Use of Regrind
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: %)
* 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.