCR) procedure is followed and reported to management.
  • Ensures machine set up procedure is followed and the appropriate materials are on line prior to each production run.
  • Maintain the integrity of all customer/company owned tools.
  • · Identify the proper tooling required for pending production.
  • · Inspect condition of molds, component parts and knives for damage and wear.
  • · Document repairs/maintenance of tools and report to management.

Education Required

  • A high school degree or G.E.D.
  • 2 – 10 years of thermoform production manufacturing experience required
  • 2 – 10 years of shop mathematics, reading shop drawings and have used a variety of precision measuring instruments
  • Thermoform machine set-up experience required
  • Must have ability to communicate clearly and concisely in English including legible handwriting
  • Must be flexible to move to another shift in order to meet production schedule and work overtime as needed