Accepting force or calibration lab results
without a statement of compliance is just hoping
for a lucky bounce. Here are three simple steps
to improving your odds:
1 Demand proof of metrological traceability
traceable to SI units through N.I.S. T. Anyone
can claim traceability but few can prove it.
2 Require your calibration laboratory to
report measurement uncertainty correctly.
If not reported properly, your measurements
are not traceable, and you are liable.
3 Evaluate your risk! Using a calibration
laboratory who calculates risk properly will put
your mind at ease.
As the leader in force and torque calibration
services, Morehouse issues proper certificates
with statements of compliance, has force
calibration equipment and processes to meet
requirements from 0.002%
of applied force, and
are met with the
lowest amount of
Until you understand
you’re just gambling
with product quality.
by calling us today.
during ejection. Also, with plastic molded parts with
little or no draft, a mold release agent may have to
be used which can cause unwanted reactions and
blemishes and may produce additional costs to your
finished plastic parts. A draft angle of 0.5° is the
minimum draft needed for most applications. Draft
angles of 1.5° to 2° per side are standard for plastic
injection molding. For surfaces that will be textured, a 3° - 5°
draft angle is required.
RUNNERS AND GATES – GOING WITH THE FLOW
Runners and gates (Figure 1) must be designed and
incorporated into a mold to ensure that a consistent flow
of material fills the mold at the right pressure. A gate is
the connection between the runner and the molded part.
The location and size of the gate is integral to the molding
process. Runners and gates control the flow of the molten
material through the mold and into the cavity to create your
Sprue: The main channel in which molten resin enters the
mold. This channel is typically larger, ensuring that enough
material is able to enter the cavity to fill the cavity completely.
Runner System: The runner system connects the sprue to
Gates: At the opposite end of the sprue, the gates are
applied to the runner controlling pressure and flow of molten
material. We utilize several gate options to ensure that your
part can be filled as completely and consistently as possible.
Gate Location: The location of your gate has a direct
impact on moldability. The best positioning is often a balance
between ease of molding and part performance.
Gate Scar: Gates can leave minor blemishes so it is
important to gate into a non-cosmetic area or where it will
not affect part function.
ABOUT TIGHT TOLERANCES
With every injection molder, you will hear the term “Tight
Tolerance”. Unfortunately, that term is thrown about loosely. If
not performed correctly, a tight tolerance part can lead to loss
in performance or even part failure.
Knowing how to safely and effectively reach exact
Figure 1. Molds should incorporate runners and gates to ensure a consistent flow of material fills the
mold at the right pressure.