乐动体育官方网址Nanoplas - Nano Molding Technology
乐动体育赞助西甲Plastic Injection Molding Defects: Splay

乐动体育赞助西甲Welcome to our Plastic Injection Molding Defects series, where we will explain some common defects seen by injection molders and offer ways of fixing or preventing them.

What is Splay?

乐动体育赞助西甲Splay is a cosmetic defect that occurs in plastic injection molding, when silver or white streaks appear on the surface of the part.

It can be difficult to determine what is truly splay, as its appearance is very similar to other defects.Lookalikes include surface scratches, scuffs, flow lines, delamination from contamination, and flaking (also known as cold slugs).

What Causes Splay?

There are many possible culprits for the appearance ofld乐动体育官方 .Chapter 42 ofld乐动体育 outlines a specific troubleshooting method for determining the source and correcting it.The defect could be due to any number of issues with themolding process, themolditself, themachine, or thematerial.

Table 42.1Splay Troubleshooting Chart, found inInjection Molding Advanced Troubleshooting Guide: The 4M Approach (p. 414)

Molding Process Mold Machine Material
drying venting screw design contamination
high melt temperature hot runner temperatures temperature control excessively wet
decompression cold slug wells damaged components wrong material
back pressure sprue and nozzle tip orifice cracked feed throat blowing agent
screw recovery rate sharp corners lack of process control
residence time gate flaking
screw recovery lubricants
feed throat temperature cracked mold
inconsistent material feed leaking air
Venturi effect

To begin, determine how the defect appears on the parts.If the marks appear consistently in the same location on parts, the problem is likely stemming from the mold itself.If the defect is all over the part and/or appears in random places, that usually means the issue comes from the molding material or process.

We recommend referencing the Troubleshooting Guide to help you fully understand which of the above may be causing the defect and how to best fix it.乐动体育官方网址At Nanoplas, we are particularly familiar with lubricants' contribution to splay through our discussions with molding professionals over the years, so we'll explore ways to address this possible culprit in the rest of this post.

Over-Lubricated Molds Can Cause Splay

If the defect appears immediately after the mold has come back from the toolroom,it may be due to too much grease or lubricant being applied to the mold.In this case, grease from the lifters or ejector pins can bleed onto the core surface, get pulled onto the surface, and leave splay marks or streaks.

Similarly, lubricants and metal protectants can become trapped in mold inserts and bleed out, getting pulled onto the mold surface and causing splay.

"Less is more" when it comes to applying mold maintenance products in a way that won't cause problems.You may need to wipe out the excess lubricant, even disassembling the mold as necessary to get all the excess.For more information related to mold maintenance, read:How to Properly Apply Injection Mold Coating.

If decreasing the amount of grease or lubricant causes wear or other issues, you may want to try higher performingmold maintenance productsthat can do the job with less volume per application.

How to Fix Splay

Again, be sure to fully troubleshoot each key area of injection molding—the molding process, mold, machine, and material—to find the true source and determine the best course for addressing your unique situation.

If you suspect the mold grease is causing the issue, it may be time to try something new.

Switch Mold Maintenance Products

乐动体育官方网址Nanoplas has several products that can eliminate splay caused by over-lubrication.

Some rust preventatives can use a heavy wax or too much solvent, making it necessary to clean the mold before use to prevent splay caused by the bleeding or breakdown of grease.乐动体育官方网址The Nanoplas family ofld乐动体育网址 are truly "dry" and leave a light film that will not bleed or break down grease.乐动体育官方网址On a typical startup, the Nanoplas rust preventatives will be gone in 2-4 shots.

If grease is getting into the molding area, that means it is breaking down from a rust preventative,cleaner, or heat.ld乐动体育武磊 do not break down and will not bleed into the molding area like other greases.This eliminates grease from the splay equation.

Feel free tocontact usif you have questions about our products and how they might solve your injection molding problems.

Want to learn more?Check out these other great articles that solve common injection mold issues:

Source:ld乐动体育 by Randy Kerkstra and Steve Brammer.

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