US Mail PO Box 4283, Chula Vista, CA 91909 Email: vicmarassy@prodigy.net.mx
Thermoset 
Urethane and Epoxy Casting
A variety of materials are used to match design parameters. Physicals, appearance and durometers of production materials are matched. These castings are excellent for plastic injection "look and feel" prototypes.
Epoxy and RTV Silicone Molding
(Epoxy Molding - click here) (RTV Molding - click here)
We produce the exact detail of your model. Undercuts, inserts, and texture are readily molded.
Soft CNC Developed Tooling Composites
Aluminum, Ren board and machinable wax are excellent for your short run molds. Precision and speed are the strengths for this method.
Epoxy Laminating
For demanding production or prototype applications, epoxy composites are perfect. Our experience includes: molds and tooling for RIM, vacuum forming, duplicating models, stamping dies, metal casting or fiberglass fabricating.
Polyester Fiberglass
Molds and parts are made with gelcoat surfaces. Polished finish is readily obtained. We also make fixtures and masks with this process.
What could you do with plastic services from VICMAR ?
Rapid prototype actual materials.
Enhance design before hard tooling.
Engineering tests.
Marketing and sales models.
Reproduction or short run parts.
Tooling and molds.
Vacuum Forming
Prototype and short-run production vacuum forming.
Specifics of VICMAR's vacuum forming:
- In house tooling
Forming up to 24" x 48" in house.
Trimming and fabricating services
Sizes up to 72" x 120" available
Epoxy Tooling - Epoxy Molds
Applicable Industries: Aerospace, Toy Manufacturers, Medical, Sports Equipment Automotive, Computer & Consumer Products
Types of Masters Used:
- Rapid Prototypes
- Machined or Fabricated Patterns
- Wax Sculptings
Types of Molds Made:
- Investment Wax Injection Molds
- Compression Molds
- Liquid Injection Molds
- Reaction Injection Molds
- Plastic Injection Molds
Types and Quantities of Parts Made:
- Polyurethane 100 to 600
- Polyurea 100 to 600
- Epoxy 50 to 300
- Investment Wax Patterns 150 to 1000+
- Low Melt Metal Alloy 50 to 700
- Polyurethane Foam 1000 to 5000+
- Silicone Rubber 200 to 5000+
Procedure:
Epoxy molds or aluminum epoxy molds are reasonably fast in comparison to machined molds and are a relatively inexpensive way to create prototype and production tooling. New epoxy products offer a much higher compression strength and heat resistance. If the molds are designed properly they can withstand injection and compression pressures with the use of aluminum standoffs or mold boxes.
A high strength mold can be achieved within a few weeks with a master pattern or rapid prototype. The steps taken to achieve this result are as follows: One must first create a pattern; as with castable silicones, these epoxy resins will reproduce surface detail and textures exactly. Therefore, the pattern is finished to the desired quality before making the mold. Typically an interim RTV mold will be made in order to create a urethane reproduction for the epoxy process. This is done because the master is usually destroyed in the epoxy molding process.
The parting lines are established in much the same way we would make a RTV tool. The epoxy is applied to one part of the mold at a time and then goes through a multilevel post curing process. The post curing is where the high strength is achieved. At this time, the mold is machined to hold square and any gates and vents that could not be molded in are applied. Often, intricate core detail will be added in with a machined aluminum or steel insert.
Curing time is dependent on the product and curing agent. Times range from 30 minutes to over 40 hours. Adding heat will speed up the curing process significantly. Aging the mold at room temperature for up to 72 hours, if possible, will increase the productive life of the mold.
Properties of epoxy such as compression strength and hardness vary considerably from product to product. Choosing the proper epoxy for a particular design is based on experience and manufacturers recommendations. The most important consideration is the intended production material.
Some considerations for the epoxy molds are: For injection molding, glass filled materials will rapidly erode the mold surface therefore reducing mold life greatly. Many part geometry's would need to be produced with a different mold process. Some thermoplastic materials have such a high viscosity that injection pressures can exceed the epoxy strength.
These types of molds can be used for very simple to very complex parts. Slides and loose pieces can be made in a similar manner to prototype injection molds. To date VICMAR has made very intricate molds with as many as 5 pieces, including low melt metal coring, to pick up undercuts and mechanical details.
RTV Molds
(Room Temperature Vulcanizing
Rubber)
Applicable Industries: Aerospace, Toy Manufacturers, Medical, Sports Equipment Automotive, Computer & Consumer Products
Types of Masters Used:
- Rapid Prototypes
- Machined or Fabricated Patterns
- Wax Sculptings
Types and Quantities of Parts Made:
- Polyurethane 20 to 60
- Polyurea 10 to 60
- Epoxy 10 to 30
- Investment Wax Patterns 50 to 300+
- Low Melt Metal Alloy 20 to 75
- Polyurethane Foam 0 to 200+
- Silicone Rubber 20 to 80+
Procedure:
Room temperature vulcanized molds are fast, easy and are a relatively inexpensive way to create prototype and production tooling. New silicone products offering greater tear strength, reduced shrink and larger useful temperature ranges have helped this mold making technique gain wide acceptance in such industries as aerospace, sporting goods, toys and decorative furniture.
There are a number of steps in the silicone mold making process. One must first create a pattern; an SLA or LOM pattern (or Master) is ideal. Because castable silicones reproduce surface detail and textures exactly, the pattern must be free of chips, burrs and scratches as well as grease and oil. Typically the master must be hand finished to the desired quality before making the mold. Choosing a logical parting line is the next step in the process. Pattern geometry determines the number of pieces needed for the mold; undercuts or internal geometry necessitate a one, two or multiple piece mold. A mold box or container needs to be constructed to hold the pattern in place and contain liquid silicone. Plastic, wood or aluminum bar stock are suitable materials. The parting line can be set by imbedding the pattern in modeling clay, surrounding the pattern with wood, or breaking the pattern apart and mounting the separate pieces on plates. Details that are not included in the first mold half need to be masked with clay.
Curing time is dependent on the product and curing agent. Times range from 30 minutes to over 40 hours. Adding heat will speed up the curing process significantly. Aging the mold at room temperature for up to 72 hours, if possible, will increase the productive life of the mold.
Properties of silicone such as tear strength and hardness vary considerably from product to product making some better suited for geometry's which require extensive stretching. The most important consideration is the intended casting material. Many silicones will not work well for casting epoxy or low melt metals. Knowing the part geometry and end application will help us to choose the right silicone to ensure a successful mold.
Some considerations for the silicone mold making process. Many materials such as sulfur in modeling clay, vinyl or neoprene will inhibit the cure of silicone. Either patch test the surface or choose a silicone that is known to work on that surface. Some silicones will shrink up to .6% after a period of days. For accuracy, choose a lower shrinkage silicone, cast parts as soon as possible, and avoid using heat to cure the mold.
These types of molds can be used for very simple to very complex parts. By establishing a parting line with wood or clay, slides and loose pieces can be made very much the same as done in prototype injection molds. To date VICMAR has made very intricate molds with as many as 13 pieces to pick up undercuts and mechanical details.
