Frequently Asked Questions

Frequently Asked Questions

What is Injection Molding

Injection molding is the process of melting plastic resin, injection of the melted resin into a closed mold, the freezing or setting of the molten plastic, the opening of the mold, and finally the ejection of the molded part.

What is Insert Molding

Sometimes referred to as over-molding, this process is identical to the Injection Molding process with the exception that one or more “inserts” are loaded into the mold prior to the injection phase. Plastic is then injected around all or part of the insert.

This process offers the ability to produce composite parts that would be difficult or impossible to assemble otherwise. Often the process is used to eliminate assembly steps thus reducing overall manufacturing costs.

What is MoldFlow Analysis

A “Mold Flow” analysis is an injection molding computer process simulation that, at a minimum, includes the filling of the part cavity with a specific plastic material. The mold flow analysis provides valuable information prior to designing and building the mold. KY Manufacturing & Technology uses the C Mold package which allows the simulation of part and mold filling and cooling. Information that can be gained from such analyses includes:

  • Cycle Time
  • Cooling Time
  • Injection Pressure
  • Sink Mark Prediciton
  • Gas Traps
  • Cooling Problem Areas
  • Weld Lines
  • Runner Balance Requirements

All that is required for a basic analysis is a solid model and material spec.

What is Moisture Analysis

It is a well known fact that many resins degrade or present cosmetic difficulties if processed with too high a moisture content. It is therefore surprising to find that many molding facilities do not directly test for moisture content but rely on “drying time” methods to achieve the appropriate moisture content. With some resins it is possible to over dry the resin, thus the window of acceptability is further narrowed. When one considers the significant effect that incoming material moisture content, changing environmental conditions, and variations in dryer efficiencies can have on drying time, one must accept the following possibilities when drying by time.

  • High Moisture Content: May result in bad parts. Material degradation may not be apparent until parts are put into service.
  • Acceptable Moisture Content: Process is repeatable and good parts result.
  • Low Moisture Content: Bad parts and/or inflated cost due to unnecessary time

What is Statistical Process Control (SPC)

A fancy name for a simple idea, Statistical Process Control, or SPC, involves the monitoring of manufacturing process variables for the purpose of defect solution and prevention. When implemented properly, SPC allows the elimination of mass inspection. For example, a variation in the amount of plastic injected would indicate a potential for an under filled part. Such parts would be diverted for later inspection. Thus, only a portion of the parts produced require inspection.

One important aspect of SPC is the ability to detect process deviations that correlate to problems not directly observable by the typical human inspector. One example would be higher than normal plastic temperatures that would warn of potential plastic property degradation.

What is Tooling Design and Materials

An injection mold is, or should be, a precision device engineered to endure thousands or millions of cycles while maintaining smooth and consistent mechanical operation as well as part geometry. Standards for mold construction have been established in the industry. Proper mold design, to include selection of core and cavity materials, can have the single most dramatic effect on part cost.

What is a Solid Model

This is a computer generated shape “model” of the part or mold you intend to create. The model is developed using software to create a digital representation of 3D objects which may have such attributes such as inside/outside, mass and volume. Once this model is developed, many applications of this digital data can be used in analyzing the part. Mold flow, tool design, finite element analysis (FEA) and CNC machining are just a few applications of usage of this data.

What is a typical flow of a project from start to finish

A typical project from conception to final packaged product ready to ship is as follows:

  1. The inital design or concept, this can be a sketch on a napkin, to a computer drawn idea.
  2. The next step is to select the right manufacturing supplier that can take your idea and concept to a design that can be manufactured for the lowest cost that achieves your intended purpose. You need a supplier that will be honest with you and inform you when something won’t work. We’ve had customers come to us to fix major issues after working with other suppliers and have scrapped out tools and started over due to the lack of proper planning and design. KY Manufacturing & Technology has many years of expierence helping you be successful on new product launch. We have probably designed and managed more projects than your company will do over a lifetime. This is the most critical stage of the entire project that is frequently overlooked and costs you money and time. The products are typically over designed or under designed, will not function as planned or fails from incorrect material selections. Typically by the time a product comes to us to build it is usually too late to make many changes. Selection of a manufacturing firm up front you intend to use, trust to work with and will be honest, will pay off many times over throughout the life of the product. Packaging and any other secondary operations are evaluated at this time.
  3. If any prototypes are made, this is the step for these to be produced. KY Manufacturing & Technology can provide various types of prototypes from actual size to scaled versions for appearance only or parts to test fit and function for testing purposes.
  4. Tool manufacturing: This step is the manufacturing of the tooling required to produce the part(s), any fixtures for manufacturing or special tooling or equipment that may be needed.
  5. The actual part sampling to qualify parts and establish any areas that may need changes. Establish quality criteria for mass production. Final packaging requirements or any secondary operations are finalized at this time.
  6. Mass Production begins at this time depending on the processes required to manufacture the product(s).
  7. Satisfied Customer