Hirel Plastics Logo

CAPABILITIES



="Product

Rotational molding, also known as rotomolding, is a plastics molding technology which is ideal for making hollow articles. It is a casting technic but unlike most other plastics processes there is no pressure involved. Molds for the process are relativelyinexpensive as they do not have to withstand pressure and therefore relatively short production runs can be made very economically.

Rotomolding is used to make a very diverse range of products. The process offers the product designer exceptional freedom as just about any shape can be produced. There is almost no limit to the size of moldings and there are literally thousands of applications.

The Process

The concept of rotational molding is very simple. A plastic material, normally in powder form is placed into a hollow mold, usually made from cast aluminium or fabricated from sheet steel. The mold is closed and rotated slowly on two axis. The mold is then heated in an oven whilst rotating and the polymer gradually melts and ‘lays-up’ on the inside of the mold. Once the polymer powder has fully melted the mold is moved to a cooling station and cooled usually with air and sometimes a fine mist of water. As the mold cools the part solidifies. When the material has finally cooled sufficiently to release away from the mold surface the process is stopped and the product is taken out of the mold (de-molded).

Whilst the concept of rotational molding is extremely simple anyone who has ever been involved in the process will tell you that it is in fact extremely complicated. It is a casting process and there is normally no pressure involved which means that the material cannot be controlled in the same way as high pressure processes such as injection molding. There are many variables that can affect production and the end product such as ambient temperature and humidity, type of mold, material specification and powder quality.

="Product

Materials

Today the industry is heavily dependent on Polyethylene (PE) and 97% of rotomolded products are made from this material. Polyethylene is a versatile, easily moldable and readily available polymer which has come to dominate the process. Rotomolding is a casting technique in which powder is nearly always used rather than granules, meaning the material must be ground. Polyethylene is relatively easy to grind at ambient temperatures. The development of other polymers has been hindered by the fact that the process is relatively long and therefore aggressive on polymers, however there is some usage of PVC (usually in liquid plastisol form), Polypropylene and Polyamide (PA6, PA11 & PA12). Many of these non-Polyethylene materials are difficult to grind and most need to be made into powder using cryogenic grinding – that is freeze grinding, which is a costlier process. There is a welcome increase in R&D to expand the range of materials available to the industry.

Key advantages

Rotomolding has several unique characteristics and advantages compared to other molding processes.

• Low tooling costs. As this is a casting process there is no pressure. This means molds are inexpensive and low volume can be economic. If you have a great idea for a new product but don’t know how many you’ll sell or simply want a low volume production

• Run, rotomolding’s low initial investment makes it particularly attractive.

• It’s easy to make complicated shapes. Rotomolding readily accommodates production complexities such as stiffening ribs, molded inserts and different surface textures.

• Uniform wall thickness. Rotomolding achieves consistent wall thickness with corners tending to be thicker. This increases product strength and integrity. Other processes such as blow molding stretch the molten material at corners or sharp edges creating potential thin spots and weaknesses.

• Rotational molding machine costs are low compared to other processes and the investment required is small. There is great production flexibility with the process.

• There is almost no limit to the size of products and several different products can be molded at the same time.

Products

This exceptionally versatile technology can produce a remarkable range of moldings. There are thousands of products that are rotomolded used in a multitude of sectors. Key areas include:

• Tanks for storing water and chemicals – up to 50,000 litres

• Material handling products such as containers, crates, pallets and insulated fish and cooler boxes.

• Environmental products which include litter bins, road cones, bollards, traffic dividers and road signs.

• Floats, buoys and pontoons.

• Automotive products such as truck mudguards, ducting, diesel fuel tanks, toolboxes and tractor dashboards.

• Kayaks, canoes and boats

• Products for the outdoors such as garden planters, water butts and furniture.

• Toys and playground equipment.




ABOUT US

Hi-Rel Plastics & Molding, Inc. offers custom plastic injection molding and blow molding for all major industries. At Hi-Rel Plastics & Molding, Inc. we serve every facet of the molding process from part evaluation, 3D Printing, prototyping, tool design, tool making, sampling and production of quality finished plastic and metal parts. Our commitment to product quality, on-time delivery, and superior customer service has enabled us to forge strong.

Hi-Rel Plastics & Molding, Inc. processes an almost infinite variety of thermoplastic resins, including engineering grade materials such as PEEK, ULTEM, PVDF, LCP, PPS, PES, PC, PBT, ABS, NYLON, Glass Filled Nylon, ACETAL, PP, HIPS, HDPE, LDPE, ELASTOMERICS (TPE), POLYURETHANES, ACRYLIC, PVC and many other specialty filled / unfilled grades too numerous to list. Since we started the business in 1984, we've built partnerships with every customer on the basic business principles of integrity, responsibility and ingenuity.

Whether you’re looking for complex technical parts for medical, aerospace, military or scientific application or luxury item components for your high end customers, the mold designed & build by Hi-Rel Plastics & Molding are always very high precision.

With more than 35+ years of experience, our employees master technical & practical knowledge of design & building of molds for plastic parts. Our team has acquired a level of technical skill & problem-solving experience that guarantees the delivery of high quality products to our clients. Some of the parts we make here we have to meet tolerances of up to ± 0.001 inch in order to maintain a low rejection rate of less than one-half percent.

Our Capabilities Include:

  • PRODUCT DESIGN
  • 3D PRINTING / RAPID PROTOTYPING
  • MOLD/TOOL MAKING
  • INJECTION MOLDING
  • BLOW MOLDING
  • CLEAN ROOM MOLDING
  • MICRO MOLDING
  • LIQUID SILICONE MOLDING
  • INSERT MOLDING
  • OVER MOLDING
  • ROTATIONAL MOLDING
  • EXTRUSION MOLDING
  • RUBBER MOLDING
  • THERMOFORMING
  • METAL STAMPING
  • COIL MANUFACTURING
Value Added Secondary Services:

  • Plastics & Metal CNC Machining
  • In-Mold Decorating
  • Color matching
  • Pad Printing
  • Hot Stamping
  • Label Application
  • Heat Transfer
  • Sterilization
  • Ultrasonic Insertion
  • Ultrasonic Welding
  • Heat Insertion / Heat Staking
  • Adhesive Bonding
  • Metal Plating
  • Product Assembly Services
  • Custom Packaging & Shipping Services

EXPERTISE

We are well-known in our industry, not only for the top quality work we produce, but also for our ability to discover unique and effective solutions to customers' dilemmas. Such difficulties may lie in the areas of design or processing or somewhere in between. Our scope of knowledge is broad and covers many topics. these include, but are not limited to, plastic injection molding and blow molding needs, machinery, auxiliary equipment, molds and their components, resins, colorants and additives, processing parameters as well as the numerous types of interactions among these and other factors.

On many occasions through the years when our competitors have been unable to successfully produce a particular part, Hi-Rel Plastics & Molding, Inc. has triumphed. The depth and breadth of our expertise make us an invaluable resource for our customers. Our customers recognize our capabilities and continue to return to us for their custom injection and blow molding needs.
WHY US?

  • 35+ years of thermoplastic injection and blow molding experience.
  • ISO 9001:2015, AS 9100 Rev D, 13485:2016 Certified
  • ISO 7 (Class 10,000) Type Clean Room Manufacturing Space
  • Consistent high-quality parts at competitive prices.
  • Environmentally clean facility.
  • Engineering Solutions for demanding applications.
  • Encompass all of the offerings of the business. ( Part Design, Mold Making, Thermoplastic Molding, Electronic Assembly, Value Added Secondary Services)
  • We offer JIT ( KANBAN ) orders.
  • We utilize our own fleet of delivery vehicles to ensure accurate just-in-time delivery.
  • We invest in training associates through a full-time trainer and pay-for-knowledge training system to ensure associates continue to learn and maintain industry skill levels.
  • We are a team of dedicated Associates ready to serve your injection and blow molding needs.
  • Our quality is superb, price is competitive, and delivery is the best in the industry.
  • Hi-Rel Plastics Molding, Inc. is serious about providing customer service.


  • Our Capabilities Include:

    • PRODUCT DESIGN
    • 3D PRINTING / RAPID PROTOTYPING
    • MOLD/TOOL MAKING
    • INJECTION MOLDING
    • BLOW MOLDING
    • CLEAN ROOM MOLDING
    • MICRO MOLDING
    • LIQUID SILICONE MOLDING
    • INSERT MOLDING
    • OVER MOLDING
    • ROTATIONAL MOLDING
    • EXTRUSION MOLDING
    • RUBBER MOLDING
    • THERMOFORMING
    • METAL STAMPING
    • COIL MANUFACTURING
    Value Added Secondary Services:

    • Plastics & Metal CNC Machining
    • In-Mold Decorating
    • Color matching
    • Pad Printing
    • Hot Stamping
    • Label Application
    • Heat Transfer
    • Sterilization
    • Ultrasonic Insertion
    • Ultrasonic Welding
    • Heat Insertion / Heat Staking
    • Adhesive Bonding
    • Metal Plating
    • Product Assembly Services
    • Custom Packaging & Shipping Services