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Use of Regrind

Contents Introduction Pre-drying Use of Regrinds Selection of Molding Machine
 Mold Designing Molding Properties Molding Conditions Safety Precautions

 

LAPEROS(R) LCP Grade Composition This page's PDF(619KB)

3. Use of Regrind

LAPEROS® LCP shows outstanding heat stability when molded under recommended molding conditions. In laboratory tests, molding of 100% regrind obtained after repeatedly regrinding for five times still retains 75% to 90% of the initial values of strength and modulus. (See Table 3-1). Furthermore, it should be noted that repeated regrinding will change the color to a slightly darker shade.

Table 3-1 Property Retention after Fifth Regrinding (Retention rate: %)

Property E130i E473i
Tensile strength 82 75
Tensile modulus 83 82
Tensile elongation 105 107
Flexural strength 86 79
Flexural modulus 93 86
Charpy impact strength 86 80

* Material of 100% regrind used

Although the above results are obtained, it is generally recommended that the ratio of regrind be limited to approximately 25% of the total at maximum. When the mixing rate of regrind is approximately 25%, the percentage of the multiple-reground material sharply decreases in the total volume, and as a result, the percentage of virgin material and one-time regrind will always be approximately 93.8% of the total. Such usage of regrind is desirable to avoid the change of hue mentioned above.

In addition, non-uniform pellet size may cause unstable metering. Therefore, it is advised to use repellet material or crushed material that is the same size as pellets after removal of powder and large particles.

 


Contents Introduction Pre-drying Use of Regrinds Selection of Molding Machine
 Mold Designing Molding Properties Molding Conditions Safety Precautions