Diversity in Rubber Manufacturing

Molded Dimensions is a provider of custom rubber molding and cast polyurethane. At MD, we take pride in the technical excellence and versatility of our rubber business unit. Our rubber molding services include:

• Wide range of thermoset polymers, from the basic EPDM to a highly engineered Fluoroelastomer
• Broad span of annual volumes - low, mid, and high volume production capabilities
• Large variety of applications - simple grommet applications, tightly-toleranced, and precision-molded diaphragms, complex hoses, highly-cosmetic medical applications, and much more
• Significant diversity in part size, from small parts that fit on a fingertip, to large parts that need to be carried with two hands
• Multiple molding technologies - compression molded, transfer molded, and high-speed rubber injection molding
• Insert molding capabilities - we can overmold rubber onto metallic (stainless or carbon steel, aluminum, etc.) and non-metallic structural components such as fiberglass and glass-filled thermoplastics
• Many value-added operations, including deflashing, grinding, kitting, assembly and testing, along with Kanban and inventory programs
• Wide range of industries from "medical to mining"

Common Materials Processed

• Natural Rubber, NR
• Styrene-Butadiene, SBR
• Butyl, Isobutylene-isoprene, IIR
• Ethylene-propylene-diene, EPDM
• Polychloroprene, Neoprene™ ,CR
• Nitrile, Buna-N, Acrylonitrile Butadiene Rubber , NBR
• Silicone, Polysiloxane, VMQ
• Epichlorohydrin, Hydrin™, ECO
• Fluoroelastomer, Viton™, FKM
• Polyurethane, Millable, Polyester and Polyether based, EU
• Fluorosilicone, FVMQ

Annual Volume Sold

MD has low-, mid-, and high-volume production capabilities. Some of our customers, including military, often only require small production runs, while other customers require weekly releases and a supporting KanBan program to keep them in supply. The systems and methodologies we learn from larger, more structured companies can be applied to benefit customers across the board.

Typical Applications

• Hoses
• Bumpers
• Grommets
• Pads
• Seals
• Diaphragms
• Bushings
• Boots
• Rollers

• Gaskets
• Mounts
• Impellors
• Bellows
• Handles
• Bladders
• Straps
• Valves
• Isolators

• Caps
• Connectors
• Gears
• Grippers
• Tubes
• Covers
• Cushions
• Plug

Part or Product Size

Precision mechanical components range in size from 1 gram to over 30 pounds. In-house production utilizes presses from 8" square to 24" square, and our Global Manufacturing presses have capabilities up to 60" square.

Molding Technologies

Multiple size presses are used to meet your program requirements. Our rubber molding technologies include:

• Injection - Strip form material is drawn into the press, heated, and then forced into the mold cavity under controlled pressure, temperature, and injection speeds.
• Ram-Injection - Billets of material are manually loaded each heat, or press cycle, into a secondary hydraulic ram, which then forces the rubber into a closed mold cavity.
• Transfer - A "preform" of material is placed between the top mold plate and an additional ram plate. This rubber transfer molding method uses the closing press to transfer rubber into the cavity. A block of material is placed in a "pot" and then, with a punch, forced into the mold cavity.
• Compression - A pre-sized, mass of rubber is set directly into the mold cavity and then squeezed into shape as the mold plates close around it.

Insert Molding

When additional structure is needed in a component, rubber materials may be overmolded onto a substrate. A variety of metals including carbon steel, aluminum, stainless, brass and bronze can be used. Non-metallic, rigid materials, such as fiberglass and glass filled nylon, are also candidates.

Molded rubber may be performed either mechanically or chemically bonded to an insert. Mechanical bond is the encapsulation of the substrate without the use of a secondary adhesive. A chemical bond utilizes an adhesive system to ensure an unyielding bond between the substrate and urethane.

Finishing Operations

• Deflashing - During the molding process, uncured rubber can seep between plates causing excess material extending from the part. This flash or excess material is removed in a batch process called cryogenic deflashing. The parts are frozen using liquid nitrogen, tumbled and blasted with media to remove the flash while retaining the part integrity.
• Machining and Grinding - Machining or grinding can be used to achieve tighter tolerances than molding alone can create.
• Kitting - Products may be special packaged, labeled or assembled per customer requirements.
• Inventory Programs - Flexible systems, including KANBAN, are set up to hold raw, WIP and/or finished goods inventory domestically or abroad depending on customer need.

Industries Served

Our diverse customer base crosses many industries, as we like to say from "medical to mining." The engineering expertise we gain based on the range of parts we manufacture benefits all customers with high quality, consistent product meeting application requirements. In addition, the knowledge and experience gained from servicing large-scale customers, with high service and quality requirements benefits all customers no matter size or industry.

Download our Rubber Molding brochure