Inserts are designed to be molded into the plastic component during the molding cycle. Typically, the insert is placed on a core pin in the mold during the molding cycle. The insert is designed with aggressive knurling and undercuts to resist rotational and tensile pull loads. The part has a closed bottom (blind thread) to eliminate plastic flow into the threads. This part is usually manufactured in stainless steel, steel and aluminum.
ADVANTAGES OF ROTATIONAL MOLDING
Rotational Molding offers many design advantages over other molding and manufacturing processes.
• Shorter production times
• Low to high volume production runs
• Utilize recycled plastics
• Double or multi wall parts
• Surface finish tailored to suit product requirements
• Hollow seamless and stress free parts
• Light weight compared to other methods
• UV stability
• Custom colors
• Clean ability
• Thicker outer corners which help strengthen the part
• Foam filled parts
• Rotolining - plastic lined steel parts
• Molded-in inserts
• Molded-in kiss-off ribbing
• Reinforced ribs and undercuts
• Corrosion and chemical resistant
• Flexibility to create intricate parts of various sizes
• Uniform and/or varying wall thickness
• Wide variety of materials available
• Mold-in or Mold-on graphics
• Low entry costs
• Tooling easily modified
• Colored resins eliminate painting
• Lower production requirements
• Product costs are reduced using lightweight plastics
• Reduced labor costs
MATERIALS WE USE
Top of the Line Quality
At Innovative Rotational Molding, Inc. we are committed to using only the best materials to create quality products our customers can rely on. We ensure that all of our materials adhere to the highest standards.
LLDPE (Linear Low Density Polyethylene) - Flexible to medium stiffness, excellent impact, chemical and environmental stress crack resistance, easy to process and most are available with UV stabilizer. Most will meet the requirements of FDA, USDA, NSF and UL (Horizontal Burn). Applications include containers, toys and playground equipment.
HDPE (High Density Polyethylene) - Stiffest of all polyethylene, it has excellent chemical resistance and good impact. It is easy to process and most are available with a UV stabilizer. Most will meet the requirements of FDA, USDA, NSF and UL (Horizontal Burn). Applications include tanks, ducting, kayaks and parts requiring maximum rigidity.
XLPE (Crosslink Polyethylene) - Contains a cross linking agent which reacts with the material during the molding cycle forming a cross-linked molecular structure similar to thermoset. Properly cross-linked resins provide excellent impact, environmental stress crack resistance and weatherability. Applications include diesel storage tanks, trash containers as well as parts requiring maximum toughness. XLPE does not meet FDA, USDA or NSF requirements.
Polyethylene can be modified to provide specific properties.
Polypropylene - This material is stiffer than most polyethylenes with higher heat distortion temperature. It is autoclavable and has excellent environmental stress crack and chemical resistance. Applications include bio-chemical vessels, solar panels and medical storage containers.
Nylon 6 — This material has excellent tensile and impact strength, chemical resistance and stiffness. In comparison to polyethylene nylon is easier to paint and has improved heat, abrasion, wear and creep resistance. Applications include military fuel tanks, hydraulic oil and solvent tanks, grain buckets and air ducts.
Nylon 12 — It’s moisture absorption, melting point and mechanical properties are lower than Nylon 6, but it is more easily processed. Applications include heating and air conditioning ducts, gasoline/diesel tanks and chemical tanks.
Polyethylene Foam - Strong resilient closed cell foam. Used for shock absorbing, vibration dampening, loose fill and it’s most common use: cushioning products in packaging applications. Polyethylene foam is lightweight, shatter proof, flexible, cost-effective and impervious to mildew, mold, rot and bacteria.
Custom Rock & Roll Machine
IRM's specialized Rock and Roll machine which uses 3-3.5m BTU Natural Gas burners for heat electronically monitors and controls the entire process. The single arm rotates (or rolls) the mold continuously 360 degrees and at the same time rocks the mold up to 45° above or below the horizontal line. Automation controls the speed of the rock and roll to any setting for even and/or varying wall thickness as required. The cooling process is electronically controlled utilizing atomized mist and forced cool air, gradually lowering the temperature to optimize the final physical properties of the finished part.
Our Machine is the largest in North America. It is capable of molding parts of various shapes and sizes up to 28' in a vertical line by 14' in diameter.
Rotoline CR 3.60
This carousel style rotational molding machine is more efficient for manufacturing parts in large quantities. The CR 3.60 has a mold temperature measuring system, RWTC. This system measures the temperature of the mold in real time. This reading is fully integrated into the machine software allowing for more accurate control of oven time and the control of cycle time by mold temperature which allows for a better cure.
It has a central axis where the arms move in a circular motion throughout the five stations of the process: oven, pre-cooling, cooling, loading/unloading and stand by. Each step of the process is performed in a specific area thus minimizing the machine downtime.
Rotoline DC 2.50
This shuttle style rotational molding machine efficiently manufactures a wide variety of small molded parts. It is an automated dual station machine equipped with a central oven, two shuttle carts and two cooling stations to optimize the highest productivity. This design gives the versatility to continue to run even during mold change over.
Innovative Rotational Molding, Inc. is a state of the art rotational molding facility with the capability to produce many different products. We have strict standards when it comes to all of our manufacturing processes. IRM, Inc. is constantly innovating and improving in order to better meet customer needs.
Polyethylene Foam Fill
The in mold foam process takes place during the oven cycle. After the outer skin forms and at a specific temperature the foam expands to form a second layer of desired thickness while maintaining a hollow part. This type of specialized application is generally used for:
Reduced part weight
Polyurethane Foam Fill
The post mold foam process takes place after the molding process. The finished part is then injected with the polyurethane foam to form a solid core. This type of specialized application is generally used for: