Jan 23, 2019
The maximum weight per square meter that can be taken by a floor without getting damaged is called floor load.
The technical design for a factory floor depends on mechanical and chemical needs.
The mechanical load for a floor is determined by the weight of the machines and shelves, trucking and forklift trucks, vibrations during production processes, and so on.
Chemical resistance is required in regard to zero emission, clean room needs, acid resistance, etc.
An architect needs to consider these requirements in planning and awarding the factory floor to comply with the building physics and production requirements.
Something important for the installation of an injection molding machine is the size of the machine feet over which the total weight is transmitted into the ground. In addition, the number of machine feet and their position to each other is significant as well.
Should the floor load be exceeded steel plates can be put below the feet for the machine to have a better weight distribution on the floor.
General: New floor with a maximum floor load of 1300 kg/m².
Related Topics:
Machine Center of Gravity
This glossary of plastic industry is provided by PLEXPERT Canada Inc.
Aug 12, 2019
Differences in wall thickness cause changes in the speed of the melt front.
This can lead to air traps, weld lines, e.g..
To get a well balanced, homogeneous flow behavior, decreasing local wall thickness, called flow deflector, can slow down the flow front in a specific area.
Quality: The melt advances in the thick area (Animation 1) leading to an
air trap. By adding a
flow deflector (Animation 2) the thick wall is reduced and the
air trap gone.
Related topics:
This glossary of plastic industry is provided by PLEXPERT Canada Inc.
Sep 3, 2019
Differences in wall thickness cause changes in the speed of the melt front.
This can lead to air traps, weld lines, e.g..
To get a well balanced, homogenous flow behavior, increasing local wall thickness, called flow leaders, can speed up the flow front in a specific area.
Quality: The melt hesitates in the thin area leading to an
air trap (Image 1). By adding a
flow leader the thin wall is increased and the
air trap gone (Image 2).
Related topics:
This glossary of plastic industry is provided by PLEXPERT Canada Inc.
Aug 14, 2019
The total amount of a medium transported through a cross section in a given time is called flow rate.
In mathematical formula, the letter Q can be found as representative of the flow rate.
The filling in injection molding is generally controlled by flow rate from the start of the injection phase until the switch over point is reached.
In this phase the machine keeps the flow rate on the set value.
Therefore dependent on the cavity volume the given flow rate results in a pressure profile.
Usually the screw moves forward until the given switch over point is reached. The movement can be done with different speeds (profile).
At the switch over point, the machine switches to pressure control until the end of packing phase.
This means that a given pressure is kept before the tip of the screw.
Based on that a flow rate is determined.
The flow rate it not only important regarding injection, but also for the coolant.
It decisively decides on the height of the Reynolds number and therefore on laminar or turbulent flow.
The possible flow rate depends on the respective cooling device and needs to be checked based on the pump curve.
Injection molding process: The
flow rate Q is the amount of a medium, which flows in a given time through a cross section.
Related topics:
This glossary of plastic industry is provided by PLEXPERT Canada Inc.
Dec 27, 2018
The investigation of the maximum flow length of a polymer at specific processing parameters (temperatures, speeds and pressures) can be done with a flow spiral mold.
The flow path needs to be long enough, so that no material can fill the cavity completely.
For easier measurement, marks will be used inside the cavity to recognize the length faster.
Comparing two materials with the flow spiral allows to find the better one for production (for the chosen parameters).
